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LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA. 
 
 Class 
 
Stephen Christie 
 
 
 BOILER 
 
 RULES AND TABLES 
 
 used in the 
 CONSTRUCTION, TESTING 
 
 AND OPERATION OF STEAM 
 
 BOILERS 
 
 Rules Comprehensive 
 
 and Exemplified 
 
 PUBLICATION 
 
 
 OP THC 
 
 UNIVERSITY 
 
 OF 
 
 
GENERAL 
 
 Copyright. 1908 
 
 by 
 STEPHEN CHRISTIE 
 
PREFACE. 
 
 THE writer, after many years of experience in connection 
 with boilers, as a boiler maker, master boiler maker, and 
 boiler inspector, has, in his vocation, found it necessary to 
 use rules, tables and formulas in conjunction with his work and 
 duties and has profited by those of older and wider experience in the 
 craft and, having had ample opportunity, inclination and resource 
 for research for comprehensive, concise and condensed formulas 
 and rules governing his daily duties, .has compiled this work. 
 
 The author does not claim originality ; it is the intention to make 
 the subject as clear as possible, to make it a pleasant study so that the 
 layman can master the many rules that may seem too intricate and 
 attention has been given to the most practical part of estimating 
 values in connection with steam boiler designing. 
 
 Many valuable and scientific books have treated the subject of 
 steam boilers and some exhaustively and from them I have learned. 
 I have quoted from those authors' fund of information and from 
 personal experience, and it will be my aim to make this compilation 
 clear and free from any technicalities that would in a measure con- 
 fuse the student and sincerely hope it may accomplish the mission 
 intended, to interest those whose duties, labors and interests are in 
 connection with the steam boiler. 
 
 STEPHEN CHRISTIE. 
 
 1 95020 
 
CHAPTER I. 
 
 MATERIALS. 
 
 It has been stated by historians that Tubal Cain was an iron 
 worker, no doubt an artificer in plow shares and pruning hooks, but 
 that in remote antiquity, when metals were few in number and 
 knowledge of their uses limited, and it is doubtful if the steam boiler 
 was among the articles made. 
 
 Historians record the nature of metals during those early ages as 
 gold, silver, brass, iron, tin and lead, and also state that bronze had 
 been in use before iron, thus we may favor doubt about boilers of 
 some description being in use during those ages of antiquity. 
 
 Aristotle seems to be the earliest authority quoted on the subject 
 of iron, saying "that iron was purified from acoria by melting, and 
 after repeated treatments by melting became purified." What state 
 of purification in relation to iron working tools or metals was not 
 stated. 
 
 Daimachus, an early writer on the. subject mentions different 
 kinds of steel and the purposes to which they were used, and sev- 
 erally suited, viz. : 
 
 Chalybdie for carpenter tools. 
 
 Lacedoemonian for files and drills and stone cutters' tools. 
 
 Lydian for knives and razors. 
 
 Thus ancient history records some notice of materials used in 
 boiler construction, but it is doubtful if ancient process of manu- 
 facturers or knowledge of material construction brought it up to 
 anything like the state of perfection that could be used in steam 
 boilers of today. 
 
 This chapter was not intended to treat on metallurgy only to 
 touch upon materials as now used in these days of high pressure 
 boilers. 
 
 Manufacturers assume great responsibilities in selecting material 
 for boilers, hence care in selection. 
 
 Boiler making today is a science, demanding scientific education 
 and knowledge gained by research, investigation and reasoning. 
 
 The writer can go back mentally to the days when boiler making 
 was apparently in its infancy, this when comparing the boilers of to- 
 
 5 
 
6 THE BOILER. 
 
 day with the demands for power and when the very low pressures 
 were then well suited to the low grade material manufactured ; de- 
 signs crude, seams out of all proportions, bracing out of reasoning, 
 and the ignorant mechanic, whose only evidence of work was strong 
 in arm, wrought defects without thought of effects. 
 
 There is evolution and revolution in boiler making today. 
 
 High pressures are necessary, also care in selecting" materials and 
 designing boilers. The construction for the demands today are high 
 pressures ; due to competition, economy and fuel and space. It is nec- 
 essary then to have all parts equal in strength, different parts favored 
 with material of specific quality, such as braces, tubes, fire sheets, 
 where circulation is least ; corrosion, expansion, contraction or pit- 
 ting active will necessitate increased thickness of plate ; again, to 
 secure complete circulation, combustion of fuel, etc. ; to arrange heat- 
 ing surface in proportion to grate area and steam space, to make the 
 form of boiler such that it can be constructed without mechanical 
 difficulty or great expense. 
 
 Designs must be made to give strength, durability under the 
 action of hot gases and corrosive elements, to be accessible, for clean- 
 ing, repairing and to provide safety appliance of ample proportions 
 and applied properly. Thus the necessity of the greater education in 
 boiler designing and construction and knowledge of material used. 
 
 Material for boiler purposes as well as other uses invariably con- 
 tains in combination sonic proportion of various elements, and 
 although these may appear small, have very marked influence upon 
 its strength, ductility and working qualities, thus making it neces- 
 sary to have both chemical as well as physical tests. In the manu- 
 facturing of boiler material the process of carburization changes the 
 nature and properties of contained carbon, thus wrought iron con- 
 tains from 5 per cent to only a trace per cent of carbon, and steel 
 including all kinds of iron contains not more than 1.75 per cent 
 of carbon and varies in fusibility, hardness, susceptibility to temper- 
 ing and malleability. The first two properties being increased by 
 increase of carbon, while the others are diminished. 
 
 All ores go through the process of reduction, and the more im- 
 purities they contain the greater amount of work is necessary to 
 treat them ; these include carbonic acid, water, combustible and 
 earthy matter. 
 
MATERIAL. 7 
 
 CAST IRON. 
 
 In cast iron these qualities looked for are taken from the fuel and 
 mode of smelting", this materially as much as the character of ore. To 
 convert cast iron into bar, forged or malleable iron, it has to be re- 
 fined by smelting with coke or charcoal ; this process eliminates the 
 oxygen and carbon which may be left, thus bringing it to a state of 
 refined metal, this is forged under hammer, passed through roll and 
 drawn into bars, cut in lengths and formed into bundles or piles, again 
 reheated and once more hammered and rolled into any shape. Cast 
 iron has in its makeup carbon-silicon ; this is a slag and its presence 
 makes iron and steel hard and brittle, but up to 6 per cent is harmless 
 providing 3 per cent, of manganese is present with it. Manganese, 
 of which 5 per cent is sufficient to make iron cold short, is valuable 
 in iron to be converted into steel. 
 
 Sulphur and phosphorus, when 8 per cent is present, make iron 
 and steel crystallized and unfits it for plate for boiler purposes. 
 
 Arsenic increases the hardness in steel at the expense of tough- 
 ness, as does carbon with it in form of graphite. The gray iron con- 
 tains most graphite and carbon, making it more fusible and softer 
 than white iron. The latter contains more combined carbon ; these 
 constituents vary, thus having various influence on the mechanical 
 properties, and, after repeated fusings, loses its carbon. 
 
 THE ELEMENTS IN CAST IRON ARE AS FOLLOWS: 
 
 ELEMENTS. PERCENTAGE. 
 
 Combined carbon 15 to 1 . 25 per cent 
 
 Graphite 1 . 85 to 3 . 25 
 
 Silicon 15 to 5 . 
 
 Sulphur to .05 
 
 Phosphorus to 1 . 3 
 
 Manganese . . : to 1 . 5 
 
 Iron 90 . to 95 . 
 
 Cast iron is not reliable for boiler construction unless for very low 
 pressure, while it resists corrosion it is brittle and to get strength 
 great thickness is necessary. 
 
 From cast iron to steel, plate is susceptible to the widest variation 
 in its character ; cast iron as extracted from ore, is melted with com- 
 parative facility and according to mode of operation in foundry, may 
 be rendered so hard that it requires special tools to work it. 
 
8 THE BOILER. 
 
 This metal by treatment with heat and air is converted into great 
 tensile strength and ductility, still soft and easily worked into shapes 
 without fracture. 
 
 The difference in molecular construction between cast and malle- 
 able iron is, the cast iron contains a larger proportion of carbon and 
 some silicon, the malleable iron practically none thus to produce 
 steel the cast iron is melted first, then wrought iron and steel scraps 
 are added by degrees (these in equal proportion), then an addition 
 of spiegeleisen is added with manganese ; as soon as this metal ceases 
 to flow it is removed and poured into moulds, reheated and rolled 
 into plate. 
 
 WROUGHT IRON. 
 
 Wrought iron is made by the process called puddling to eliminate 
 the graphite and combined carbon from the pig iron, leaving sufficient 
 to give strength in this new combination. In operation the mass is 
 heated and kneaded by the paddles into blooms, and these are com- 
 pressed under a hammer to remove the slag, again heated, rolled out 
 and further squeezed by passing through rolls, thus forming a puddle 
 bar. These bars are broken up and worked by hammering and roll- 
 ing more or less according to degree of purity and strength required, 
 thus iron plates retain the fibrous quality imparted to the bar, but 
 owing to the secretion of cinder scale between the layers (thus pro- 
 ducing. blisters), careful tests are necessary by eye or hammer. 
 
 Wrought iron, while possessing great tenacity combined with 
 toughness and ductility is well adapted to resist sudden strains. 
 
 While the puddle bars are going through the rolls oxide of iron 
 is formed in scales, caused by the hot iron coming in contact with the 
 air; these scales are collected for the puddling furnace, with use 
 being that of absorbing the carbon from the iron. 
 
 The wrought iron is Lamina in its construction, is ductile and has 
 a tensile strength varying up to 55,000 pounds per square inch and 
 a ductility to 40 per cent ; its uses in boiler construction are in tubes, 
 rivets, braces and for reinforcement. .One objectional feature in 
 iron plates is the smallness of plate that can be manufactured with- 
 out chance of blistering or lamination ; another is the excess of labor 
 due to more seams, thus reducing the strength of boiler. 
 
 The great advantages steel has over wrought iron are, plate can 
 
MATERIAL. 9 
 
 he made in sizes of larger dimensions, boilers can be made of lighter 
 material, greater power of conductivity of heat can be secured, but it 
 necessitates greater care in flanging the material and in fitting up. 
 
 MATERIAL. 
 
 Average crushing and breaking strains of iron and steel : 
 
 Breaking strain of wrought iron 23 tons 
 
 Crushing " 17 
 
 Breaking strain of cast iron 7^ 
 
 Crushing " " " " 50 
 
 Breaking strain of steel bars 55 
 
 Crushing " " " " 110 
 
 this per square inch of section. 
 
 STEEL PLATE. 
 
 Steel is a carburet of iron and the earliest invention of same was 
 prepared by fusion and not by cementation ; in this later process the 
 metal is surrounded by charcoal, and thus it draws its supply of 
 carbon, the molecules of iron taking up the latter. 
 
 Since that early process there have been several methods em- 
 ployed to produce the steel, viz. : 
 
 1st Direct from ores. 
 
 2nd By addition of carbon and malleable iron. 
 
 3rd By the partial decarburization of pig iron. 
 
 4th By diluting the carbon in pig iron and the addition of malleable iron. 
 
 Steel plate is termed mild steel, low steel and high steel, which 
 contains a high percentage of carbon. The following table will show 
 the proportion of carbon and corresponding hardness : 
 
 NO. OF 
 HARDNESS. 
 
 PER CENT OF 
 CARBON. 
 
 OBSERVATION. 
 
 1 
 2 
 
 3 
 
 4 
 
 1.58 to 1.38. . 
 1.38 to 1.12 
 1.12 to .88 
 .88 to .62 
 
 . . . cannot be welded. 
 . . .welds easily and used for chisels. 
 . . .used for cutting tools. 
 . . .mild steel for tires, etc 
 
 5 
 6 
 
 7 
 
 .62 to .38and\ 
 .38 to .15 / 
 
 15 to 05 
 
 /tempers slightly, steel for boiler 
 \ plates, 
 /does not temper, used for 
 \ machinery 
 
 
 
 
 Steel and iron, like all other metals, are composed of atoms 
 grouped in molecules, and any force that alters the relations of the 
 atoms in the molecules modifies the physical properties of the metal, 
 thus in heating, cooling and crushing the physical properties of 
 metals vary with its degree of purity. 
 
10 THE BOILER. 
 
 Density of a metal is dependent on the intimacy of the contact 
 between the molecules and is influenced by temperature and rate of 
 cooling; its density can be augmented by hammering or any com- 
 pressing stress ; pressure on all sides increases its density. 
 
 Malleability is the property of permanently extending in all 
 directions without rupture by pressure produced by slow stress or 
 by impact. 
 
 Ductility is the property that enables metal to be worked into 
 flanges or drawn into wire, and this ductility increases with increased 
 temperature. 
 
 Tenacity is a property possessed by metals in varying degree, 
 it is the resisting, the separating of the molecules after the limit of 
 elasticity has passed. 
 
 Hardness is the resistance offered by the molecules of a substance 
 to their separation by penetrating action of another substance. 
 
 Brittleness is the sudden interruption of molecules, cohesion, 
 when substances are subjected to the action of some extraneous 
 force, such as a blow or change of temperature and largely influ- 
 enced by purity of metal. 
 
 Elasticity is the power a body possesses of resuming its original 
 form after removal of an external force which has changed its 
 form, and to measure the strength of metals it is necessary to deter- 
 mine : 
 
 First. The greatest stress the metal can sustain within the limits 
 of elasticity. 
 
 Second. The total exent of strain before rupture takes place. 
 
 Third. The ultimate tensile strength or maximum stress the 
 metals can sustain without rupture. 
 
 The difference between steel and iron is seen when subjected to 
 a high temperature and suddenly cooled by plunging in cold water. 
 The iron is affected very little while the steel becomes hardened. 
 
 A chemical test to distinguish iron from steel is by placing a drop 
 of diluted nitric acid upon a clean surface of the metal ; a greenish- 
 gray stain appears upon iron ; on the steel a black spot, this latter is 
 due to the separation of carbon. 
 
 The processes of making boiler plate are the Siemens-Martin or 
 open hearth process, and by the Bessemer converter. The latter is 
 costly. The former offers better facilities for testing the quality 
 
MATERIAL. 
 
 11 
 
 while still in a molten state and its character modified at will by addi- 
 tion of such material required to produce desired results. While the 
 Bessemer process is not as desirable owing to its not offering facil- 
 ities for testing or adjustment. The elements that increase tensile 
 strength will reduce ductility, as carbon increases strength up to a 
 certain limit then beyond excess reduces it, as a certain limit separ- 
 ates steel from cast iron. 
 
 The hardening elements are carbon, silicon, manganese and phos- 
 phorus. 
 
 Manganese steel contains a high percentage of the latter, having 
 a little carbon and is avoided in boiler construction. 
 
 The qualities in steel for boilers are homogenity, tenacity, elas- 
 ticity and ductility ; distinct from steel used for other purposes boiler 
 plate should be tcugh and not of such a character that it might 
 harden under the action of sudden great changes of temperature. 
 
 Steel is structural and chemical, it is a compound or an alloy of 
 elements, silver, tungsten, chromium, titanium, silicon and cyanogen. 
 It forms an intermediate link between ordinary cast iron and 
 wrought iron, uniting with the properties, of both and its distin- 
 guishness or characteristic is its capability of being hardened or 
 softened by rapid or slow cooling. 
 
 TABLE SHOWING COMPARISONS OF IRON AND STEEL: 
 
 IRON 
 
 STEEL. 
 
 
 SWEDISH. 
 
 PENN. 
 
 MILD. 
 
 VERY MILD. 
 
 Carbon 
 Silicon 
 Sulphur 
 Phosphorus 
 Manganese 
 Iron. 
 
 .087 
 .56 
 .005 
 
 
 
 99 '220 
 
 .067 
 .020 
 .001 
 .075 
 .009 
 99.828 
 
 .238 
 .105 
 .012 
 .034 
 .184 
 99.427 
 
 .009 
 .163 
 .009 
 .084 
 .620 
 99.115 
 
 U. S. GOVERNMENT SPECIFICATIONS FOR MATERIAL. 
 
 Fire-box steel should show a tensile strength of not less than 
 52,000 pounds, and not over 62,000 pounds per square inch, an 
 elastic limit not less than one-half ( l / 2 ) the ultimate strength, elon- 
 gation 25 per cent and tested as follows: Cold and quench bends 
 
12 THE BOILER. 
 
 180 degrees flat on itself without fracture on outside of bent portion, 
 not over .04 per cent of sulphur or .04 per cent phosphorus. 
 
 Flange steel to show a tensile strength of from 55,000 to 65,000 
 pounds per square inch, elastic limit not less than one-half of its 
 ultimate strength, elongation 25 per cent, cold and quench bends 180 
 degrees flat on itself, without fracture on one side of bent portion 
 and not over .04 per cent of phosphorus and not over .05 per cent 
 of sulphur. 
 
 Extra soft steel to show a tensile strength of, 45,000 to 55,COO 
 pounds per square inch, elastic limit not less than one-half its ulti- 
 mate strength, elongation 28 per cent, cold and quench bends 180 
 degrees flat on itself without fracture on outside of bent portion, not 
 over .04 per cent of sulphur or phosphorus. 
 
 Plates and steel rivets to be made by the open hearth process and 
 tests to be made to determine tensile strength, ductility, elasticity, 
 elongation ; physical and chemical tests to be made at place of manu- 
 facture, all plates to be plainly stamped at corner near center. Mate- 
 rial for stay bolts and braces to have a tensile strength of not less 
 than 46,000 pounds per square inch when made of iron and not less 
 than 55,000 pounds when made of steel. 
 
 Steel rivet material to have a tensile strength of 50,000 to 60,000 
 pounds per square inch of sectional area and elastic limit not less 
 than one-half the ultimate strength, a bending test as follows at 180 
 degrees flat on itself without fracture on outside portion ; elonga- 
 tion 26 per cent. 
 
 Iron rivet material to have a tensile strength of 40,000 pounds 
 per square inch. 
 
 SPECIFICATION AND TESTING OF MATERIALS. 
 
 The U. S. Government rules as specified for the construction of 
 boilers coming under federal supervision are as follows : 
 
 "That iron or steel plate intended for construction of boiler to be 
 used in steam vessels shall be stamped in at least five different places 
 by the manufacturer at place where made, viz., at corners about 
 eight inches from edges and near center and with number of pounds 
 per square inch of tensile strength ; it will be the sectional inch and 
 which must not be less than 45,000 pounds for iron or 50,000 pounds 
 
MATERIAL. 13 
 
 for steel ; from plates shall be taken coupons and prepared, by plain- 
 ing edges, these test pieces shall be at least 16 inches in length and 
 from one and one-half (1^) inches to three and one-half (3^) 
 inches in width at ends, which ends shall join by an easy fillet, a 
 straight in the center of at least 9 inches in length and 1 inch in 
 width, in form to the following diagram marked with light prick 
 punch marks at distances one inch apart, spaced so as to give 8 
 inches in length." 
 
 About 8 inches. ). 
 
 iMnchee. 
 
 About 8 inches, j. 
 
 The strain necessary to break the test pieces as described is taken 
 the proportion of the T S (tensile strength) per square inch. 
 
 EXAMPLES. 
 
 Test piece or coupon reduced to smallest part is one-fourth of a 
 square inch and is broken at 15,000 pounds. 
 
 15000 
 
 4 
 
 60000 TS per square inch 
 
 To determine the elongation, the part cut out in test piece 
 marked at inch sections and the force necessary to break it asunder 
 is the proportionate part of the T S per square inch, and distance 
 stretched represents percentage of elongation. 
 
 EXAMPLE. 
 
 To find percentage of elongation in a test piece. Coupon 8" 
 before testing, elongated to 
 
 10. 5 =10^" after testing 
 8 = before testing 
 
 10 . 5) 2 . 500 (23 per cent of elongation 
 2 10 
 
 400 
 315 
 
 85 
 
14 THE BOILER. 
 
 Test piece 1 /8 x ^ breaks at 34,000 pounds. 
 
 1.625 
 .375 
 
 8125 
 11375 
 4875 
 
 .609375)34000.0000(55829 Ibs. TS 
 3045 
 
 3550 
 3045 
 
 5050 
 
 4872 
 
 1780 
 1218 
 
 5620 
 5481 
 
 139 
 
 Strain necessary to break a test piece is the proportionate part 
 of the tensile strength per square inch. 
 
 A piece of plate sectional area .5 square inch breaks at 30,000 
 pounds. 
 
 .5000)30000.0000(60000 Ibs. TS 
 300000 
 
 000 
 
 TABLE. 
 
 Showing width of plate expressed in 100th of an inch that will 
 equal one quarter of one square inch of section of the various thick- 
 ness of plate. 
 
 Example. If plate is y\ inch in thickness the width should be 
 100th of an inch wide to equal one quarter of one square inch of 
 section or as follows : 
 
 .21X119 ......................................... 33X76 
 
 . 23 X 109 ......................................... 35X71 
 
 MX100 ........................................ \ X67 
 
 .26X 96 ................................ . 
 
 .29X 86 
 
MATERIAL. 15 
 
 Only steel plates manufactured by what is known as the basic or 
 acid open hearth process will be allowed to be used in the con- 
 struction of boilers for marine purposes and manufacturer shall 
 furnish a certificate with each order of steel tested stating technical 
 process by which said steel was manufactured, this is not intended 
 to apply to plates used in construction of Bessemer steel tubes. 
 
 No plate made by acid process shall contain more than 0.06 per 
 
 f cent of phosphorus or 0.04 per cent of sulphur, and no plate made by 
 
 Jfche basic process shall contain more than .04 per cent of sulphur or 
 
 /phosphorus. This to be determined by analysis by the manufacturer. 
 
 Steel plates must have a tensile" strength not less than 55,000 
 pounds and not. over 75,000 pounds per square inch of section, but 
 boilers whose construction is commenced after June 30, 1905, where 
 plate will come in contact with fire either in use or in course of con- 
 struction of the boiler the tensile strength shall not be more than 
 70,000 pounds per square inch of section. 
 
 No plate shall be stamped with a greater tensile strength than 
 70,000. 
 
 Elongation shall show at least 25 per cent in a length of 2 inches 
 for thickness to one-fourth (*4 ) inclusive in a length of 4 inches for 
 over one-fourth to seven-sixteenths inch, inclusive ; in a length of 6 
 inches for all plates over seven-sixteenths inch. The sample must 
 show a reduction of sectional area as follows : 
 
 At least 50 per cent for thickness over one-half to three-fourths 
 inch inclusive, 45 per cent for thickness over one-half to three- 
 fourths inclusive, and 32.5 per cent for thickness over three-fourths 
 of an inch. 
 
 Quenching and bending test pieces shall be at least 12 inches in 
 length and from 1 to 3j/2 inches in width. The sides where sheared 
 or planed must not be rounded, but the edges may have the sharp- 
 ness taken off with a fine file. The test piece shall be heated to a 
 cherry red (as seen in a dark place) and then plunged into water at 
 a temperature of about 82 degrees F. Thus prepared the sample 
 shall be bent to a curve, the inner radius of which is not greater than 
 one and one-half times the thickness of the sample without cracks 
 or flaws, the ends must be parallel after bending. 
 
 Iron plates when tested must show a tensile strength of not less 
 than 45,000 pounds and not over 60,000 pounds per square inch of 
 
16 THE BOILER. 
 
 sectional area and show an elongation of at least 15 per cent in a 
 length of 8 inches and a reduction of area as follows : For plate 
 having 45,000 T S 15 per cent, and for each additional 1,000 pounds 
 up to 55,000 add 1 per cent ; for samples over 55,000 pounds up to 
 60,000 T S 25 per cent shall be required ; a bending test as follows : a 
 piece 12 inches in length and from 1 to 3 T / 2 inches in width, the edge 
 not to be rounded, then bent cold to an angle of 90 degrees to a curve 
 the inner radius of which no greater than one and one-half times' the 
 thickness of the sample without cracks or flaws." 
 
 The chemical or analytical test is for the purpose to show right 
 proportions of elements and properties useful in the material's 
 make-up, for specific purposes, and if free from those whose pres- 
 ence are bad, a certain proportion of carbon gives it a given degree 
 of strength, while a small percentage of sulphur will render it use- 
 less for boiler purposes. The effect of the latter and phosphorus is 
 crystalization of metal. 
 
 Plates are usually ordered by thickness, but there are occasions 
 when weight is defined rather than the thickness and rejected unless 
 up to demands. The effects sometimes are that owing to the plates 
 being made of large dimensions and cut up to demands for smaller 
 sizes some of uneven thickness are left ; this is due to the process of 
 rolling, the center of rolls expanding, thus leaving center of plate 
 thicker ; while rolls are turned in center to obviate this effect the 
 heating of rolls must offset the turning down. 
 
 BOILER DESIGNING. 
 
 Boiler designing is a science and much depends on the accuracy 
 of details. 
 
 Modern engines, higher pressure, and that potent factor of the 
 times, competition, demand the greatest efficiency from fuel and 
 engine. 
 
 But a few years ago comparatively, the rule was "thumb" in the 
 designing of a boiler, of "what had been done" without any reason- 
 ing ; this apparently when we see some of the boilers now in use ; 
 plates, seams, rivets, location of same, brace design, number, and 
 method of attaching them, tubes, size, number and distribution ; 
 domes, their ratio to boiler, old-time makers and engineers said, 
 "one-fifth the size of boiler was a fair ratio ;" all giving evidence that 
 
MATERIAL. 17 
 
 it was no defined rule from reasoning, but following what had been 
 done. Today the designing of a boiler is a problem to be worked 
 out, solved by factors entering into the matter ; location, space 
 economy, fuel economy, engine design and efficiency, arrangement 
 of furnaces that available heat can be most completely absorbed and 
 utilized, effects of contraction and expansion, the various types of 
 boiler must be considered for their niche of maximum usefulness, 
 for often times one will excel in certain duties and fail in another. 
 Requirements must be looked into and the one factor, location, 
 would change a design completely, for instance, where space is 
 limited, cost and life may be sacrificed, another where fuel would bo 
 for life, again, locations where fuel must be sacrificed, where water 
 is bad, and a design must be made to suit the accessibilities to clean. 
 Again, an illustration of what must be considered, and the sacrifice 
 for demands and conditions to obtain results, is the fire engine 
 boiler, life, cost, fuel, and access to clean and repair, all for quick 
 steaming qualities. Then grate proportion for heating surface in 
 different types of boiler, and the necessity of steam space and tube 
 arrangement to avoid obstruction of steam passages that retard cir- 
 culation ; points which in early boiler designing were badly neg- 
 lected. 
 
 Increased pressure has been demanded due to space and type 
 of engine would often times vary proportions. 
 
 The power of boilers today is estimated from an evaporative 
 measure, not from the old-time commercial rating, i. e., so many 
 square feet of heating surface per H. P., leaving design or type out 
 of the question. Thus we see the importance of boiler designing. 
 The earliest known steam generator was a sphere. In the boiler of 
 Worcester and Papin and Savery the flue encircled the outside of 
 shell. Newcomen substituted that by having a hemispherical top 
 and flat arch or bottom. The wagon boiler designed by Watt re- 
 sembled a wagon and hence its name. Boilers have been made in 
 many and various forms, classified by designer's name, their uses or 
 form. Today boilers are generally classed as internal, external, 
 water tube, pipe, and sectional (the latter used extensively for heat- 
 ing), each class usually bearing a name incident to their use, such as 
 locomotive or marine, again boilers are further classed as vertical, 
 horizontal, tubular, cylinder and flue. 
 
CHAPTER II. 
 
 SELECTION OF BOILER. 
 
 In estimating the power of a boiler it was formerly a custom to 
 have a certain number of square feet of heating surface to repre- 
 sent a H. P. (horse power) and the different types were supposed 
 to have better or inferior efficiencies due to design for instance. 
 
 The cylinder type of boiler was reckoned from a unit of 10 
 square feet of heating surface per horse power, the horizontal 
 tubular type, 12 to 15 square feet; the reason for the difference was 
 the former type of boiler's heating surface was considered as all 
 active and exposed to the highest temperature, while the latter had 
 the heating surface of tubes that was exposed to the waste gases 
 after coming in contact with the bottom thus a lower temperature, 
 while as a fact the tubes were thinner and had more conductivity for 
 heat; thus 15 square feet was considered the unit of measurement 
 for that type. 
 
 Internal fire boilers were measured from the 10 square feet 
 standard. 
 
 But as fuels now are valued by their heating values, the amount 
 of water they will evaporate per pound of class fuel, so with the 
 boiler, it must be measured from its efficiency from an evaporative 
 point, other factors entering into its performances are hardness of 
 water and temperature of feed water. 
 
 As the subject of the steam boiler is one that can be treated 
 almost inexhaustibly, it is the writer's intention to devote this work 
 to boiler rules and tables governing their construction. 
 
 ENGINE POWER. 
 
 Power, or as it is mechanically expressed, heat, is measured, and 
 the unit of this measurement is the amount of heat which will raise 
 the temperature of one pound of water one degree F at its point of 
 greatest density (39 deg. F.). The number of heat units in one 
 pound of water at any given temperature is called the "Heat in 
 liquid," when heat is applied to water in open vessel the temperature 
 
 18 
 
SELECTION OF BOILER. 19 
 
 will rise until its boiling point is reached, beyond this point no in- 
 crease of temperature will result ; the heat absorbed being employed 
 in transforming the water from liquid to steam ; this is called the 
 "heat of vaporization," and diminishes as the temperature and pres- 
 sure increases. The "heat in liquid," added to the "heat of vapori- 
 zation," is equal to the total heat. The ratio of the amount of heat 
 required to make one pound of steam under any given conditions to 
 that required to make a pound of steam from and at 212 is 
 called the "factor of evaporation." 
 
 This factor is found by subtracting the heat units in one pound 
 of the feed water at the given temperature from the heat units or 
 total heat of one pound of the steam at the given pressure, and 
 dividing the result by 965.7, which is the heat of vaporization, or 
 number of heat units required to evaporate one pound of water at 
 212 into steam at 212. 
 
 The total number of pounds of water to be evaporated per hour 
 under a given steam pressure multiplied by its particular factor of 
 evaporating gives us the "equivalent evaporation," from and at 
 212, or in other words, the amount of water which would have 
 been evaporated, with the same amount of fuel, had the feed water 
 been at 212 degrees and the pressure that of the atmosphere. 
 
 Assuming an engine to be one of 200 H. P. and the boiler to be 
 selected according to the commercial rating of boilers. The given 
 data to determine from would be : 
 
 200 HP engine, 
 engine taking 20 Ibs. of steam per HP per hour 
 
 120 absolute pressure (by gauge 105) 
 
 190 temperature of feed water 
 the evaporation of 34.5 Ibs. of water at 212. 
 
 As stated, the number of pounds of water to be evaporated to 
 produce a horse power from an engine will be computed from the 
 type of engine used. See table of engine efficiencies, Standards of 
 Steam Engine. 
 
20 
 
 THE BOILER. 
 TABLE OF STANDARD OF STEAM ENGINES. 
 
 TYPE OF BOILERS. 
 
 TYPE OF ENGINES. 
 
 1 t*<2 
 
 PH Q 03 
 
 as y *-j o 
 
 i> C J^ O r/i 
 
 & 8/8 
 
 bjo ' <u 
 I S * 
 
 M c/3 
 
 iif* 
 
 S C 
 
 d 
 
 8 ^o 
 
 'w ^ w 
 
 |P 
 
 1i;i 
 
 D O 
 
 OfM S3 
 
 VH 
 
 C -M ^ 
 
 ^ 'SjOO 
 
 I8 8 
 
 **% 
 
 % w 
 
 0) '~ l 
 
 c S T 4" 
 
 P3 
 
 g rt ^- 3 
 
 MM ^ fe^ 
 
 ;^ 
 1.1*1 
 Stlli 
 
 o offi^^ 
 
 ^^^^0 
 
 llfj! 
 
 imple non- co 
 automatic cu 
 gine, steam 
 80 to 90 Ibs. 
 
 imple condens 
 matic cut-off 
 steam pressu 
 90 Ibs. 
 
 s 
 
 - 1 
 
 C W)A W - 
 
 3 G rj ,Q 
 
 5'fi -* 
 
 g|S 
 
 5T3 W-l 
 
 80j t 1 
 <D 
 -M O 
 
 W +j 
 
 ^ g $w 
 
 ^ 
 
 PM 
 
 
 c/2 
 
 O 
 
 O 
 
 H 
 
 Water consumption of dif- 
 
 
 
 
 
 
 ferent types of engines 
 
 
 
 
 
 
 per 1 HP per hour 
 
 32 Ibs 
 
 22 Ibs. 
 
 20 Ibs. 
 
 16 Ibs 
 
 13 Ibs. 
 
 
 
 
 
 
 
 Coal consumption per 1 HP 
 
 
 
 
 
 
 per hour with a modern 
 
 
 
 
 
 
 water tube boiler 
 
 3^ Ibs. 
 
 2Y 2 Ibs. 
 
 2^ Ibs. 
 
 1M Ibs. 
 
 l^lbs. 
 
 Coal consumption per 1 HP 
 
 
 
 
 
 
 per hour with a common 
 HT boiler 
 
 4 Ibs. 
 
 3 Ibs. 
 
 2% Ibs. 
 
 2M Ibs. 
 
 1% Ibs. 
 
 RULES FOR CALCULATION. 
 
 THE CIRCLE. 
 
 Multiply diameter by 3.1416 to find circumference. Multiply cir- 
 cumference by .31831 to find diameter. Multiply square of diameter 
 by .7854 to find area. Multiply the square root of area by 1.12837 
 to find diameter. Multiply diameter by .8862 to find side of a square 
 equal to area. Multiply diameter by .7071 product is side of an 
 inscribed square. 
 
 Rule to find area of a circular ring formed by two concentric 
 circles: Multiply the sum of the two diameters by their difference 
 and the product by .7854 the result is area. Multiply radius by 
 6.2831 to find circumference. 
 
 Rule to find area of a section of a circle : Multiply one-half the 
 length of arc by the radius of circle. 
 
 Rule to find area of a sector : Multiply length of arc by the 
 radius and. divide the product by 2 for the area. 
 
SELECTION OF BOILER. 21 
 
 EXAMPLE: 
 
 50" = length of arc of sector 
 30" -radius 
 
 2)1500 
 
 750 =area of sector 
 
 Rule to find area of a triangle : Multiply base by height and 
 divide the product by 2 for the area. 
 
 EXAMPLE: 
 
 38" =base of triangle 
 20" = height of triangle 
 
 2)760 
 
 380 =area of triangle 
 
 Rule to find area of a segment of a circle : Subtract area of 
 triangle from area of sector. The result will be the area of seg- 
 ment. 
 
 EXAMPLE: 
 
 750 =area of sector 
 380 =area of triangle 
 
 370 ==area of segment 
 
 Rule to find one dimension of triangle when area and one 
 dimension is given : Double the area and divide by given dimension. 
 
 Rule to find area of triangle when dimensions of three sides are 
 given : From half the sum of the three sides, subtract each side 
 separately ; multiply the half sum and the three remainders to- 
 gether ; the square root of the product is the area. 
 
 Rule to find hypothenuse of a triangle when dimensions of base 
 and perpendicular are given : Extract the square root of the sum 
 of the squares of the base and the perpendicular ; the result is the 
 length of hypothenuse. 
 
 Rule to find the base or perpendicular when hypothenuse is 
 given : Extract the square root of the difference between the square 
 of the squares of the base and the perpendicular ; the result is the 
 required side. 
 
 QUADRILATERALS. 
 
 Rule to find area of a parallelogram : Multiply base by altitude. 
 Rule to find area of a trapezoid : Multiply one-half sum of the 
 parallel sides by the altitude. 
 
22 THE BOILER. 
 
 Rule to find area of a trapezium : Multiply the diagonal by one- 
 half sum of the perpendiculars drawn to it from the vertices of 
 opposite angle. 
 
 Rule to find area of a rectangle : Multiply length by width. 
 
 Doubling the diameter of a circle increases its area four times. 
 
 The side of a square multiplied by 1.128 equals diameter of 
 circle of equal area. 
 
 Rule to find volume of a pyramid or cone : Multiply the area of 
 the base by one-third the altitude. 
 
 Rule to find the convex surface of a frustrum of a pyramid or of 
 a cone : Multiply the sum of the perimeters or of the circumference 
 by one-half the slant height. 
 
 Rule to find the volume of a frustrum of a pyramid or of a cone : 
 To the sum of the areas of both bases add the square root of the 
 product and multiply this sum by one-third of the altitude. 
 
 THE SPHERE. 
 
 Rule to find the surface of a sphere : Multiply the diameter by 
 the circumference of a great circle of a sphere. 
 
 Rule to find the volume of a sphere : Multiply the surface by 1/6 
 of the diameter or 1/3 of the radius. 
 
 Rule to find the three dimensions of a rectangular solid, the 
 volume and ratio of the dimensions being given : First, divide the 
 volume by the product of the terms proportional to the three dimen- 
 sions, and extract the cube root of the quotient. Second, multiply 
 the root obtained by each proportional term ; the products will be the 
 corresponding side. 
 
 Rule to find solidity of a sphere : Multiply cube of diameter by 
 .5236. 
 
 Rule to find surface of a ball : Multiply square of diameter by 
 3.1416. 
 
UNIVERSITY 
 
 OF . 
 
 SELECTION OF BOILER. 23 
 
 A TRAPEZOID. 
 
 A plane four sided figure having two of the opposite sides 
 parallel to each other. 
 
 Rule to find area of a trapezoid whose sides are 26" and 14" 
 altitude 10" : Multiply one-half the sums of parallel sides by the 
 altitude. 
 
 EXAMPLE: 
 26" 
 14 
 
 2)40 
 
 20 
 10 
 
 200 area of trapezoid 
 
 SOLIDS. 
 
 Rule to find volume of a prism or cylinder : Multiply area of the 
 base by the altitude. 
 
 Rule to find convex surface of a prism or cylinder : Multiply the 
 perimeter or circumference of the base by the altitude. 
 
 SIGNS USED IN MATHEMATICAL CALCULATIONS. 
 77 Ratio of circumference of a circle to a diam., as 3.1416 
 
 Equal, as 12 inches =1 foot 
 + Plus , addition , as 2 + 4 = 6 
 
 Minus, substraction, as 8-4=4 
 
 Multiply, as 4x4 = 16 
 -r- Divide, as 10 -=-2 =5 
 
 : : : Proportion, as 2 : 4 :: 8 : 16; or 2 is to 4 as 8 is to 16 
 x/ Square root is required; cube root, 3 \/27 =3 
 
 5 2 Number is to be squared, 5 2 =25 
 
 5 3 Number is to be cubed, 5 3 = 125 
 Decimal point, as .1 = 1 1 ; .14=^% 
 
 () Parenthesis, all numbers between to be taken as one 
 
 Vinculum signifies the numbers over which it is placed are to be 
 
 taken together. 
 Degrees 
 
 Minutes or feet 
 Seconds or inches 
 
 A coefficient is a prescribed amount to make up for any defects 
 reducing the strength of plate due to punching, caulking, etc. 
 
 A factor of safety is the difference between the safe working 
 and bursting pressures. 
 
24 
 
 THE BOILER. 
 CIRCUMFERENCES AND AREAS OF CIRCLES. 
 
 OF ONE INCH. 
 
 OF INCHES OR FEET. 
 
 Fract. 
 
 Dec. 
 
 Circ. 
 
 Area 
 
 Dia. 
 
 Circ. 
 
 Area 
 
 Dia. 
 
 Circ. 
 
 Area. 
 
 1-64 
 
 .015625 
 
 .04909 
 
 .00019 
 
 1 
 
 3.1416 
 
 .7854 
 
 64 
 
 201.06 
 
 3216.99 
 
 1-32 
 
 .03125 
 
 .09818 
 
 .00077 
 
 2 
 
 6 . 2832 
 
 3.1416 
 
 65 
 
 204 . 20 
 
 3318.31 
 
 3-64 
 
 .046875 
 
 . 14726 
 
 .00173 
 
 3 
 
 9 . 4248 
 
 7.0686 
 
 66 
 
 207 . 34 
 
 3421.19 
 
 
 .0625 
 
 . 19635 
 
 .00307 
 
 4 
 
 12 . 5664 
 
 12.5664 
 
 67 
 
 210.49 
 
 3525 . 65 
 
 5-64 
 
 .078125 
 
 . 24545 
 
 . 00479 
 
 5 
 
 15.7080 
 
 19.635 
 
 68 
 
 213.63 
 
 3631.68 
 
 3-32 
 
 .09375 
 
 . 29452 
 
 .00690 
 
 6 
 
 18.850 
 
 28 . 274 
 
 69 
 
 216.77 
 
 3739.28 
 
 7-64 
 
 . 109375 
 
 .34363 
 
 . 00939 
 
 7 
 
 21.991 
 
 38.485 
 
 70 
 
 219.91 
 
 3848 . 45 
 
 1-8 
 
 .125 
 
 .39270 
 
 .01227 
 
 8 
 
 25.133 
 
 50 . 266 
 
 71 
 
 223.05 
 
 3959 . 19 
 
 9=64 
 
 . 140625 
 
 .44181 
 
 .01553 
 
 9 
 
 28 . 274 
 
 63.617 
 
 72 
 
 226.19 
 
 4171.50 
 
 5=32 
 
 . 15625 
 
 .49087 
 
 .01917 
 
 10 
 
 31.416 
 
 78.540 
 
 73 
 
 229.34 
 
 4185.39 
 
 11=64 
 
 .171875 
 
 .53999 
 
 .02320 
 
 11 
 
 34 . 558 
 
 95.033 
 
 74 
 
 232.48 
 
 4300.84 
 
 3=16 
 
 .1875 
 
 . 58905 
 
 .02761 
 
 12 
 
 37.699 
 
 113.1 
 
 75 
 
 235 . 62 
 
 4417.86 
 
 13=64 
 
 .203125 
 
 .63817 
 
 .03241 
 
 13 
 
 40.841 
 
 132.73 
 
 76 
 
 238 . 76 
 
 4536.46 
 
 7=32- 
 
 .21875 
 
 .68722 
 
 .03758 
 
 14 
 
 43 . 982 
 
 153.94 
 
 77 
 
 241.90 
 
 4656.63 
 
 15-64 
 
 .234375 
 
 . 73635 
 
 .04314 
 
 15 
 
 47.124 
 
 176.71 
 
 78 
 
 245.04 
 
 4778.36 
 
 1=4 
 
 .25 
 
 . 78540 
 
 .04909 
 
 16 
 
 50 . 265 
 
 201.06 
 
 79 
 
 248 . 19 
 
 4901.67 
 
 17=64 
 
 . 265625 
 
 .83453 
 
 .05542 
 
 17 
 
 53.407 
 
 226.98 
 
 80 
 
 251.33 
 
 5026.55 
 
 9=32 
 
 .28125 
 
 .88357 
 
 .06213 
 
 18 
 
 56.549 
 
 254.47 
 
 81 
 
 254.47 
 
 5153. 
 
 19=64 
 
 . 296875 
 
 .93271 
 
 .06922 
 
 19 
 
 59 . 690 
 
 283 . 53 
 
 82 
 
 257.61 
 
 5281.02 
 
 5-16 
 
 .3125 
 
 .98175 
 
 .07670 
 
 20 
 
 62 . 832 
 
 314.16 
 
 83 
 
 260 . 75 
 
 5410.61 
 
 21=64 
 
 .328125 
 
 .0309 
 
 . 08456 
 
 21 
 
 65 . 973 
 
 346.36 
 
 84 
 
 263.89 
 
 5541.77 
 
 11=32 
 
 .34375 
 
 .0799 
 
 .09281 
 
 22 
 
 69.115 
 
 380 . 13 
 
 85 
 
 267.04 
 
 5674 . 50 
 
 23=64 
 
 .359375 
 
 .1291 
 
 . 10144 
 
 23 
 
 72.257 
 
 415.48 
 
 86 
 
 270 . 18 
 
 5808.80 
 
 3=8 
 
 .375 
 
 .1781 
 
 .11045 
 
 24 
 
 75 . 398 
 
 452.39 
 
 87 
 
 273 . 32 
 
 5944 . 68 
 
 25=64 
 
 .390625 
 
 .2273 
 
 .11984 
 
 25 
 
 78 . 540 
 
 490 . 87 
 
 88 
 
 276.46 
 
 6082.12 
 
 13=32 
 
 .40625 
 
 .2763 
 
 . 12962 
 
 26 
 
 81.681 
 
 530.93 
 
 89 
 
 279.60 
 
 6221.14 
 
 27=64 
 
 .421875 
 
 1.3254 
 
 . 13979 
 
 27 
 
 84 . 823 
 
 572 . 56 
 
 90 
 
 282 . 74 
 
 6361.73 
 
 7=16 
 
 .4375 
 
 1.3744 
 
 . 15033 
 
 28 
 
 87.965 
 
 615.75 
 
 91 
 
 285.88 
 
 6503.88 
 
 29=64 
 
 .453125 
 
 1.4236 
 
 .16126 
 
 29 
 
 91 . 106 
 
 660 . 52 
 
 92 
 
 289 . 03 
 
 6647.61 
 
 15=32 
 
 .46875 
 
 1.4726 
 
 . 17257 
 
 30 
 
 94 . 248 
 
 706.86 
 
 93 
 
 292.17 
 
 6792.91 
 
 31=64 
 
 .484375 
 
 1.5218 
 
 . 18427 
 
 31 
 
 97.389 
 
 754 . 77 
 
 94 
 
 295.31 
 
 6939.78 
 
 1=2 
 
 .5 
 
 1.5708 
 
 . 19635 
 
 32 
 
 100.53 
 
 804.25 
 
 95 
 
 298.45 
 
 7088 . 22 
 
 33=64 
 
 .515625 
 
 1.6199 
 
 . 20880 
 
 33 
 
 103.67 
 
 855 . 30 
 
 96 
 
 301.59 
 
 7238 . 23 
 
 W 
 
 .53125 
 . 546875 
 
 1 . 6690 
 1.7181 
 
 .22166 
 . 23489 
 
 34 
 35 
 
 106.81 
 109 . 96 
 
 907.92 
 962.11 
 
 97 
 
 98 
 
 304 . 73 
 307.88 
 
 7339.81 
 7542 . 96 
 
 9-16 
 
 .5625 
 
 1.7671 
 
 .24850 
 
 36 
 
 113.10 
 
 1017.88 
 
 99 
 
 311.02 
 
 7697.69 
 
 37=64 
 
 .578125 
 
 1.8163 
 
 . 26248 
 
 37 
 
 116.24 
 
 1075.21 
 
 100 
 
 314.16 
 
 7853 . 98 
 
 19=32 
 
 .59375 
 
 1.8653 
 
 . 27688 
 
 38 
 
 119.38 
 
 1134.11 
 
 101 
 
 317.30 
 
 8011.85 
 
 39=64 
 
 .609375 
 
 1.9145 
 
 .29164 
 
 39 
 
 122.52 
 
 1194.59 
 
 102 
 
 320.44 
 
 8171.28 
 
 5=8 
 
 .625 
 
 1.9635 
 
 . 30680 
 
 40 
 
 125.66 
 
 1256.64 
 
 103 
 
 323 . 58 
 
 8332.29 
 
 
 
 
 
 
 
 
 
 
 41=64 
 
 . 640625 
 
 2.0127 
 
 32232 
 
 41 
 
 128.81 
 
 1320.25 
 
 104 
 
 326.73 
 
 8494.87 
 
 21=32 
 
 .65625 
 
 2.0617 
 
 .33824 
 
 42 
 
 131.95 
 
 1385.44 
 
 105 
 
 329.87 
 
 8659.01 
 
 43=64 
 
 .671875 
 
 2.1108 
 
 .35453 
 
 43 
 
 135.09 
 
 1452 . 20 
 
 106 
 
 333.01 
 
 8824 . 73 
 
 11=16 
 
 45=64 
 
 .6875 
 .703125 
 
 2.1598 
 2 . 2090 
 
 .37122 
 
 .38828 
 
 44 
 45 
 
 138.23 
 141.37 
 
 1520.53 
 1590.43 
 
 107 
 108 
 
 336.15J 8992.02 
 339.29| 9160.88 
 
 23=32 
 
 .71875 
 
 2 . 2580 
 
 . 40574 
 
 46 
 
 144.51 
 
 1661.90 
 
 109 
 
 342.43 
 
 9331.32 
 
 47=64 
 
 . 734375 
 
 2.3072 
 
 .42356 
 
 47 
 
 147.65 
 
 1734.94 
 
 110 
 
 345.58 
 
 9503.32 
 
 3=4 
 
 .75 
 
 2.3562 
 
 .44179 
 
 48 
 
 150.80 
 
 1809 . 56 
 
 111 
 
 348 . 72 
 
 9676.89 
 
 49=64 
 
 . 765625 
 
 2.4054 
 
 .45253 
 
 49 
 
 153.94 
 
 1885 . 74 
 
 112 
 
 351.86 
 
 9852.03 
 
 W 
 
 13=16 
 
 .78125 
 . 796875 
 .8125 
 
 2.4544 
 2.5036 
 2 . 5525 
 
 .47937 
 .49872 
 .51849 
 
 50 
 51 
 52 
 
 157.08 
 160.22 
 163.36 
 
 1963.50 
 2042.82 
 2123.72 
 
 113 
 114 
 115 
 
 355. 
 358.14 
 361.28 
 
 10028 . 75 
 10207.03 
 10386.89 
 
 53=64 
 
 .828125 
 
 2.6017 
 
 .53862 
 
 53 
 
 166.50 
 
 2206 . 18 
 
 116 
 
 364.42 
 
 10568.32 
 
 27=32 
 
 .84375 
 
 2.6507 
 
 .55914 
 
 54 
 
 169.65 
 
 2290.22 
 
 117 
 
 367 . 57 
 
 10751.32 
 
 55=64 
 
 .859375 
 
 2 . 6999 
 
 . 58003 
 
 55 
 
 172.79 
 
 2375.83 
 
 118 
 
 370.71 
 
 10935 . 88 
 
 7=8 
 
 .875 
 
 2 . 7489 
 
 .60132 
 
 56 
 
 175.93 
 
 2463.01 
 
 119 
 
 373.85 
 
 11122.02 
 
 57-64 
 
 . 890625 
 
 2.7981 
 
 .62298 
 
 57 
 
 179.07 1 2551.76 
 
 120 
 
 376.99 
 
 11309.73 
 
 29=32 
 
 .90625 
 
 2.8471 
 
 . 64504 
 
 58 
 
 182.21 1 2642.08 
 
 121 
 
 380 . 13 
 
 11499.01 
 
 59=64 
 
 .921875 
 
 2 . 8963 
 
 . 66746 
 
 59 
 
 185.35 
 
 2733.97 
 
 122 
 
 383 . 27 
 
 11689.87 
 
 15=16 
 
 .9375 
 
 2.9452 
 
 . 69029 
 
 60 
 
 188.50 
 
 2827.43 
 
 123 
 
 386.42 
 
 11882.29 
 
 61=64 
 
 .953125 
 
 2 . 9945 
 
 .71349 
 
 61 
 
 191.64 
 
 2922.47 
 
 124 
 
 389 . 56 
 
 12076.28 
 
 31=32 
 
 .96875 
 
 3.0434 
 
 . 73708 
 
 62 
 
 194.78 
 
 3019.07 
 
 125 
 
 392 . 70 
 
 12271.85 
 
 63-64 
 
 .984375 
 
 3 . 0928 
 
 . 76097 
 
 63 
 
 197.92 
 
 3117.25 
 
 126 395.84 
 
 12468.98 
 
SELECTION OF BOILER. 
 
 25 
 
 AREAS OF CIRCLES FROM ^ INCH UP TO 10 INCHES IN DIAMETER, ADVANCING 
 BY THIRTY-SECONDS OF AN INCH. 
 
 INCHES. 
 
 
 0" 
 
 1" 
 
 2" 
 
 3" 
 
 4" 
 
 5" 
 
 6" 
 
 7" 
 
 8" 
 
 9" 
 
 
 
 
 
 .7854 
 
 3.1416 
 
 7.068 
 
 12.56 
 
 19.63 
 
 28.27 
 
 38.48 
 
 50.26 
 
 63.62 
 
 
 
 3*2 
 
 ' 000767 
 
 .8352 
 
 3.240 
 
 7.216 
 
 12.76 
 
 19.88 
 
 28.57 
 
 38.83 
 
 50.66 
 
 64.06 
 
 3*2" 
 
 A 
 
 .00306 
 
 .8866 
 
 3.341 
 
 7.366 
 
 12.96 
 
 20.13 
 
 28.87 
 
 39.17 
 
 51.05 
 
 64.50 
 
 A 
 
 A 
 
 .0069 
 
 .9395 
 
 3.443 
 
 7.516 
 
 13.16 
 
 20.38 
 
 29.16 
 
 39.52 
 
 51.45 
 
 64.95 
 
 A 
 
 H 
 
 .0123 
 
 .9940 
 
 3.546 
 
 7.669 
 
 13.36 
 
 20.63 
 
 29.46 
 
 39.87 
 
 51.85 
 
 65.40 
 
 Ys 
 
 _5_ 
 
 .0192 
 
 1.050 
 
 3.651 
 
 7.824 
 
 13.57 
 
 20.88 
 
 29.77 
 
 40.22 
 
 52.25 
 
 65.84 
 
 & 
 
 _^ 
 
 .0276 
 
 1.107 
 
 3.758 
 
 7.970 
 
 13.77 
 
 21.13 
 
 30.07 
 
 40.57 
 
 52.65 
 
 66.30 
 
 A 
 
 J^ 
 
 .0376 
 
 1.166 
 
 3.866 
 
 8.137 
 
 13.98 
 
 21.39 
 
 30.37 
 
 40.93 
 
 53.05 
 
 66.75 
 
 
 
 .0491 
 
 1.227 
 
 3.976 
 
 8.295 
 
 14.19 
 
 21.65 
 
 30.68 
 
 41.28 
 
 53.46 
 
 67.20 
 
 F 
 
 
 .0621 
 
 1.289 
 
 4.087 
 
 8.456 
 
 14.40 
 
 21.91 
 
 30.99 
 
 41.64 
 
 53.86 
 
 67.65 
 
 & 
 
 A 
 
 .0767 
 
 1.353 
 
 4.199 
 
 8.618 
 
 14.61 
 
 22.17 
 
 31.30 
 
 42.00 
 
 54.27 
 
 68.11 
 
 A 
 
 1^ 
 
 .0928 
 
 1.418 
 
 4.314 
 
 8.781 
 
 14.82 
 
 22.43 
 
 31.61 
 
 42.36 
 
 54.68 
 
 68.57 
 
 44 
 
 H 
 
 .1104 
 
 1.484 
 
 4.430 
 
 8.946 
 
 15.03 
 
 22.69 
 
 31.92 
 
 42.72 
 
 55.09 
 
 69.03 
 
 
 4* 
 
 .1296 
 
 1.553 
 
 4.547 
 
 9.112 
 
 15.25 
 
 22.95 
 
 32.23 
 
 43.08 
 
 55.50 
 
 69.49 
 
 M 
 
 T^ 
 
 .1503 
 
 1.623 
 
 4.666 
 
 9.280 
 
 15.47 
 
 23.22 
 
 32.55 
 
 43.45 
 
 55.91 
 
 69.95 
 
 & 
 
 M 
 
 .1725 
 
 1.694 
 
 4.786 
 
 9.450 
 
 15.68 
 
 23.49 
 
 32.86 
 
 43.81 
 
 56.33 
 
 70.42 
 
 M 
 
 H 
 
 .1963 
 
 1.767 
 
 4.908 
 
 9.621 
 
 15.90 
 
 23.76 
 
 33.18 
 
 44.18 
 
 56.74 
 
 70.88 
 
 
 4i 
 
 .2216 
 
 1.840 
 
 5.032 
 
 9.794 
 
 16.13 
 
 24.03 
 
 33.50 
 
 44.55 
 
 57.16 
 
 71.35 
 
 44 
 
 
 .2485 
 
 1.917 
 
 5.157 
 
 9.968 
 
 16.35 
 
 24.30 
 
 33.82 
 
 44.92 
 
 57.58 
 
 71.82 
 
 T% 
 
 M 
 
 .2770 
 
 1.994 
 
 5.283 
 
 10.14 
 
 16.57 
 
 24.58 
 
 34.15 
 
 45.29 
 
 58.00 
 
 72.29 
 
 
 
 ^ 
 
 .3067 
 
 2.073 
 
 5.411 
 
 10.32 
 
 16.80 
 
 24.85 
 
 34.47 
 
 45.66 
 
 58.43 
 
 72.76 
 
 6 /s 
 
 21 
 
 .3382 
 
 2.154 
 
 5.541 
 
 10.50 
 
 17.03 
 
 25.13 
 
 34.80 
 
 46.04 
 
 58.85 
 
 73.23 
 
 4 
 
 II 
 
 .3712 
 
 2.236 
 
 5.672 
 
 10.68 
 
 17.26 
 
 25.41 
 
 35.12 
 
 46.41 
 
 59.28 
 
 73.71 
 
 tt 
 
 M 
 
 .4057 
 
 2.319 
 
 5.805 
 
 10.86 
 
 17.49 
 
 25.68 
 
 35.45 
 
 46.79 
 
 59.70 
 
 74.18 
 
 Jf 
 
 
 .4417 
 
 2.405 
 
 5.939 
 
 11.04 
 
 17.72 
 
 25.97 
 
 35.78 
 
 47.17 
 
 60.13 
 
 74.66 
 
 
 M 
 
 .4793 
 
 2.492 
 
 6.075 
 
 11.23 
 
 17.95 
 
 26.25 
 
 36.11 
 
 47.55 
 
 60.56 
 
 75.14 
 
 M 
 
 *t 
 
 .5184 
 
 2.581 
 
 6.212 
 
 11.41 
 
 18.19 
 
 26.53 
 
 36.45 
 
 47.94 
 
 60.99 
 
 75.62 
 
 i| 
 
 
 .5591 
 
 2.669 
 
 6.351 
 
 11.60 
 
 18.43 
 
 26.82 
 
 36.79 
 
 48.32 
 
 61.24 
 
 76.10 
 
 M 
 
 j^ 
 
 .6013 
 
 2.761 
 
 6.491 
 
 11.79 
 
 18.66 
 
 27.11 
 
 37.12 
 
 48.71 
 
 61.86 
 
 76.59 
 
 Ji 
 
 
 j 
 
 
 
 
 
 
 
 
 
 
 1 
 
 .6450 
 
 2.854 
 
 6.633 
 
 11.98 
 
 18.91 
 
 27.40 
 
 37.46 
 
 49.09 
 
 62.30 
 
 77.07 
 
 ft 
 
 it 
 
 .6903 
 
 2.948 
 
 6.777 
 
 12.18 
 
 19.15 
 
 27.69 
 
 37.80 
 
 49.48 
 
 62.74 
 
 77.56 
 
 
 H 
 
 .7370 
 
 3.044 
 
 6.922 
 
 12.37 
 
 19.39 
 
 27.98 
 
 38.14 
 
 49.87 
 
 63.18 
 
 78.05 
 
 M 
 
26 
 
 THE BOILER. 
 DECIMALS OF A FOOT FOR EACH 
 
 OF AN INCH. 
 
 INCH 
 
 0" 
 
 1" 
 
 2" 
 
 3" 
 
 4" 
 
 5" 
 
 6" 
 
 ' 7" 
 
 8" 
 
 9" 
 
 10" 
 
 11" 
 
 
 
 
 .0026 
 
 .0833 
 .0859 
 
 .1667 
 .1693 
 
 .2500 
 .2526 
 
 .3333 
 .3359 
 
 .4167 
 .4193 
 
 .5000 
 .5026 
 
 .5833 
 . 5859 
 
 .6667 
 . 6693 
 
 .7500 
 .7526 
 
 .8333 
 .8359 
 
 .9167 
 .9193 
 
 iV 
 
 .0052 
 
 .0885 
 
 .1719 
 
 . 2552 
 
 .3385 
 
 .4219 
 
 .5052 
 
 . 5885 
 
 .6719 
 
 .7552 
 
 .8385 
 
 .9219 
 
 
 .0078 
 
 .0911 
 
 . 1745 
 
 .2578 
 
 .3411 
 
 .4245 
 
 .5078 
 
 .5911 
 
 .6745 
 
 .7578 
 
 .8411 
 
 .9245 
 
 H 
 
 .0104 
 
 .0937 
 
 .1771 
 
 .2604 
 
 .3437 
 
 .4271 
 
 .5104 
 
 .5937 
 
 .6771 
 
 . 7604 
 
 .8437 
 
 .9271 
 
 
 
 .0130 
 
 .0964 
 
 .1797 
 
 . 2630 
 
 .3464 
 
 .4297 
 
 .5130 
 
 .5964 
 
 .6797 
 
 .7630 
 
 .8464 
 
 .9297 
 
 ft 
 
 .0156 
 
 .0990 
 
 .1823 
 
 .2656 
 
 .3490 
 
 .4323 
 
 .5156 
 
 .5990 
 
 .6823 
 
 .7656 
 
 .8490 
 
 .9323 
 
 T7 
 
 .0182 
 
 .1016 
 
 .1849 
 
 .2682 
 
 .3516 
 
 .4349 
 
 .5182 
 
 .6016 
 
 .6849 
 
 .7682 
 
 .8516 
 
 . 9349 
 
 H 
 
 .0208 
 
 .1042 
 
 .1875 
 
 .2708 
 
 .3542 
 
 .4375 
 
 .5208 
 
 . 6042 
 
 .6875 
 
 .7708 
 
 .8542 
 
 .9375 
 
 & 
 
 .0234 
 
 .1068 
 
 .1901 
 
 .2734 
 
 .3568 
 
 .4401 
 
 .5234 
 
 .6068 
 
 .6901 
 
 .7734 
 
 .8568 
 
 .9401 
 
 -h 
 
 .0260 
 
 .1094 
 
 .1927 
 
 .2760 
 
 .3594 
 
 .4427 
 
 . 5260 
 
 .6094 
 
 .6927 
 
 .7760 
 
 .8594 
 
 .9427 
 
 1 
 
 .0286 
 
 .1120 
 
 .1953 
 
 .2786 
 
 .3620 
 
 .4453 
 
 .5286 
 
 .6120 
 
 .6953 
 
 .7786 
 
 .8620 
 
 . 9453 
 
 
 .0312 
 
 .1146 
 
 .1979 
 
 .2812 
 
 .3646 
 
 .4479 
 
 .5312 
 
 .6146 
 
 .6979 
 
 .7812 
 
 .8646 
 
 .9479 
 
 if 
 
 . 0339 
 
 .1172 
 
 . 2005 
 
 .2839 
 
 .3672 
 
 . 4505 
 
 .5339 
 
 .6172 
 
 .7005 
 
 .7839 
 
 .8672 
 
 .9505 
 
 j_ 
 
 .0365 
 
 .1198 
 
 .2031 
 
 . 2865 
 
 .3698 
 
 .4531 
 
 . 5365 
 
 .6198 
 
 .7031 
 
 . 7865 
 
 .8698 
 
 .9531 
 
 M 
 
 .0391 
 
 .1224 
 
 .2057 
 
 .2891 
 
 .3724 
 
 .4557 
 
 .5391 
 
 .6224 
 
 .7057 
 
 .7891 
 
 .8724 
 
 .9557 
 
 V* 
 
 .0417 
 
 .1250 
 
 . 2083 
 
 .2917 
 
 .3750 
 
 .4583 
 
 .5417 
 
 . 6250 
 
 .7083 
 
 .7917 
 
 .8750 
 
 .9583 
 
 H 
 
 .0443 
 
 .1276 
 
 .2109 
 
 . 2943 
 
 .3776 
 
 .4609 
 
 .5443 
 
 .6276 
 
 .7109 
 
 .7943 
 
 .8776 
 
 .9609 
 
 j_ 
 
 .0469 
 
 .1302 
 
 .2135 
 
 .2969 
 
 .3802 
 
 .4635 
 
 .5469 
 
 . 6302 
 
 .7135 
 
 .7969 
 
 .8802 
 
 .9635 
 
 41 
 
 .0495 
 
 .1328 
 
 .2161 
 
 .2995 
 
 .3828 
 
 .4661 
 
 .5495 
 
 .6328 
 
 .7161 
 
 .7995 
 
 .8828 
 
 .9661 
 
 H 
 
 .0521 
 
 .1354 
 
 .2188 
 
 .3021 
 
 .3854 
 
 .4688 
 
 .5521 
 
 .6354 
 
 .7188 
 
 .8021 
 
 .8854 
 
 .9688 
 
 
 .0547 
 
 . 1380 
 
 .2214 
 
 .3047 
 
 . 3880 
 
 .4714 
 
 .5547 
 
 . 6380 
 
 .7214 
 
 .8047 
 
 .8880 
 
 .9714 
 
 
 .0573 
 
 .1406 
 
 .2240 
 
 .3073 
 
 . 3906 
 
 .4740 
 
 .5573 
 
 .6406 
 
 . 7240 
 
 .8073 
 
 .8906 
 
 .9740 
 
 
 .0599 
 
 . 1432 
 
 .2266 
 
 .3099 
 
 .3932 
 
 .4766 
 
 .5599 
 
 .6432 
 
 .7266 
 
 .8099 
 
 .8932 
 
 .9766 
 
 M 
 
 .0625 
 
 .1458 
 
 9 i ?go 
 
 .3125 
 
 .3958 
 
 .4792 
 
 .5625 
 
 .6458 
 
 .7292 
 
 .8125 
 
 .8958 
 
 .9792 
 
 ii 
 
 .0651 
 
 .1484 
 
 .2318 
 
 .3151 
 
 . 3984 
 
 .4818 
 
 .5651 
 
 .6484 
 
 .7318 
 
 .8151 
 
 .8984 
 
 .9818 
 
 .13 
 
 .0677 
 
 .1510 
 
 .2344 
 
 .3177 
 
 .4010 
 
 .4844 
 
 .5677 
 
 .6510 
 
 .7344 
 
 .8177 
 
 .9010 
 
 .9844 
 
 p. 
 
 . 0703 
 
 . 1536 
 
 .2370 
 
 .3203 
 
 . 4036 
 
 .4870 
 
 .5703 
 
 .6536 
 
 .7370 
 
 .8203 
 
 .9036 
 
 .9870 
 
 78 
 
 .0729 
 
 .1562 
 
 . 2396 
 
 .3229 
 
 . 4062 
 
 .4896 
 
 .5729 
 
 . 6562 
 
 .7396 
 
 .8229 
 
 .9062 
 
 .9896 
 
 
 .0755 
 
 .1589 
 
 2422 
 
 .3255 
 
 . 4089 
 
 .4922 
 
 .5755 
 
 .6589 
 
 . 7422 
 
 .8255 
 
 . 9089 
 
 .9922 
 
 
 .0781 
 
 .1615 
 
 | '.2448 
 
 .3281 
 
 .4115 
 
 .4948 
 
 .5781 
 
 .6615 
 
 .7448 
 
 .8281 
 
 .9115 
 
 .9948 
 
 
 .0807 
 
 .1641 
 
 .2474 
 
 .3307 
 
 .4141 
 
 .4974 
 
 .5807 
 
 .6641 
 
 .7474 
 
 .8307 
 
 .9141 
 
 .9974 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 1 . 0000 
 
 HORSE POWER MEASUREMENT. 
 
 In calculating the H. P. boiler required for a given engine it is 
 customary to calculate what amount of water would be evaporated 
 per hour at the temperature of 212 atmospheric pressure. 
 
 The ratio of the amount of heat required to make one pound of 
 steam under any given condition to that required to make a pound 
 of steam from 212 is called the factor of evaporation, and this is 
 found by subtracting the heat units in one pound of the feed water 
 at the given temperature, from the heat units in one pound of steam 
 at the given pressure, and dividing the result by 965.7, which is the 
 heat of evaporation, or number of heat units required to evaporate 
 one pound of water at 212 into steam of 212. 
 
SELECTION OF BOILER. 27 
 
 The number of pounds of water to be evaporated per hour under 
 a given steam pressure, multiplied by its particular factor of evap- 
 oration, gives the factor of evaporation from and at 212 (or the 
 amount of water which would have been evaporated with the same 
 amount of fuel, had the feed water been at 212 degrees atmospheric 
 pressure. 
 
 Hence it is first necessary to find the amount of water the engine 
 is to use per hour ; then the factor of evaporation and the product of 
 these two will be the equivalent from and at 212 ; 34 T / 2 pounds of 
 water at 212 evaporated into steam at atmospheric pressure 
 equals a horse power ; dividing the equivalent evaporation by 34*/2 
 gives the horse power required. 
 
 Rule to find capacity of boiler for any engine, this according to 
 the commercial rating of boilers : Multiply the horse power of 
 the engine by the number of pounds of steam the engine will- con- 
 sume per indicated horse power per hour and call this product 
 No. 1 ; from the number of heat units contained in one pound 
 of the steam at absolute pressure subtract the number of heat units 
 in one pound of feed water, and divide by 965.7 to get factor of evap- 
 oration, and call this product No. 2; multiply product No. 1 
 by product No. 2 and divide by 34^ (the number of pounds of 
 water evaporated from and at 212, to develop one horse power), 
 and this product will be the required commercial rating of boiler. 
 
 LEGEND: 
 
 E = Power of engine 
 
 = Lbs. of steam per horse power 
 P = Pressure 
 
 T = Temperature of feed water 
 
 W = Water to be evaporated per HP per hour 
 
 TSH = Total heat units in steam 
 HU =Heat units in feed water 
 HE =Heat of evaporation 
 FE = Factor of evaporation 
 W of W = Weight of water used per HP per hour 
 
 FORMULA: 
 
 E x L X (TSH HU- 965. 7) 
 
 - = commercial rating of boiler. 
 
28 THE BOILER. 
 
 No. 1 200 HP engine 
 
 20 No. of Ibs. of steam per HP per hour 
 
 4000 =the weight in Ibs. of water used per hour 
 No. 2 
 
 Heat units to 
 
 evaporate one 1217 . 9445 = total heat of given steam 
 
 Ib. of water at 190 . 643 =heat units in feed water 
 
 212 into steam 
 
 at 212= 965.7)1027.3015(1.063 factor of evaporation 
 
 965 7 
 
 61 601 
 57 942 
 
 3 6595 
 
 2 8971 
 
 7624 
 
 1 . 063 factor of evaporation = product No. 2 
 
 4000 weight of water in Ib. use per hour = product No. 1 
 
 4252.000 the equivalent evaporation from and at 212 F. 
 
 Weight of water 
 required per hour 
 per HP for high 
 
 pressure engine = 34 . 5 ) 4252 . 000 (123 . 24 commercial HP of boiler required 
 345 
 
 802 
 690 
 
 1120 
 
 1035 This example was figured on a 
 
 basis of 34i^ Ibs. of water per 
 850 engine HP. The consumption 
 
 690 of steam of modern engine, 
 
 per HP, varies in limits, de- 
 1600 pending on type of engine. 
 
 1380 
 
 220 
 
 PROPERTIES OF STEAM. 
 
 The temperature at which water is converted into steam varies 
 with the pressure. At atmospheric the steaming point is 212 de- 
 grees F., less at low pressure and higher at higher pressure. When 
 water reaches the boiling point, further addition of heat effects no 
 change in temperature, the heat absorbed in producing steam 
 having the same temperature and pressure as that at which it is 
 
SELECTION OF BOILER. 
 
 29 
 
 evaporated. The heat thus absorbed is known as the latent heat, so 
 called because it produces effects other than those of change of tem- 
 perature. The amount of heat rendered latent by each pound of 
 water in becoming steam varies with the pressure, decreasing as the 
 pressure rises. The latent heat added to the sensible heat (this 
 latter as shown by the thermometer) gives the total heat, this term 
 used to designate the number of heat units contained in one pound 
 of steam above a given temperature. Total heat is calculated from 
 32 degrees F. as the total heat is greater the higher the pressure ; 
 the amount of fuel necessary to evaporate a pound of water in- 
 creases with the pressure ; saturated steam cannot be superheated in 
 contact with water, that is, its temperature cannot be raised above 
 the point normal to the pressure, neither can it be cooled without 
 change of pressure, for any loss of heat is compensated by the latent 
 heat of the steam which is condensed. 
 
 Saturated steam is that which has the minimum temperature at 
 which it can exist as a vapor under the given pressure. 
 
 Superheated steam has a temperature higher than that of satura- 
 tion at the same pressure. The same pressure above vacuum is the 
 gauge pressure plus 14.7 pounds. 
 
 TABLE 
 PRESSURE OF STEAM AT DIFFERENT TEMPERATURES. 
 
 Pounds 
 
 pressure 
 per square 
 inch above 
 vacuum 
 
 Temperature 
 Fahr. 
 
 Heat units in 
 water above 
 32" 
 
 Latent heat in 
 Heat of 
 Vaporization 
 
 Total 
 heat units 
 above 32" 
 
 Volume of 
 one pound in 
 cubic foot 
 
 1 
 
 101.99 
 
 70.0 
 
 1043 . 
 
 1113.1 
 
 334.5 
 
 5 
 
 162.34 
 
 130.7 
 
 1000.8 
 
 1131.5 
 
 73.21 
 
 10 
 
 193.25 
 
 161.9 
 
 979.0 
 
 1140.9 
 
 38.15 
 
 15 
 
 213.03 
 
 181.8 
 
 965.1 
 
 1146.9 
 
 26.14 
 
 20 
 
 227.95 
 
 196.9 
 
 954.6 
 
 1151.5 
 
 19.91 
 
 25 
 
 240.04 
 
 209.1 
 
 946.0 
 
 1155.1 
 
 16.13 
 
 30 
 
 250.72 
 
 219.4 
 
 938.9 
 
 1158.3 
 
 13.59 
 
 35 
 
 259.19 
 
 228.4 
 
 932.6 
 
 1161.0 
 
 11.75 
 
 40 
 
 267.13 
 
 236.4 
 
 927.0 
 
 1163.4 
 
 10.37 
 
 45 
 
 274.29 
 
 243.6 
 
 922.0 
 
 1165.6 
 
 9.285 
 
 50 
 
 280.85 
 
 250.2 
 
 917.4 
 
 ' 1167.6 
 
 8.418 
 
 55 
 
 286.89 
 
 256.3 
 
 913.1 
 
 1169.4 
 
 7.698 
 
 60 
 
 292.51 
 
 261.9 
 
 909.3 
 
 1171.2 
 
 7.097 
 
 65 
 
 297.77 
 
 267.2 
 
 905.5 
 
 1172.7 
 
 6.583 
 
 70 
 
 302.71 
 
 272.2 
 
 902.1 
 
 1174.3 
 
 6.143 
 
 75 
 
 307.38 
 
 276.9 
 
 898.8 
 
 1175.7 
 
 5.760 
 
30 
 
 THE BOILER. 
 PRESSURE OF STEAM AT DIFFERENT TEMPERATURES. 
 
 Pounds 
 pressure 
 per square 
 inch above 
 vacuum 
 
 Temperature 
 Fahr. 
 
 Heat units in 
 water above 
 
 32" 
 
 Latent heat in 
 Heat of 
 Vaporization 
 
 Total 
 heat units 
 above 32" 
 
 Volume of 
 of one pound 
 cubic foot 
 
 80 
 
 311.80 
 
 281.4 
 
 895.6 
 
 1177.0 
 
 5.426 
 
 85 
 
 316.02 
 
 285.8 
 
 892.5 
 
 1178.3 
 
 5.126 
 
 90 
 
 320.04 
 
 290.0 
 
 889.6 
 
 1179.6 
 
 4.859 
 
 95 
 
 323.89 
 
 294.0 
 
 886.7 
 
 1180.7 
 
 4.619 
 
 100 
 
 327.58 
 
 297.9 
 
 884.0 
 
 1181.9 
 
 4.403 
 
 105 
 
 331.13 
 
 301.6 
 
 881.3 
 
 1182.9 
 
 4.205 
 
 110 
 
 334.56 
 
 305.2 
 
 878.8 
 
 1184.0 
 
 4.026 
 
 115 
 
 337.86 
 
 308.7 
 
 876.3 
 
 1185.0 
 
 3.862 
 
 120 
 
 341.05 
 
 312.0 
 
 874.0 
 
 1186.0 
 
 3.711 
 
 125 
 
 344.13 
 
 315.2 
 
 871.7 
 
 1186.9 
 
 3.572 
 
 130 
 
 347.12 
 
 318.4 
 
 869.4 
 
 1187.8 
 
 3.444 
 
 135 
 
 350.03 
 
 321.4 
 
 867.3 
 
 1188.7 
 
 3.323 
 
 140 
 
 352.85 
 
 324.4 
 
 865.1 
 
 1189.5 
 
 3.212 
 
 145 
 
 355.59 
 
 327.2 
 
 863.2 
 
 1190.4 
 
 3.107 
 
 150 
 
 358.26 
 
 330.0 
 
 861.0 
 
 1191.2 
 
 3.011 
 
 155 
 
 360.86 
 
 332.7 
 
 859.3 
 
 1192.0 
 
 2.919 
 
 160 
 
 363.40 
 
 335.4 
 
 857.4 
 
 1192.8 
 
 2.833 
 
 165 
 
 365.88 
 
 338.0 
 
 855.6 
 
 1193.6 
 
 2.751 
 
 170 
 
 368.29 
 
 340.5 
 
 853.8 
 
 1194.3 
 
 2.676 
 
 175 
 
 370.65 
 
 343.0 
 
 852.0 
 
 1195.0 
 
 2.603 
 
 180 
 
 372.97 
 
 345.4 
 
 850.3 
 
 1195.7 
 
 2.535 
 
 185 
 
 375.23 
 
 347.8 
 
 848.6 
 
 1196.4 
 
 2.470 
 
 190 
 
 377.44 
 
 350.1 
 
 847.0 
 
 1197.1 
 
 2.408 
 
 195 
 
 379.61 
 
 352.4 
 
 845.3 
 
 1197.7 
 
 2.349 
 
 200 
 
 381.73 
 
 354.6 
 
 843.8 
 
 1198.4 
 
 2.294 
 
 205 
 
 383.82 
 
 356.8 
 
 842.2 
 
 1199.0 
 
 2.241 
 
 210 
 
 385.87 
 
 358.9 
 
 840.7 
 
 1199.6 
 
 2.190 
 
 215 
 
 387.88 
 
 361.0 
 
 839.2 
 
 1200.2 
 
 2.142 
 
 220 
 
 389.84 
 
 363.0 
 
 837.8 
 
 1200.8 
 
 2.096 
 
 225 
 
 391.79 
 
 365.1 
 
 836.3 
 
 1201.4 
 
 2.051 
 
 250 
 
 400.99 
 
 374.7 
 
 829.5 
 
 1204.2 
 
 1.854 
 
 275 
 
 409.50 
 
 383.6 
 
 823.2 
 
 1206.8 
 
 1.691 
 
 300 
 
 417.42 
 
 391.9 
 
 817.4 
 
 1209.3 
 
 1.553 
 
 325 
 
 424.82 
 
 399.6 
 
 811.9 
 
 1211.5 
 
 1.437 
 
 350 
 
 431.90 
 
 406.9 
 
 806.8 
 
 1213.7 
 
 1.337 
 
 375 
 
 438.40 
 
 414.2 
 
 801.5 
 
 1215.7 
 
 1.250 
 
 400 
 
 445.15 
 
 421.4 
 
 796.3 
 
 1217.7 
 
 1.172 
 
 500 
 
 466.57 
 
 444.3 
 
 779.9 
 
 1224.2 
 
 .939 
 
 ENGINE NOTES. 
 
 Steam at atmospheric pressure flows into a Vacuum at the rate 
 of about 1,550 feet per second, and into the Atmosphere at the rate 
 of 650 feet per second. 
 
 The specific gravity of steam (at atmospheric pressure) is .411, 
 that of air at 34 deg. Fahrenheit, and .0006 that of water at same 
 temperature. 
 
SELECTION OF BOILER. 31 
 
 33000 minute foot pounds equal 1 H. P. 
 
 396000 minute inch pounds equal 1 H. P. 
 
 A cubic inch of water evaporated under atmospheric pressure is 
 approximately converted into 1 cubic foot of steam. 
 
 The horse power of boilers, as per standard adopted by the Am. 
 S. M. E., is 30 pounds water evaporated per hour at a pressure of 70 
 pounds per square inch and from a temperature of 100 degrees 
 Fahr. 
 
 Well designed boilers, under successful operation, will evaporate 
 from 7 to 10 pounds of water per pound of first-class coal. 
 
 Each square foot of heating surface is considered sufficient to 
 evaporate 3*/> pounds of water; therefore, for an engine using 30 
 pounds of water per horse power per hour, each horse power of the 
 engine reqttiresg.75square feet heating surface in the boiler. 
 
 On one square foot of fire grate can be burned on an average 
 from 10 to 12 pounds hard coal, or 18 to 35 pounds soft coal, per 
 hour, with natural draft. 
 
 Two and one-quarter pounds of dry wood is equal to 1 pound of 
 average quality soft coal. 
 
 Condensing engines require from 20 to 30 times the amount of 
 feed water for condensing purposes; approximately for most en- 
 gines, 1 to \y 2 gallons condensing water per minute per indicated 
 horse power, -depending on temperature of injection water. 
 
 Surface condensers for compound steam engines require about 
 2 square feet of cooling surface per horse power ; ordinary engines 
 will require more surface according to their economy in the use of 
 steam. It is absolutely necessary that the air pump should be set 
 lower than the condenser for satisfactory results. 
 
 The effect of a good air pump and condenser should be to get 
 25 inches of vacuum and to make available about 10 pounds more 
 mean effective pressure with the same terminal pressure, or to give 
 the same mean effective pressure with a correspondingly less ter- 
 minal pressure. Approximately, a good condenser will save one- 
 fourth of the fuel consumed, or, in other words, increase the power 
 of the engine one-fourth, the fuel consumption remaining the same. 
 
 One pound of water evaporated from, and at 212 F. is equiv- 
 alent to 965.7 British thermal units. 
 
 The evaporation of 30 pounds of water per hour, from a temper- 
 
32 THE BOILER. 
 
 ature of 100 F., into steam at 70 pounds gauge pressure = one 
 H. P. This is equivalent to 34^ pounds of water from and at 
 212 F. 
 
 A common rule to find horse power on an engine : Multiply area 
 of piston by pressure per square inch and by length of stroke and 
 again by number of revolutions per minute; divide this sum by 
 constant 16500. 
 
 LEGEND: FORMULA: 
 
 P = pressure = 100 Ibs. A X P X S X R 
 
 A = area of piston = 7 8. 5 400 =H.P. 
 
 S = length of stroke in feet = 1 ft. C 
 
 R = number of revolutions = 70 
 
 C = constant = 16500 
 
 EXAMPLE: 
 
 78 . 5400 =area of piston 
 100=lbs. pressure 
 
 7854.0000 
 
 1 ft. stroke 
 
 7854.0000 
 
 70 = number of revolutions 
 
 constant = 16500) 549780.0000 (33 . 3 = horse power 
 49500 
 
 54780 
 49500 
 
 52800 
 49500 
 
 3300 
 
 THE THERMOMETER. 
 
 To convert Fahrenheit degrees to centigrade, subtract 32 de- 
 grees from number of degrees Fahrenheit; multiply the sum by 5 
 and divide product by 9. 
 
 LEGEND: FORMULA: 
 
 F = Fahrenheit =32 5 X (F 32) 
 
 C = Centigrade = 100 = Centigrade 
 
 R = Reaumur = 80 9 
 
SELECTION OF BOILER. 33 
 
 EXAMPLE: 
 
 212=degrees Fahrenheit 
 32 
 
 180 
 5 - 
 
 9)900 
 
 100= Centigrade 
 
 To convert Centigrade degrees to Fahrenheit : Multiply the 
 number of degrees centigrade by 9, divide result by 5 and add 32 to 
 quotient. 
 
 FORMULA: EXAMPLE: 
 
 9 X C 100= degrees Centigrade 
 
 - + 32 = Fahrenheit 9 
 
 SJ 
 
 5)900 
 
 180 
 32 to be added 
 
 212 = degrees Fahrenheit 
 
 To convert Fahrenheit degrees to Reaumur subtract from num- 
 ber of degrees Fahrenheit 32; multiply result by 4 and divide 
 product by 9. 
 
 FORMULA: EXAMPLE: 
 
 4 X (F 32) 2 12= degrees Fahrenheit 
 
 = Reaumur 32 
 g 
 
 180 
 
 4 
 
 9)720 
 
 80 = degrees Reaumur 
 
 To convert Reaumur degrees to Fahrenheit: Multiply number 
 of degrees of Reaumur by 9; divide product by 4 and add 32 to 
 quotient. 
 
 FORMULA: EXAMPLE: 
 
 9 X R 80= degrees Reaumur 
 
 + 32 = Fahrenheit 9 
 
 4 
 
 4)720 
 
 180 
 32 to be added 
 
 212 = degrees Fahrenheit 
 
34 
 
 THE BOILER. 
 
 COMPARISONS OF THERMOMETER SCALES. 
 
 Fahrenheit 
 
 Centigrade 
 
 Reaumur 
 
 Fahrenheit 
 
 Centigrade 
 
 Reaumur 
 
 4 
 
 20 
 
 -16 
 
 113 
 
 45 
 
 36 
 
 + 5 
 
 15 
 
 12 
 
 112 
 
 50 
 
 40 
 
 14 
 
 10 
 
 8 
 
 131 
 
 55 
 
 44 
 
 23 
 
 5 
 
 4 
 
 140 
 
 60 
 
 48 
 
 32 
 
 
 
 
 
 149 
 
 65 
 
 52 
 
 41 
 
 + 5 
 
 + 4 
 
 158 
 
 70 
 
 56 
 
 50 
 
 10 
 
 8 
 
 167 
 
 75 
 
 60 
 
 59 
 
 15 
 
 12 
 
 176 
 
 80 
 
 64 
 
 68 
 
 20 
 
 16 
 
 185 
 
 85 
 
 68 
 
 77 
 
 25 
 
 20 
 
 194 
 
 90 
 
 72 
 
 86 
 
 30 
 
 24 
 
 203 
 
 95 
 
 76 
 
 95 
 
 35 
 
 28 
 
 212 
 
 100 
 
 80 
 
 104 
 
 40 
 
 32 
 
 
 
 
 BOILING 
 
 BOILING 
 
 BOILING 
 
 FREEZING 
 
 FREEZING 
 
 FREEZING 
 
 POINT 
 
 POINT 
 
 POINT 
 
 POINT 
 
 POINT 
 
 POINT 
 
 212 
 
 100 
 
 80 
 
 32 
 
 
 
 
 
CHAPTER III. 
 
 BOILER CONSTRUCTION. 
 
 Boiler construction can be classed as one of the highest among 
 crafts. In old-time boiler making holes were punched leaving in- 
 itial fractures around edge of holes and often times, when assem- 
 bling joints, holes were found out of alignment, and to admit a 
 rivet the plate had to be cut by reaming to make the holes coincide, 
 thus reducing the percentage of strength, at best, very low. Today 
 drilled holes are specified by reliable authorities and followed up by 
 reputable boiler makers. Modern machinery of today has developed 
 a wonderful improvement in the craft ; it has taken the place of old- 
 time hand methods ; accuracy, efficiency and strength have been 
 gained ; improved tools to facilitate work, brain and not all muscle 
 employed by the mechanics ; he reasons, conceives, then executes 
 with these modern conveniences ; his aim is to produce results, bet- 
 terment of his work. Flanging machines have added factors to 
 safety ; that old methods of flanging were not conducive to good 
 effects or results is now apparent ; for when the part of work 
 to be flanged was heated, hammered, reheated and hammered again 
 hot and cold often resulting in defects in plates that made them 
 unfit for use, time and material would be wasted. With the 
 modern flanging machine time is saved, expense lessened and work 
 turned out as near perfect as possible, one heat and the cooling 
 having an annealing effect, general and gradual, gang punches ad- 
 justed accurately, time and labor saved and the efficiency of joint 
 holes not impaired. 
 
 Rivet machinery with its power of compression ensures strength 
 of rivet joints and lessens the effect of injury to plate by caulking as 
 done by the old-time hand riveted joint, especially when left to the 
 novice, defects were developed and material operated on was de- 
 stroyed. 
 
 Electric cranes and air lifts are found necessary for facilitating 
 work by aiding in assembling or fitting up parts of boilers under 
 construction. 
 
 35 
 
36 THE BOILER. 
 
 Thus we find boiler making today one of the scientific mechanical 
 crafts and with the expectations that work carried out as designed 
 produce the best results. 
 
 This book will give general rules and tables used in the construc- 
 tion of the steam boiler and governing their use in safety. 
 
 RIVETS AND RIVETING. 
 
 In designing a joint like any part of the construction of boilers, 
 care in calculation and proportioning of rivet are very essential. 
 Shearing strength and ductility are important factors; perfect 
 alignment of holes, size of same, and method of making same, must 
 not be overlooked. 
 
 On the driving of a rivet will depend much. Without going into 
 the details on the subject of riveting it may be well to say that in the 
 old-time methods of hand riveting the structural makeup of a rivet 
 was changed ; when the rivet should have been finished, the many 
 repeated blows soon changed its nature, and, unnecessary to say, 
 "it was near finished." But improved machinery has wrought 
 changes and with it the changing of rivet material this in turn has 
 provided a larger factor of safety using old rules, and has provided 
 greater efficiency by lighter material. 
 
 The heating of rivet to proper degree of heat is another im- 
 portant measure and with modern forges as used this can be ac- 
 complished with no difficulty or more than ordinary attention. 
 
BOILER CONSTRUCTION. 
 
 37 
 
 TABLE OF RIVETS AND BOLTS WITHOUT NUTS IN 100 LBS. 
 Average number. 
 
 Length 
 of 
 Rivets. 
 
 DIAMETER OF RIVETS. 
 
 H 
 
 A 
 
 H 
 
 A 
 
 1 A 
 
 5 A 
 
 tt 
 
 M 
 
 K 
 
 M 
 
 8000 
 
 5100 
 
 3200 
 
 1900 
 
 
 
 
 
 
 5 /8 
 
 7000 
 
 4500 
 
 2900 
 
 1800 
 
 
 
 
 
 
 H 
 
 6300 
 
 4100 
 
 2373 
 
 1476 
 
 1103 
 
 642 
 
 
 
 
 H 
 
 5700 
 
 3700 
 
 2190 
 
 1371 
 
 1030 
 
 604 
 
 
 
 
 i 
 
 5200 
 
 3400 
 
 2034 
 
 1280 
 
 968 
 
 571 
 
 400 
 
 345 
 
 
 IH 
 
 4700 
 
 3100 
 
 1898 
 
 1200 
 
 910 
 
 541 
 
 382 
 
 322 
 
 208 
 
 IH 
 
 4400 
 
 2900 
 
 1780 
 
 1129 
 
 862 
 
 514 
 
 365 
 
 311 
 
 206 
 
 IH 
 
 4100 
 
 2700 
 
 1675 
 
 1066 
 
 815 
 
 489 
 
 350 
 
 295 
 
 204 
 
 m 
 
 4000 
 
 2500 
 
 1582 
 
 1010 
 
 776 
 
 462 
 
 335 
 
 284 
 
 201 
 
 IS 
 
 3800 
 
 2300 
 
 1498 
 
 960 
 
 740 
 
 446 
 
 324 
 
 275 
 
 199 
 
 m 
 
 3500 
 
 2200 
 
 1424 
 
 914 
 
 707 
 
 428 
 
 311 
 
 266 
 
 192 
 
 IK 
 
 3400 
 
 2000 
 
 1356 
 
 872 
 
 672 
 
 411 
 
 302 
 
 257 
 
 185 
 
 2 
 
 3000 
 
 1900 
 
 1295 
 
 834 
 
 648 
 
 395 
 
 293 
 
 249 
 
 178 
 
 2y 8 
 
 
 
 1238 
 
 800 
 
 623 
 
 381 
 
 285 
 
 240 
 
 172 
 
 2^4 
 
 2800 
 
 1800 
 
 1187 
 
 768 
 
 599 
 
 367 
 
 277 
 
 233 
 
 167 
 
 2Ys 
 
 
 
 1139 
 
 738 
 
 577 
 
 354 
 
 269 
 
 226 
 
 162 
 
 2 1 A 
 
 2500 
 
 1700 
 
 1095 
 
 711 
 
 556 
 
 343 
 
 261 
 
 219 
 
 157 
 
 1% 
 
 
 
 1052 
 
 687 
 
 537 
 
 332 
 
 253 
 
 212 
 
 152 
 
 2% 
 
 
 
 1017 
 
 662 
 
 519 
 
 321 
 
 245 
 
 206 
 
 148 
 
 2y 
 
 
 
 982 
 
 636 
 
 503 
 
 311 
 
 237 
 
 201 
 
 144 
 
 3 8 
 
 .... 
 
 .... 
 
 949 
 
 611 
 
 487 
 
 302 
 
 230 
 
 196 
 
 140 
 
 3^ 
 
 
 
 890 
 
 581 
 
 459 
 
 285 
 
 218 
 
 186 
 
 132 
 
 3^9 
 
 
 
 837 
 
 548 
 
 433 
 
 270 
 
 208 
 
 177 
 
 126 
 
 /^ 
 
 3% 
 
 
 
 791 
 
 519 
 
 411 
 
 257 
 
 198 
 
 168 
 
 120 
 
 ** X 4- 
 
 3^ 
 
 
 
 
 
 395 
 
 250 
 
 195 
 
 165 
 
 119 
 
 
 
 
 '749 
 
 "400 
 
 390 
 
 244 
 
 189 
 
 161 
 
 115 
 
 4K 
 
 
 
 
 
 372 
 
 233 
 
 180 
 
 155 
 
 110 
 
 4V4 
 
 
 
 
 
 355 
 
 223 
 
 172 
 
 149 
 
 105 
 
 4% 
 
 
 
 
 
 339 
 
 214 
 
 166 
 
 143 
 
 101 
 
 5 
 
 
 
 
 
 
 325 
 
 205 
 
 160 
 
 136 
 
 97 
 
 5M 
 
 
 
 
 
 312 
 
 197 
 
 154 
 
 131 
 
 94 
 
 ^ /4r 
 
 5U 
 
 
 
 
 
 300 
 
 190 
 
 149 
 
 127 
 
 91 
 
 5M 
 
 
 
 
 
 289 
 
 183 
 
 144 
 
 123 
 
 88 
 
 6 
 
 
 
 
 
 279 
 
 177 
 
 139 
 
 118 
 
 85 
 
 The measurement of a cone or button head rivet is taken 
 under the head; rivets for counter sunk holes measured over all. 
 
38 
 
 THE BOILER. 
 
 to "\ 
 
BOILER CONSTRUCTION. 
 
 39 
 
 .- 43 OJ 
 
 JL> 
 
 rt 
 
 ^= 
 
 cn 
 
 C/5 -2 
 
 
 
 <L> OS 
 
 OJ ^i 
 
 W3 ^ 
 
 t/5 
 V-i U 
 
 O ^> 
 
 -I 
 
 O u, 
 
 *4J cn 
 
 "C 
 ri 
 O 
 
 <U T3 *H 
 
 _<-! flj Q 
 
 ^ tj r- 
 
 o3 ^. O 
 
 cos 
 ^ o > 
 c c 
 
 3 4J O 
 
 H5 C V 
 
40 
 
 THE BOILER. 
 
 OO 
 OS O 
 
 OCOt^C5<MCO^iOOO<Mt^<M t^ CO Ci U5 T-< 
 
 >O'-"NCO TfiiOCOt^OO 
 I <N <N <N <N <M(M<MC^(M 
 
BOILER CONSTRUCTION. 
 
 - CO 00 CO O5 CO * .-H OS 00 t^ CO CO l> b- 
 
 CO CO CO 5- -t Ic IO IO CO CO b- t- f- 00 
 
 .-...T-HTtHb-OTj-OSTfO COC 
 
 COCOO5COOO'-"OO5 IN 5 
 
 O^ C^ W CO CO ^ ^ ^ IO I 
 
 o <N <N 
 
 Jb-i-H IO 
 
 >COb- b- 
 
 ) <M iO OJ CO CO OS (N m 00 <-i i 
 !i i^Hi-HC^JiNlN COCOCOTtH' 
 
 > 5 i i 00 Tf O O CO <N i-iOCOSOO 
 )00' H COCOOCOCOOS C-l iO 00 O ^ b- 
 lOSOOO'-i'-i^'-H (N(NO)COCOCO 
 
 "- 1 CO 
 OOOO 
 
 OSCOCOCOOC 
 
 i i Tfi r- o <N 
 
 
 SS^2 2 
 
 i-t t>. CO N X ** ! 
 -H(NTt< C l^ O5 "M 
 
 "^T^Tf TjHTtl^OlO' 
 
 X 
 
 ^Scot-os OMcoScoc 
 
 COCOCOCOCO TfTti^T(<Tj<' 
 
 (Ob-^INOCOb-CDlO -<tCOCOCO( 
 ~5 1-1 M O b- OJ i CO O b- < 
 
 IS S 
 
 ic?5co^ ot^6oo5C?i 
 
 
 
 
 o ^o o ^o o ^c 
 
 i-H C^ Tf Ifl I s - X 
 
 CO CO CO CO CO CO 
 
 CO i OS b- O Tf*CO(N^O OO5OSOOOOOO 
 - 'M >! CO Tfi 1C CO b- 00 OS O -* i C^ CO * O 
 <M <M (N <N CN <N <N IN S 
 
 COCOCOCOCOCOCOCOCOTj<-<J<'<tTjHT}*Tj<Tf-<f<t 
 
 OiiNCOOOCOOI^| O -< CO CO i ' 
 i-HWCOTtHOb-OOOSI OINCO^fiOt^C 
 
 s 
 
 (MC<1(N(NCOCOCOCOCOCOCOCOCOCO 
 
 l~- ^- 1 l^ t>. 
 
 O i (N CO * 
 
42 
 
 THE BOILER. 
 
 C CO 10 00 <M O i O i t- (M OC 
 
 > ' O Oi CO 00 CH^. ^ CD C O O5 
 C5C5C1CC'-*' i ?) C^l fO CO CO 
 
 ' O O <-> 01 CO i-O t- C CO >0 00 *H CO Tfe C5 < 
 
 oscoi^'-noairor-T-itooTfasco t^ -* o < 
 
 t^ 00 00 C5 Ci C5 C O --I ^ !M <N 7-1 CO CO * Tf 
 
 _, H ; ^ ,-n _ <M N ^ IM (M c^j (M (M IM (M (M ( 
 
 ! C CO 1 ** 1 > 
 
 ) 71 CDC- 
 
 Slsiillllsf g **' s?"* 15 " 9 ' 
 
 W NCiC^d 01 (M c-i c^i ( 
 
 wfio>MoS5D5wSroi> "* 
 
 r^woo VBuiHBagHn 
 
 i 
 
 p 
 
 OW(Ml^O-H(NI>Wt^(N>0 P O 50 N h- M O >C p 
 
 12 
 
 i 
 
 ~ 
 
 ooboocosaojooocqi 
 
 CD 
 X 
 
 <> CO 5O CO ^- 1^ t^ t^ t- t^ 00 00 66 00 00 00 00 O O5 O 
 
 ^ 
 
 ^g 
 
 -a 
 
 I 
 
 M 
 
 a 
 
 I 
 
 
 
 73 
 
 Q 
 
BOILER CONSTRUCTION. 43 
 
 ESTIMATING THE WEIGHT OF STEEL PLATES. 
 
 The table of the weight of steel plates is based upon the as- 
 sumption that one cubic inch of rolled steel weighs .2833 pounds 
 and that this is increased, by the springage of the rolls, by a certain 
 percentage depending upon the width and thickness of the plate 
 and which is assumed to be in accordance with a table given here- 
 with : 
 
 PERCENTAGE OF INCREASE OF DENSITY OF ROLLED STEEL PLATES. 
 
 THICKNESS 
 OF PLATE. 
 
 Inch. 
 
 WIDTH OF PLATE. 
 
 Up to 75 
 Inches. 
 Per cent. 
 
 75 to 100 
 
 Inches. 
 Per cent. 
 
 100 to 115 
 Inches. 
 Per cent. 
 
 Over 115 
 Inches. 
 Per cent. 
 
 17 
 13 
 12 
 11 
 10 
 9 
 
 Over y % 
 
 10 
 
 8 
 7 
 6 
 5 
 
 4 
 
 14 
 
 12 
 10 
 8 
 7 
 
 6 2 
 5 
 
 18 
 
 16 
 13 
 10 
 9 
 
 8 
 
 To illustrate the method used in calculating the table fol- 
 lowing this article, we will calculate the estimated weight of a 
 Y 4 " plate 38" wide and 138" long. Multiplying these three 
 dimensions together gives us the number of cubic inches of 
 steel in the plate as follows: J4 X 38 X 138= 1311. As the 
 increase in density is 10 per cent for this size plate, according 
 to the table, we add 10 per cent to the weight of one cubic 
 inch of steel (.2833) as follows: .2833 X .10 = .02833 and 
 .2833 + .02833 = .31163 the weight in pounds of one cubic 
 inch of steel in this particular plate. Multiplying the number 
 of cubic inches in the plate (1311) by this gives us the 
 weight of the plate in pounds as follows: 131 IX -31 16 = 
 408.55 = weight of plate in pounds. Taking the nearest unit 
 makes it 409, which agrees with the table, but no allowance has 
 been made here for springage of the rolls and in using this table 
 the percentage given in the table above must be added. By so doing 
 we get a result which will agree very closely with the table. 
 
44 THE BOILER. 
 
 WEIGHT PER SQUARE FOOT OF ROLLED STEEL PLATE NOT ALLOWING FOR 
 SPRINGAGE OF ROLLS. 
 
 Thickness of Pounds per Thickness of Pounds per 
 
 Plate, inches. Sq. Foot. Plate, inches Sq. Foot. 
 
 y 8 25.497 
 
 & 1 . 2748 ft 28 . 047 
 
 A 2.5496 % 30.596 
 
 :& 3 . 8244 if 33 . 146 
 
 y 8 5.0992 y 8 35.696 
 
 6.3740 ft 38.245 
 
 ^ 7.6488 1 40.795 
 
 & 8.9236 1^ 43.344 
 
 JJ 10.199 iy 8 45.894 
 
 & 11.474 1& 48.444 
 
 & 12 . 749 I & 50 . 993 
 
 & 14.024 1& 53.543 
 
 Y % 15.299 -IJj 56.092 
 
 M 16.574 1^6 58.642 
 
 A 17.849 1^ 61.192 
 
 || 19.124 l^C 71.390 
 
 % 20.398 lJ/ 8 76.489 
 
 A. ..22.948 2 ..81.588 
 
 The weight per square foot of l /^" plate as given by this 
 table is 10.199 and in a piece of 38" X 138", according to the 
 first table, the increase would be 10 per cent, making the in- 
 crease 10.199 X -10 = 1.0199. Adding the increase to the weight 
 per square foot given in the table makes it 11.2189 as follows: 
 10.199 + 1.0199 = = 11.2189. The area of the plate in square feet 
 is obtained by multiplying its width by its length in inches 
 and dividing by 144 the number of square inches in a square 
 foot, as follows : 38 X 138 = 5244 = number of square inches in 
 plate. Dividing this by 144 gives us the arek of the plate 
 in square feet, as follows : 5244 4- 144 = 36.417 = number of 
 square feet in plate. Multiplying this by the weight per 
 square foot as calculated above (11.219) gives us the weight of 
 the plate as follows: 36.417 X 11.219 = 408.56 = weight of plate 
 in pounds. This agrees practically with the table given below 
 and the weight calculated by the other method at the beginning 
 of this article. 
 
BOILER CONSTRUCTION. 
 
 45 
 
 WEIGHT OF STEEL BOILER PLATES. 
 
 PLATE. 
 
 Size. Weight, 
 
 Pounds. 
 
 26X120 243 
 
 26X138..'. 280 
 
 30X120 280 
 
 30X138 323 
 
 36X120 . 337 
 
 36X138 387 
 
 38X120 355 
 
 38X138 409 
 
 40X120 374 
 
 40X138 .430 
 
 40X143 446. 
 
 42X120 393 
 
 42X138 452 
 
 43X138 462 
 
 43X143 479 
 
 43X156 523 
 
 44X120 411 
 
 44X138 473 
 
 46X120 430 
 
 46X138 495 
 
 48X120 449 
 
 48X138 516 
 
 49X 98 374 
 
 49X138 552 
 
 49X143 572 
 
 49X156 624 
 
 50X120 467 
 
 Size. 
 
 Weight, 
 Pounds. 
 
 50 X138 538 
 
 54 X120 505 
 
 57 X138 613 
 
 57 X143 635 
 
 57 X156 693 
 
 60 X 98 458 
 
 60 X120 561 
 
 60 X138 645 
 
 64%X138 696 
 
 64% X 143 721 
 
 64%X156 787 
 
 64% X 175 883 
 
 64% X 194 979 
 
 72 X 98 550 
 
 72 X120 673 
 
 72 X138 774 
 
 72 X143 802 
 
 72 X156 875 
 
 72 x'175 982 
 
 72 X194 1088 
 
 84 x 98 665 
 
 84 X120 814 
 
 84 X138 936 
 
 84 X143 970 
 
 84 X156 .1058 
 
 84 X175 :1187 
 
 84 X194.. ..1316 
 
 PLATE. 
 
 26 X 80 199 
 
 26 X 90 223 
 
 26 X 99 246 
 
 26X120 298 
 
 26X138 ...343 
 
 30 X 80 229 
 
 30 X 90 258 
 
 30 X 99 284 
 
 30X120 344 
 
 30X138 396 
 
 36 X 80 275 
 
 36X 90 310 
 
 36X 99 341 
 
 36X120 413 
 
 36X138 475 
 
 38X 80 291 
 
 38 X 90 327 
 
 38X 99 360 
 
 38X120 435 
 
 38X138 501 
 
 40X 80 306 
 
 40 X 90 344 
 
 40X 99.. ..379 
 
 49 X143 670 
 
 49 X156 731 
 
 49 X175 820 
 
 49 X194 909 
 
 50 X120 574 
 
 50 X138 660 
 
 54 X120 620 
 
 57 X 80 436 
 
 57 X 90 490 
 
 57 X 99 540 
 
 57 X138 752 
 
 57 X143 779 
 
 57 X156 850 
 
 57 X175 954 
 
 57 X194 1057 
 
 60 X120 688 
 
 60 X138 792 
 
 64%X 90 557 
 
 64% X 99 613 
 
 64% X 138 854 
 
 64%X143 885 
 
 64%X156 966 
 
 64%X175 1083 
 
46 
 
 THE BOILER. 
 
 PLATE. 
 
 Size. 
 
 40X120 
 
 40X138 
 
 42X120 
 
 42X138 
 
 43 X 80 
 
 43 X 90 
 
 43 X 99 
 
 43X138 
 
 Weight, 
 Pounds. 
 . .. .459 
 ....528 
 
 482 
 
 554 
 
 329 
 
 370 
 
 407 
 
 .-...567 
 
 Size. 
 
 64 ''4X194. 
 72^,X 99. 
 72^X120. 
 72^X138. 
 72^X143. 
 72^X156. 
 72^X175. 
 72^X194. 
 
 Weight, 
 
 Pounds. 
 
 1201 
 
 686 
 
 832 
 
 957 
 
 991 
 
 1081 
 
 1213 
 
 1345 
 
 PLATE. 
 
 30 X120 499 
 
 36 X120 491 
 
 36 X138 565 
 
 40 X120 546 
 
 40 X138 627 
 
 44 X120 600 
 
 44 X138 690 
 
 48 X120 655 
 
 48 X138 753 
 
 50 X120 682 
 
 50 X138 784 
 
 54 X120 737 
 
 54 X138 847 
 
 60 X120 818 
 
 60 X138 941 
 
 64^X118 869 
 
 64MX194 1428 
 
 64^X212^ 1564 
 
 64^X231^ 1704 
 
 65MX108J4 799 
 
 72^X108^ ............ 894 
 
 72^X118 .............. 972 
 
 72^X212^ ............ 1751 
 
 72^X231^ ............ 1908 
 
 84 
 84 
 84 
 84 
 84 
 96 
 96 
 96 
 96 
 96 
 
 X118 
 X194 
 
 1065 
 1158 
 1904 
 2086 
 2282 
 1217 
 1324 
 2176 
 2384 
 2597 
 107^X108^ ............ 1400 
 
 107^X118 ' ............ 1523 
 
 107^X194 ............ 3504 
 
 107^X212^ ............ 2742 
 
 107^X231^ ............ 2988 
 
 XH8 
 
 X194 
 
 36X120. 
 40X120. 
 48X120. 
 
 568 
 631 
 
 757 
 
 PLATE. 
 
 60X120 946 
 
 72X120.. 1135 
 
 36X120 643 
 
 40X120 714 
 
 48X120.. . 857 
 
 PLATE. 
 
 60X120 1071 
 
 72X120 1285 
 
 36X120 950 
 
 40X120 ...1056 
 
 48X120.. ..1267 
 
 PLATE. 
 
 60X120 1583 
 
 72X120.. ..1900 
 
 40X112 1149 
 
 40X154^.... 1996 
 
 53X112 1523 
 
 PLATE. 
 
 53X133 1809 
 
 53X154 2094 
 
BOILER CONSTRUCTION. 
 
 47 
 
 TABLES OF WIDTH, LENGTH AND THICKNESS OF PLATES THAT CAN BE MADE 
 FOR BOILER PURPOSES, ALSO DIAMETER OF HEADS. 
 
 Thickness. 
 
 Diameter of 
 Heads. 
 
 Width and Length of Plate. 
 
 Width. 
 
 Length. 
 
 1 A 
 A 
 
 1 
 
 y* 
 
 5 /s 
 
 115 
 120 
 126 
 126 
 126 
 126 
 
 114' 
 126' 
 140' 
 140' 
 144' 
 144' 
 
 200' 
 240' 
 180' 
 180' 
 180' 
 180' 
 
 Longer lengths can be made but would be less in width. 
 
 Rules adopted by the Association of American Steel Manu- 
 facturers : "When ordering plates \2 l / 2 pounds to square footer 
 heavier, up to 100 inches wide, by weight, they shall not average 
 more than 2 l / 2 per cent above or below the theoretical weight, when 
 100 inches and over the limit is 5 per cent." 
 
 TABLE OF ALLOWANCES FOR OVERWEIGHT FOR RECTANGULAR PLATE 
 WHEN ORDERED BY GAUGE. 
 
 Thickness 
 of 
 Plate. 
 
 WIDTH OF PLATE. 
 
 Up to 
 50 inches. 
 
 50 inches 
 and above. 
 
 Up to 
 75 inches. 
 
 75 inches 
 to 100 in. 
 
 over 100 
 
 inches. 
 
 y% up to -3% 
 
 & up to ^ 
 
 T\ U P to y 
 A- 
 
 1 
 
 I 
 
 y% 
 
 over *A 
 
 10 per ct. 
 
 SK ;; ;; 
 
 15 per ct. 
 
 12^" " 
 10 " " 
 
 
 
 
 
 
 
 
 
 
 10 p< 
 
 8 
 7 
 6 
 5 
 4^ 
 4 
 ZVo 
 
 ;r c 
 
 t. 
 
 14 p ( 
 12 
 10 
 8 
 7 
 6^ 
 6 
 5 
 
 jr c 
 
 t. 
 
 18 p 
 16 
 13 
 10 
 9 
 8^ 
 8 
 6K 
 
 er ct 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
48 
 
 THE BOILER. 
 DOME PLATE ALLOWANCES. 
 
 Diame- 
 
 DIAMETER OF SHELLS. 
 
 ter of 
 
 
 Domes. 
 
 
 
 
 
 
 
 
 
 
 
 30 
 
 36 
 
 42 
 
 48 
 
 54 
 
 60 
 
 66 
 
 72 
 
 84 
 
 20 
 
 6K 
 
 ST/ 
 
 5 K 
 
 
 
 
 
 
 
 22 
 
 7 if 
 
 6}/ 
 
 5% 
 
 5 V 
 
 
 
 
 
 
 24 
 
 gi/ 
 
 7 */ 
 
 
 5% 
 
 5 1/ 
 
 
 
 
 
 26 
 
 
 g{/ 
 
 7 1/ ' 
 
 
 6 
 
 
 
 
 
 28 
 
 
 9^/ 
 
 8 
 
 7% 
 
 
 6 
 
 
 
 
 30 
 
 
 10% 
 
 9 
 
 8 
 
 7% 
 
 6% 
 
 6% 
 
 5% 
 
 5% 
 
 32 
 
 
 
 10 
 
 8% 
 
 8 
 
 7% 
 
 6% 
 
 6% 
 
 5% 
 
 34 
 
 
 . . . 
 
 
 9% 
 
 8% 
 
 8 
 
 7M 
 
 7 
 
 6 
 
 36 
 
 
 . . . 
 
 
 10% 
 
 93^ 
 
 8/^ 
 
 8 
 
 7% 
 
 6;Hj 
 
 38 
 
 
 
 
 
 10% 
 
 9/^ 
 
 8% 
 
 8 
 
 7 
 
 40 
 
 
 
 
 
 
 10M 
 
 
 9% 
 
 71^ 
 
 42 
 
 
 
 
 
 
 11 M 
 
 10% 
 
 10 
 
 8 
 
 44 
 
 
 
 
 
 
 
 11 
 
 10 Vo 
 
 9 
 
 46 
 
 
 
 
 
 
 
 12% 
 
 10% 
 
 9^ 
 
 48 
 
 
 
 
 
 
 
 13 
 
 11^ 
 
 10 
 
 The above table is based on single riveting, and the allowances named 
 are those commonly used in figuring the finished length of domes. For 
 double riveting add 2 inches. 
 
BOILER CONSTRUCTION. 
 
 49 
 
 m 
 
 < X 
 
 7. D 
 
 c/2 
 
 H 
 
 X 
 
 W 
 
 CSdlS 
 
 3^ 
 
 Iffi 
 
 0^ C/} 
 
 s 1 
 
 o 
 
 a "-^ 
 
 c o 
 
 i> C8 
 
 "S 3 
 
 - cK 
 
 5 
 
 i 
 
 J3 
 
 ^ o 
 
 ^ o 
 
 'i E "5 
 
 HH W C 
 
 Q 
 
 vO N OO t^ O\ 
 
 VO i-H t^ VO VO OO rH 
 
 OO> 1 i li t 
 
 H\ 
 
50 
 
 THE BOILER. 
 
 Rule to find number of square feet of heating' surface in tubes : 
 Multiply the number of tubes by the diameter of a tube in 
 inches and by its length in feet, and by .2618 constant. 
 
 LEGEND: 
 
 D=Tubes 4" 
 L= Length =16' 
 N= Number = 44 
 C= Constant = .26 18 
 
 FORMULA: 
 N XDxLx .2618 (constant) =heating surface 
 
 EXAMPLE: 
 
 44 = number of tubes 
 4 = diameter in inches 
 
 176 
 
 16 = length in feet 
 
 1056 
 176 
 
 2816 
 
 261 8= constant 
 
 22528 
 2816 
 
 16896 
 
 5632 
 
 737.2288 =total square feet of heating sur- 
 face in 44 4" tubes. 
 
 HEATING SURFACE OF BOILER TUBES. 
 
 Diameter X 3.1416 = circumference X 12 = number of square 
 inches in tube one foot of length -=- 144 = number of square feet 
 (in decimals) one foot of length. 
 
 EXAMPLE: 
 
 2 inch tube one foot in length : 
 2X3. 1416 =6 . 2832 X 12 = 75 . 3984 
 
 = . 5236 of a square foot 
 144 
 
BOILER CONSTRUCTION. 
 
 51 
 
 TABLE. 
 
 Diam. 
 
 
 Diam. 
 
 
 Diam. 
 
 
 Diam. 
 
 
 in. 
 
 Multipl'r 
 
 in. 
 
 Multipl'r 
 
 in. 
 
 Multipl'r 
 
 in. 
 
 Multipl'r 
 
 1 
 
 .2618 
 
 11^ 
 
 3.0107 
 
 | 32 
 
 8.3776 
 
 53 
 
 13.8754 
 
 1M 
 
 .3272 
 
 H 
 
 3.0761 
 
 32^ 
 
 8.5085 
 
 53^ 
 
 14.0063 
 
 1H 
 
 .3927 
 
 12 
 
 3.1416 
 
 33 
 
 8.6394 
 
 54 
 
 14.1372 
 
 134 
 
 .4581 
 
 12^ 
 
 3.2725 
 
 33 H 
 
 8.7703 
 
 54^ 
 
 14.2681 
 
 2 
 
 .5236 
 
 13 
 
 3.4037 
 
 34 
 
 8.9012 
 
 55 
 
 14.399 
 
 2M 
 
 .589 
 
 U% 
 
 3.5343 
 
 34^ 
 
 9.0321 
 
 55^ 
 
 14.5299 
 
 2K 
 
 .6545 
 
 14 
 
 3.6652 
 
 35 
 
 9.163 
 
 56 
 
 14.6608 
 
 2M 
 
 .7199 
 
 14^ 
 
 3.7961 
 
 35^ 
 
 9.2939 
 
 56^ 
 
 14.7917 
 
 3 
 
 .7854 
 
 15 
 
 3.927 
 
 36 
 
 9.4248 
 
 57 
 
 14.9226 
 
 34 
 
 .8508 
 
 15^ 
 
 4.0579 
 
 36^ 
 
 9.5557 
 
 57^ 
 
 15.0536 
 
 3^ 
 
 .9163 
 
 16 
 
 4.1888 
 
 37 
 
 9.6866 
 
 58 
 
 15.1844 
 
 3i4 
 
 .9817 
 
 16^ 
 
 4.3197 
 
 37^ 
 
 9.8175 
 
 58^ 
 
 15.3153 
 
 4 
 
 1.0472 
 
 17 
 
 4.4506 
 
 38 
 
 9.9844 
 
 59 
 
 15.4462 
 
 4M 
 
 1.1126 
 
 17^ 
 
 4.5815 
 
 38^ 
 
 10.0793 
 
 59^ 
 
 15.5771 
 
 4H 
 
 1.1781 
 
 18 
 
 4.7124 
 
 39 
 
 10.2102 
 
 60 
 
 15.708 
 
 4% | 1.2435 
 
 18H 
 
 4.8433 
 
 39^ 
 
 10.3411 
 
 60^ 
 
 15.8389 
 
 5 
 
 1.309 
 
 19 
 
 4.9742 
 
 40 
 
 10.472 
 
 61 
 
 15.9698 
 
 5M 
 
 1.3744 
 
 19^ 
 
 5.1051 
 
 40^ 
 
 10.6029 
 
 61^ 
 
 16.1007 
 
 5H 
 
 1.4399 
 
 20 
 
 5.236 
 
 41 
 
 10.7338 
 
 62 
 
 16.2316 
 
 5M 
 
 1.5053 
 
 20^ 
 
 5.3669 
 
 41^ 
 
 10.8647 
 
 62^ 
 
 16.3625 
 
 6 
 
 1.5708 
 
 21 
 
 5.4978 
 
 42 
 
 10.9956 
 
 63 
 
 16.4934 
 
 64 
 
 1.6362 
 
 21^ 
 
 5.6287 
 
 42 Y 2 
 
 11.1265 
 
 63^ 
 
 16.6243 
 
 6^ 
 
 1.7017 
 
 22 
 
 5.7596 
 
 43 
 
 11.2574 
 
 64 
 
 16.7552 
 
 6-M 
 
 1.7671 
 
 22^ 
 
 5.8905 
 
 43^ 
 
 11.3883 
 
 64 H 
 
 16.8861 
 
 7 
 
 1.8326 
 
 23 
 
 6.0214 
 
 44 
 
 11.5192 
 
 65 
 
 17.017 
 
 7K 
 
 1.8980 
 
 23^ 
 
 6.1523 
 
 44^ 
 
 11.6501 
 
 65^ 
 
 17.1479 
 
 7^ 
 
 1.9335 
 
 24 
 
 6.2832 
 
 45 
 
 11.781 
 
 66 
 
 17.2788 
 
 7*4 
 
 2.0289 
 
 24^ 
 
 6.4141 
 
 45^ 
 
 11.9119 
 
 66^ 
 
 17.4097 
 
 8 
 
 2.0944 
 
 25 
 
 6.545 
 
 46 
 
 12.0428 
 
 67 
 
 17.5406 
 
 8M 
 
 2.0598 
 
 25^ 
 
 6.6759 
 
 46^ 
 
 12.1735 
 
 67^ 
 
 17.6715 
 
 8H 
 
 2.2253 
 
 26 
 
 6.8034 
 
 47 
 
 12.3045 
 
 68 
 
 17.8024 
 
 8-M 
 
 2.2907 
 
 26^ 
 
 6.9377 
 
 47^ 
 
 12.4355 
 
 68^ 
 
 17.9333 
 
 9 
 
 2.3562 
 
 27 
 
 7.0686 
 
 48 
 
 12.5664 
 
 69 
 
 18.0642 
 
 9M 
 
 2.4216 
 
 27^ 
 
 7.1995 
 
 48^ 
 
 12.6973 
 
 69^ 
 
 18.1951 
 
 9^ 
 
 2.4872 
 
 28 
 
 7.3384 
 
 49 
 
 12.8282 
 
 70 
 
 18.326 
 
 94 
 
 2.5525 
 
 28^ 
 
 7.4614 
 
 49 H 
 
 12.9591 
 
 70^ 
 
 18.4569 
 
 10 
 
 2.618 
 
 29 
 
 7.5913 
 
 50 
 
 13.09 
 
 71 
 
 18.5868 
 
 iOM 
 
 2.6834 
 
 29^ 
 
 7.7231 
 
 50^ 
 
 13.2209 
 
 71^ 
 
 18.7187 
 
 ion 
 
 2.7489 
 
 30 
 
 7.8554 
 
 51 
 
 13.3518 
 
 72 
 
 18.8496 
 
 IOM 
 
 2.8143 
 
 30^ 
 
 7.9849 
 
 51^ 
 
 13.4827 
 
 78 
 
 20.3370 
 
 11 
 
 2.8798 
 
 31 
 
 8.1158 
 
 52 
 
 13.6136 
 
 84 
 
 21.9912 
 
 HM 
 
 2.9452 
 
 31H 
 
 8.2467 
 
 52^ 
 
 13.7445 
 
 96 
 
 25.1328 
 
52 
 
 THE BOILER. 
 
 APPROXIMATE WEIGHT OF ROUND BRACES WITH FLAT ENDS. 
 
 Length of 
 Braces, inches 
 
 Diameter of 
 Braces, inches 
 
 SIZE OF ENDS. 
 
 Weight, 
 Ibs. 
 
 Width, inches 
 
 Thickness, in. 
 
 14 
 
 1 
 
 2M 
 
 )4 
 
 7 
 
 16 
 
 1 
 
 2M 
 
 y* 
 
 7M 
 
 18 
 
 1 
 
 2^ 
 
 y* 
 
 7)4 
 
 20 
 
 1 
 
 
 y* 
 
 8 
 
 22 
 
 1 
 
 2^ 
 
 y* 
 
 &)4 
 
 24 
 
 1 
 
 
 y* 
 
 9 
 
 26 
 
 1 
 
 P 
 
 y* 
 
 9y> 
 
 28 
 
 1 
 
 
 )4 
 
 10 
 
 30 
 
 1 
 
 2 M 
 
 H 
 
 10/^ 
 
 32 
 
 1 
 
 2M 
 
 
 
 11 
 
 34 
 
 1 
 
 2M 
 
 
 111^ 
 
 36 
 
 1 
 
 2M 
 
 i^ 
 
 12 
 
 38 
 
 1 
 
 Ip 
 
 '^ 
 
 12^ 
 
 40 
 
 1 
 
 
 /^ 
 
 13 
 
 42 
 
 1 
 
 2M 
 
 Yt 
 
 13J^ 
 
 44 
 
 1 
 
 
 y^ 
 
 14 
 
 46 
 
 1 
 
 2M 
 
 y% 
 
 143^ 
 
 48 
 
 1 
 
 2M 
 
 % 
 
 15 
 
 50 
 
 1 
 
 2M 
 
 x^ 
 
 15/^9 
 
 52 
 
 1 
 
 2M 
 
 /^2 
 
 16 
 
 54 
 
 1 
 
 2M 
 
 1 
 
 16)4 
 
 56 
 
 1 
 
 
 
 17 
 
 58 
 
 1 
 
 2M 
 
 ^ 
 
 173^ 
 
 60 
 
 1 
 
 2M 
 
 x^ 
 
 18 
 
 14 
 
 1 /^ 
 
 
 5^ 
 
 7)4 
 
 16 
 
 1^8 
 
 2M 
 
 % 
 
 8 
 
 18 
 
 l//g 
 
 2M 
 
 Y% 
 
 8/^2 
 
 20 
 
 \^/Q 
 
 
 % 
 
 9 
 
 22 
 
 l/"8 
 
 2M 
 
 % 
 
 10 
 
 24 
 
 1^8 
 
 2M 
 
 % 
 
 11 
 
 26 
 
 \y % 
 
 2^ 
 
 5 /8 
 
 12 
 
 28 
 
 \y> 
 
 
 %> 
 
 13 
 
 30 
 
 \y 
 
 2M 
 
 H 
 
 14 
 
 32 
 
 \y 
 
 2M 
 
 
 15 
 
 34 
 
 \V& 
 
 2M 
 
 sh 
 
 16 
 
 36 
 
 \y^ 
 
 2 M 
 
 /R 
 
 17 
 
 38 
 
 1 ^ 
 
 2/4 
 
 % 
 
 17/^2 
 
 40 
 
 \y % 
 
 2 M 
 
 y% 
 
 18 
 
 42 
 
 \y. 
 
 2/^ 
 
 % 
 
 is y^ 
 
 44 
 
 \y% 
 
 2K 
 
 % 
 
 19 
 
 46 
 
 \y. 
 
 2/4 
 
 % 
 
 19^ 
 
 48 
 
 1)4 
 
 2M 
 
 5 /8 
 
 20 f 
 
 50 
 
 1 ^8 
 
 
 5 /8 
 
 21 
 
 52 
 
 \~\/ 
 
 2M 
 
 5 /8 
 
 22 
 
 54 
 
 \y^ 
 
 2M 
 
 5 /8 
 
 23 
 
 56 
 
 \y^ 
 
 2M 
 
 5 /8 
 
 24 
 
 58 
 
 ITX 
 
 
 5 /8 
 
 25 
 
 60 
 
 1)4 
 
 2M 
 
 5 /8 
 
 26 
 
BOILER CONSTRUCTION. 
 
 53 
 
 NUMBER MODERN FORMED BRACES COMMONLY USED IN STANDARD TUBULAR 
 
 BOILERS. 
 
 Length 
 of 
 Brace. 
 
 DIAMETER OF SHELL. 
 
 36 
 
 42 
 
 44 
 
 54 
 
 60 
 
 66 
 
 72 
 
 84 
 
 30 
 
 42 
 48 
 60 
 72 
 
 6 
 
 2 
 
 6 
 
 4 
 
 8 
 
 '4 
 
 10 
 '6 
 
 10 
 
 '6 
 
 4 
 
 10 
 8 
 
 '4 
 
 12 
 
 'k 
 
 '4 
 
 16 
 16 
 '6 
 
 Under the diameter of each shell will be found the number of each 
 length of brace generally used. The thickness of brace varies with thickness 
 of shell. 
 
 METALS. 
 WEIGHT OF SUPERFICIAL FOOT. 
 
 Thick- 
 
 
 
 
 
 
 
 
 ness. 
 
 W Iron. 
 
 C Iron. 
 
 Steel. 
 
 Copper. 
 
 Brass. 
 
 Lead. 
 
 Zinc. 
 
 Inch. 
 
 Lbs. 
 
 Lbs. 
 
 Lbs. 
 
 Lbs. 
 
 Lbs. 
 
 Lbs. 
 
 Lbs. 
 
 TV 
 
 2.52 
 
 2.34 
 
 2.55 
 
 2.89 
 
 2.73 
 
 3.71 
 
 2.34 
 
 y s 
 
 5.05 
 
 4.69 
 
 5.10 
 
 5.78 
 
 5.47 
 
 7.42 
 
 4.69 
 
 & 
 
 7.58 
 
 7.03 
 
 7.66 
 
 8.67 
 
 8.20 
 
 11.13 
 
 7.03 
 
 x 
 
 10.10 
 
 9.38 
 
 10.21 
 
 11.56 
 
 10.94 
 
 14.83 
 
 9.38 
 
 A 
 
 12.63 
 
 11.72 
 
 12.76 
 
 14.45 
 
 13.67 
 
 18.54 
 
 11.72 
 
 y% 
 
 15.16 
 
 14.06 
 
 15.31 
 
 17.34 
 
 16.41 
 
 22.25 
 
 14.06 
 
 A 
 
 17.68 
 
 16.41 
 
 17.87 
 
 20 23 
 
 19.14 
 
 25.96 
 
 16.41 
 
 H 
 
 20.21 
 
 18.75 
 
 20.42 
 
 23 13 
 
 21.88 
 
 29.67 
 
 18.75 
 
 5 /8 
 
 25.27 
 
 23 44 
 
 25.52 
 
 28.91 
 
 27.34 
 
 37.08 
 
 23.44 
 
 Y* 
 
 30.31 
 
 28.13 
 
 30.63 
 
 34.69 
 
 32.81 
 
 44.50 
 
 28.13 
 
 K 
 
 35.37 
 
 32.81 
 
 35.73 
 
 40.47 
 
 38.28 
 
 51.92 
 
 32.81 
 
 l 
 
 40.42 
 
 37.50 
 
 40.83 
 
 46.25 
 
 43.75 
 
 59.33 
 
 37.50 
 
54 
 
 THE BOILER. 
 
 BIRMINGHAM GAUGE. 
 
 U. S. STANDARD GAUGE. 
 
 No. of 
 Gauge. 
 
 Thick- 
 ness, 
 Inches. 
 
 Weight. 
 
 No. of 
 Gauge. 
 
 THICKNESS, IN. 
 
 Weight, 
 Iron. 
 
 Iron. 
 
 Steel. 
 
 Frac- 
 tions. 
 
 Deci- 
 mals. 
 
 0000 
 
 .454 
 
 18,22 
 
 18.46 
 
 0000000 
 
 /v 
 
 .5 
 
 20. 
 
 000 
 
 .425 
 
 17.05 
 
 17.28 
 
 000000 
 
 i 
 
 .468 
 
 18.75 
 
 00 
 
 .38 
 
 15.25 
 
 15.45 
 
 00000 
 
 T6 
 
 .437 
 
 17.50 
 
 
 
 .34 
 
 13.64 
 
 13.82 
 
 0000 
 
 H 
 
 .406 
 
 16.25 
 
 1 
 
 .3 
 
 12.04 
 
 12.20 
 
 000 
 
 3 '8 
 
 .375 
 
 15. 
 
 2 
 3 
 
 .284 
 .259 
 
 11.40 
 10.39 
 
 11.55 
 10.53 
 
 00 
 
 
 
 1 
 
 .343 
 .312 
 
 13.75 
 12.50 
 
 4 
 
 .238 
 
 9.55 
 
 9.68 
 
 1 
 
 A 
 
 .281 
 
 11.25 
 
 5 
 
 .22 
 
 8.83 
 
 8.95 
 
 2 
 
 tt 
 
 .265 
 
 10.625 
 
 6 
 
 .203 
 
 8.15 
 
 8.25 
 
 3 
 
 X 
 
 .25 
 
 10. 
 
 7 
 
 .18 
 
 7.22 
 
 7.32 
 
 4 
 
 
 .234 
 
 9.375 
 
 8 
 
 .165 
 
 6.62 
 
 6.71 
 
 5 
 
 Jy 
 
 .218 
 
 8.75 
 
 9 
 
 .148 
 
 5.94 
 
 6.02 
 
 6 
 
 t 
 
 .203 
 
 8.125 
 
 10 
 
 .134 
 
 5.38 
 
 5.45 
 
 7 
 
 T 
 
 .187 
 
 7.5 
 
 11 
 
 .12 
 
 4.82 
 
 4.88 
 
 8 
 
 M 
 
 .171 
 
 6.875 
 
 12 
 
 .109 
 
 4.37 
 
 4.43 
 
 9 
 
 A 
 
 .156 
 
 6.25 
 
 13 
 
 .095 
 
 3.81 
 
 3.86 
 
 10 
 
 * 
 
 .140 
 
 5.625 
 
 14 
 
 .083 
 
 3.33 
 
 3.37 
 
 11 
 
 
 .125 
 
 5. 
 
 15 
 
 .072 
 
 2.89 
 
 2.93 
 
 12 
 
 Ft 
 
 .109 
 
 4.375 
 
 16 
 
 .065 
 
 2.61 
 
 2.64 
 
 13 
 
 $2 
 
 .093 
 
 3.75 
 
 17 
 
 .058 
 
 2.33 
 
 2.36 
 
 14 1 A 
 
 .078 
 
 3.125 
 
 18 
 
 .049 
 
 1.97 
 
 1.99 
 
 15 
 
 llj^ 
 
 .070 
 
 2.8125 
 
 19 
 
 .042 
 
 1.69 
 
 1.71 
 
 16 
 
 
 .062 
 
 2.5 
 
 20 
 
 .035 
 
 1.40 
 
 1.42 
 
 17 
 
 iftf 
 
 .056 
 
 2.25 
 
 21 
 
 .032 
 
 1.28 
 
 1.30 
 
 18 
 
 jfa 
 
 .05 
 
 2. 
 
 22 
 
 .028 
 
 1.12 
 
 1.14 
 
 19 
 
 _i 
 
 .043 
 
 1.75 
 
 23 
 
 .025 
 
 1.00 
 
 1.02 
 
 20 
 
 \ 
 
 .037 
 
 1.50 
 
 24 
 
 .022 
 
 .883 
 
 .895 
 
 21 
 
 VsV 
 
 .034 
 
 1.375 
 
 25 
 
 .02 
 
 .803 
 
 .813 
 
 22 
 
 T2 
 
 .031 
 
 1.25 
 
 26 
 
 .018 
 
 .722 
 
 .732 
 
 23 
 
 T*0 
 
 .028 
 
 1.125 
 
 27 
 
 .016 
 
 .642 
 
 .651 
 
 24 
 
 & 
 
 .025 
 
 1. 
 
 28 
 
 .014 
 
 .562 
 
 .569 
 
 25 
 
 ifao 
 
 .021 
 
 .875 
 
 
 26 
 
 _JL 
 
 018 
 
 . 75 
 
 
 27 
 28 
 
 1^0 
 
 S 
 
 [017 
 
 .015 
 
 ^6875 
 .625 
 
 The U. S. Standard is the one in common use. 
 
 To CONVERT WEIGHT OF METALS MULTIPLY BY FOLLOWING CONSTANTS: 
 
 Wrought iron into cast iron X -928 
 
 " steel X 1.014 
 
 " zinc X -918 
 
 " brass X 1.082 
 
 " copper X 1.144 
 
 " " lead XI. 468 
 
 Square iron into round X 7854 
 

 BOILER CONSTRUCTION. 
 WEIGHT OF CAST IRON BALLS. 
 
 55 
 
 DIAMETER. 
 
 WEIGHT. 
 
 DIAMETER. 
 
 WEIGHT. 
 
 DIAMETER. 
 
 WEIGHT. 
 
 1 
 1H 
 
 .136 
 .460 
 
 5 
 
 5^ 
 
 17.04 
 22.68 
 
 9 
 
 9^ 
 
 99.40 
 116.90 
 
 2 
 
 1.09 
 
 6 
 
 29.45 
 
 10 
 
 136.35 
 
 2^ 
 
 2.13 
 
 63^ 
 
 37.44 
 
 10^ 
 
 157.84 
 
 3 
 
 3.68 
 
 7 
 
 46.76 
 
 11 
 
 181.48 
 
 3^ 
 
 5.84 
 
 7^ 
 
 57.52 
 
 11^ 
 
 207.37 
 
 4 
 
 8.72 
 
 8 
 
 69.81 
 
 12 
 
 235.62 
 
 4^ 
 
 12.42 
 
 8]jj 
 
 83.73 
 
 
 
 ANGLES. 
 
 WEIGHTS PER FOOT, CORRESPONDING TO THICKNESS VARYING BY -fa INCH, ONE CUBIC FOOT 
 
 WEIGHING 480 LBS. 
 
 Sizes, 
 inches. 
 
 
 
 A 
 
 X 
 
 A 
 
 H 
 
 A 
 
 H 
 
 A 
 
 % 
 
 H 
 
 H 
 
 H 
 
 H 
 
 Equal 
 Legs. 
 
 6 x6 
 5 x5 
 4 x4 
 
 3^x3^ 
 
 3Mx3M 
 3 x3 
 2x2% 
 
 2 J^ x 2 .^ 
 
 2^x2^ 
 2 x2 
 1 M x 1 % 
 IMxlX 
 
 \K*lX 
 
 1 X 1 
 
 &x M 
 
 
 
 
 
 
 16.75 
 14.28 
 11.16 
 9.75 
 
 9.05 
 8.51 
 7.70 
 7.00 
 
 6.29 
 5.60 
 5.00 
 
 19.14 
 16.56 
 12.82 
 11.20 
 
 10.40 
 9.74 
 8.80 
 8.00 
 
 7.20 
 
 21.53 
 18.84 
 14.49 
 12.65 
 
 11.75 
 10.97 
 
 23.92 
 21.13 
 16.16 
 14.10 
 
 13.10 
 12.20 
 
 26.31 
 23.42 
 17.83 
 15.55 
 
 14.45 
 
 28.70 
 25.71 
 19.20 
 17.00 
 
 15.80 
 
 31.10 
 26.85 
 
 33.50 
 28.00 
 
 
 
 
 
 12.00 
 9.50 
 8.30 
 
 7.70 
 7.28 
 6.60 
 6.00 
 
 5.38 
 4.80 
 4.28 
 3.60 
 
 's.'io 
 
 2.90 
 2.60 
 2.40 
 2.20 
 
 2.00 
 1.66 
 1.45 
 1.23 
 
 1.02 
 .79 
 
 .60 
 
 '4.50 
 
 4.20 
 
 3.80 
 3.50 
 3.00 
 
 2.80 
 2.42 
 2.13 
 1.80 
 
 1.50 
 1.20 
 .90 
 
 'h'.QO 
 
 8.66 
 6.95 
 
 
 
 
 
 
 4.83 
 4.41 
 4.00 
 
 3.57 
 3.21 
 2.84 
 2.40 
 
 2.00 
 
 6.05 
 5.50 
 5.00 
 
 4.47 
 
 4.00 
 3.56 
 3.00 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Unequal 
 Legs. 
 
 6 x4 
 6 x3^ 
 5 x4 
 5 x3^ 
 
 5 x3 
 4 X3J4 
 4 x3 
 
 3.^x2% 
 
 3^x3 
 3^x2H 
 3 x 2 > 
 3^x2 
 
 3 x2 
 
 2^x2 
 2 xl^ 
 
 
 
 
 
 12.00 
 11.50 
 10.80 
 10.20 
 
 9.50 
 8.90 
 8.30 
 7.50 
 
 7.70 
 7.30 
 6.70 
 6.37 
 
 5.88 
 4.92 
 
 14.44 
 13.24 
 12.61 
 11.26 
 
 11.16 
 10.46 
 9.75 
 
 8.75 
 
 9.05 
 8.55 
 7.85 
 7.43 
 
 6.84 
 5.66 
 
 16.38 
 14.98 
 14.42 
 13.72 
 
 12.82 
 12.02 
 11.20 
 10.00 
 
 10.40 
 9.80 
 8.80 
 8.50 
 
 7.80 
 6.40 
 
 18.32 
 16.72 
 16.24 
 15.49 
 
 14.49 
 13.59 
 12.65 
 11.25 
 
 11.75 
 
 20.26 
 18.47 
 18.06 
 17.26 
 
 16.16 
 15.16 
 14.10 
 12.50 
 
 13.00 
 
 22.20 
 20.22 
 19.88 
 19.03 
 
 17.83 
 16.73 
 15.55 
 13.75 
 
 24.15 
 21.97 
 21.70 
 20.40 
 
 19.50 
 18.30 
 17.00 
 15.00 
 
 26.10 
 23.72 
 23.45 
 
 28.00 
 26.60 
 25.20 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 '.'.','.'. 
 
 
 
 
 
 
 6.50 
 6.05 
 5.55 
 5.31 
 
 4.93 
 4.18 
 
 
 
 4.80 
 4.40 
 4.20 
 
 3.98 
 3.45 
 2.90 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3.03 
 
 2.72 
 2.20 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
56 
 
 THE BOILER. 
 WEIGHTS AND MEASUREMENTS OF STEEL "I" BEAMS. 
 
 Depth, 
 Inches. 
 
 Min. 
 Weight, 
 Ibs. 
 per foot. 
 
 Inner Weights. 
 
 Max. 
 
 Weight, 
 Ibs. 
 per foot. 
 
 Min. 
 Flange, 
 inches. 
 
 Min. 
 Web, 
 inches. 
 
 Min. 
 Area, 
 square 
 inches. 
 
 4 
 
 7 5 
 
 Vary by 1 Ib 
 
 10 5 
 
 2 66 
 
 19 
 
 2 2 
 
 5 
 6 
 
 9.75 
 12 25 
 
 Vary by 2^ Ibs 
 Vary by 2U Ibs. . 
 
 14.75 
 17.25 
 
 3.00 
 3 33 
 
 .21 
 .23 
 
 2.9 
 3 6 
 
 7 
 
 15 
 
 Vary by 2^ Ibs 
 
 20.0 
 
 3 66 
 
 .25 
 
 4 4 
 
 8 
 
 17 75 
 
 Vary by 2^ Ibs 
 
 25.25 
 
 4.00 
 
 .27 
 
 5 2 
 
 9 
 10 
 
 21.0 
 25.0 
 
 25 Ibs. then vary by 5 Ibs. 
 Vary by 5 Ibs 
 
 35.0 
 40.0 
 
 4.33 
 4.66 
 
 .29 
 .31 
 
 6.3 
 
 7.4 
 
 12 
 12 
 
 31.5 
 40 
 
 35 Ibs. then vary by 5 Ibs. 
 Vary by 5 Ibs 
 
 45.0 
 55 
 
 5.00 
 5 25 
 
 .35 
 
 41 
 
 9.3 
 
 11 85 
 
 15 
 15 
 
 42.0 
 60.0 
 
 45 Ibs. then vary by 5 Ibs. 
 Varv bv 5 Ibs . .' 
 
 60.0 
 80.0 
 
 5.50 
 6.00 
 
 .46 
 .59 
 
 12.5 
 17.68 
 
 WEIGHTS AND MEASUREMENTS OF STEEL CHANNELS. 
 
 Depth, 
 Inches. 
 
 Min. 
 Weight, 
 Ibs. 
 per foot. 
 
 Inner Weights. 
 
 Max. 
 
 Weight, 
 Ibs. 
 per fool. 
 
 Min. 
 Flange, 
 inches. 
 
 Min. 
 Web, 
 inches. 
 
 Min. 
 Area, 
 square 
 inches. 
 
 4 
 
 5 25 
 
 Vary by 1 Ib 
 
 7.25 
 
 1.58 
 
 .18 
 
 1.6 
 
 5 
 
 6 5 
 
 Varv by 2^ Ibs 
 
 11.5 
 
 1.75 
 
 .19 
 
 2.0 
 
 6 
 
 8 
 
 Vary by 2 y> Ibs 
 
 15 5 
 
 1 92 
 
 20 
 
 2.4 
 
 7 
 
 9 75 
 
 Vary by 2 y> Ibs 
 
 19 75 
 
 2 09 
 
 .21 
 
 2.9 
 
 8 
 
 11 25 
 
 Vary by 2^ Ibs 
 
 21 25 
 
 2 26 
 
 .22 
 
 3.4 
 
 9 
 10 
 
 13^25 
 15 
 
 15 Ibs. then vary by 5 Ibs. 
 Vary by 5 Ibs 
 
 25.0 
 35 
 
 2.43 
 2.60 
 
 .23 
 .24 
 
 3.9 
 4.5 
 
 12 
 15 
 
 20.5 
 33.0 
 
 25 Ibs. then vary by 5 Ibs. 
 33 Ibs. then vary by 5 Ibs. 
 
 40.0 
 55.0 
 
 2.94 
 3.40 
 
 .28 
 .40 
 
 6.0 
 9.9 
 
 PIPE AND PIPING. 
 
 Rule to find pressure allowed on a main steam pipe or header 
 when thickness of pipe and diameter is known: From thickness 
 of plate subtract the constant .1250, then multiply by one-sixth of 
 tensile strength of plate and divide this product by diameter; the 
 sum will be pressure allowed. 
 
 LEGEND: 
 
 T = Thickness of plate = . 4850 
 C = Constant =.1250 
 
 T. S = Tensile strength = 60000 
 D = Diameter =24" 
 
 FORMULA : 
 (T . 1250) X ( l/6th of TS) 
 
 = pressure 
 
BOILER CONSTRUCTION. 57 
 
 EXAMPLE: 
 
 .4850 = thickness of plate 
 .1250= constant 
 
 .3600 
 
 10000 = 1/6 of tensile strength 
 
 diameter 24") 3600. 0000(150 Ibs. pressure allowed 
 24 
 
 120 
 120 
 
 Rule to find thickness of material for a main, steel or iron, 
 steam pipe or cylinder lap welded: Multiply pressure by diameter 
 and divide by one-sixth of the tensile strength, and add .125 
 
 LEGEND. FORMULA: 
 
 P= pressure = 150 Ibs. PXD 
 
 D = diameter = 24" \-. 125 =thickness 
 
 T.S. = tensile strength = 60,000 1/6 of T. S. 
 
 EXAMPLE: 
 
 150 =lbs. pressure 
 24"= diameter 
 
 600 
 300 
 
 1/6 of tensile strength = 10, 000) 3600 00( .36 
 
 3000 . 125 added 
 
 600 00 . 485 =thickness or 31/64 
 
 600 00 approximately 
 
 Rule to find thickness of plate for a 5" copper pipe : Multiply 
 pressure by inside diameter of pipe and divide by constant 8000; 
 add to quotient the constant .0625. 
 
 LEGEND: FORMULA: 
 
 P= pressure = 175 PXlD 
 
 I D =inside diameter of pipe = . 5 f- . 062 5 = thickness of plate 
 
 C = constant = 8000 C 
 
 EXAMPLE: 
 175 =pressure 
 . S" =iriside diameter of pipe 
 
 8000) 87. 50000 (.109 
 
 80 00 .062 5= constant 
 
 75 00 . 1 7 1 5 = approximately 
 72 00 
 
 3 00 
 
58 
 
 THE BOILER. 
 
 RADIATION OF DIFFERENT SIZES OF WROUGHT- 
 
 IRON PIPE. 
 
 The following table gives the actual lengths of different sizes 
 of pipe sufficient to make ten square feet of radiation : 
 
 1 inch Pipe, 28 lineal feet = 10 square feet radiation. 
 
 i 
 
 24 
 
 " =10 
 
 
 . ' 
 
 20 
 
 " =10 
 
 
 * 
 
 16 
 
 " =10 
 
 
 -' 
 
 13 
 
 " =10 
 
 
 
 
 11 
 
 " =10 
 
 
 TABLE OF EXPANSION OF WROUGHT-!RON PIPE. 
 
 Temperature 
 of the Air 
 when the Pipe 
 is fitted. 
 
 Length of 
 Pipe 
 when fitted. 
 
 LENGTH OF PIPE WHEN HEATED TO 
 
 160 Degrees. 
 
 180 Degrees. 
 
 200 Degrees. 
 
 Degrees Fahr. 
 
 Feet. 
 
 Feet. 
 
 Inches. 
 
 Feet 
 
 Inches 
 
 Feet 
 
 Inches 
 
 
 32 
 64 
 
 100 
 100 
 100 
 
 100 
 100 
 100 
 
 1.28 
 1.02 
 .77 
 
 100 
 100 
 100 
 
 1.44 
 1.18 
 .93 
 
 100 
 100 
 100 
 
 1.60 
 1.34 
 1.09 
 
 STANDARD FLANGES. SIZES: THREADED OR PLAIN. 
 
 Size Pipe, 
 Inches. 
 
 Diameter 
 Flange. 
 
 Thickness 
 of Flanges. 
 
 Equivalent 
 to Cast Iron. 
 
 1- Inch 
 
 6- Inch 
 
 2^- Inch 
 
 1^-Inch 
 
 1 L/ 
 
 
 6 
 
 
 3^ 
 
 
 ii4 
 
 
 i'H 
 
 
 6 
 
 
 jl 
 
 
 11^ 
 
 
 2 
 
 
 8 
 
 
 1^ 
 
 
 2 
 
 
 21^ 
 
 
 9 
 
 
 ^ 
 
 
 2 
 
 
 3 
 
 
 9 
 
 
 H 
 
 
 2 
 
 
 3^3 
 
 
 10 
 
 
 H 
 
 
 2 
 
 
 4 
 
 
 10 
 
 
 
 
 2 
 
 
 4^3 
 
 
 lO^j 
 
 
 /^ 
 
 
 2 
 
 
 5 
 
 
 11^ 
 
 
 Ni 
 
 
 2 
 
 
 6 
 
 
 WH 
 
 
 ^ 
 
 
 2 
 
 
 7 
 
 
 133^ 
 
 
 g 
 
 
 2 
 
 
 8 
 
 
 15^ 
 
 
 
 
 2^ 
 
 
 9 
 
 
 16^ 
 
 
 ' - : ?J 
 
 
 
 
 10 
 
 
 17^ 
 
 
 
 
 2M 
 
 
 12 
 
 
 21 
 
 
 N 
 
 
 2K 
 
 
BOILER CONSTRUCTION. 
 
 59 
 
 73. - 
 
 '53 S o 
 
 t^ OO OO -f Tfr- 
 CN) i-H rH i-H i I 
 
 rHn-li-lrHOOOOOOOOOOOOOOOOOOOOOOOOOO 
 
 i (vn C<J(Ni lt^.r \ if) OQ if) 
 
 N c<i <M ro ro 
 
 W l 
 
 f-O I-H t*. OO ro vo 
 
 re . 
 
 c re 
 
 S 
 
 t^ F-H oooo Osrooo 
 
 C<1 c^ c^l ro ro ro 
 
 C<J C<J CM ro ro ro 
 
 ? 
 
 Actu 
 nti-rn 
 Inch 
 
 - 
 
60 
 
 THE BOILER. 
 
 TABLE GIVING DIAMETER AND AREA AT THE BOTTOM OF THE THREAD OF 
 
 STAY-BOLTS AND STAYS OF USEFUL SIZES FOR CALCULATING 
 
 THEIR STRENGTH, ETC. 
 
 Diam. 
 of Stay 
 Bolt 
 
 Thread 
 per inch 
 
 Diam. at 
 bottom of 
 thread 
 U. S. 
 
 Area in sq. 
 inches at 
 bottom of 
 thread 
 
 UQ 
 
 Diam. at 
 bottom of 
 thread 
 V 
 
 Area in sq. 
 inches at 
 bottom of 
 thread 
 
 y 
 
 
 
 Standard 
 
 . o. 
 Standard 
 
 thread 
 
 thread 
 
 H 
 
 12 
 
 .51675 
 
 .2097 
 
 .48067 
 
 .1815 
 
 H 
 
 12 
 
 .57925 
 
 .2635 
 
 .54317 
 
 .2317 
 
 H 
 
 12 
 
 .64175 
 
 .3235 
 
 .60567 
 
 .2881 
 
 T 
 
 12 
 
 . 70425 
 
 .3895 
 
 .66817 
 
 .3506 
 
 1 
 
 12 
 
 .76675 
 
 .4617 
 
 .73067 
 
 .4193 
 
 it 
 
 12 
 
 .82925 
 
 .5409 
 
 .79317 
 
 .4941 
 
 1 
 
 12 
 
 .89175 
 
 .6246 
 
 .85567 
 
 .5750 
 
 1A 
 
 12 
 
 .95425 
 
 .7152 
 
 .91817 
 
 .6621 
 
 iH 
 
 12 
 
 1.01675 
 
 .8119 
 
 .98067 
 
 .7553 
 
 iA 
 
 12 
 
 1.07925 
 
 .9148 
 
 1.04317 
 
 .8547 
 
 \U 
 
 12 
 
 1.14175 
 
 1.0238 
 
 1.10567 
 
 .9601 
 
 1 ~fs 
 
 12 
 
 1.20425 
 
 1.1390 
 
 1.16817 
 
 1.0718 
 
 1% 
 
 12 
 
 1.26675 
 
 1.2603 
 
 1.23067 
 
 1.1895 
 
 1^ 
 
 12 
 
 1.39175 
 
 1.5213 
 
 1.35567 
 
 1.4434 
 
 
 6 
 
 1.28350 
 
 1.2939 
 
 1.21134 
 
 1.1525 
 
 1% 
 
 5^ 
 
 1.38882 
 
 1.5149 
 
 1.31010 
 
 1.3480 
 
 \y 
 
 5 
 
 1.49020 
 
 1.7441 
 
 1.40350 
 
 1.5471 
 
 ! 7 /8 
 
 5 
 
 1.61520 
 
 2.0490 
 
 1.52850 
 
 1.8349 
 
 2 
 
 4^ 
 
 1.71134 
 
 2.3001 
 
 1.61512 
 
 2.0487 
 
 2 l /8 
 
 4^ 
 
 1.83634 
 
 2.6485 
 
 1.74012 
 
 2.3782 
 
 2^ 
 
 4^ 
 
 1.96134 
 
 3.0213 
 
 1.86512 
 
 2.7321 
 
 2^ 
 
 4 
 
 2.05025 
 
 3.3014 
 
 1.94200 
 
 2.9620 
 
 2^ 
 
 4 
 
 2.17525 
 
 3.7163 
 
 2.06700 
 
 3.3556 
 
 2^ 
 
 4 
 
 2.30025 
 
 4.1557 
 
 2.19200 
 
 3.7738 
 
 2% 
 
 4 
 
 2.42525 
 
 4.6196 
 
 2.31100 
 
 4.1946 
 
 2 7 /8 
 
 3^ 
 
 2.50386 
 
 4.9239 
 
 2.38015 
 
 4.4494 
 
 
 3^ 
 
 2.62886 
 
 5.4278 
 
 2.50515 
 
 4.9290 
 
BOILER CONSTRUCTION. 
 
 TAP DRILLS. 
 
 THIS TABLE SHOWS THE DIFFERENT SIZES OF DRILL THAT SHOULD BE USED 
 WHEN FULL THREAD is TO BE TAPPED. 
 
 FOR MACHINE AND HAND TAP. 
 
 Diameter of Tap 
 
 No. of 
 Threads to 
 Inch 
 
 Size Drill 
 for 
 V Thread 
 
 Size Drill 
 for U. S. 
 Standard 
 Thread 
 
 Size Drill 
 for 
 Whitworth 
 Thread 
 
 !& - 
 
 16 18 20 
 
 5 5 11 
 
 A 
 
 A 
 
 A 
 
 16 18 20 
 
 3 13 13 
 
 
 
 ft 
 
 16 18 
 
 7 15 
 
 U 
 
 ii 
 
 2 
 
 16 18 
 
 H 8 ' 
 
 
 
 H" 
 
 14 16 18 
 
 M & %i 
 
 A 
 
 A 
 
 w 
 
 14 16 18 
 
 u n n 
 
 
 
 t" 
 
 14 16 
 
 21 11 
 
 ii 
 
 ii 
 
 & 
 
 14 16 
 
 n y 
 
 
 
 
 12 13 14 
 
 y* 54. u 
 
 ia 
 
 % 
 
 ?f 
 
 12 13 14 
 
 u n n 
 
 
 
 A 
 
 12 14 
 
 7" 29 
 
 ^ 
 
 -f& 
 
 n 
 
 12 14 . 
 
 15 31 
 
 
 
 YC, 
 
 10 11 12 
 
 
 y> 
 
 U 
 
 n . 
 
 10 11 12 
 
 ?/ i? 11 
 
 
 
 %. . 
 
 10 11 12 
 
 n y- y 
 
 5 A 
 
 5i 
 
 B 
 
 10 11 12 
 
 y* n n 
 
 
 
 5 
 
 9 10 . . 
 
 45 23 
 
 ii 
 
 
 8? 
 
 9 10 
 
 i| ^J 
 
 
 
 i 
 
 8 
 
 
 
 i 
 
 
 g 
 
 
 
 
 iH 
 
 7 8 
 
 15 
 
 ii 
 
 14 
 
 1A 
 
 7 8 
 
 15 31 
 
 
 
 in 
 
 7 
 
 i* 
 
 ITS 
 
 IX 
 
 i* 
 
 7 
 
 if 
 
 
 
 1% 
 
 6 
 
 1U 
 
 Ifk 
 
 1A 
 
 1W 
 
 6 
 
 
 
 
 
 6 
 
 1? 
 
 l^f 
 
 iili 
 
 j'if 
 
 6 
 
 1^ 1A 
 
 
 
 1%. . 
 
 S 5U 
 
 l^J 1^ 
 
 l^g 
 
 l*f 
 
 IS- 
 
 5 5K 
 
 
 
 
 iH 
 
 5 
 
 113 
 
 1U 
 
 1^ 
 
 134 
 
 5 
 
 j3L 
 
 
 
 iH 
 
 4U 5 
 
 1^ 111 
 
 15^ 
 
 1M 
 
 
 4U 5 
 
 1A 14J 
 
 
 
 2 
 
 4U . 
 
 li 
 
 1M 
 
 1 
 
 
 
 
 
 
 OF THE 
 
 UNIVERSITY 
 
62 
 
 THE BOILER. 
 
 PIPE TAPS. 
 
 Size Pipe 
 
 No. of 
 Threads to 
 the Inch 
 
 Diameter 
 of Drill 
 
 Size Pipe 
 
 No. of 
 Threads to 
 the Inch 
 
 Diameter 
 of Drill 
 
 U 
 
 27 
 
 ft 
 
 3 
 
 8 
 
 3A 
 
 M- 
 
 18 
 
 
 zy>. . 
 
 8 
 
 313. 
 
 R 
 ^ 
 % 
 
 iii. 
 
 18 
 14 
 14 
 1W 
 \\y> 
 
 1 
 
 !*:::::: 
 
 6 
 7 
 
 8 
 8 
 8 
 8 
 8 
 
 4^8 
 
 . 5% 
 
 ^Te 
 
 5*: -.:: 
 
 HH 
 
 11^ 
 
 2 
 
 8 
 9 
 
 8 
 8 
 
 8 I/ 
 
 vy> 
 
 2K.-. 
 
 8 
 
 2U 
 
 10. . 
 
 8 
 
 10 U 
 
 WEIGHTS OF ROUND AND SQUARE STEEL. PER LINEAL FOOT. 
 
 
 Round, 
 
 Square, 
 
 
 Round, 
 
 Square, 
 
 Size, 
 inches. 
 
 Weight, 
 Ibs. 
 
 Weight, 
 Ibs. 
 
 Size, 
 inches. 
 
 Weight, 
 Ibs. 
 
 Weight, 
 Ibs. 
 
 P 
 
 .094 
 
 .120 
 
 2 y s 
 
 12.06 
 
 15.36 
 
 
 .167 
 
 .213 
 
 2/4 
 
 13.52 
 
 17.22 
 
 A 
 
 .261 
 
 .332 
 
 2% 
 
 15.07 
 
 19.19 
 
 N 
 
 .375 
 
 .478 
 
 2}4 
 
 16.70 
 
 21.26 
 
 T$ 
 
 .511 
 
 .651 
 
 2% 
 
 18.41 
 
 23.44 
 
 7& 
 
 .668 
 
 .851 
 
 2% 
 
 20.21 
 
 25.73 
 
 A 
 
 .845 
 
 1.076 
 
 
 24.05 
 
 30.62 
 
 
 1.044 
 
 1.329 
 
 3M 
 
 28.23 
 
 35.94 
 
 M 
 
 1.503 
 
 1.914 
 
 31^ 
 
 32.74 
 
 41.68 
 
 j^ 
 
 2.046 
 
 2.605 
 
 3^ 
 
 37.57 
 
 47.84 
 
 i 
 
 2.672 
 
 3.402 
 
 4 
 
 42.77 
 
 54.45 
 
 iK 
 
 3.382 
 
 4.306 
 
 4^> 
 
 54.83 
 
 69.81 
 
 i-M 
 
 4.175 
 
 5.316 
 
 5 
 
 66.82 
 
 85.08 
 
 1% 
 
 5.052 
 
 6.432 
 
 5L/ 
 
 80.85 
 
 102.94 
 
 ijjj 
 
 6.012 
 
 7.655 
 
 6 
 
 96.22 
 
 122.51 
 
 15^ 
 
 7.056 
 
 8.984 
 
 6^? 
 
 112.92 
 
 143.78 
 
 1% 
 
 8.183 
 
 10.419 
 
 7 
 
 131.97 
 
 166.75 
 
 1 7^ 
 
 9.394 
 
 11.961 
 
 7;M> 
 
 150.34 
 
 191.42 
 
 2 
 
 10.69 
 
 13.61 
 
 8 
 
 171.04 
 
 217.78 
 
BOILER CONSTRUCTION. 63 
 
 WEIGHTS OF FLAT STEEL. PER LINEAL FOOT. 
 
 -C t/3 
 
 T3 J: 
 
 THICKNESS, INCHES. 
 
 ?J3 
 
 A 
 
 l /s 
 
 & 
 
 M 
 
 A 
 
 *A 
 
 r 7 * 
 
 1 A 
 
 5 /S 
 
 H 
 
 % 
 
 1 
 
 1 
 
 .21 
 
 .43 
 
 .638 
 
 .850 
 
 1.06 
 
 1.28 
 
 1.49 
 
 1.70 
 
 2.12 
 
 2.55 
 
 2.98 
 
 
 1H 
 
 .24 
 
 .48 
 
 .720 
 
 .955 
 
 1.20 
 
 1.43 
 
 1.68 
 
 1.92 
 
 2.39 
 
 2.87 
 
 3.35 
 
 '3!88 
 
 iM 
 
 .27 
 
 .53 
 
 .797 
 
 1.06 
 
 1.33 
 
 1.59 
 
 1.86 
 
 2.12 
 
 2.65 
 
 3.19 
 
 3.72 
 
 4.21 
 
 iH 
 
 .30 
 
 .59 
 
 .875 
 
 1.17 
 
 1.46 
 
 1.76 
 
 2.05 
 
 2.34 
 
 2.92 
 
 3.51 
 
 4.09 
 
 4.68 
 
 W 
 
 .32 
 
 .64 
 
 .957 
 
 1.28 
 
 1.59 
 
 1.92 
 
 2.23 
 
 2.55 
 
 3.19 
 
 3.83 
 
 4.47 
 
 5.10 
 
 1^ 
 
 .35 
 
 .69 
 
 1.04 
 
 1.38 
 
 1.73 
 
 2.08 
 
 2.42 
 
 2.77 
 
 3.46 
 
 4.15 
 
 4.84 
 
 5.53 
 
 1; 1 4 
 
 .38 
 
 .75 
 
 1.11 
 
 1.49 
 
 1.86 
 
 2.23 
 
 2.60 
 
 2.98 
 
 3.72 
 
 4.47 
 
 5.20 
 
 5.95 
 
 2 
 
 .43 
 
 .85 
 
 1.28 
 
 1.70 
 
 2.12 
 
 2.55 
 
 2.98 
 
 3.40 
 
 4.25 
 
 5.10 
 
 5.95 
 
 6.80 
 
 2M 
 
 .48 
 
 .96 
 
 1.44 
 
 1.91 
 
 2.39 
 
 2.87 
 
 3.35 
 
 3.83 
 
 4.78 
 
 5.75 
 
 6.69 
 
 7.65 
 
 2^ 
 
 .53 
 
 1.06 
 
 1.59 
 
 2.12 
 
 2.65 
 
 3.19 
 
 3.72 
 
 4.25 
 
 5.31 
 
 6.38 
 
 7.44 
 
 8.50 
 
 2^ 
 
 .59 
 
 1.17 
 
 1.75 
 
 2.34 
 
 2.92 
 
 3.51 
 
 4.09 
 
 4.67 
 
 5.84 
 
 7.02 
 
 8.18 
 
 9.35 
 
 3 
 
 .64 
 
 1.28 
 
 1.91 
 
 2.55 
 
 3.19 
 
 3.83 
 
 4.46 
 
 5.10 
 
 6.38 
 
 7.65 
 
 8.93 
 
 10.20 
 
 3}4 
 
 .69 
 
 1.38 
 
 2.07 
 
 2.76 
 
 3.45 
 
 4.15 
 
 4.83 
 
 5.53 
 
 6.91 
 
 8.29 
 
 9.67 
 
 11.05 
 
 3^ 
 
 .75 
 
 1.49 
 
 2.23 
 
 2.98 
 
 3.72 
 
 4.47 
 
 5.20 
 
 5.95 
 
 7.44 
 
 8.93 
 
 10.41 
 
 11.90 
 
 3^ 
 
 .80 
 
 1.60 
 
 2.39 
 
 3.19 
 
 3.99 
 
 4.78 
 
 5.58 
 
 6.38 
 
 7.97 
 
 9.57 
 
 11.16 
 
 12.75 
 
 4 
 
 .85 
 
 1.70 
 
 2.55 
 
 3.40 
 
 4.25 
 
 5.10 
 
 5.95 
 
 6.80 
 
 8.50 
 
 10.20 
 
 11.90 
 
 13.60 
 
 4^ 
 
 .96 
 
 1.92 
 
 2.87 
 
 3.83 
 
 4.78 
 
 5.74 
 
 6.70 
 
 7.65 
 
 9.57 
 
 11.48 
 
 13.39 
 
 15.30 
 
 5 
 
 1.07 
 
 2.13 
 
 3.19 
 
 4.25 
 
 5.31 
 
 6.38 
 
 7.44 
 
 8.50 
 
 10.63 
 
 12.75 
 
 14.87 
 
 17.00 
 
 5^ 
 
 1.17 
 
 2.34 
 
 3.51 
 
 4.67 
 
 5.84 
 
 7.02 
 
 8.18 
 
 9.35 
 
 11.69 
 
 14.03 
 
 16.36 
 
 18.70 
 
 6 
 
 1.28 
 
 2.55 
 
 3.83 
 
 5.10 
 
 6.38 
 
 7.65 
 
 8.93 
 
 10.20 
 
 12.75 
 
 15.30 
 
 17.85 
 
 20.40 
 
 7 
 
 1.49 
 
 2.98 
 
 4.46 
 
 5.95 
 
 7.44 
 
 8.93 
 
 10.41 
 
 11.90 
 
 14.87 
 
 17.85 
 
 20.83 
 
 23.80 
 
 8 
 
 1.70 
 
 3.40 
 
 5.10 
 
 6.80 
 
 8.50 
 
 10.20 
 
 11.90 
 
 13.60 
 
 17.00 
 
 20.40 
 
 23.80 
 
 27.20 
 
 RULES FOR OBTAINING APPROXIMATE WEIGHT OF 
 WROUGHT IRON. 
 
 FOR ROUND BARS. 
 
 RULE : Multiply the square of the diameter in inches by the 
 length in feet, and that product by 2.6. The product will be the 
 weight in pounds, nearly. 
 
 FOR SQUARE AND FLAT WROUGHT BARS. 
 
 RULE : Multiply the area of the end of the bar in inches by 
 the length in feet, and that 3.32. The product will be the weight 
 in pounds, nearly. 
 
 WROUGHT IRON, ASSUMED WEIGHT. 
 
 A cubic foot 
 
 A square foot, 1 inch thick 
 
 A bar 1 inch square, 1 foot long 
 
 A bar 1 inch square, 1 yard long 
 
 = 480 Ibs. 
 
 40 Ibs. 
 
 3 1-3 Ibs 
 
 = 10 Ibs. 
 
64 THE BOILER. 
 
 RULE FOR FINDING THE SECTIONAL AREA OF A BAR OF WROUGHT 
 IRON, WHEN WEIGHT PER FOOT IS GIVEN. 
 
 Multiply by 3 and divide by 10. 
 
 RULE FOR FINDING THE WEIGHT PER FOOT., WHEN AREA IS GIVEN. 
 
 Divide by 3 and multiply by 10. 
 
 NOTES ON CONSTRUCTION. 
 
 The necessity for vigilance and supervision of boiler designing 
 and construction is made apparent in England by the stringent 
 laws and by enforced rules and practices governing the same in 
 way of additional factors for safety. They result in promoting 
 good work and care in the operating and management of steam 
 boilers. 
 
 Additional factors for safety are added to the established one 
 of 5 due to deterioration by usage, age or fuel. 
 
 The English Board of Trade has established and tabulated a 
 table of percentage of increase of factor of safety and cites reasons 
 for such additional proportions. 
 
 All boilers must be designed and constructed according to their 
 specifications, viz. : Holes to be drilled when shell plates have 
 been rolled ; straps or cover plates not less than jj^j of plates they 
 cover; in butt joints rivet sections must be 75 per cent over 
 rivets in single shear and circumferential seams at least one-half 
 the percentage of longitudnal seam. 
 
 The increased factor of safety is insisted on when conditions 
 are as follows : 
 
 TABLE. 
 
 PERCENTAGE 
 
 OF 
 INCREASE 
 
 A. = .1 To be added when all holes are fair and good in the long seam, 
 
 but drilled out of place after bending. 
 
 B. = .2 When all holes are fair and good in longitudinal seams, but 
 
 drilled before bending. 
 
. 
 
 BOILER CONSTRUCTION. 65 
 
 PERCENTAGE 
 
 OF 
 
 INCREASE 
 
 C. = .2 When all holes are fair and good in longitudinal seams, but 
 
 punched after bending. 
 
 D. = .3 When all holes are lair and good in longitudinal seam but 
 
 punched before bending. 
 
 E. = .7 When all holes are not fair and good in longitudinal seam (and 
 
 increased according to values). 
 
 F. = .8 When holes are all fair and good in the circumferential seams, 
 
 but drilled out of place after bending. 
 
 G. = .1 When all holes are fair and good in the circumferential seams, 
 
 but drilled before bending. 
 H. = .1 When holes are fair and good in the circumferential seams, but 
 
 punched after bending. 
 I. = .15 If the holes are all fair and good in the circumferential seams, 
 
 but punched before bending. 
 J. = .15 If the holes are not fair and good in the circumferential seams 
 
 (and increased according to values). 
 K .2 If the double butt straps are not fitted to the longitudinal 
 
 seams and said seams are lap and double riveted. 
 L. . 07 If double butt straps are not fitted to the longitudinal seams 
 
 and said seams are lap and triple riveted. 
 M. = .3 If only single butt straps are fitted to the longitudinal seams 
 
 and said seams are double riveted. 
 N. = .15 If only single butt straps are fitted to the longitudinal seams 
 
 and said seams are triple riveted. 
 O. = .1 When any description of joint in the longitudinal seam is 
 
 single riveted. 
 P. = . 2 If all holes are punched small and reamed afterwards or 
 
 drilled out in place. 
 Q. = .4 If the longitudinal seams are fitted with single butt straps 
 
 and are single riveted. 
 R. = .4 When material or workmanship is according to inspector 
 
 doubtful or not the best (then the factor is increased accord- 
 ingly). 
 
 S. = . 1 If the circumferential seams are lap joints and double riveted. 
 T. = .2 If the circumferential seams are lap joints and single riveted. 
 U. = .25 When the circumferential seams are lap and the plates are 
 
 not entirely under or over covers, and 1.65 to be added if the 
 
 boiler is not open to inspection during the whole period of 
 
 its construction. 
 
 The benefits derived from these additional factors of safety will 
 be the means of bringing the science of boiler designing and work 
 of construction up to a high standard. 
 
 In designing seams reason must govern when calculations are 
 made, for if too great a pitch is used the plate cannot be drawn 
 together without springing of plate or heads of rivets coming off, 
 and so prevent making a tight caulking edge. 
 
66 THE BOILER. 
 
 Each joint will be taken np separately as the strength of a joint 
 is less than that of the solid plate due to cutting away for rivet holes 
 and the single riveted lap joint is the weakest designed. 
 
 Tests have been made on various designed joints, and as it 
 would be impossible to test all joints constructed, calculations from 
 practice, factors and co-efficients must be relied on and followed up ; 
 these have proved satisfactory when construction has been care- 
 fully complied with according to designs. 
 
 The aim in boiler construction is to have the percentage of 
 strength in rivet and plate as near equal as possible. 
 
 The maximum strength of a boiler is calculated from its weakest 
 point, and the subject of seams in various forms and design will be 
 taken up later ; also boiler diameter, material thickness of same ; 
 rivets, their diameter; shearing strength, if single or double; pitch 
 of rivets, number of rivets in joints; butt straps and factors, such 
 as constants, taken into consideration when calculating the strength 
 of a seam and varying according to conditions ; methods of construc- 
 tion and design of joint or difference in material. 
 
 The necessity for care in designing and constructing to resist 
 great forces is clearly shown by the following calculation : A com- 
 mon size boiler 60" X 16' has approximately 32,145 square inches 
 of bursting area and at a pressure of 100 pounds it has a total of 
 1,607 tons of energy or bursting pressure; with the higher pressures 
 now used, this hazard increases. 
 
 The English Board of Trade, a recognized authority on steam 
 boilers, says that the rivet percentage of seam should be in excess 
 of the plate and when computing the rivet section when steel plates 
 and rivets are used the rivet section must be divided by 28/23. If 
 iron rivets are used with steel plates then the rivet section must be 
 y% times greater than plate section and be divided by 13/8. 
 
 When describing strains, the action of shearing rivets means to 
 shear across its diameter. The tearing strain refers to the action 
 of tearing apart of plate. The crushing strain is the action to 
 crush or rupture the plate between rivet holes and edge of plate. 
 
 In calculations for rivet strength the diameter of the rivet hole 
 will be taken and not the diameter of the rivet, for the rivet must 
 fill the rivet hole. 
 
BOILER CONSTRUCTION. 67 
 
 The reader will observe in following calculations that decimals 
 will be omitted when of minor value. 
 
 LEGEND. 
 SYMBOLS USED IN FORMULAS 
 
 P= pressure 
 
 p= pitch of rivets 
 Pm = maximum pitch 
 
 N = number of rivets 
 Pd = diagonal pitch of rivets 
 
 D = diameter of boiler 
 
 d = diameter of rivet hole 
 
 T = Thickness of plate 
 % = percentage 
 
 V= distance between rows 
 
 E = distance center of rivets to edge of plate (lap) 
 TS = tensile strength of plate 
 AR =area of rivet hole 
 
 F = factor of safety 
 
 A coefficient is a prescribed amount to make up for any defects 
 reducing" strength of plate due to punching, riveting, caulking, &c. 
 
 A factor of safety is the difference between the safe working and 
 bursting pressures. 
 
 It is well to explain here that calculations of joints are based on 
 the principle that sections of the same do not vary, except according 
 to the joints designed; the boiler, figuratively speaking, is composed 
 of rings, each one having the same amount of plate width and pitch 
 of rivets and the weakest part of this supposed ring is the base of 
 the maximum strength. In the process of computing calculations 
 this will appear clear to the student. 
 
 The rules for calculating strength of joints vary in formulas 
 and results, but as stated in previous pages the rules the writer has 
 used in connection with designing, testing and inspecting have been 
 based on experiments and found in practice to have a factor of safety 
 of reasonable margin. 
 
 While in computing joints the aim is to get the plate and rivet 
 strength as near equal ; favoring the rivet ; it must be remembered 
 that a variance in pitch will vary efficiencies as will also the diameter 
 of a rivet, these being of standard sizes and varying in sixteenths ; 
 some of the rules will show an excess of rivet strength or even 
 plate, and will appeal to the reader that a smaller diameter of rivet 
 or greater pitch, or a lower or higher tensile strength, would affect 
 the factors in securing the best possible efficiencies. 
 
68 
 
 THE BOILER. 
 
 In the following rules in connection with boiler as outlined there 
 are calculations to make from material and ratios for efficiencies. 
 The strength of rivets has been computed from exhaustive tests and 
 as the subject of rivet shearing will be a factor in calculating seams 
 of efficiency it may be well to make some explanations. The neces- 
 sary force to shear a rivet in single shear is 38,000 Ibs. to square 
 inch of cross section of rivet. The strain necessary to shear a rivet 
 in double shear is 85 per cent more than in single shear. 
 
 EXAMPLE: 
 
 Rule to find strength of rivet in single shear: Multiply area of rivet 
 hole by shearing resistance of rivet. 
 
 FORMULA: 
 
 A X S = strength of rivet in single shear 
 EXAMPLE: 
 
 .5185 =area of rivet hole 
 
 3 8000= shearing resistance 
 
 41480000 
 15555 
 
 SHEAR 
 
 19,703 =strength of one rivet in single shear 
 
 38000 =lbs. single shear 
 
 . 85 = % more for double 
 shear 
 
 190000 
 304000 
 
 32300.00 Ibs. =85% of 38000 
 Ibs. 
 
 DOUBLE SHEAR 
 
 adding the value to the above 
 
 3 8000= single shearing strength 
 32300 = 85% added 
 
 70300 = shearing strength of a rivet in double shear 
 
CHAPTER IV. 
 
 BRACES AND REINFORCING. 
 
 While there are boilers being made today that have strength 
 in designed circular forms, the many in use and those being con- 
 structed have surfaces requiring reinforcements, some having an 
 excess over other types and the high pressures now in demand re- 
 quire the best methods and improved design of brace. 
 
 This is a subject of as much importance as the designing of a 
 joint and requires careful selection, proportioning and attaching 
 braces to counteract strains that may be due to resisting bursting 
 pressures, and those of contraction, expansion and collapsing. 
 
 Various designed braces and stays have been in use and are as 
 varied in stability, some having minimum amount of strength, due 
 to their structural weakness; again while some have the desired 
 form and strength, location or principle of attaching same has de- 
 preciated their value as a reinforcement. 
 
 The subject of bracing is broad and could be treated inexhaust- 
 ively, this owing to the many necessities and forms where each 
 must necessarily be worked out separately. It is the intention 
 to take up the most general methods, such as stay bolts, formed 
 braces, stay tubes, crown bars, and angle irons. 
 
 Factors that are taken into consideration are 
 Structural, 
 Design, 
 
 Tensile strength, 
 Location, and 
 Principle of attaching. 
 
 In using rivets for braces it is customary to have the combined 
 area equal to \ l /\. times the brace area. 
 
 STAY BOLTS. 
 
 The use of stay bolts or stud stays for bracing is not at best a 
 very satisfactory method of reinforcement, this owing to position 
 
 69 
 
70 THE BOILER. 
 
 and conditions, especially in fire box boilers where strains are caused 
 by a bending force through the expansion of fire sheet, a pulling 
 strain by the collapsing and bursting pressures and by that of 
 vibration. 
 
 Care is necessary in selecting the best material ; the U. S. Govern- 
 men requires the same tests to be made in accordance with those of 
 plate used in connection with boilers coming under the supervision 
 of the Federal Government. In physical and chemical tests results 
 must show according to prescribed rules. Constant vibration is a 
 menace to safety and braces are subject to and effected more by it 
 than the strains from the pressures and more than the shell tubes 
 or rivets are by it. 
 
 The best material for this strain is that made from piling material 
 over that which is made from the bloom, this being due to its 
 lamina structure. 
 
 Requirements to look for in brace materials are : 
 
 Tensile strength, 
 
 Elongation, 
 
 Reduction of area, 
 
 Elasticity. 
 
 Vigilance, careful and frequent tests and inspections of the stay 
 bolts are necessary, for the force of expansion, contraction, tension, 
 bending and vibration are severe. In the work of inserting and 
 finishing this part of boiler construction defects often develop, this 
 by stripping of threads when entering inner plate, again by hammer- 
 ing over ends ; when this does occur the value of the brace is gone. 
 The design of the brace (stay bolt) is weak in the first place 
 for the threads act in a measure as an initial fracture, especially so 
 when one portion of thread is cut a little deeper than the balance. 
 The hollow type of stay bolt has commendable features, viz. : The 
 available admission of air to the (rich in heat units) volatile gases 
 from fuel in furnace (these gases having a heat value of 62,000 heat 
 units per pound, while the carbon or coke has only 14,500), the 
 heating of the air before coming in contact and mixing with same, 
 thus producing economical results, from minimum "heat absorbed by 
 air from water ; another feature that commends itself is instant 
 notice of any failure. 
 
BRACES AND REINFORCING. 71 
 
 Rule to find safe working pressure on flat surfaces when thick- 
 ness of plate and pitch of stay bolts are known : 
 
 Multiply the constant given for the specified thickness by the 
 thickness of plate squared in sixteenths and divide by the greatest 
 pitch squared. 
 
 FORMULA: 
 C X T 2 
 
 'Safe working pressure 
 
 What is the safe working pressure on a curved surface less than 
 a true circle ? Plate 7/16 thick and stay bolts 5" X 6" centers. 
 
 EXAMPLE: 
 7 = &= thickness 
 7 112 = constant as provided for 
 
 49 = thickness squared 
 49 = thickness squared 
 
 pitch = 6" 1008 
 6 448 
 
 pitch squared =36 )S488 (152 Ibs. safe working pressure 
 36 
 
 188 
 180 
 
 88 
 72 
 
 16 
 
 Note constants for specific conditions as used in following ex- 
 amples : 
 
 For a plate three-fourths of an inch thick, stayed 9-inch by 
 10-inch centers : 
 
 120X144 
 
 Working pressure = = 172 pounds. 
 
 100 
 
 For a plate nine-sixteenths of an inch thick, screw stays with 
 nuts, stays pitched 9-inch by 10-inch centers: 
 
 135X81 
 
 Working pressure = = 109 pounds. 
 100 
 
72 THE BOILER. 
 
 For a plate three-fourths of an inch thick, supported by stays 
 with double nuts, without washers or doubling plates, 10-inch by 
 12-inch centers: 
 
 170X144 
 
 Working pressure = = 170 pounds. 
 
 144 
 
 For plate one-half inch thick, with washers three-eighths of an 
 inch thick, stayed 10-inch by 12-inch centers: 
 
 160X101.60 
 
 Working pressure = = 112 pounds 
 
 144 
 
 For plate five-eighths of an inch thick, with doubling plate seven- 
 sixteenths of an inch thick, stayed by 14-inch by 14-inch centers : 
 
 200X149.81 
 
 Working pressure = = 152 pounds. 
 
 196 
 
 For plate five-eighths of an inch thick, with tees or angle bars 
 one-half of an inch thick, stayed by 14-inch by 14-inch centers : 
 
 200X167.96 
 
 Working pressure = = 171 pounds. 
 
 196 
 
 Plates heated for working must be annealed afterwards. 
 The diameter of a screw stay shall be taken at the bottom of 
 the thread, provided it is the least diameter of the stay. 
 
 Flat heads not exceeding 20 inches in diameter may be used 
 unsupported at pressure allowed by following rule : 
 
 Multiplying constant by thickness of head in sixteenths squared, 
 and dividing by half of area to be supported, gives the pressure 
 allowed. 
 
 FORMULA: 
 CXT 2 
 
 = P 
 
 y 2 ot A 
 
 Where P=steam pressure allowable in pounds. 
 T = thickness of material = % =}f . 
 A =area of head in inches =314". 
 C = 112 for plates -^ of an inch and under. 
 C =120 for plates over ^ of an inch. 
 Provided, The flanges are made to an inside radius of at least 1^ inches. 
 
BRACES AND REINFORCING. 73 
 
 EXAMPLE: 
 
 Required the working pressure of a flat head 20 inches in diameter and 
 
 of an inch thick. 
 
 120 = constant as provided for 
 144=head in sixteenths squared 
 
 480 
 480 
 120 
 
 one-half area of head = 157) 17280 (110 pounds safe working pressure 
 
 158 
 157 
 
 10 
 FLAT SURFACES. 
 
 The maximum stress allowable on flat plates supported by stays 
 shall be determined by the following rule : 
 
 All stayed surfaces formed to a curve the radius of which is 
 over 21 inches, excepting surfaces otherwise provided for, shall be 
 deemed flat surfaces. 
 
 CONSTANTS. 
 
 C = 112 for screw stays with riveted heads, plates seven-sixteenths of an inch 
 thick and under. 
 
 C = 120 for screw stays with riveted heads, plates above seven-sixteenths 
 
 of an inch thick. 
 C = 120 for screw stays with nuts, plates seven-sixteenths of an inch thick 
 
 and under. 
 
 C=125 for screw stays with nuts, plates above seven-sixteenths of an inch 
 
 thick and under nine-sixteenths of an inch. 
 C =135 for screw stays with nuts, plates nine-sixteenths of an inch thick and 
 
 above. 
 
 C = 170 for stays with double nuts having one nut on the inside and one 
 nut on the outside of plate, without washers or doubling plates. 
 
 C =160- for stays fitted with washers or doubling strips which have a thick- 
 ness of at least .5 of the thickness of the plate and a diameter of at 
 least .5 of the greatest pitch of the stay, riveted to the outside of 
 the plates, and stays having one nut inside of the plate, and one nut 
 outside of the washer or doubling strip. For T take 72 per cent of 
 the combined thickness of the plate and washer or plate or doubling 
 strip. 
 
 C =200 for stays fitted with doubling strips which have a thickness equal to 
 at least .5 of the thickness of the plate reinforced, and covering the 
 full area braced (up to the curvature of the flange, if any), riveted 
 to either the inside or outside of the plate, and stays having one nut 
 outside and one inside of the plates. Washers or doubling plates to 
 be substantially riveted. For T take 72 per cent of the combined 
 thickness of the two plates. 
 
74 THE BOILER. 
 
 C=200 for stays with plates stiffened with tees or angle-bars having a 
 thickness of at least two-thirds the thickness of plate and depth of 
 webs at least one-fourth of the greatest pitch of the stays, and sub- 
 stantially riveted on the inside of the plates, and stays having one 
 nut inside bearing on washers fitted to the edges of the webs, that 
 are at right angles to the plate. For T take 72 per cent of the 
 combined thickness of web and plate. 
 
 No flat plates or surfaces shall be unsupported at a greater 
 distance than 18 inches. 
 
 Multiply the constant 120 by the thickness squared in six- 
 teenths and divide product by the pitch of stay squared : 
 
 FORMULA: 
 
 CXT 2 
 
 = working pressure 
 P 2 
 
 LEGEND: 
 
 T = thickness of plate = ^ = 7 
 P=pitch = 10" 
 C= constant = 120 
 
 EXAMPLE: 
 
 120= constant 
 49=plate squared in 16ths 
 
 1080 
 480 
 
 pitch squared = 100)5880 (58. 8 Ibs. pressure allowed or 59 Ibs. nearly 
 500 
 
 880 
 800 
 
 80 
 
 Rules adopted by authorities that have proven satisfactory from 
 tests and usage and adopted by the U. S. Government and reputable 
 boiler manufacturers are given in this chapter, and in connection 
 material and workmanship is considered to be the best, fitted accur- 
 ately and properly secured. 
 
 Exhaustive tests have been made by the highest authorities, 
 governments, scientific and mechanical and results have shown that 
 there are some differences; sufficient reasons in the fact show that 
 the majority are near enough to establish formulas that have liberal 
 margins of safety. 
 
 Judgment must be governed by conditions and construction 
 when out of the ordinary and special consideration given, always 
 
BRACES AND REINFORCING. 75 
 
 allowing" a reasonable factor of safety for an unusual form or 
 position. 
 
 For all stays the least sectional area shall be taken in calculating 
 the stress allowable. 
 
 All screw stay bolts shall be drilled at the ends with a one- 
 eighth inch hole to at least a depth of one-half inch beyond the 
 inside surface of the sheet. Stays through laps or butt straps may 
 be drilled with larger hole to a depth so that the inner end of said 
 larger hole shall not be nearer than the thickness of the boiler plates 
 from the inner surface of the boiler. 
 
 Such screw stay bolts, with or without sockets, may be used in 
 the construction of marine boilers where fresh water is used for 
 generating steam: Provided, hoiucver, that screw stay bolts of a 
 greater length than 24 inches will not be allowed in any instance, 
 unless the ends of said bolts are fitted with nuts. Water used from 
 a surface condenser shall be deemed fresh water. 
 
 Holes for screwed stays must be tapped fair and true and full 
 thread. 
 
 The ends of stays which are upset to include the depth of thread 
 shall be thoroughly annealed after being upset. 
 
 The sectional area of pins to resist double shear and bending, 
 accurately fitted and secured in crow feet, sling, and similar stays, 
 shall be at least equal to required sectional area of the brace. 
 Breadth across each side and depth to crown of eye shall be not 
 less than .35 to .55 of diameter of pin. In order to compensate for 
 inaccurate distribution the forks should be proportioned to support 
 two-thirds of the load, thickness of forks to be not less than .66 to .75 
 of the diameter of pins. 
 
 The combined sectional area of rivets used in securing tee irons 
 and crow feet to shell, said rivets being in tension, shall be not less 
 than the required sectional area of brace. To insure a well-pro- 
 portioned rivet point, the total length of shank shall closely approx- 
 imate the grip plus 1.5 times the diameter of the shank. All rivet 
 holes shall be drilled. Distance from center of rivet hole to edge 
 of tee irons, crow feet, and similar fastenings shall be so propor- 
 tioned that the net sectional areas through sides at rivet holes shall 
 equal the required rivet section. Rivet holes shall be slightly coun- 
 tersunk in order to form a fillet at point and head. 
 
76 THE BOILER. 
 
 CONSTANTS PROVIDED FOR THE VARYING REQUIREMENTS. 
 
 C=9,000 for tested steel stays exceeding 2^ inches in diameter. 
 
 C = 8,000 for tested steel stays 1^ inches and not exceeding 2^ inches in 
 diameter, when such stays are not forged or welded. The ends, how- 
 ever, may be upset to a sufficient diameter to allow for the depth of 
 the thread. The diameter shall be taken at the bottom of the thread, 
 provided it is the least diameter of the stay. All such stays after 
 being upset shall be thoroughly annealed. 
 
 C=8,000 for a tested Huston or similar type of brace, the cross-sectional 
 area of which exceeds 5 square inches. 
 
 C=7,000 for such tested braces when the cross-sectional area is not less 
 than 1.227 and not more than 5 square inches, provided such braces 
 are prepared at one heat from a solid piece of plate without welds. 
 
 C =6,000 for all stays not otherwise provided for. 
 
 Rule to find sectional area of a brace to support a given area 
 when pressure is known : Multiply area to be supported by pressure 
 per square inch and divide by constant as provided for size and ma- 
 terial of brace. 
 
 FORMULA: 
 
 AxP 
 
 = sectional area of brace 
 LEGEND: C 
 
 A =area to be supported =36 square inches 
 
 P = pressure = 150 Ibs. 
 
 C = co nstant= brace steel having 1^ diameter = 8000 
 
 EXAMPLE: 
 
 36" = sectional area to be supported 
 150 = Ibs. pressure 
 
 1800 
 36 
 
 constant for 1M steel brace = 8000) 54000000 (.6750 =43/64 or ^ cross-sec- 
 
 48000 tional area nearly 
 
 60000 
 56000 
 
 40000 
 40000 
 

 BRACES AND REINFORCING. 77 
 
 Rule to find strain on a stay bolt : Multiply the area supported by 
 the stay, by the pressure. 
 
 FORMULA: 
 
 A X P = strain on stay 
 LEGEND: 
 
 A =area =6" X6" = 36 square inches 
 
 P ^pressure = 150 Ibs. EXAMPLE: 
 
 36 square inches =area 
 150=lbs. pressure 
 
 1800 
 36 
 
 5400 =lbs. strain on bolt 
 
 Rule to find greatest area one stay bolt may support : Multiply 
 area of stay bolt by constant and divide by working pressure. 
 
 FORMULA: 
 AXC 
 
 = limit of area to be supported by one bolt 
 P 
 LEGEND: 
 
 C =constant =6000 Ibs. allowed per cross-sectional area 
 A =area of stay bolt = j| = . 69029 
 P = pressure = 150 Ibs. 
 
 EXAMPLE: 
 
 . 69029 =area of ft bolt 
 6000= constant 
 
 pressure = 150) 41417. 000(27. 6" =limit of area to be sup 
 300 ported by one bolt 
 
 1141 
 1050 
 
 917 
 900 
 
 17 
 
 Rule to find number of stay bolts to support a given area when 
 pressure is given : 
 
 Multiply area to be supported by pressure and divide sum by 
 constants as provided for. Constants for the different size bolts to 
 be used are as follows: 
 
 for %" diameter use constant 4000, 
 " W 6000, 
 
 if for over that diameter and up to 2^" 8000, 
 
 being pounds pressure per square inch of cross-sectional area. 
 
THE BOILER. 
 
 FORMULA : 
 
 AXP 
 
 = number of stay bolts 
 
 The following example is where bolts are %" in diameter 
 
 LEGEND: 
 
 A =area to be supported =800 square inches 
 P = pressure = 100 Ibs. 
 C = constant =4000 
 
 EXAMPLE : 
 
 800 =area to be supported 
 100=lbs. pressure 
 
 constant =4000) 80000 (20 stay bolts required 
 8000 
 
 
 
 The following example is where bolts are 1^6" diameter 
 
 LEGEND: 
 
 A =area to be supported = 500 
 P =pressure = 120 Ibs. 
 C = constant =6000 
 
 EXAMPLE: 
 
 500 =area to be supported 
 120=lbs. pressure 
 
 10000 
 500 
 
 constant =6000)60000(10 stay bolts required 
 6000 
 
 Rule to find centers for stay bolts when pressure, area to be 
 supported and constant provided for stay bolt are known : Multiply 
 area. of stay bolt by constant and divide by pressure. 
 
 FORMULA: 
 
 AXC 
 
 = centers of stay bolts 
 P 
 LEGEND: 
 
 A =area to be supported = . 3750 
 C = constant = 4000 
 P = pressure = 150 Ibs. 
 
BRACES AND REINFORCING. 79 
 
 EXAMPLE : 
 
 .3750 =area of stay bolt 
 4000 = constant 
 
 pressure = 1 50)1 500. 0000 ( 10"= centers of stay bolts 
 150 
 
 Rule to find area of stay bolt. Multiply centers of stay bolt by 
 pressure and divide by constant 4,000; the quotient is area of stay 
 bolt required. 
 
 FORMULA: 
 
 CBXP 
 
 =area of stay bolt 
 
 LEGEND: 
 
 P =pressure = 150 Ibs. 
 C = constant = 4000 . 
 CB = center of stay bolt =10" 
 
 EXAMPLE: 
 
 10" = center of stay bolt 
 150 = pressure 
 
 500 
 10 
 
 constant =4000) 1500. 0000 (. 3750 =area of stay bolt 
 1200 
 
 300 00 
 280 00 
 
 20 000 
 20 000 
 
 English Board of Trade rule to find safe working pressure when 
 steel stay bolts are used and are screwed into plates and fitted with 
 nuts : 
 
 Multiply constant 80 (plus 25% for steel) by thickness of plate 
 in sixteenths plus one sixteenth squared; divide by pitch of rivet 
 squared minus 6; product is safe working pressure. 
 
 FORMULA: 
 - =safe working pressure 
 
 P 2 6 
 
80 THE BOILER. 
 
 LEGEND: 
 
 T = thickness of plate = 
 
 P = pitch = 7 
 
 C = constant =80 
 
 % =25% added for steel 
 
 EXAMPLE: 
 
 80 = constant 
 
 20 =25% added for steel 
 
 pitch = 7 100 
 
 7 64 = ^ + ^ or T 8 6 , squared 
 
 pitch squared = 49 400 
 minus 6 600 
 
 43 ) 6400 (148 =lbs. pressure for steel bolts 
 43 
 
 210 7= ;&= thickness of plate 
 
 172 1 = A added 
 
 380 8=A 
 
 344 8 
 
 36 64 = T 8 e squared 
 
 Rule to find pitch of stay bolts : 
 
 Multiply constant 112 by the square of the thickness of plate in 
 sixteenths of an inch; divide this product by steam pressure and 
 extract the square root of quotient. 
 
 FORMULA : 
 
 CXT 2 
 \/ = pitch of stay 
 
 LEGEND: 
 
 C= constant = 112 
 
 T = thickness of plate = & 
 
 P= pressure = 150 
 
 EXAMPLE: 
 
 112 = constant 
 49= the square of 
 
 1008 
 448 
 
 150)5488(36 
 
 450 square root of 36 is 6" pitch 
 
 988 
 
 900 6)36(6" = square root = pitch of bolts 
 
 36 
 88 
 
BRACES AND REINFORCING. 81 
 
 TABLE OF STAY BOLTS, PLATE, PITCH AND PRESSURE. 
 
 Pressure 
 in 
 pounds. 
 
 Centers of Stay Bolts. 
 
 %" Plate 
 
 tV' Plate. 
 
 Y*' Plate. 
 
 20 
 40 
 60 
 80 
 100 
 120 
 140 
 150 
 160 
 
 llM"pi 
 8 
 6^ 
 5^ 
 5 
 4^ 
 4M 
 4^ 
 4 
 
 tch 
 
 13" pi 
 9M 
 
 7^ 
 
 $ 
 
 $ 
 
 4<4 
 4^ 
 
 tch 
 
 15" pi 
 
 W sH 
 
 $ 
 
 f>Ys 
 $ 5 A 
 5^ 
 5^ 
 
 tch 
 
 Diam. of 
 stay bolt 
 
 H" 
 
 1" 
 
 IK" 
 
 CROW FOOT OR FORMED BRACES. 
 
 As stated in preceding pages the many and varied surfaces to 
 be braced requiring specific methods and application of bracing, the 
 H. T. boiler, having the minimum amount of flat surface and condi- 
 tions favorable to apply the selection for suitable type of brace, is 
 confined to the one with minimum structural weakness, taking the 
 Huston, McGregor, or of equal stability. 
 
 In calculating the necessary reinforcement by bracing the area 
 of surface to be stayed, and working pressure is considered ; while 
 the thickness of head is a factor in its strength, the necessity for 
 braces in lieu of increasing the thickness of head to self supporting, 
 is without comment. 
 
 In all types of stays the least sectional area must be taken in 
 calculating the stress allowable and the combined sectional area of 
 rivets used in securing crow feet, angle irons and such form of 
 braces, necessitating rivets, must not be less than the required sec- 
 tional area of brace; all rivet holes to be drilled, and the distance 
 from center of hole to edge of palm or brace surface shall be so 
 proportionate that the net sectional areas through sides at rivet holes 
 shall equal the rivet section; rivet holes in plate to be slightly 
 countersunk. 
 
 Taking a flat surface in head above water line, say 800 square 
 inches, to proportionate a proper thickness of head for that unstated 
 
82 THE BOILER. 
 
 portion it would be necessary to have the thickness of head by rule 
 as follows : 
 
 Multiply area by pressure and again by constant ; divide product 
 by tensile strength multiplied by 10; the quotient will be the thick- 
 ness for unstayed portion. 
 
 LEGEND: FORMULA: 
 
 A = area 800 square inches AxPxC 
 
 P = pressure = 100 = thickness for un- 
 
 C = constant =7000 Ibs. per square inch TS X 10 stayed portion 
 
 TS = tensile strength =60000 
 
 EXAMPLE: 
 
 800= area 
 
 100 = pressure 
 
 tensile strength =60000 80000 
 multiplied by 10 7000 = constant 
 
 600000)560000000(933 =ftf inch nearly in thickness 
 5400000 
 
 2000000 
 1800000 
 
 2000000 
 1800000 
 
 200000 
 
 This would not be desirable for reasons of cost, labor attached 
 to working it and conductivity of heat, therefore heads must be of 
 less thickness and bracing resorted to. 
 
 To find the area of an unstayed segment is the first thing neces- 
 sary and that is a simple rule as used in boiler construction, as 
 calculations for such measures are always favored. 
 
 Rule to find minimum area of stay or brace to support a given 
 area: Divide load on stay by allowable strain per square inch of 
 sectional area as provided ; the quotient is minimum area of stay. 
 
 FORMULA: 
 
 L 
 
 =area of brace 
 S 
 LEGEND: 
 
 L = load on stay =6750 Ibs. 
 
 S =strain per square inch of sectional area =6000 Ibs. 
 
BRACES AND REINFORCING. 83 
 
 EXAMPLE: 
 
 strain allowed per sq. in. =6000)6750 . 000(1 . 125 or \y%' diameter 
 
 6000 
 
 750 
 600 
 
 150 00 
 
 120 00 
 
 300 00 
 300 00 
 
 Rule to find area of stay beyond maximum of curved surface 
 unsupported when thickness of plate and pressure are known : Mul- 
 tiply constant 112 by thickness of plate in sixteenths of an inch and 
 divide product by the pressure in pounds per square inch; the 
 quotient is area of stay required. 
 
 LEGEND: FORMULA: 
 
 C = constant = 112 CxT 
 
 T = thickness of plate = Tg =area of stay 
 
 P = pressure = 150 Ibs. P 
 
 EXAMPLE: 
 
 112 = constant 
 . 7 = thickness in 16ths 
 
 pressure = 150) 78. 4000 (. 5226 =area or | approximately 
 75 
 
 3 40 
 3 00 
 
 400 
 300 
 
 1000 
 900 
 
 100 
 
 To determine the areas of diagonal stays : Multiply the area of 
 a direct stay required to support the surface by the slant or diagonal 
 length of the stay ; divide this product by the length of a line drawn 
 at right angles to surface supported to center of palm of diagonal 
 stay. The quotient will be the required area of the diagonal stay. 
 
 FORMULA: 
 AXL 
 
 = sectional area of diagonal stay 
 
84 THE BOILER. 
 
 LEGEND: 
 
 A = sectional area of direct stay = . 7854 
 L =length of diagonal stay =60" 
 
 1= length of line drawn at right angles to boiler head or surface 
 supported to center of palm of diagonal stay = 48" 
 
 EXAMPLE: 
 
 .7854 =area of 1" direct stay 
 
 60 = length of stay 
 length of line drawn at right 
 
 angles to boiler = 48") 47. 1240 (. 9817 =sectional area of a diag- 
 43 2 onal brace = 1^" nearly 
 
 3 92 
 3 84 
 
 84 
 48 
 
 360 
 336 
 
 24 
 
 When diagonal braces are applied the angle should not exceed 
 over 30 degrees. 
 
 Rule to find the load on a stay : Multiply area to be supported 
 by pressure and divide by sectional area of stay bolt. 
 LEGEND: FORMULA: 
 
 A = area to be supported =50" AxP 
 
 P =pressure = 160 Ibs. =strain on sectional area 
 
 SB =area of stay bolt = . 69029 SB of stay 
 
 EXAMPLE: 
 
 50" =area to be supported 
 
 160= pressure 
 
 3000 
 50 
 
 area of stay bolt = .69029)8000.00000(11589 Ibs. =strain on sec- 
 6902 9 tional area of stay 
 
 1097 10 
 690 29 
 
 406 810 
 345 145 
 
 61 6650 
 55 2232 
 
 6 44180 
 6 21261 
 
 22919 
 
BRACES AND REINFORCING. 85 
 
 HEADS. 
 
 All heads employed in the construction of cylindrical externally 
 fired boilers, for steamers navigating- the Red River of the North and 
 rivers that flow into the Gulf of Mexico, shall have a thickness of 
 material as follows : 
 
 For boilers having a diameter - 
 
 Over 32 inches and not over 36 inches, not less than 1^ inch. 
 Over 36 inches and not over 40 inches, not less than ^ inch. 
 Over 40 inches and not over 48 inches, not less than ^ inch. 
 Over 48 inches, not less than % inch. 
 
 Where flat heads do not exceed 20 inches in diameter they may 
 be used without being stayed, and the steam pressure allowable shall 
 be determined by the following formula : 
 
 CxT 2 
 P= 
 
 Where P = steam pressure allowable in pounds. 
 
 T = thickness of material in sixteenths of an inch. 
 A = one-half the area of head in inches. 
 C = 112 for plates -fa of an inch and under. 
 C = 120 for plates over fa of an inch. 
 
 Provided, The flanges are made to an inside radius of at least 
 \ l /2 inches. 
 
 EXAMPLE. 
 
 Required the working pressure of a flat head 20 inches in diame- 
 ter and y^ of an inch thick. Substituting values, we have 
 
 120X144 
 
 P = =110 pounds 
 
 157 
 
 The heads of steam and mud drums of such boilers shall have 
 a thickness of material of not less than half an inch ; pressure to be 
 determined by formula for flatheads. 
 
86 THE BOILER. 
 
 CONVEXED HEAD. 
 
 Rule to find pressure allowed on a convexed head : Multiply the 
 thickness of the plate by one-sixth of the tensile strength and divide 
 by one-half of radius to which head is bumped ; result gives pressure 
 allowed per square inch. 
 
 Add 20 per cent to pressure when the head is double riveted to the shell 
 and the holes are fairly drilled. 
 
 LEGEND: FORMULA: 
 
 TS = tensile strength =60000 T X ( 1/6 of TS ) 
 
 T = thickness of plate = ^ = . 625 =lbs. pressure al- 
 
 R=radius of bump =60" }/% of R lowed 
 
 EXAMPLE : 
 
 . 625 = thickness of plate 
 10000 = 1/6 of TS 
 
 half of radius =30)6250.p00 (208 Ibs. = pressure allowed on single 
 60 riveted circumferential seam 
 
 250 
 240 
 
 10 
 
 208 Ibs. = pressure allowed on single riveted 
 41.6= 20% added for double riveted 
 
 249 . 6 Ibs. pressure allowed double riveted 
 
 Rule to find bursting pressure on flat head : Multiply thickness 
 of plate by ten times the tensile strength and divide by area of head 
 in inches ; the sum is bursting pressure. 
 
 LEGEND: FORMULA: 
 
 T = thickness of plate = & = .5625 Tx(lOXTS) 
 
 TS =tensile strength =60000 =bursting pressure 
 
 A = area of head =934. 822 inches AxC 
 
 D = diameter of head =34^" 
 
 EXAMPLE: 
 
 . 5625 = thickness of plate 
 
 600000 =ten times tensile strength 
 
 area of head =934822)337500. 0000 (361 Ibs. bursting pressure 
 280446 6 
 
 57053 40 
 56089 32 
 
 964 080 
 934 822 
 
 29 258 
 Divide bursting pressure by 5 and this will give working pressure 
 
BRACES AND REINFORCING. 
 
 87 
 
 CONCAVED HEAD. 
 
 Rule to find pressure allowed on a concave head : Multiply the 
 pressure per square inch allowed on a bumped head attached con- 
 vexly by the constant 6, and the product will give the pressure per 
 square inch allowed on concaved head. 
 
 LEGEND: 
 
 FORMULA: 
 
 P XC = pressure on concaved head 
 
 P= pressure allowed on a bumped head =208 Ibs. 
 C = constant =.6 
 
 EXAMPLE: 
 
 208 = pressure allowed on a bumped head 
 .6 = constant 
 
 124.8 =lbs. pressure on a concaved head 
 
 NOTE ON DISHED HEADS. 
 
 Dished or bumped heads have strength due to form and thickness 
 depending on diameter. 
 
 Bumped heads may contain a manhole opening flanged inwardly, 
 when such flange is turned to a depth of three times the thickness 
 of the material in the head. 
 
 DEPTHS OF DISH AND FLANGE HEADS. 
 
 
 Diam. after 
 
 
 
 Diam. Heads. 
 
 Dishing and 
 Flanging. 
 
 Depth 
 of Dish. 
 
 Depth 
 of Flange. 
 
 34 
 
 30 
 
 3 
 
 2 
 
 40 
 
 36 
 
 3 
 
 2 
 
 46 
 
 42 
 
 4 
 
 2 
 
 52^ 
 
 48 
 
 5 
 
 2 
 
 58^ 
 
 54 
 
 6 
 
 2 
 
 65 
 
 60 
 
 6 
 
 2 
 
 71 
 
 66 
 
 7 
 
 2 
 
 77 
 
 71^ 
 
 7 
 
 2 
 
 78 
 
 72 
 
 8 
 
 2 
 
 87 
 
 80 
 
 8 
 
 2-L/ 
 
 91 
 
 84 
 
 9 
 
 2^ 
 
 97 
 
 90 
 
 10 
 
 2 J^> 
 
 102 
 
 96 
 
 12 
 
 2J*| 
 
88 
 
 THE BOILER. 
 
 CAST IRON HEADS. 
 
 Rule to find thickness of an unstayed boiler head so it will equal 
 in strength the shell : Multiply square root of radius by the thick- 
 ness of the shell plate in inches ; the product is the required thickness 
 of head. 
 
 LEGEND: FORMULA: 
 
 T=thickness of plate %," = .375 (\/IR) XT=thicknessof head 
 
 IR =inside radius = 19 . 9809 
 
 EXAMPLE: 
 
 4.47 =square root of radius 
 .375 = thickness of shell 
 
 2235 
 3129 
 1341 
 
 1.67625 = thickness of head required =1^" approx. 
 
 A rule" to find area of a segment of a circle as outlined by A, B 
 and C. 
 
 Divide the diameter of circle by height of the segment, subtract 
 608 from quotient and extract the square root of the remainder; 
 this result multiplied by four times the square of the height of the 
 segment and divided by three, will give the area. 
 
 FORMULA: 
 
 f V D ~r f 4XHM 
 
 { . 608 > X { r = area of segment 
 
 1 H J I 3 J 
 
BRACES AND REINFORCING. 89 
 
 LEGEND: 
 
 H = height of segment 22" 
 D =diam. of boiler 72" 
 C= constant = .608 
 
 EXAMPLE: 
 (diameter) 
 height 22") 72. 0000 (3. 2727 
 
 66 
 
 60 
 
 44 
 
 3.2727 
 
 160 . 608 constant 
 
 1)2.66470000(1.6323 sq. root 
 154 1 
 
 60 26 1 66 1.6323 
 
 44 1 56 645 
 
 160 323 1047 8 1615 
 154 969 65 292 
 
 979 38 
 
 6 3262 7800 
 
 22" height of segment 6524 1052 . 8335 
 
 22 or 1053"=area of 
 
 32643 127600 segment. 
 
 44 97929 
 
 44 
 
 29671 
 
 484 height squared 
 4 four times 
 
 3) 1936 =4 times square of height 
 645.33 
 
 Rule to find number of braces to support a segment as just 
 described: Multiply area of segment by pressure in pounds per 
 square inch and divide by number of pounds pressure form or type 
 of brace sectional area is allowed. To illustrate : A modern formed 
 brace by 8,000 when sectional area exceeds 5 square inches ; 7,000 
 when sectional area is less than 5 square inches, and 6,000 for all 
 stays not otherwise provided for. 
 
 FORMULA: 
 
 A X Pressure 
 
 = number of braces required 
 Brace supporting value 
 
90 THE BOILER. 
 
 EXAMPLE: 
 
 1053 =area of segment required 
 160 =lbs. pressure 
 
 63180 
 1053 
 
 modern brace =8000)168480(21 + or 22 braces 
 16000 
 
 8480 
 8000 
 
 480 
 
 The table given below is an extract from Trautwine's Engineers' 
 Pocket Book, and will be found of great value in arriving at an 
 accurate solution. 
 
 The first column marked height, is the height of the segment in 
 parts of the diameter of the boiler. The first number .001 refers to 
 a segment whose height is 1/1000 of the diameter of the boiler, the 
 second number refers to 2/1000 of the diameter of the boiler, and 
 the third 3/1000 of the diameter of the boiler and so on until it 
 reaches a complete semi-circle or half-diameter of the boiler. 
 
 CUBICAL CONTENTS. 
 
 Suppose now we desire to find the cubical contents by the table 
 of the steam space in a boiler 48 inches in diameter by 14 feet long. 
 The water line say is 4" above the top row of tubes and the height 
 of the segment is 12 inches. 
 
 The area of circles or similar parts of circles of different sizes 
 are directly proportional to the square of their diameter. Hence, it 
 will only be necessary to find what part of the diameter, 12 inches 
 (the height of the steam space), is. This is done by dividing 12 
 by 48 = .250. Find this quotient in the column of heights in the 
 table, take the corresponding area and multiply it by the square of 
 the diameter. Then 4X4 equals 16 and 12-^-48 equals .250. By 
 the table we find that the area of a segment whose height is .250 
 is seen to be .153546. This multiplied by 16 gives 2.4567 square 
 feet of the cross sectional area of the steam space. This area multi- 
 plied by 14, which is the length of the boiler in feet, or 2.4567 X 14 
 equals 34.39, which is the volume of steam space in cubic feet. 
 
 The same result in cubic feet can be obtained by the first method, 
 which I do not think can be simplified any further. 
 
BRACES AND REINFORCING. 
 
 91 
 
 AREAS OF CIRCULAR ARCS. 
 By This Table May be Obtained the Area of Segments of Circles. 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 .001 
 .002 
 .003 
 
 .000 042 
 .000 119 
 .000 219 
 
 .040 
 .041 
 .042 
 
 .010 538 
 .010 932 
 .011 331 
 
 079 
 .080 
 .081 
 
 .028 894 
 .029 435 
 .029 979 
 
 .118 
 .119 
 .120 
 
 .052 090 
 .052 737 
 .053 385 
 
 .004 
 .005 
 .006 
 
 .000 337 
 .000 471 
 .000 619 
 
 .043 
 
 .044 
 .045 
 
 .011 734 
 .012 142 
 .012 555 
 
 .082 
 .083 
 .084 
 
 .030 526 
 .031 077 
 .031 630 
 
 .121 
 .122 
 .123 
 
 .054 037 
 .054 690 
 .055 346 
 
 .007 
 .008 
 .009 
 
 .000 779 
 .000 952 
 .001 135 
 
 .046 
 .047 
 .048 
 
 .012 971 
 .013 393 
 .013 818 
 
 .085 
 .086 
 .087 
 
 .032 186 
 .032 746 
 .033 308 
 
 .124 
 .125 
 .126 
 
 .056 004 
 .056 664 
 .057 327 
 
 .010 
 .011 
 
 .012 
 
 .001 329 
 .001 533 
 .001 746 
 
 .049 
 .050 
 .051 
 
 .014 248 
 .014 681 
 .015 119 
 
 .088 
 .089 
 .090 
 
 .033 873 
 .034 441 
 .035 012 
 
 .127 
 .128 
 .129 
 
 .057 991 
 .058 658 
 .059 328 
 
 .013 
 .014 
 .015 
 
 .001 969 
 .002 199 
 .002 438 
 
 .052 
 .053 
 .054 
 
 .015 561 
 .016 008 
 .016 458 
 
 .091 
 .092 
 .093 
 
 .035 586 
 .036 162 
 .036 742 
 
 .130 
 .131 
 .132 
 
 .059 999 
 .060 673 
 .061 349 
 
 .016 
 .017 
 .018 
 
 .002 685 
 . 002 940 
 . 003 202 
 
 .055 
 .056 
 .057 
 
 .016 912 
 .017 369 
 .017 831 
 
 .094 
 .095 
 .096 
 
 .037 324 
 .037 909 
 .038 497 
 
 .133 
 .134 
 .135 
 
 .062 027 
 .062 707 
 .063 389 
 
 .019 
 .020 
 021 
 
 .003 472) 
 .003 749 
 004 032 
 
 .058 
 .059 
 .060 
 
 .018 297 
 .018 766 
 .019 239 
 
 .097 
 .098 
 .099 
 
 .039 087 
 .039 681 
 .040 277 
 
 .136 
 .137 
 .138 
 
 .064 074 
 .064 761 
 .065 449 
 
 .022 
 .023 
 .024 
 
 .004 322 
 .004 619 
 .004 922 
 
 .061 
 .062 
 .063 
 
 .019 716 
 .020 197 
 .020 681 
 
 .100 
 .101 
 .102 
 
 .040 875 
 .041 477 
 .042 081 
 
 .139 
 .140 
 .141 
 
 .066 140 
 .066 833 
 .067 528 
 
 .025 
 .026 
 .027 
 
 .005 231 
 .005 546 
 .005 867 
 
 .064 
 .065 
 .066 
 
 .021 168 
 .021 660 
 .022 155 
 
 .103 
 .104 
 .105 
 
 .042 687 
 .043 296 
 . 043 908 
 
 .142 
 .143 
 .144 
 
 .068 225 
 .068 924 
 .069 626 
 
 .028 
 .029 
 .030 
 
 .006 194 
 .006 527 
 .006 866 
 
 .067 
 .068 
 .069 
 
 .022 653 
 .023 155 
 . 023 660 
 
 .106 
 .107 
 .108 
 
 .044 523 
 .045 140 
 .045 759 
 
 .145 
 .146 
 .147 
 
 .070 329 
 .071 034 
 .071 741 
 
 .031 
 .032 
 .033 
 
 .007 209 
 .007 559 
 .007 913 
 
 .070 
 .071 
 .072 
 
 .024 168 
 .024 680 
 .025 196 
 
 .109 
 .110 
 .111 
 
 .046 381 
 .047 006 
 .047 633 
 
 .148 
 .149 
 .150 
 
 .072 450 
 .073 162 
 .073 875 
 
 .034 
 .035 
 .036 
 
 .008 273 
 .008 638 
 .009 008 
 
 .073 
 
 .074 
 .075 
 
 .025 714 
 .026 236 
 .026 761 
 
 .112 
 .113 
 .114 
 
 .048 262 
 .048 894 
 .049 529 
 
 .151 
 .152 
 .153 
 
 .074 590 
 .075 307 
 .076 026 
 
 .037 
 .038 
 .039 
 
 .009 383 
 .009 764 
 .010 148 
 
 . .076 
 .077 
 .078 
 
 .027 290 
 .027 821| 
 .028 356| 
 
 .115 
 .116 
 .117 
 
 .050 165 
 .050 805 
 .051 446 
 
 .154 
 .155 
 .156 
 
 .076 747 
 .0^7 470 
 .078 194 
 
92 
 
 THE BOILER. 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 .157 
 .158 
 .159 
 
 .078 921 
 .079 650 
 .080 380 
 
 .199 
 .200 
 .201 
 
 .111 025 
 .111 824 
 .112 625 
 
 .241 
 .242 
 .243 
 
 . 145 800 
 .146 656 
 .147 513 
 
 .281 
 .282 
 .283 
 
 .180 918 
 .181 818 
 .182 718 
 
 .160 
 .161 
 .162 
 
 .081 112 
 .081 847 
 .082 582 
 
 .202 
 .203 
 .204 
 
 .113 427 
 .114 231 
 .115 036 
 
 .244 
 .245 
 .246 
 
 .148 371 
 .149 231 
 .150 091 
 
 .284 
 .285 
 .286 
 
 .183 619 
 .184 522 
 .185 425 
 
 .163 
 .164 
 .165 
 
 .083 320 
 .084 090 
 .084 801 
 
 .205 
 .206 
 .207 
 
 .115 842 
 .116 651 
 .117 460 
 
 .247 
 .248 
 .249 
 
 .150 953 
 .151 816 
 .152 681 
 
 .287 
 .288 
 .289 
 
 .186 329 
 .187 235 
 .188 141 
 
 .166 
 .167 
 .168 
 
 .085 545 
 .086 200 
 .087 037 
 
 .208 
 .209 
 .210 
 
 .118 271 
 .119 084 
 .119 898 
 
 .250 
 
 .153 546 
 
 .290 
 .291 
 .292 
 
 .189 048 
 .189 956 
 .190 865 
 
 .169 
 .170 
 .171 
 
 .087 785 
 .088 536 
 .089 288 
 
 .211 
 .212 
 .213 
 
 .120 713 
 .121 530 
 .122 348 
 
 .251 
 .252 
 .253 
 
 .154 413 
 .155 281 
 .156 149 
 
 .293 
 .294 
 .295 
 
 .191 774 
 .192 685 
 .193 597 
 
 .172 
 .173 
 .174 
 
 . 090 042 
 .090 797 
 .091 555 
 
 .214 
 .215 
 .216 
 
 .123 167 
 .123 988 
 .124 811 
 
 .254 
 .255 
 .256 
 
 .157 019 
 .157 891 
 .158 763 
 
 .296 
 .297 
 .298 
 
 .194 509 
 . 195 423 
 .196 337 
 
 .175 
 .176 
 .177 
 
 .092 314 
 .093 074 
 .093 837 
 
 .217 
 .218 
 .219 
 
 .125 634 
 .126 459 
 .127 286 
 
 .257 
 .258 
 .259 
 
 .159 636 
 .160 511 
 .161 386 
 
 .299 
 .300 
 .301 
 
 .197 252 
 .198 168 
 .199 085 
 
 .178 
 .179 
 .180 
 
 .094 601 
 .095 367 
 .096 135 
 
 .220 
 .221 
 .222 
 
 .128 114 
 . 128 943 
 .129 773 
 
 .260 
 .261 
 .262 
 
 .162 263 
 .163 141 
 .164 020 
 
 .302 
 .303 
 .304 
 
 .200 003 
 .200 922 
 .201 841 
 
 .181 
 .182 
 .183 
 
 .096 904 
 .097 675 
 .098 447 
 
 .223 
 .224 
 .225 
 
 . 130 605 
 .131 438 
 .132 273 
 
 .263 
 .264 
 .265 
 
 . 164 900 
 .165 781 
 .166 663 
 
 .305 
 .306 
 .307 
 
 .202 762 
 .203 683 
 . 204 605 
 
 .184 
 .185 
 .186 
 
 .099 221 
 .099 997 
 . 100 774 
 
 .226 
 .227 
 .228 
 
 . 133 109 
 .133 946 
 . 134 784 
 
 .266 
 .267 
 .268 
 
 .167 546 
 .168 431 
 .169 316 
 
 .308 
 .309 
 .310 
 
 .205 528 
 .206 452 
 .207 376 
 
 .187 
 .188 
 .189 
 
 .101 553 
 .102 334 
 .103 116 
 
 .229 
 .230 
 .231 
 
 .135 624 
 .136 465 
 .137 307 
 
 .269 
 .270 
 .271 
 
 .170 202 
 .171 090 
 .171 978 
 
 .311 
 .312 
 .313 
 
 .208 302 
 .209 228 
 .210 155 
 
 .190 
 .191 
 .192 
 
 . 103 900 
 .104 686 
 .105 472 
 
 .232 
 .233 
 .234 
 
 .138 151 
 .138 996 
 . 139 842 
 
 .272 
 .273 
 .274 
 
 .172 868 
 .173 758 
 .174 650 
 
 .314 
 .315 
 .316 
 
 .211 083 
 212 Oil 
 212 941 
 
 .193 
 .194 
 .195 
 
 .106 261 
 .107 051 
 . 107 843 
 
 .235 
 .236 
 .237 
 
 .140 689 
 .141 538 
 .142 388 
 
 .275 
 .276 
 .277 
 
 .175 542 
 .176 436 
 177 330 
 
 .317 
 .318 
 .319 
 
 213 871 
 214 802 
 215 734 
 
 .196 
 .197 
 .198 
 
 .108 636 
 .109 431 
 .110 227 
 
 .238 
 .239 
 .240 
 
 . 143 239 
 .144 091 
 . 144 945 
 
 .278 
 .279 
 .280 
 
 .178 226 
 .179 122 
 .180 020 
 
 .320 
 .321 
 .322 
 
 216 666 
 217 600 
 218 534 
 
BRACES AND REINFORCING. 
 
 93 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 Height 
 
 Area 
 
 .323 
 .324 
 .325 
 
 .219 469 
 .220 404 
 .221 341 
 
 .368 
 .369 
 .370 
 
 .262 249 
 .263 214 
 .264 179 
 
 .413 
 .414 
 .415 
 
 .306 140 
 .307 125 
 .308 110 
 
 .458 
 .459 
 .460 
 
 .350 749 
 .351 745 
 .352 742 
 
 .326 
 .327 
 .328 
 
 .222 278 
 .223 216 
 .224 154 
 
 .371 
 .372 
 373 
 
 .265 145 
 266 111 
 .267 078 
 
 .416 
 .417 
 .418 
 
 .309 096 
 .310 082 
 .311 068 
 
 .461 
 .462 
 .463 
 
 .353 739 
 .354 736 
 .355 733 
 
 .329 
 .330 
 .331 
 
 .225 094 
 .226 034 
 .226 974 
 
 .374 
 .375 
 .376 
 
 .268 046 
 .269 014 
 .269 982 
 
 .419 
 .420 
 .421 
 
 .312 055 
 .313 042 
 .314 029 
 
 .464 
 .465 
 .466 
 
 .356 730 
 .357 728 
 .358 725 
 
 .332 
 .333 
 .334 
 
 .227 916 
 .228 858 
 .229 801 
 
 .377 
 .378 
 .379 
 
 .270 951 
 .271 921 
 .272 891 
 
 .422 
 .423 
 .424 
 
 .315 017 
 .316 005 
 .316 993 
 
 .467 
 .468 
 .469 
 
 .359 723 
 .360 721 
 .361 719 
 
 .335 
 .336 
 .337 
 
 .230 745 
 .231 689 
 .232 634 
 
 .380 
 .381 
 .382 
 
 .273 861 
 .274 832 
 .275 804 
 
 .425 
 .426 
 .427 
 
 .317 981 
 .318 970 
 .319 959 
 
 .470 
 .471 
 .472 
 
 .362 717 
 .363 715 
 .364 714 
 
 .338 
 .339 
 .340 
 
 .233 580 
 .234 526 
 .235 473 
 
 .383 
 .384 
 .385 
 
 .276 776 
 .277 748 
 .278 721 
 
 .428 
 .429 
 .430 
 
 .320 949 
 .321 938 
 .322 928 
 
 .473 
 .474 
 .475 
 
 .365 712 
 .366 711 
 .367 710 
 
 .341 
 .342 
 .343 
 
 .236 421 
 .237 369 
 .238 319 
 
 .386 
 .387 
 .388 
 
 .279 695 
 .280 669 
 .281 643 
 
 .431 
 .432 
 .433 
 
 .323 919 
 .324 909 
 .325 900 
 
 .476 
 .477 
 .478 
 
 .368 708 
 .369 707 
 .370 706 
 
 .344 
 .345 
 .346 
 
 .239 268 
 .240 219 
 .241 170 
 
 .389 
 .390 
 .391 
 
 .282 618 
 .283 593 
 .284 569 
 
 .434 
 .435 
 .436 
 
 .326 891 
 .327 883 
 .328 874 
 
 .479 
 
 .480 
 .481 
 
 .371 705 
 .372 704 
 .373 704 
 
 .347 
 .348 
 .349 
 
 .242 122 
 .243 074 
 .244 027 
 
 .392 
 .393 
 .394 
 
 .285 545 
 .286 521 
 .287 499 
 
 .437 
 .438 
 .439 
 
 .329 866 
 .330 858 
 .331 851 
 
 .482 
 .483 
 .484 
 
 .374 703 
 .375 702 
 .376 702 
 
 .350 
 
 .351 
 .352 
 
 .244 980 
 .245 935 
 .246 890 
 
 .395 
 .396 
 .397 
 
 .288 476 
 .289 454 
 .290 432 
 
 .440 
 .441 
 .442 
 
 .332 843 
 .333 836 
 .334 829 
 
 .485 
 .486 
 .487 
 
 .377 701 
 .378 701 
 .379 701 
 
 .353 
 .354 
 .355 
 
 .247 845 
 .248 801 
 .249 758 
 
 .398 
 .399 
 .400 
 
 .291 411 
 .292 390 
 .293 370 
 
 .443 
 
 .444 
 .445 
 
 .335 823 
 .336 816 
 .337 810 
 
 .488 
 .489 
 .490 
 
 .380 700 
 .381 700 
 .382 700 
 
 .356 
 
 .357 
 .358 
 
 .*250 715 
 .251 673 
 .252 632 
 
 .401 
 .402 
 .403 
 
 .294 350 
 .295 330 
 .296 311 
 
 .446 
 .447 
 .448 
 
 .338 804 
 .339 799 
 . 340 793 
 
 .491 
 .492 
 .493 
 
 .383 700 
 .384 699 
 .385 699 
 
 .359 
 .360 
 .361 
 
 .253 591 
 .254 551 
 .255 511 
 
 .404 
 . 105 
 .406 
 
 .297 292 
 .298 274 
 .299 256 
 
 .449 
 .450 
 .451 
 
 .341 788 
 .342 783 
 .343 778 
 
 .494 
 .495 
 .496 
 
 .386 699 
 .387 699 
 .388 699 
 
 .362 
 .363 
 .364 
 
 .256 472 
 .257 433 
 .258 395 
 
 .407 
 .408 
 .409 
 
 .300 238 
 .301 221 
 .302 204 
 
 .452 
 .453 
 .454 
 
 .344 773 
 .345 768 
 .346 764 
 
 .497 
 .498 
 .499 
 
 .389 699 
 .390 699 
 .391 699 
 
 .365 
 .366 
 .367 
 
 .259 358 
 .260 321 
 .261 285 
 
 .410 
 
 .411 
 .412 
 
 .303 187 
 .304 171 
 .305 156 
 
 .455 
 .456 
 ,457 
 
 .347 760 
 .348 756 
 .349 752 
 
 .500 
 
 .392 699 
 
94 THE BOILER. 
 
 Rule to find pressure allowed on a brace for given size : Multiply 
 area of brace by pressure allowed per square inch cross sectional 
 area. 
 
 LEGEND: FORMULA: 
 
 A = area of brace 3"x^" =1.5" area AxS=pressure allowed 
 
 S =strain allowed = 6000 Ibs. 
 that size brace 
 
 EXAMPLE: 
 3" 
 .5 
 
 1.5= area 
 
 6000 Ibs. allowed per square inch 
 
 9000J3 Ibs. allowed on brace of that size 
 
 THROUGH BRACE RODS. 
 
 Through brace rods are often used when conditions are favor- 
 able, space ample for cleaning and inspection. 
 
 These rods are usually 1^4 to 2^/2 inches diameter and washer 
 or plates riveted to heads to increase holding or breaking surface ; 
 thickness of heads are governed by pressure, also by the size and 
 number of rods. Same rule is used that governs the palm or formed 
 brace. 
 
 Rule to find working pressure allowed on a through brace rod. 
 Multiply area of rod by strain allowed according to corresponding 
 diameter and divide by area supported by rod. 
 
 LEGEND: FORMULA: 
 
 AR= 2" rod =3. 1416= area of rod ARxS 
 
 A = 16x14 surface =224" area =working pressure 
 
 S = strain allowed on that size A 
 
 brace = 8000 
 
 EXAMPLE: 
 3.1416=area of 2" rod 
 
 8000 Ibs. allowed on sectional area 
 
 surface area =224)25132. #000 (112 Ibs. working pressure 
 224 
 
 273 
 224 
 
 492 
 448 
 
 44 
 
BRACES AND REINFORCING. 95 
 
 CURVED SURFACES. 
 
 To find safe working pressure on curved sufrace when stiffened 
 by angle, single or double, or tee bars ; for single, the angle iron 
 should have a thickness of at least eight-tenths that of plate and a 
 depth of at least one-half pitch ; where stiffened with double angle 
 or tee irons, to have at least two-thirds that of thickness of plate 
 and a depth of at least one-fourth of pitch ; angles or tee bars being 
 substantially riveted to the plate supported. 
 
 Where rounded tops of combustion chambers are stiffened with 
 single or double angle-iron stiffeners, or tee bars, such angles or tee 
 bars, shall be of thickness and depth of leaf not less than specified 
 for rounded bottoms of combustion chambers. Said angles or tee 
 bars shall be supported on thimbles and riveted through with rivets 
 not less than one inch in diameter and spaced not to exceed six 
 inches between centers. 
 
 Rule to find working pressure allowed on rounded surfaces sup- 
 ported by angle irons or tee bars: Multiply constant by thickness 
 squared in sixteenths and divide by the pitch multiplied by the 
 diameter of curve. 
 
 FORMULA: 
 
 CxT 2 
 
 = working pressure 
 PXD 
 
 LEGEND: 
 
 T = thickness of plate in sixteenths of an inch = & = 81 
 
 P = pitch of angle or tee stiffeners in inches = 7 inches 
 
 D = diameter of curve to which plate is bent, in inches =51 inches 
 
 C = constant = 900 
 
 EXAMPLE: ^ 
 
 900 = constant 51" =diameter 
 
 81 = thickness squared in 16ths 7" = pitch 
 
 900 357 
 
 7200 
 
 72900 714 
 
 1500 
 1428 
 
 72 
 
 357)72900(204 Ibs. = working pressure 
 
96 THE BOILER. 
 
 TUBE PLATE 
 
 Rule to find the working pressure of a tube sheet supporting a 
 crown sheet braced by crown bars: Subtract inside diameter of 
 tubes in inches from the least horizontal distance between tube cen- 
 ters in inches ; multiply the remainder by thickness of tube plate and 
 then by constant 27,000; divide product by extreme width of com- 
 bustion chamber multiplied by least horizontal distance between 
 tube centers. 
 
 FORMULA: 
 
 (D d)TxC 
 
 = working pressure 
 WXD 
 
 LEGEND: 
 
 D =least horizontal distance between tube centers in inches = 4^ inches 
 d =inside diameter of tubes in inches = 2 . 782 inches 
 T = thickness of tube plate in inches =^ inches = . 6875 
 W ^extreme width of combustion chamber in inches =34*4 inches 
 C =27,000. 
 
 EXAMPLE: 
 
 4. 125 = least horizontal distance 
 2 . 782 = inside diameter 
 
 1.343 
 
 .6875 = thickness of tube plate 
 
 6715 
 9401 
 
 10744 34. 25= extreme width 
 
 8058 4 . 125 = least horizontal distance 
 
 .9233125 17125 
 
 2 7000= constant 6850 
 
 3425 
 
 646 31875000 13700 
 1846 6250 
 
 141. 
 24929. ^3WP0 
 
 141)24929(176 Ibs. = working pressure 
 141 
 
 1082 
 987 
 
 959 
 846 
 
 113 
 
BRACES AND REINFORCING. 97 
 
 Rule to find thickness of plate for a tube sheet : Multiply 
 pressure by width of fire box and by pitch of tubes (distance 
 between centers) and divide this sum by pitch of tubes minus one 
 inside diameter of one tube multiplied by constant. 
 
 FORMULA: 
 PxWxp 
 (p d)xC 
 LEGEND: 
 
 = thickness of plate 
 
 p = pitch of tube =4^ 
 
 d = inside diam. of tube =2. 7 82 
 
 P = pressure = 176 Ibs. 
 
 C = constant =2 7000 
 
 W = width of combustion chamber =34)4 inches 
 
 EXAMPLE: 
 
 176 = pressure Ibs. per square inch 
 34.25 = width of fire box 
 
 880 
 352 
 704 
 528 
 
 pitch of tubes =4. 12 5 
 inside diam. =2.782 6028.00 
 
 4. 12 5= pitch of tubes 
 
 1.343 
 
 constant = 27000 3014000 
 
 1205600 
 
 9401000 602800 
 2686 2411200 
 
 36261000)24865. 5000 (.6857 or ft nearly 
 217566 
 
 310890 
 290088 
 
 208020 
 181305 
 
 267150 
 253827 
 
 13323 
 
98 THE BOILER. 
 
 U. S. RULES. 
 
 The compressive stress on tube plates, as determined by the 
 following formula, must not exceed 13,500 pounds per square inch, 
 when pressure on tops of combustion chamber is supported by 
 vertical plates of such chamber. 
 
 PxDxW 
 
 = compressive stress 
 2X(D d)XT 
 
 P = working pressure in pounds = 176 Ibs. 
 
 D =least horizontal distance between tube centers in inches =4. 1250" 
 d =inside diameter of tube in inches =2 . 782. 
 W = extreme width of combustion chamber in inches =34^ 
 T = thickness of tube sheet in inches =^ = . 6875. 
 
 EXAMPLE: 
 
 176 = pressure 
 4. 1250=distance tubes horizontally 
 
 8800 
 352 
 176 
 704 
 
 726.0000 
 
 34 . 25 = width of combustion chamber 
 
 36300000 4. 1250 =dis. bet. tubes 
 
 14520000 2.782 =inside diam. tube 
 
 29040000 
 21780000 1.3430 
 
 2 = twice 
 1.84662500)24865. 50000000 (13465 =compres- - 
 
 184662500 sive strain 2.6860 
 
 .6875=^ = thickness of 
 
 6399 25000 tube sheet 
 
 5539 87500 134300 
 
 188020 
 
 859 375000 214880 
 
 738 650000 161160 
 
 120 7250000 1.84662500 
 
 110 7975000 
 
 9 92750000 
 9 23312500 
 
 69437500 
 
 Sling stays may be used in lieu of girders in all cases, provided, 
 however, that when such sling stays are used, girders or screw 
 stays of the same sectional area must be used for securing the 
 bottom of combustion chamber to the boiler shell. 
 
BRACES AND REINFORCING. 99 
 
 Rule to find thickness of steel girder : From length of girder sub- 
 tract pitch of bolts and multiply by centers of girders and by length 
 of same and this sum by pressure; divide this product by depth of 
 girder squared multiplied by constant and then multiplied by the 
 square root of number of supporting bolts. 
 
 FORMULA: 
 
 (L P)XGXLXP 
 
 = thickness of girder required. 
 d 2 xCX\/N 
 
 LEGEND: 
 
 L = length of girder = 32" 
 P =pitch of bolts =9" 
 G = girder centers = 8 3^" 
 d = depth of girder = 5.18" 
 C= constant =6000 
 N = number of bolts =9 
 
 EXAMPLE: 
 
 32 . 000" = length of girder 
 9 . 000" = pitch of bolts 
 
 23.000" 
 
 8 . 5" =girder centers 
 
 115000 
 184000 
 depth of girders =5.18 
 
 5.18 195.5000 
 
 32" = length of girder 
 4144 
 
 518 3910000 
 
 2590 5865000 
 
 26.8324 6256.0000 
 
 constant = 6000 160=pressure 
 
 160994.4000 3753600000 
 sq. rt. of bolts = 3 62560000 
 
 4829832000) 1000960000 (2 . = thickness of girder 
 965966 
 
 349940 
 
100 THE BOILER. 
 
 In connection with rules covering girder calculations there are 
 constants used and varying according to plate thickness and design of 
 bolt, such as screwed stayed bolts with and without lock nuts, 
 sockets, with riveted heads, number of bolts and water used, as 
 follows : 
 
 Use constant 5400 for roof stays, wrought iron. 
 Use constant 6000 for roof stays, steel. 
 
 A constant used by Joshua Rose for computing girder or crown 
 bar supporting bolts 9000 (this for steel). 
 
 Rule to find area of supporting bolts (steel) for a girder stay or 
 crown bar. Multiply pressure by area to be supported and divide 
 this product by constant 9000, this will give the pounds strain 
 allowed per square inch of sectional area for a mild steel bolt. 
 
 FORMULA: 
 
 AXP 
 
 = afea supporting bolt required 
 
 LEGEND: 
 
 A =area to be supported =8" X 8" = 64 square inches 
 P = pressure = 170 Ibs. 
 C= constant =9000 
 
 EXAMPLE: 
 
 64= square inches to be supported 
 170= pressure 
 
 4480 
 64 
 
 constant = 9000) 10880 . 0000 (1 . 2088 =area = 1 ^ approximately 
 9000 
 
 1880 
 1800 
 
 800 00 
 720 00 
 
 80 000 
 72 000 
 
 8 000 
 
BRACES AND REINFORCING. 101 
 
 Rule to find safe working pressure on a girder supporting a 
 crown sheet of a back smoke box connection, when not subjected to 
 heat in excess of ordinary steam pressures and assuming the com- 
 bustion chamber ends are fitted to the edge of tube plate and the 
 back of plate of the combustion box, four supporting bolts being 
 used. Multiply constant by depth of girder squared in inches and 
 multiply this sum by thickness of girder in inches; divide product 
 by width of combustion chamber in inches minus pitch of supporting 
 bolts multiplied by distance between girders from center to center 
 in inches and again by length of girder in feet. 
 
 FORMULA: 
 : Cxd 2 XT 
 
 = pressure 
 
 (W P)XDXL 
 
 LEGEND: 
 
 W = width of combustion box in inches = 36" 
 P = pitch of supporting bolts in inches =7^=7.5 
 D = distance between girder centers in inches =7% =7. 75 
 L = length of girder in feet =3 feet =3 
 d = depth of girder in inches = 7^=7.5 
 T = thickness of girder in inches =2" = 2 
 C = constant 
 
 = 550 when girder is fitted with one supporting bolt 
 825 two or three supporting bolts 
 
 93 5 four supporting bolts 
 
 EXAMPLE: 
 width =3 6" 
 pitch = 7.5 
 
 28.5 
 distance = 7.75 
 
 56.25 
 935 
 
 1 425 
 19 95 
 199 5 
 
 281 25 
 1687 5 
 50625 
 
 220.875 
 length = 3 
 
 52593.75 
 2 
 
 93 5= constant 
 
 = thickness 
 662.02^ 105187.^ 
 
 662)105187. (158 or 159 Ibs. nearly 
 662 
 
 3898 
 3310 
 
 5887 
 5296 
 
 591 
 
102 
 
 THE BOILER. 
 
 Rule to find depth of steel girder for top of a combustion cham- 
 ber : Multiply pressure by centers of girder and by length of girder 
 bolts and multiply this sum by length of girder bolts minus pitch of 
 same; divide this product by constant multiplied by thickness of 
 girder and again by square root of number of bolts. The square 
 root of quotient is depth of girder. 
 
 FORMULA : 
 
 PXGXLX (L p) 
 
 = depth of girder 
 
 LEGEND: 
 
 CxTXx/N 
 
 P = pressure = 160 Ibs. 
 G = girder centers =8 J^. 
 L=length of girder = 32" 
 C = constant 6000 for steel 
 C = constant 54000 for iron 
 T =thickness of girder = 2" 
 p = pitch of bolts = 9" 
 N = number of bolts = 9 
 d= depth of girder = 9" 
 
 EXAMPLE: 
 160= pressure 
 8 . 5 = girder centers 
 
 800 
 1280 
 
 1360.0 
 
 32 ^length of girder 
 
 27200 
 40800 
 
 constant = 6000 
 thickness of girder = 2" 
 
 square root of 
 no. of bolts 
 
 12000 
 
 '.' 3 
 
 43520 
 
 23 = length of girder minus pitch of bolts 
 
 1305600 
 870400 
 
 36000) 1000960 . 0000 (27 . 8044 
 72000 
 
 280960 
 252000 
 
 289600 
 288000 
 
 5)27. 8044 (5 . 272 = 5& nearly 
 )25 depth of girder 
 
 102) 280 
 ) 204 
 
 160000 
 144000 
 
 1047) 
 ) 
 
 160000 10542) 
 144000 ) 
 
 7644 
 7329 
 
 31500 
 21084 
 
 16000 
 
 ) 10416 
 
BRACES AND REINFORCING. 103 
 
 ENGLISH BOARD OF TRADE RULES GOVERNING GIRDERS. 
 
 LEGEND: 
 P = pressure. 
 W = width of combustion chamber 
 
 p = pitch of bolts 
 
 = distance between girder centers 
 L= length of girder 
 d = depth of girder 
 T = thickness of girder 
 C = constant for number of bolts 
 Constants vary according to the iron or steel used, the lower constant for 
 
 iron. 
 Constant =6000 =when only one supporting bolt 
 
 9000 to 9900 =when two or three supporting bolts 
 10200 to 11220 =when four to five supporting bolts 
 For five bolts use same constant as for four 
 For six or seven bolts use constant 10500 for iron 
 
 11550 " steel 
 
 FORMULAS: 
 
 Cxd 2 xT 
 
 = working pressure 
 (W pitch) XD XL 
 
 PX(W pitch) XD XL 
 
 = thickness of girder 
 
 Cxd 2 
 PX (W pitch) XDXL 
 
 CXT 
 
 : depth of girder 
 
 REINFORCEMENT FOR HOLES CUT IN BOILER SHELL. 
 
 All holes exceeding 6 inches in diameter cut in either the flat 
 heads or circumferential shell of steel boilers shall be reinforced 
 with wrought or cast steel rings to compensate for the material 
 removed. In lieu of such a reinforce ring, holes in flat heads may, 
 if preferred, be reinforced by flanging the metal about the hole 
 inward to a depth of not less than three-quarters of an inch 
 measured from the inner surface. Reinforce rings on flat heads 
 must be efficiently riveted to the head, and must have a sectional 
 area not less than .8 the section of metal removed, the latter being 
 measured across the shorter axis of the opening. 
 
 Reinforce rings on the circumferential shell must be efficiently 
 riveted to the shell, and must have a sectional area not less than 
 .7 the section of metal removed, the latter being measured across 
 the hole in a direction parallel to the length of the boiler. 
 
 Reinforce rings should be of thickness not less than that of plate 
 to which attached. 
 
104 THE BOILER. 
 
 Rule to find width of ring to reinforce an opening in a boiler 
 shell such as a man-hole, when one ring is used : Multiply diameter 
 of opening longitudinally by the thickness of plate and divide the 
 product by twice the thickness of reinforcement ring; add the 
 diameter of rivet hole to quotient. This will be for single riveting 
 and when double riveted add twice the diameter of rivet hole. 
 
 FORMULA: 
 OXT 
 
 + 1R =width of ring for single riveted 
 
 2XN 
 LEGEND: 
 
 R = rivet diameter hole = . 9375 
 O = diameter of opening = 11" 
 T = thickness of shell = %" = . 5000 
 N = thickness of ring = %" = . 6250 
 
 EXAMPLE: 
 
 thickness of ring = . 6250 11" =diameter of opening 
 
 2 . 5000 = thickness of shell plate 
 
 twice thickness of ring = : JU2500 ) 5 . 50000 (4 . 4 
 
 5 0000 . 9375 = diam. of rivet hole 
 
 50000 5.3375=5^" nearly 
 50000 
 
 When two rings are used the thickness of each must be at least 
 that of shell and have same tensile strength as that of shell plate; 
 a single ring not less than 1J4 the thickness of shell. 
 
 Rule to find number of rivets to be used in a reinforcement ring 
 for reinforcing an opening such as a man-hole in boiler shell : Multi- 
 ply the net section of the ring by four times the tensile strength of 
 the material and divide this product by the product of the shearing 
 strength of rivet multiplied by its area. 
 
 FORMULA: 
 
 NSX(^XTS) 
 
 = number of rivets required 
 
 SSXA 
 
 LEGEND: 
 
 NS =net section = 1 . 5625 
 SS = shearing strength =38000 
 TS = tensile strength = 60000 
 A =area of rivet = . 6013 
 
BRACES AND REINFORCING. 105 
 
 EXAMPLE: 
 
 38000 = shearing strength 60000 = tensile strength 
 
 . 6013 -area of rivet 4 times 
 
 114000 240000 
 
 38000 
 228000 1 . 5625 = net section 
 
 240000 =4 times tensile strength 
 22849.^000 
 
 625000000 
 31250 
 
 22849)375000.0000(16 rivets %" diameter required 
 22849 
 
 146510 
 137094 
 
 9416 
 
 For a double riveted ring multiply net section of one ring by 
 eight times the tensile strength of material and divide product by 
 the sum obtained by multiplying 1.85 times the shearing strength of 
 rivet's sectional area and the area of rivet. 
 
CHAPTER V. 
 
 AMENDMENTS OF STEAMBOAT INSPECTION RULES 
 AND REGULATIONS. 
 
 Lap welded boiler flues over 4 inches up to and including" 30 
 inches in diameter shall be made of wrought iron or mild steel made 
 by any process. 
 
 A test piece, 2 inches in length, cut from a tube, must stand 
 being flattened by hammering until the sides are brought parallel 
 with the curve on the inside at the ends not greater than three times 
 the thickness of the metal without showing cracks or flaws, with 
 bend at one side in the weld. 
 
 Each tube shall be subjected to an internal hydrostatic pressure 
 of 500 pounds per square inch without showing signs of weakness 
 or defects. 
 
 All steel tubes shall have ends properly annealed by the manu- 
 facturer before shipment. Tubes must stand drilling, riveting, and 
 calking, and work necessary to install them into the tube head with- 
 out showing any signs of weakness or defects. 
 
 No tube increased in thickness by welding one tube inside of 
 another shall be allowed for use. 
 
 SEAMLESS STEEL BOILER TUBES. 
 
 MATERIAL. 
 
 The steel shall be made by the open-hearth process. 
 
 SURFACE INSPECTION. 
 
 The pipe must be free, inside and outside, from all surface 
 defects that would materially weaken it or form starting points of 
 corrosion. The defects to be especially avoided are snakes, checks, 
 slivers, laps, pits, etc. Pipe must be smooth and straight. 
 
 The following tests shall be made before shipment by the manu- 
 facturer : 
 
 (a) A test piece, 2 inches in length, cut from a tube, must stand 
 being flattened by hammering until the sides are brought parallel 
 with the curve on the inside at the ends not greater than three times 
 the thickness of the metal without showing cracks or flaws. 
 
 106 
 
GOVERNMENT'S RULESFLUES AND FURNACES. 107 
 
 (b) Pulling tests must be made from every 50 pieces furnished, 
 or fraction thereof, and must show the following results: 
 
 Tensile strength, not less than 48,000 pounds per square inch. 
 
 Elongation in 8-inch specimen, not less than 12 per cent. 
 
 The results of the pulling tests must be forwarded by the manu- 
 facturer to the purchaser of steam pipe, who will forward same to 
 local inspector. 
 
 Any pipe used for mud or steam drums must have the ends of 
 same properly annealed before the holes are drilled or the heads 
 are riveted in : Provided, That this paragraph shall apply only to 
 drums not exceeding 15 inches in diameter for use on pipe and coil 
 boilers. 
 
 When pipe is used for steam lines where flanges are riveted on 
 and calked, the ends of the pipe shall be properly annealed before 
 drilling or riveting the flanges on. 
 
 When pipes are expanded into flanges by proper and approved 
 machinery, and flared out at the ends to an angle not exceeding 20 
 (said angle to be taken in the direction of the length of the pipe) 
 and having a depth of flare equal to at least one and one-half times 
 the thickness of the material in said pipe, such pipes may be used 
 for all steam and exhaust pipes when tested to two and one-half 
 times the working pressure and found perfect in every respect. 
 
 If the pipe is used for steam lines where the pipe is peened in 
 and 'flanged over, the ends of the pipe should be properly annealed 
 before the peening or flanging is done. 
 
 The use of a square-nosed tool is recommended for cutting tubes 
 and pipe. 
 
 Provided, That this entire section shall apply only to tubes 
 and pipes used or to be used in boilers built after June 30, 1905, and 
 to all other pipes referred to in this section subject to pressure in- 
 stalled for use on steam vessels after that date. 
 
 TABLES AND EXAMPLES. 
 
 Flues and furnaces safe working pressures. 
 
 The following table shows diameters, thickness of plate and safe 
 working pressure on flues in sections of 3 feet, maximum length 
 allowed 5 feet ,also sections of 30" in length, maximum 40". 
 
108 
 
 THE BOILER. 
 
 ! 
 
 gf 
 
 s.1 
 
 J: 
 
 II 
 
 'S 5 I 
 
 0* 
 
 O< o 
 
 (5 
 
 Oco o 
 
 ON o 
 
 ^a 
 
 >oooc>oo>coco 
 co >* rf< 10 10 co CD r- b- oo 
 
 co co * * 10 co to i> oc 
 
 Oo o 
 
 fc2 
 
 > a >t--G 
 
 6--S s 
 
 s I 
 
 o d 
 
 ecsccccccccccccccccccccccc 
 
 oo<ori(ro < ocoroo<'ccoo-ori5 
 
 ^i r-t t?) .\ c^| C-l 7-1 O-l (M <N (M <N CO 00 CO CO CO CO CO CO CO CO 't 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 109 
 
 & 
 
 o 
 
 .S 
 
 .^COlOt~Ci^COOt>.O<N 
 
 bS 
 
 IS 
 
 o IM 10 1^ o IM 
 
 ^i-i '^WfNM 
 
 CO O5 M & t>- O WO 00 O CO 
 
 OO-H-l^iM^1WMCOCO 
 
 . -H i-( ^-1 (M C-l (M (N CO CO 01 -^ 
 
 "-I >-i iM IN <N M CO CO * Tf 
 
 T-T'V-T- 
 
 ICOCOCO^*' 
 
110 THE BOILER. 
 
 Rule to find steam pressure allowed on any flue in table : Multi- 
 ply crushing strain 8,000 pounds (constant) by thickness noted in 
 column and divide the product by diameter of flue. 
 
 FIRST EXAMPLE: FORMULA: 
 
 CXT 
 
 = working pressure allowed 
 D 
 
 LEGEND: 
 
 D = diameter of flue =15" EXAMPLE: 
 
 T =thickness of plate = M = 25" 
 
 C = constant = crushing strain = 8000 8000 = constant 
 
 . 25 = thickness of plate 
 
 40000 
 16000 
 
 flue diameter = 15) 2000.00(133^ Ibs. working pressure 
 
 50 
 
 45 
 
 50 
 
 45 
 
 SECOND EXAMPLE: 
 
 LEGEND: 
 
 T = thickness of plate = % = . 375 
 
 D = diameter of furnace =36" 
 
 C = constant = 8000 = crushing strain EXAMPLE : 
 
 8000= constant 
 
 .375 = 3^= thickness of plate 
 
 40000 
 56000 
 24000 
 
 diameter =36") 3000000 (83. 3 =lbs. working pressure 
 288 
 
 120 
 108 
 
 120 
 108 
 
 12 
 
GOVERNMENT'S RULES FLUES AND FURNACES. Ill 
 
 FLUES. 
 
 The preceding table includes all such riveted and lap-welded 
 flues, exceeding- 6 inches in diameter and not exceeding 40 inches 
 in diameter, not otherwise provided for by law. 
 
 For any such flue requiring more pressure than is given in table, 
 the same will be determined by proportion of thickness to any given 
 pressure in table to thickness for pressure required, as per example : 
 
 A flue not over 19 inches in diameter and 3 feet long requires 
 a thickness of .39 of an inch for 176 pounds pressure ; what thickness 
 would be required for 250 pounds pressure? 
 
 FORMULA: 
 
 Pressure required X T 
 
 = thickness of plate required 
 P 
 
 LEGEND: 
 
 P = pressure = 176 Ibs. 
 
 T = thickness of plate = . 39 or % nearly 
 
 EXAMPLE : 
 
 250 =increased pressure required 
 . 39 = thickness of plate 
 
 2250 
 750 
 
 first pressure = 176) 97. 5000 (.5539 = & nearly = thickness of 
 88 plate required 
 
 9 50 
 8 80 
 
 700 
 528 
 
 1720 
 1580 
 
 136 
 
 Or, if .39 inch thickness gives a pressure of 176 pounds, what 
 will .554 inch thickness give? 
 
 FORMULA: 
 
 Thickness of plate required X P 
 
 =pressure 
 
112 THE BOILER. 
 
 EXAMPLE: 
 
 .554 = thickness of plate 
 176 = first pressure 
 
 3324 
 3878 
 554 
 
 original thickness of plate = .39)97.504(250 =lbs. pressure 
 
 78 
 
 195 
 195 
 
 And all such flues shall be made in sections, according to their 
 respective diameters, not to exceed the lengths prescribed in the 
 table, and such sections shall be properly fitted one into the other 
 and substantially riveted, and the thickness of material required for 
 any such flue of a given diameter shall in no case be less than the 
 least thickness prescribed in the table for any such given diameter; 
 and all such flues may be allowed the prescribed working steam 
 pressure if, in the opinion of the inspectors, it is deemed safe to 
 make such allowance. Inspectors are therefore required, from 
 actual measurement of each flue, to make such reduction from the 
 prescribed working steam pressure for any material deviation in the 
 uniformity of the thickness of material, or for any material deviation 
 in the form of the flue from that of a true circle, as in their judg- 
 ment the safety of navigation may require. 
 
 FURNACES. 
 
 The tensile strength of steel used in constructing furnaces shall 
 not exceed 67,000, and be not less than 58,000 pounds. The mini- 
 mum elongation in 8 inches shall be 20 per cent. 
 
 All corrugated furnaces having plain parts at the ends not ex- 
 ceeding 9 inches in length (except flues especially provided for), 
 when new, and made to practically true circles, shall be allowed a 
 steam pressure in accordance with the following formula : 
 
 CXT 
 
 = pressure 
 
 D 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 113 
 
 - 
 
 Rule to find collapsing pressure of a spirally corrugated furnace, 
 corrugations \ l / 2 " deep: Multiply square of thickness of flue in 
 thirty-seconds of an inch by the constant 1200 and divide by external 
 diameter of flue in inches multiplied by square root of length in 
 inches. 
 
 FORMULA: 
 
 LEGEND: T 2 xl200 
 
 L = length =81" = collapsing pressure 
 
 D= diameter = 40" Dx\/L 
 
 T = thickness = % =20/32 
 C = constant = 1200 
 
 9)81" (9=sq. root EXAMPLE: 
 
 81 of length 20 = thickness in 32nds of an inch 
 
 20 
 
 400 = thickness squared 
 1200= constant 
 
 40" diameter 80000 
 
 9 square root of length 400 
 
 360 360)480000(1333 Ibs. collapsing pressure 
 
 360 
 
 1200 
 1080 
 
 1200 
 1080 
 
 1200 
 1080 
 
 120 
 MORISON CORRUGATED TYPE. 
 
 [In calculating the mean diameter of the Morison furnace, the 
 least inside diameter plus 2 inches may be taken as the mean diam- 
 eter, thus 
 
 (Mean diameter = least inside diameter + 2 inches. ) 
 
 Rule to find safe working pressure on a Morison corrugated 
 furnace: Multiply constant 15,600 by thickness of plate and divide 
 by diameter. 
 
 T = thickness in inches, not less than five-sixteenths of an inch. 
 
 C= 15600, a constant, determined from an actual destructive test 
 under the supervision of the Board of Supervising Inspectors, 
 when corrugations are not more than 8 inches from center to 
 center, and the radius of the outer corrugations is not more 
 than one-half of the suspension curve. 
 
114 THE BOILER. 
 
 FORMULA: 
 
 CXT 
 
 = working pressure 
 D 
 
 LEGEND: 
 
 EXAMPLE: 
 D= diameter = 42" 
 
 T = thickness of plate = % = .$ 15600= constant 
 C = constant = 15600 . 5 = thickness of plate 
 
 diameter = 42" ) 7800 .0(185 Ibs. working pressure 
 42 
 
 360 
 336 
 
 240 
 210 
 
 30 
 
 COLLAPSING. 
 
 Rules for determining the collapsing pressures on furnace flues 
 are given by eminent authorities, and these after many tests and 
 experiments. These rules vary in method of computing and in the 
 results; however, there is a reasonable margin for safety in the 
 maximum results. 
 
 Mutton's rule for rinding collapsing pressure : 
 
 Multiply the constant 806,300 by thickness of plate squared in 
 inches and divide product by length of furnace in feet multiplied by 
 diameter in inches. 
 
 FORMULA: 
 CXT 2 
 
 LxD 
 
 : collapsing pressure 
 
 LEGEND: 
 
 C = constant =806300 
 
 T = thickness of plate = ^ = . 3750 
 
 D = diameter = 3 8" 
 
 L = length of furnace = 14 feet 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 115 
 
 EXAMPLE: 
 
 806300 -constant 
 . 14062500 -thickness squared 
 
 length = 14 403150000 
 
 diameter- 38 1612600 
 
 4837800 
 
 152 3225200 
 
 38 806300 
 
 532) 113385. ^7^0000(213 Ibs -collapsing pressure 
 1064 
 
 698 
 532 
 
 1665 
 1596 
 
 69 
 
 Nystronvs rule for finding collapsing pressure : 
 
 FORMULA : 
 
 C= constant -200000 T 2 XC 
 
 Other data same collapsing pressure 
 
 D X\/L 
 
 EXAMPLE: 
 
 . 14062500 -thickness squared 
 200000 constant 
 
 142. 12)28125.00000000(197 Ibs. -collapsing pressure 
 
 14212 
 
 diameter 38 
 
 sq. rt. of length = 3 . 74 139130 
 
 127908 
 1 52 
 
 26 6 112220 
 114 99484 
 
 142.12 12736 
 
 Rule by Michael Longridge for finding collapsing pressure: 
 Multiply constant 174,000 by thickness of plate squared in inches; 
 divide product by diameter multiplied by the square root of length. 
 
 FORMULA: 
 T 2 XC 
 
 = collapsing pressure 
 
 Dx\/L 
 C= constant = 174000 
 other data same 
 
1-16 THE BOILER. 
 
 EXAMPLE: 
 
 length 38 . 14062500 =thickness squared 
 
 sq. rt.of diam. = 3.74 174000 = constant 
 
 1 52 56250000000 
 26 6 98437500 
 114 14062500 
 
 142. 12)24468.7500000(172 Ibs. = collapsing pressure 
 14212 
 
 102567 
 99484 
 
 30835 
 28424 
 
 2411 
 
 LEEDS SUSPENSION BULB FURNACE. 
 
 Rule to find safe working pressure on a Leeds suspension bulb 
 furnace : Multiply constant 17,300 by thickness of plate and divide 
 by diameter. 
 
 T =thickness in inches, not less than five-sixteenths of an inch. 
 
 C =a constant, 17300, determined from an actual destructive test 
 under the supervision of the Board, when corrugations are 
 not more than 8 inches from center to center, and not less than 
 2 34 inches deep. 
 
 FORMULA: 
 
 CXT 
 
 = working pressure 
 
 D 
 
 LEGEND: EXAMPLE: 
 
 C = constant = 17300 17300 = constant 
 
 T = thickness = % = . 375 .375= thickness of plate 
 
 D = diameter = 3 6" 
 
 86500 
 
 121100 
 
 51900 
 
 diameter 36") 6487 . 000 (180 Ibs. working pressure 
 36 
 
 288 
 288 
 
 07 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 117 
 
 FOX TYPE. 
 
 Rule to find safe working pressure on the above type of furnace : 
 Multiply constant 14,000 by thickness of plate and divide by diam- 
 eter. 
 
 T = thickness in inches, not less than five-sixteenths. 
 C = 14000, a constant, when corrugations are not more than 8 
 inches from center to center and not less than 1 ^ inches deep. 
 
 FORMULA: 
 
 CxT 
 
 =safe working pressure 
 D 
 LEGEND: 
 
 D= diameter = 40" 
 
 T = thickness of plate = Y 2 " = . 5 
 
 C = constant = 14000 EXAMPLE: 
 
 14000= constant 
 
 . 5 = thickness of plate 
 
 Diameter =40") 7000 . (175 Ibs. working pressure 
 40 
 
 300 
 280 
 
 200 
 200 
 
 PURVES TYPE. 
 FORMULA : 
 
 CXT 
 
 = pressure 
 D 
 
 T =thickness in inches not less than seven-sixteenths. 
 D = least outside diameter in inches. 
 
 C= 14000, a constant, when rib projections are not more than 9 
 inches from center to center and not less than 1 3/g inches deep. 
 
 BROWN TYPE. 
 
 CXT 
 
 = pressure 
 D 
 
 T = thickness in inches, not less than five-sixteenths 
 
 D =least outside diameter in inches. 
 
 C= 14000, a constant (ascertained by an actual destructive test 
 under the supervision of the Board of Supervising Inspec- 
 tors), when corrugations are not more than 9 inches from 
 center to center and not less than 1 finches deep. 
 
118 THE BOILER. 
 
 The thickness of corrugated and ribbed furnaces shall be ascer- 
 tained by actual measurement. The manufacturer shall have said 
 furnace drilled for a one-fourth inch pipe tap and fitted with a 
 screw plug that can be removed by the inspector when taking this 
 measurement. For the Brown and Purves furnaces the holes shall 
 be in the center of the second flat ; for the Morison, Fox, and other 
 similar types in the center of the top corrugation, at least as far 
 in as the fourth corrugation from the end of the furnace. 
 
 TYPE HAVING SECTIONS 18 INCHES LONG. 
 
 CXT 
 
 = pressure 
 
 T = thickness in inches, not less than seven-sixteenths. 
 
 D =mean diameter in inches. 
 
 C= 100000, a constant, when corrugated by sections not more 
 than 18 inches from center to center and not less than 2J^ 
 inches deep, measuring from the least inside to the greatest 
 outside diameter of the corrugations, and having the ends 
 fitted one into the other and substantially riveted together, 
 provided that the plain parts at the ends do not exceed 12 
 inches in length. 
 
 CONES. 
 
 Rule to find collapsing pressure on a truncated cone up to 42 
 inches in length: Multiply twice thickness of plate by the tensile 
 strength and by the hypothenuse length of cone ; divide this sum by 
 the square inches in a trapezoid of equal dimensions of truncated 
 cone. 
 
 FORMULA: 
 
 2 X T X TS X Hypothenuse 
 
 =bursting pressure 
 Area of trapezoid 
 
 LEGEND: 
 
 T = thickness of plate = % = . 375 
 TvS = tensile strength =60000 
 Hypothenuse =40" 
 Area of trapezoid = 1200 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 119 
 
 EXAMPLE: 
 
 . 7500 = twice thickness of %" plate 
 60000= tensile strength 
 
 45000.00^0 
 
 40" = length of hypothenuse of cone 
 
 area of a traoezoid = 1200) 1800000 .0000 (1500 Ibs. bursting pressure 
 1200 
 
 6000 
 6000 
 
 CONE TOPS. 
 
 Flues used in vertical boilers as upper combustion chambers 
 formed in the shape of a cone, when new and made to practically 
 true circles, shall be allowed a steam pressure according to the 
 following 1 formula : 
 
 CxT 
 
 = pressure 
 D 
 
 T = thickness of flue in inches, not less than five-sixteenths. 
 
 D =outside diameter in inches, at the center of the length of the flue, 
 
 not to exceed 42 inches. 
 C =10153, a constant, when the length of the flue does not exceed 
 
 42 inches, measuring from center of rivet holes in top of head 
 
 to the center of rivet holes in the tube head. 
 
 When the flue exceeds 42 inches in diameter at the center, it 
 shall be deemed flat surface and must be stayed accordingly. 
 
 Rule to find safe working pressure on a truncated cone as in a 
 submerged tube upright boiler, length limited to 40": Multiply 
 constant 8000 by thickness of plate, minimum limit 5/16, and divide 
 by diameter (small and large diameter added together and divided 
 by 2). 
 
 LEGEND: FORMULA: 
 
 C= constant =8000 CxT 
 
 T = thickness of plate = ^ = . 4375 = working pressure 
 
 D = diameter, small =3 0" D 
 
 large =40" 
 
 EXAMPLE: 
 
 8000= constant 
 large diam. 40" . 4375 = ^ plate 
 
 small diam. 30" 
 
 2)70 35 
 
 35' 00 
 
 35)3500. 0000(100 Ibs. pressure 
 
120 THE BOILER. 
 
 ADAMSON TYPE. 
 
 When plain horizontal flues are made in sections not less than 
 18 inches in length, and not less than five-sixteenths of an inch thick, 
 and flanged to a depth of not less than three times the diameter of 
 rivet hole plus the radius at furnace wall (inside diameter of fur- 
 nace), the thickness of the flanges shall be as near the thickness of 
 the body of the plate as practicable. 
 
 The radii of the flanges on the fire side shall be not less than 
 three times the thickness of plate. 
 
 The distance from the edge of the rivet hole to the edge of the 
 flange shall be not less than the diameter of the rivet hole, and the 
 diameter of the rivets before driven shall be at least one-fourth 
 inch larger than the thickness of the plate. 
 
 The depth of the ring between the flanges shall be not less than 
 three times the diameter of the rivet holes, and the ring shall be 
 substantially riveted to the flanges. The fire edge of the ring shall 
 terminate at or about the point of tangency to the curve of the flange, 
 and the thickness of the ring shall be not less than one-half inch. 
 
 PLAIN CIRCULAR FURNACES OR FLUES, AND ADAMSON FURNACES MADE 
 IN SECTIONS NOT LESS THAN 18 INCHES IN LENGTH. 
 
 Rule to find safe working pressure of an Adamson furnace: 
 Multiply length of section by thickness of plate in sixteenths; from 
 this, product subtract the length of furnace multiplied by constant 
 1.03; multiply result by constant 51.5 divided by the diameter. 
 
 FORMULA: 
 
 51.5 
 
 [SxT (Lxl-03)]X -- = pressure 
 :""; - i- ' D 
 
 LEGEND: 
 
 S = length of section = 
 D =outside diameter of furnace in inches = 44" 
 L = length of furnace in inches = 48" 
 T = thickness of plate in sixteenths of an inch = 
 C = constant =51.5 
 C= constant -1.03 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 121 
 
 EXAMPLE: 
 
 diameter = 44) 5 1.5(1. 17 18.75 = length of section 
 
 41 8 = thickness of plate in 16ths 
 
 75 150.00 48 = length of furnace 
 
 44 49 . 44 1 . 03 = constant 
 
 3 10 100.56 1 44 
 
 3 08 1.17 48 
 
 7 0392 49.44 
 10 056 
 100 56 
 
 117 . 6552 = safe working pressure 
 
 VERTICAL TYPE. 
 
 Cylindrical flues used as furnaces in vertical boilers, when new, 
 and made to practically true circles, shall be allowed a steam pressure 
 by the following formula : 
 
 CxT 
 
 = pressure 
 D 
 
 T = thickness of flue in inches, not less than one-fourth. 
 
 D =outside diameter of flue in inches, not to exceed 42 inches. 
 
 C = 10,577, a constant, when the length of the flue does not exceed 
 
 42 inches, measuring from the center of the rivet holes in the 
 
 head to the center of the rivet holes in the leg. 
 
 When the flue exceeds 42 inches in diameter, it is deemed to be 
 flat surface and must be stayed accordingly. 
 
 STEAM CHIMNEY FLUES. 
 
 The Morison, Fox, Purves, or Brown types of corrugated fur- 
 naces may be used as flues for steam chimneys or superheaters and 
 shall be allowed a steam pressure by their respective formulas, and 
 other flues, as described below, when new and made to practically 
 true circles and shall be allowed a steam pressure by the following 
 formula : 
 
 CxT 
 
 = pressure 
 D 
 
THE BOILER. 
 
 T = thickness of material in inches. 
 D =outside diameter of flue in inches. 
 
 C = 12000 for flues under 30 inches in diameter, plates at least 
 five-sixteenths of an inch thick, supported by angle rings at 
 least 23^ by 2^ inches. 
 
 C = L2000 for flues 30 inches and under 45 inches in diameter, 
 plates^ at least three-eighths of an inch thick, supported by 
 angle rings at least 2 ^ by 2 }/% inches. 
 
 C= 12000 for flues 45"inehes and under 55 inches in diameter, 
 ^ plates at least seven^ixteenths of an inch thick, supported 
 
 by angle rings at least 3 by 3 inches. 
 
 C = 12000 for flues 55 inches and under 65 inches in diameter, 
 plates at least one-half inch thick, supported by angle rings at 
 least 3 by 3 inches. 
 
 C = 12000 for flues 65 inches and under 75 inches in diameter, plates 
 least nine-sixteenths of an inch thick, supported by angle 
 rings at least 3^ by 3^ inches. 
 
 C = 12000 for flues 75 inches and under 85 inches in diameter, ^ 
 plates at least five-eighths of an inch thick, supported by angle 
 rings at least 3^j by 3 finches. 
 
 C = 12000 for flues 85 inahes in diameter, plates at least eleven- 
 sixteenths of an inch thick, supported by angle rings at least 
 4 by 4 inches. 
 
 For flues over 85 inches in diameter, add one-sixteenth of an 
 inch to eleven-sixteenths of an inch for every 10 inches increase in 
 the diameter of the flue. 
 
 The distance, center to center, between angle rings, or center of 
 angle rings to center of rivets in the heads, shall in no case exceed 
 2y 2 feet. 
 
 The angle rings shall be accurately fitted and substantially riveted 
 to the flue and connected to the outer shell by braces, which braces 
 shall not exceed 20 inches from center to center on the flue. 
 
 ADAMSON RINGS. 
 
 Adamson rings may be substituted for the angle rings, but each 
 ring shall not be at a greater distance than 2 l / 2 feet from center to 
 center of rings, which rings shall not be required to be braced to 
 the outer shell. 
 
 Rule to find the working pressure of an Adamson flue used in a 
 steam chimney: Multiply constant by thickness of plate in inches 
 and divide by diameter. 
 
 LEGEND: FORMULA: 
 
 T = thickness of plate = ^ = . 5 C X T 
 
 D = diameter = 45" = working pressure 
 
 C= constant =12000 D 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 123 
 
 EXAMPLE: 
 
 12000 = constant 
 
 . 5 = thickness of plate 
 
 diameter = 45 ) 60000 (133 Ibs. pressure 
 45 
 
 150 * 
 
 135 . - 
 
 
 
 150 
 
 135 
 
 15 
 
 Rule by Hutton to find collapsing- pressure of ribbed furnace 
 with ribs 9 inches centers and not less Jthan 15/16 deep: Multiply 
 thickness of straight or plain part of furnace flue in squared thirty- 
 seconds by constant 1350 and divide by external diameter multiplied 
 by square root of length. 
 
 FORMULA: 
 T 2 X1350 
 
 =collapsing pressure 
 
 LEGEND: 
 
 D= diameter = 30" 
 
 L=length=81" 
 
 T = thickness of plate = 13/32 
 
 EXAMPLE: 
 
 169 = 13/32 squared 
 13 50= constant 
 
 8450 
 
 diameter = 30" 507 
 square root of length =9 169 
 
 270)228150(845 Ibs. collapsing pressure 
 2160 
 
 1215 
 1080 
 
 1350 
 1350 
 
124 THE BOILER. 
 
 Rule to get compressive strain on a furnace flue from a collapsing 
 pressure : Multiply diameter of flue by pressure and divide product 
 by twice the thickness of flue plate. 
 
 FORMULA : 
 
 DXP 
 
 = compressive strain 
 2 XT 
 
 LEGEND: 
 
 D = diameter =30" 
 
 P = collapsing pressure = 845 
 
 T = thickness of flue plate = 13/32 = . 40625 
 
 EXAMPLE: 
 
 30"= diameter 
 845 Ibs. = collapsing pressure 
 
 150 
 
 thickness = . 40625 120 
 2 240 
 
 twice thickness = .81250) 25350. 0000 (3 120 Ibs. compressive strain 
 243750 
 
 97500 
 81250 
 
 162500 
 162500 
 
 PLAIN FLUES. 
 
 Rule to find the working pressure of a plain flue used in a steam 
 chimney: Multiply constant by thickness in inches and divide by 
 diameter. 
 
 FORMULA: 
 
 CXT 
 
 = pressure 
 D 
 
 LEGEND: 
 
 L = length of chimney =8 ft. 
 
 T = thickness of material in inches = ^ . 
 
 D = outside diameter of flue in inches = 46". 
 
 C =8000 for flues under 32 inches in diameter, plates at least five- 
 eighths of an inch thick, and not exceeding 8 feet in length. 
 
 C =8000 for flues over 32 inches and under 46 inches in diameter, 
 plates at least eleven-sixteenths of an inch thick, and not 
 exceeding 8 feet in length. 
 
GOVERNMENT'S RULES FLUES AND FURNACES. 125 
 
 SOCKET BOLTS. 
 
 For all boilers carrying a steam pressure of 60 pounds and under 
 per square inch the flue may be braced with socket bolts in lieu of 
 angle rings, such bolts to have heads and the ends to be threaded 
 for nuts, with plate washers not over 12 inches between centers (or 
 equivalent) on the inside of the flue; bolts to be at least 1 inch in 
 diameter at bottom of thread. 
 
 For all boilers carrying a steam pressure of over 60 pounds and 
 not over 120 pounds per square inch the flue may be braced with 
 socket bolts in lieu of angle rings, such bolts to have heads and the 
 ends to be threaded for nuts, with plate washers not over 10 inches 
 between centers (or equivalent) on the inside of flue; bolts to be 
 at least 1^ inches in diameter at bottom of thread. 
 
 Plain flues, Adamson flues, and flues supported by angle bars, 
 when used as furnaces, shall in no case be allowed a greater work- 
 ing pressure than found by the above formulas. 
 
 LIMITED FORMULA: 
 CXT 
 
 D 
 
 = pressure 
 
 LEGEND: 
 
 C = constant =9900 
 
 T = thickness of plate = ^ = . 5 
 
 D= diameter = 40" 
 
 EXAMPLE: 
 
 9900= constant 
 
 . 5 = thickness of plate 
 
 diameter = 40")49500 (123% Ibs. pressure 
 40 
 
 95 
 80 
 
 150 
 120 
 
 30 
 
126 
 
 THE BOILER. 
 
 Mutton's rule to find collapsing pressure on a furnace flue lap 
 riveted or flange connected : Multiply thickness of plate squared 
 32nds by constant 660 and divide by diameter multiplied by square 
 root of length. 
 
 LEGEND: 
 
 T = thickness = ^ = . if 
 C= constant =660 
 D= diameter = 3 6" 
 L=length=64" 
 
 FORMULA: 
 T 2 XC 
 
 DX\/L 
 
 Collapsing pressure 
 
 EXAMPLE: 
 
 . 144 = thickness squared in 32nds 
 660 = constant 
 
 diameter = 36 8640 
 sq. root of length = 8 864 
 
 288)95040 (330 Ibs. 
 864 
 
 864 
 864 
 
 = collapsing pressure 
 
 TABLE OF COLLAPSING PRESSURES OF FURNACES BY W. S. HUTTON. 
 
 Diameter in 
 inches 
 
 Length in 
 inches 
 
 Thickness in 
 32nd 
 
 Collapsing pressures, 
 square inch 
 
 Ibs. per 
 
 33.5 
 
 360 
 
 11 
 
 113 
 
 
 42 
 
 420 
 
 12 
 
 100 
 
 
 42 
 
 300 
 
 12 
 
 119 
 
 
 54 
 
 36 
 
 8 
 
 120 
 
 
 38 
 
 86 
 
 16 
 
 436 
 
 
 36 
 
 24 
 
 8 
 
 218 
 
 
 36 
 
 24 
 
 12 
 
 490 
 
 
 36 
 
 48 
 
 12 
 
 350 
 
 
 43 
 
 23 
 
 17 
 
 842 
 
 
CHAPTER VI. 
 
 SINGLE RIVETED LAP JOINT. 
 
 Causes for failure at joint : 
 
 First Shearing of one rivet. 
 
 Second Tearing of plate between rivets. 
 
 Third Crushing of rivet or plate. 
 
 In calculating seams it will be necessary to have some data, and 
 to follow this out we will assume it to be as follows: 
 
 LEGEND: 
 
 TS = tensile strength =60000 
 
 CS = resistance to crushing =95000 
 
 SS = resistance to shearing of rivet =38000 
 
 D = diameter of boiler =48" 
 
 d= diameter of rivet hole =13/16 = .8125 
 
 A =area of rivet hole = . 5185 
 
 T = thickness of plate = 5/16 = . 3125 
 
 P=pitch = lJ/ 8 = 1.8750 
 
 F = factor of safety = 5 
 
 First : resistance to shear one rivet 
 
 FORMULA: 
 
 A X SS = resistance to shearing of one rivet. 
 EXAMPLE: 
 
 . 5185 =area of rivet 
 
 38000 =shearing strength of rivet, 
 
 single shear 
 41480000 
 15555 
 
 19,703 Ibs. shearing strength of one rivet. 
 127 
 
128 THE BOILER. 
 
 Second : tearing the plate between rivets. 
 
 Rule to find strength of net section of plate: From pitch of 
 
 rivet, subtract diameter of rivet hole and multiply this sum by 
 
 thickness of plate. Multiply this product by the tensile strength 
 of plate. 
 
 FORMULA: 
 (P d) XT XTS= strength of net section of plate. 
 
 EXAMPLE: 
 
 1.8750=pitch 
 . 8125 = diameter of rivet 
 
 1.0625 
 . 3125 =thickness of plate 
 
 53125 
 21250 
 10625 
 31875 
 
 33203125 
 
 60000 = tensile strength 
 
 19,921 = strength of net section of plate. 
 
 Third: resistance to crushing of rivet or plate. 
 
 FORMULA: 
 P X T X TS = strength of solid plate. 
 
 EXAMPLE: 
 
 1 . 8750 = pitch of rivets 
 .3125 = thickness of plate 
 
 93750 
 37500 
 18750 
 56250 
 
 .58593750 
 
 60000 -tensile strength 
 
 35156. 
 
 35,156 Ibs. strength solid plate 
 
LAP JOINTS. 129 
 
 The net section of rivets is the weakest part of joint. To find 
 the efficiency of joint, multiply the weakest section by constant 
 100 and divide by the strength of solid plate. 
 
 EXAMPLE: 
 
 19,703 =shearing resistance of one rivet 
 35,156 *= strength of solid plate 
 
 35, 156) 19, 703. 00 (.56 =56% efficiency of joint 
 17 579 
 
 2 125 00 
 2 109 36 
 
 Rule to find safe working pressure from these calculations : Mul- 
 tiply the tensile strength of plate by the efficiency of joint and this 
 sum by twice the thickness of plate ; divide this product by diame- 
 ter of boiler multiplied by factor of safety. 
 
 FORMULA: 
 TSX%X(2XT) 
 
 DxF 
 
 = safe working pressure 
 
 EXAMPLE : 
 
 60000 = tensile strength 
 .56=% efficiency 
 
 3600 00 
 30000 
 
 33600.00 
 
 .6250 = twice thickness of plate 
 
 168000000 
 
 diam. of boiler = 48" 6720000 
 factor of safety = 5 20160000 
 
 240)21000 . Op^0 (87.5 Ibs. = working pressure 
 1920 
 
 1800 
 1680 
 
 1200 
 1200 
 
130 THE BOILER. 
 
 Rule to find thickness of plate: Multiply pressure by factor 6 
 and multiply again by radius or one-half diameter of boiler and 
 divide product by tensile strength of plate ; the quotient will be 
 thickness of plate. 
 
 LEGEND: 
 F=factor = 6 
 
 R = radius = 30" or one-half diameter. 
 TS = tensile strength = 60000 
 P = pressure =125 Ibs. 
 
 FORMULA: 
 
 PxFxR 
 
 = thickness of plate 
 TS 
 
 EXAMPLE: 
 
 125 =lbs. pressure 
 6 = factor 
 
 750 
 
 30 = radius 
 
 tensile strength = 60000) 22500000 (3750 = ^ plate 
 180000 
 
 450000 
 420000 
 
 300000 
 300000 
 
 Rule to find pitch of rivets for single, double and triple riveted 
 lap joints when the shearing strength of rivets is near equal to 
 strength of net section of plate : Multiply area of rivet hole by 
 the shearing resistance of rivets and by number of rows of rivets; 
 divide product by thickness of plate multiplied by tensile strength; 
 add to quotient the diameter of rivet hole. 
 
 FORMULA : 
 
 AXSSXN 
 
 - + DH = pitch single riveted joint 
 TXTS 
 
 LEGEND: 
 
 A =area of rivet = 15/16 = . 6903 
 SS = shearing strength of rivet =38000 
 N = number of rows of rivets = 1 
 T = thickness of plate = . 4375 
 TS = tensile strength =60000 
 DH = diameter of rivet hole = . 9375 
 
LAP JOINTS. 131 
 
 EXAMPLE: 
 
 .6903 = area of rivet 
 
 38000 = shearing strength 
 
 plate thickness = . 4375 55224000 
 
 tensile strength = 60000 20709 
 
 26250 .0000)26231 - 4000 ( . 9992 
 
 23625 . 9375 = diameter of rivet hole 
 
 2606 40 1.9367 = 115/16 -pitch 
 
 2362 50 
 
 243 900 
 236 250 
 
 7 6500 
 5 2500 
 
 2 4000 
 
 Custom through using iron rivets has established a rule to 
 make the rivet hole 1-16 larger than the rivet, but owing to a 
 better rivet material and use of steel rivets, experience has 
 proved that less than 1-16 larger is better. 
 
 Rule to find diameter of a rivet for a single riveted lap joint 
 steel rivets and plate: Add to plate thickness 7-16 of an inch. 
 
 FORMULA: 
 
 T plus -fe = diameter of rivet for sing'e riveted lap joint 
 LEGEND: EXAMPLE: 
 
 T = thickness of plate = y % = . 3750 . 3750 =thickness of plate 
 
 .4375 = ^ 
 
 ^f rivet (this sectional area 
 after rivet has been driven) 
 
 The Board of Supervising Inspectors of Steam Vessels, in their 
 rules and regulations governing the construction of steam boilers 
 for marine purposes, prescribe the following rules for single and 
 double riveted lap joints : 
 
 d =T+ y% inch for iron plates and iron rivets, single riveted lap joints, 
 d =T+ T^ inch for iron plates and iron rivets, double riveted lap joints, 
 d =T+ ^ inch for steel plates and steel rivets, single riveted lap joints, 
 d =T+ y% inch for steel plates and steel rivets, double riveted lap joints. 
 
 It has been generally considered good practice to have rivet 
 section percentage of strength higher, this for the benefits of caulk- 
 
132 THE BOILER. 
 
 ing and increasing rivet strength and to make up for depreciation 
 due to heating and driving rivet; but one authority on boiler con- 
 struction says to have plate higher in efficiency to provide for plate 
 deteriorating due to pitting and corrosion; however, in designing 
 seams these conditions can be provided for when computing boiler 
 joints. 
 
 Rule to find center of rivet to edge of plate (lap) : Multiply 
 diameter of rivet hole by 1.5 (one and a half) constant. 
 
 FORMULA: 
 dxC=lap 
 
 LEGEND: FORMULA: 
 
 d = diameter of rivet hole = % = . 750 .750 = rivet diameter 
 
 C = constant = 1.5 1.5= constant 
 
 3750 
 750 
 
 1.1250 = W lap 
 
 Rule to find percentage of rivet in a single riveted lap joint, 
 steel plate and steel rivets: Multiply area of rivet by number of 
 rows in one pitch and by the constant 100; divide this product 
 by pitch of rivet multiplied by thickness of plate in inches. 
 
 LEGEND: FORMULA: 
 
 P= pitch of rivets =lif = 1.9375 AxNxC 
 
 A =area of rivet % hole = . 44179 = rivet percentage 
 
 C = constant =100 P X T 
 
 T = thickness of plate = % = . 375 
 
 N = number of rows of rivets = 1 
 
 D = diameter of rivet hole = % = . 750 
 
 EXAMPLE: 
 
 pitch of rivet = 1 . 9375 
 
 thickness of plate = .375 .44179 =area of rivet 
 -- - - 1 =no. of rows 
 
 96875 
 
 135625 .44179 
 
 58125 100=constant 
 
 7265625)44. 1790000(. 60 =60% rivet percentage 
 43 593750 
 
 5852500 
 
LAP JOINTS. 
 
 133 
 
 Rule to find percentage of plate in single riveted joint, steel 
 plate and steel rivets, when pitch and diameter of rivet are given : 
 From pitch of rivet subtract sum of diameter of hole, multiply by 
 constant 100 and divide by pitch. 
 
 FORMULA: 
 
 P dXC 
 
 = percentage of plate 
 
 P 
 
 EXAMPLE: 
 
 1.9375=pitch 
 . 750 = rivet hole diameter 
 
 1.1875 
 
 100= constant 
 
 pitch = 1 . 9375 ) 118 . 7500 (61% = percentage of plate 
 116 250 
 
 2 5000 
 1 9375 
 
 5625 
 
 LLOYDS RULES. 
 
 Rule to find working pressure: Multiply constant by thickness 
 of plate and by per cent of joint efficiency ; divide this product by 
 diameter of boiler. 
 
 CONSTANTS USED. 
 
 'For iron plate punched, lap joint 
 
 drilled 
 
 " punched double strap 
 " " " drilled 
 
 For Steel Plate. 
 
 Lap joints punched 
 
 drilled 
 double strap 
 
 punched 
 
 double strap 
 
 drilled 
 
 LEGEND: 
 
 T = thickness of plate 
 D = diameter 
 % = joint efficiency 
 
 
 Thick- 
 
 Thick- 
 
 Thick- 
 
 
 ness 
 
 ness 
 
 ness 
 
 rap 
 
 H 
 
 155 
 170 
 170 
 180 
 
 2 165 /4 
 180 
 180 
 190 
 
 % & over 
 170 
 190 
 190 
 200 
 
 Thick- 
 
 Thick- 
 
 Thick- 
 
 Thick- 
 
 ness 
 
 ness 
 
 ness 
 
 ness 
 
 y 8 & 
 
 under 
 200 
 
 215 
 
 230 
 
 % & over 
 240 
 
 215 
 
 230 
 
 250 
 
 260 
 
134 THE BOILER. 
 
 FORMULAS: 
 CXTX% 
 
 D 
 PXD 
 
 cx% 
 
 ' working pressure 
 = thickness of plate 
 
 MANCHESTER STEAM USERS ASSOCIATION FORMULAS: 
 TX2X%XTS 
 
 ; DXSXIOO 
 
 DXPXSXIOO 
 TX%X2 
 
 = working pressure 
 = thickness of plate 
 
 APPENDIX. 
 
 The following formulas are taken from those of the British Board 
 of Trade and are given for the determination of the pitch, distance 
 between rows of rivets, diagonal pitch, maximum pitch and distance 
 from centers of rivets to edge of lap of single and double riveted 
 lap joints, for both iron and steel boilers : 
 
 Let p = greatest pitch of rivets in inches. 
 
 n = number of rivets in one pitch, 
 pd = diagonal pitch in inches, 
 d = diameter of rivets in inches. 
 T = thickness of plate in inches. 
 V = distance between rows of rivets in inches. 
 E ^distance from edge of plate to center of rivet in inches. 
 
 TO DETERMINE THE PITCH. 
 
 Iron plates and rivets: 
 
 d 2 X-7854Xn 
 
 1- d pitch 
 
 T 
 
 Example, first, for single-riveted joint: Given, thickness of 
 plate (T) == Y-2 inch, diameter of rivet (d) = % inch. In this 
 case n=l. Required the pitch. 
 
 (%) 2 X. 7854X1 7 
 
 1 = 2.077 inches = pitch 
 
LAP JOINTS. 135 
 
 Example for double-riveted joint: Given, t = J^ inch and d = 
 13/16 inch. In this case n = 2. 
 
 2 X. 7854X2 13 
 
 -H -- = 2 . 886 inches =pitch 
 ^ 16 
 
 For steel plates and steel rivets : 
 
 23Xd 2 X.7854Xn 
 
 28XT 
 
 + d.= pitch 
 
 Example for single-riveted joint: Given, thickness of plate 
 inch, diameter of rivet = 15/16 inch. In this case n = 1. 
 
 23X(if) 2 X. 7854X1 15 
 
 -H =2 . 071 inches = pitch 
 
 28X^ 16 
 
 Example for double-riveted joint: Given, thickness of plate = 
 inch, diameter of rivet = % inch, n = 2. 
 
 23X(^) 2 X. 7854X2 
 
 \-% =2. 85 inches = pitch 
 
 FOR DISTANCE FROM CENTER OF RIVET TO EDGE OF LAP. 
 3Xd 
 
 = E or lap 
 
 Example: Given, diameter of rivet (d) = % inch; required 
 the distance from center of rivet to edge of plate. 
 
 3X% 
 
 = 1 . 312 inches =E, for single or double riveted lap joint. 
 
 2 
 
 FOR DISTANCE BETWEEN ROWS OF RIVETS. 
 
 The distance between lines of centers of rows of rivets for dou- 
 ble, chain-riveted joints (V) should not be less than twice the 
 diameter of rivet, but it is more desirable that V should not be 
 less than 4d+l. ' 
 
136 THE BOILER. 
 
 Example under latter formula : Given, diameter of rivet 
 inch ; 
 
 - =2. 25 inches =V 
 
 2 
 For ordinary, double, zigzag riveted joints: 
 
 (p + 4d) 
 
 10 
 
 Example : Given, pitch = 2.85 inches, and diameter of rivet 
 
 = inch : 
 
 - = 1.487 inches =V 
 
 10 
 
 DIAGONAL PITCH. 
 
 For double, zigzag riveted lap joint. Iron and steel: 
 
 6p + 4d 
 
 10 
 
 Example : Given, pitch = 2.85 inches, and d = % inch ; 
 
 (6X2.85) + (4xJ^) 
 
 =2.06 inches =pd 
 10 
 
 MAXIMUM PITCHES FOR RIVETED LAP JOINTS. 
 
 For single-riveted lap joints: 
 
 Maximum pitch = (1 . 31 XT) + 1% 
 
 For double-riveted lap joints: 
 
 Maximum pitch = (2 . 62 X T) + 1 % 
 
 Example : Given, a thickness of plate = J/ inch, required the 
 maximum pitch allowable. 
 
LAP JOINTS. 137 
 
 For single-riveted lap joint: 
 
 Maximum pitch =(1.3lX^)+l;^=2.28 inches 
 
 For double-riveted lap joint: 
 
 ' Maximum pitch = (2 . 62 X J^) + 1 ?s =2 . 935 inches 
 
 To determine the pitch of rivets from the above formulas, use 
 the diameter and area of the rivet holes. The diameter of the 
 rivets as given in the following tables is the diameter of the driven 
 rivet. 
 
 Any riveted joint will be allowed when it is constructed so as 
 to give an equal percentage of strength to that obtained by the 
 use of the formula given. 
 
 Following are single and double-riveted lap joints tables, taken 
 from the handbook of Thomas W. Traill, entitled Boilers, Marine 
 and Land; Their Construction and Strength, may be taken for use 
 in single and double riveted joints as approximating the formulas 
 of the British Board of Trade for such joints. 
 
 STEEL PLATES AND STEEL RIVETS. 
 SINGLE-RIVETED LAP JOINTS. 
 
 THICKNESS 
 OF PLATE 
 IN INCHES 
 
 DIAMETER 
 OF RIVET 
 IN INCHES 
 
 PITCH IN 
 INCHES 
 
 LAP IN 
 INCHES 
 
 EFFICIENCY 
 
 y 
 
 1 A 
 
 1% 
 
 1 
 
 50 
 
 % 
 
 5 /8 
 
 1/^8 
 
 I L/ 
 
 57 
 
 y 
 
 
 1% 
 
 1 3^ 
 
 60 
 
 & 
 
 % 
 
 1% 
 
 i y$ 
 
 50 
 
 TV 
 
 tt . 
 
 15^ 
 
 !f\ 
 
 54 
 
 P 
 
 
 m 
 
 1M 
 
 56 
 
 
 H 
 
 
 IK 
 
 52 
 
 % 
 
 
 1 7^ 
 
 
 53 
 
 % 
 
 j/% 
 
 2^ 
 
 ITS 
 
 55 
 
 T5 
 
 
 
 1& 
 
 1M 
 
 47 
 
 I 
 
 
 2K 
 
 1 
 
 51 
 53 
 
 
 J/8 
 
 114 
 
 1 ^ 
 
 48 
 
 % 
 
 15. 
 
 2 
 
 \\ 
 
 50 
 
 1^. 
 
 1 
 
 2 TTi 
 
 1*2 
 
 51 
 
 i 
 
 f 
 
 2A 
 
 iH 
 
 46 
 48 
 
138 
 
 THE BOILER. 
 
 COMPUTING STRENGTH OF A DOUBLE RIVETED LAP 
 
 JOINT. 
 
 Causes for failure at joint. 
 
 1st. Resistance to shearing two rivets. 
 
 2nd. Resistance to tearing of plate between two rivets. 
 
 3rd. Resistance to crushing in front of two rivets. 
 
 Assuming a given boiler of dimensions and data as follows 
 LEGEND: 
 
 D = diameter of boiler = 54" 
 
 T = thickness of plate = % = . 3750 
 
 P =pitch of rivets = 3^=3. 0625 
 TS = tensile strength = 55000 
 CS = crushing strength of rivets = 95000 
 SS =shearing strength o;4Jvets =38000 
 
 A =area of rivet hole ~\l -)= . 69029 or . 69 
 
 d = diameter of rivet hole =if = . 9375 
 
 First. Resistance to shearing two rivets. 
 
 Rule to find shearing strength of rivets in single shear: Multi- 
 ply area of rivet hole by number of rivets in single shear and this 
 sum by shearing resistance of rivet. 
 
 FORMULA: 
 
 A X 2 X SS = strength of two rivets in single shear 
 EXAMPLE: 
 
 . 69 =area of rivet hole 
 2 = number of rows 
 
 1.38 
 
 38000 = shearing strength of rivet in 
 
 single shear 
 1104000 
 414 
 
 52440.00 
 52,440 = strength of two rivets in single shear 
 
LAP JOINTS. 139 
 
 Second. Resistance to tearing of plate between two rivets. 
 
 Rule to find strength in net section of plate : From pitch of rivet 
 subtract diameter of rivet; multiply this sum by thickness of plate 
 multiplied by tensile strength. 
 
 FORMULA: 
 
 (P d) X T X TS -strength in net section of plate 
 EXAMPLE: 
 
 3. 0625 -pitch 
 . 9375 -diameter of rivet hole 
 
 2.1250 
 20625 thickness X tensile strength .3750 thickness of plate 
 
 55000 -tensile strength 
 106250 
 
 42500 18750000 
 
 127500 18750 
 
 42500 
 
 20625.0000 
 
 43828.. 
 43, 82 8 -strength of net section of plate 
 
 Third. Resistance to crushing of plate in front of two rivets. 
 
 FORMULA: 
 
 d X2 XT XCS resistance to crushing in front of two rivets 
 EXAMPLE: 
 
 .9375 = diameter of rivet hole 
 2 two times 
 
 1.8750 
 
 . 375 thickness of plate 
 
 93750 
 131250 
 56250 
 
 .7031250 
 
 95000 -crushing strength 
 
 35156250000 
 63281250 
 
 66796. 
 66,796 resistance to crushing in front of two rivets 
 
 Rule to find strength of solid plate : Multiply pitch of rivets by 
 the thickness of plate and this sum by tensile strength. 
 
 FORMULA: 
 P XT XTS = strength of solid plate 
 
140 THE BOILER. 
 
 EXAMPLE: 
 
 3. 062 5 =3, A pitch 
 
 .375 = thickness of pla-te 
 
 153125 
 214375 
 91875 
 
 1.1484375 
 
 55000 = tensile strength 
 
 5742 1875000 
 57421 875 
 
 63 , 164 = strength of solid plate 
 
 Rule to find efficiency from weakest section of joint: Multiply 
 sum of weakest section by 100 and divide by sum of strength of 
 solid plate. 
 
 FORMULA: 
 43,828X100 
 
 63,163 
 
 = efficiency of joint 
 
 EXAMPLE: 
 
 43,828 = strength of net section of plate 
 100= constant 
 
 strength of solid plate = 63,164)4382800(69 per cent efficiency of 
 
 378984 joint 
 
 592960 
 568476 
 
 24484 
 
 Rule to find safe working pressure from these calculations : 
 Multiply tensile strength of plate by joint's efficiency and multiply 
 this sum by twice the thickness of plate and divide this product by 
 the diameter of boiler in inches multiplied by factor of safety. 
 
 FORMULA: 
 TSX%X(2XT) 
 
 DxF 
 
 = working pressure 
 
LAP JOINTS. 141 
 
 EXAMPLE : 
 
 55000 = tensile strength 
 . 69 = efficiency of joint 
 
 495000 
 330000 
 
 37950.00 
 
 750 = twice thickness of plate 
 
 diam of boiler = 54" 1897500 
 factor of safety = 5 265650 
 
 270)28462 . $J0 (105 Ibs. working pressure 
 270 
 
 1462 
 1350 
 
 112 
 
 When finding diameter of rivet holes for lap and butt joints, the 
 following constants are used: 
 
 C=2.25 for lap joints double riveted up to and including y 2 " 
 plate. 
 
 C=1.9 for triple riveted lap joint up to J/" plate. 
 
 C=1.8 for butt joints triple and quadruple riveted. 
 
 Rule to find diameter of rivet hole : The square root of product 
 of thickness of plate in inches multiplied by constant used in con- 
 nection with joint form and plate will give diameter of rivet hole. 
 
 LEGEND: FORMULA: 
 
 T = thickness of plate = & = . 4375 N/TxC = diameter of rivet hole 
 
 C= constant =2. 2 5 
 
 EXAMPLE: 
 
 .4375 = thickness of plate 
 2.25 = constant 
 
 21875 
 8750 
 8750 
 
 9) . 984375 (. 9921 =1" nearly or hole for 
 . 81 rivet 
 
 189) 1743 
 ) 1701 
 
 1982) 4275 
 
 ) 3964 
 \ 
 
 19841) 31100 
 
 J 19841 
 
 \ 
 
 ) 11259 
 
142 THE BOILER. 
 
 Rule to find diameter of shell : Multiply tensile strength by 
 thickness of plate in inches and by per cent of joint; divide this 
 product by pressure multiplied by the factor. 
 
 FORMULA: 
 TSxTx%of joint 
 
 PXF 
 LEGEND: 
 
 X 2 = diameter of shell 
 
 P= pressure = 130 
 
 T = thickness of plate = % = . 5 
 
 % = percentage of joint = 80 EXAMPLE : 
 
 TS = tensile strength = 60000 60000 tensile strength 
 
 . 5 = thickness of plate 
 
 pressure = 130 30000.0 
 
 constant = 6 80 = joint efficiency 
 
 780) 24000. 00(30= radius 
 2340 2 
 
 600 60" diameter 
 
 Rule to find tensile strength of plate for boiler : Multiply given 
 pressure per square inch by tensile strength; multiply this by one- 
 half diameter of boiler ; divide by the given thickness of material in 
 inches, and the quotient will give the required tensile strength per 
 square inch in pounds. 
 
 FORMULA: 
 
 (PxT$)X(^of D) 
 
 = tensile strength 
 T 
 
 LEGEND: 
 
 TS = tensile strength = 60000 
 P = pressure = 125 Ibs. 
 D =diameter of boiler = 60" 
 T = thickness of plate = . 3750 
 
 EXAMPLE: 
 
 125 = pressure 
 
 60000 = tensile strength 
 
 7500000 
 
 30 = Y<>, the diameter 
 
 thickness of plate = . 3750)225000000 (60000 Ibs. =tensile strength 
 22500 
 
 00000 
 
LAP JOINTS. 143 
 
 Rule to find thickness of shell plate when percentage of joint is 
 known : Multiply diameter of shell by pressure and again by factor 
 of safety and multiply this sum by 100 ; divide product by tensile 
 strength multiplied by efficiency of seam multiplied by 2. 
 
 LEGEND: FORMULA: 
 
 D= diameter = 60" DxPXFXlOO 
 
 P = pressure = 150 = thickness of shell plate 
 
 F=f actor of safety = 5 TSX%X2 
 
 % = percentage of seam strength = 80 
 TS = tensile strength = 60000 
 C = constant = 100 
 
 EXAMPLE: 
 
 60" = diameter of shell 
 ISO = pressure 
 
 3000 
 60 
 
 tensile strength = 60000 9000 
 
 percentage = 80 5 =factor 
 
 4800000 45000 
 two times = 2 100= constant 
 
 9600000) 4500000 . 0000 ( . 4687 = 15/32" = thickness 
 3840000 required 
 
 660000 00 
 576000 00 
 
 84000 000 
 76800 000 
 
 7200 0000 
 6720 0000 
 
 480 0000 
 
 Rule to find diameter of steel rivet for steel plate double riveted 
 lap joint : Add y% of an inch to plate thickness. 
 
 FORMULA: 
 ^ plus T = diameter of rivet 
 
 T =thickness of plate = & = . 4375 EXAMPLE : 
 
 .4375 = plate 
 .375 = 
 
 8125 = rivet diameter 
 
144 THE BOILER. 
 
 Rule to find pitch of rivet in a double riveted lap joint steel 
 plate, steel rivets : Multiply square of diameter of rivet hole by 
 constant 23, this sum by .7854; then multiply this product by the 
 number of rows of rivets; divide by diameter of rivet multiplied 
 by constant 28, and add diameter of rivet hole to quotient. Result 
 gives pitch of rivet. 
 
 FORMULA: 
 d 2 X23X.7854xN 
 
 dx28 
 
 + d = pitch 
 
 d = diameter of rivet hole = % = . 9375 
 
 N = number of rows = 2 EXAMPLE: 
 
 .9375 = diameter rivet hole 
 .9375 
 
 46875 
 65625 
 28125 
 84375 
 
 [squared 
 
 .87890625= diameter of rivet hole 
 23= constant 
 
 263671875 
 175781250 
 
 20 
 
 .7854 
 
 808592 
 1010740 
 
 diam. of rivet hole = . 9375 1617184 
 constant = 28 1415036 
 
 75000 15,87670392 
 19750 2 rows of rivets 
 
 26 . 2500)31.75340784 (1 . 2096 
 
 262500 . 9375 =diameterof rivethole 
 
 550340 2. 1471= 2 & nearly =pitch 
 525000 
 
 2534078 
 2362500 
 
 1715784 
 1S75000 
 
 140784 
 
LAP JOINTS. 145 
 
 Rule to find distance between rows of chain double riveted joint: 
 To four times the diameter of one rivet hole add one and divide by 
 two. 
 
 FORMULA: 
 4d plus 1 
 
 = distance between rows chain riveted joint 
 
 2 
 
 LEGEND: 
 d = diameter of rivet hole = J/g = . 8750 
 
 EXAMPLE : 
 . 8750 = diameter of rivet hole 
 
 3.5000 
 
 1 . 0000 added 
 
 2)4.5000 
 
 2 . 2500 = 2 }' distance between rows 
 
 Rule to find diagonal pitch of rivet : To four times the diameter 
 of rivet hole add six times the pitch on straight line and divide by 10. 
 
 FORMULA: 
 
 4d + 6P 
 
 = diagonal pitch 
 10 
 LEGEND: 
 
 d =diameter of rivet hole = % = . 8750 
 p=pitch=3^=3.3750 
 
 EXAMPLE: 
 
 3 . 3750 = pitch .8750 = diameter of rivet hole 
 
 6 times 4 times 
 
 20.2500 3.5000=4 times diameter 
 
 V- - 20. 2500 =6 times pitch 
 
 10)23 . 7500 (2 . 3750 =2 % diagonal pitch of 
 20 rivets 
 
 37 
 30 
 
 75 
 70 
 
 50 
 50 
 
146 THE BOILER. 
 
 Rule to find spacings center of rivet to edge of plate. Multiply 
 diameter of rivet by 3 and divide by 2. 
 FORMULA: 
 
 3Xd 
 
 - = distance from center of rivet to edge of plate 
 2 
 
 d=diam. of rivet % = . 8750 EXAMPLE: 
 
 .8750 
 3 
 
 2)2.6250 
 
 1.3 125=1^ inch distance 
 
 Rule to find pitch of rivet to give best percentage of strength 
 in a double zig zag riveted joint: Multiply twice the rivet sectional 
 area by the shearing strength of rivet and divide by thickness of 
 plate multiplied by its tensile strength ; add to product one diameter 
 of rivet. 
 
 FORMULA: 
 (2XA)XSS 
 
 plus 1 diam. of rivet = pitch 
 LEGEND: TxTS 
 
 A = rivet area = ! =.5185 
 SS = shearing strength one rivet =38000 
 T = plate thickness = % = . 3750 
 TS = tensile strength of plate = 60000 
 d = diameter of rivet =f =.8125 EXAMPLE: 
 
 .5185 = sectional area of rivet 
 2 
 
 1 . 0370 =twice sectional area of rivet 
 
 38000 = shearing strength of one rivet 
 
 Y % plate = .3750 82960000 
 
 tensile strength = 6000031110 
 
 22500. 0000)39406. 0000 (1.7513 
 
 22500 . 8125 =diam. of one rivet 
 
 169060 2. 5 638= 2 & inch pitch 
 
 157500 
 
 115600 
 112500 
 
 31000 
 22500 
 
 85000 
 67500 
 
 17500 
 
LAP JOINTS. 
 
 147 
 
 Rule to find plate percentage in a double riveted lap joint 
 From pitch of rivet subtract diameter of rivet and multiply by con- 
 stant 100; divide this product by pitch of rivet. 
 
 LEGEND- FORMULA: 
 
 P -pitch =3^ -3. 125 (P d)XlOO 
 
 = percentage of plate 
 
 d = diameter of rivet hole 
 C= constant = 100 
 
 = .8750 
 
 EXAMPLE: 
 
 3 . 1250 =pitch of rivet 
 . 8750 =diameterof rivet hole 
 
 2.2500 
 
 100= constant 
 
 3 . 1250)225 . 0000 (72 = percentage of plate 
 218750 
 
 62500 
 62500 
 
 Rule to find percentage of rivet in a double riveted lap joint: 
 Multiply area of rivet by the number of rows of rivet in one pitch ; 
 multiply this product by 100 and by the constant 23; divide this 
 product by pitch multiplied by thickness of plate and constant 28. 
 
 FORMULA: 
 .4375 AXNX100X23 
 
 =per cent, of rivet 
 
 LEGEND: 
 
 T = thickness of plate = 
 P -pitch =3% =3. 125 
 A =area of rivet hole = % = . 6013 
 d =diameter of rivet = % = . 8750 
 N = number of rows == 2 
 
 pitch =3. 125 
 thickness of plate = .4375 
 
 PXTX28 
 
 section 
 
 EXAMPLE: 
 
 6013 =area of rivet hole 
 2 rows 
 
 15625 
 21875 
 9375 
 1 2500 
 
 1.3671875 
 
 constant= 28 
 
 1.2026 
 100 
 
 = constant 
 
 120.2600 
 
 23 = constant 
 
 10 9375000 
 27 343750 
 
 38.2812500 
 
 3607800 
 2405200 
 
 38 . 281 )2765 . 9800 (72.2= % of rivet strength 
 2679 67 
 
 86 310 
 76 562 
 
 9 7480 
 7 6562 
 
 2 0918 
 
148 THE BOILER. 
 
 Rule to find bursting pressure of boiler: Multiply tensile 
 strength by twice the thickness of plate and divide by the internal 
 diameter of boiler. 
 
 FORMULA : 
 TSX(2XT) 
 
 D 
 LEGEND : 
 
 = bursting pressure 
 
 TS = tensile strength =60000 
 T = thickness of plate = % = . 375 
 D =internal diameter = 60" 
 
 EXAMPLE: 
 
 thickness of plate = .375 60000 = tensile strength 
 
 2 . 750 = twice thickness of plate 
 
 twice thickness = .750 3000000 
 
 420000 
 
 internal diameter =60") 45000. 000 (750 Ibs. per square inch burst- 
 420 ing pressure 
 
 300 
 300 
 
 The bursting pressure divided by the factor of safety will give the safe 
 working pressure. The factor of safety of 5 has been generally accepted by 
 eminent engineers and boilermakers. 
 
 factor = 5) 750 per sq. inch bursting pressure 
 150 Ibs. working pressure 
 
 Rule to find working pressure on boilers from a lowest per- 
 centage of joint: Multiply tensile strength of material by the lowest 
 percentage of joint, then by twice the thickness of plate and divide 
 by diameter multiplied by factor of safety. 
 
 FORMULA: 
 
 TSX%X(2XT) 
 
 =working pressure 
 
 DXF 
 
 LEGEND: 
 
 TS =tensile strength = 60000 
 % = lowest percentage of joint = 80 
 
 T = thickness of plate = % = . 500 
 
 D =internal diameter = 71.1250 (outside = 72" ) 
 
Internal 
 
 LAP JOINTS. 
 
 EXAMPLE : 
 
 60000 = tensile strength 
 80 = percentage of joint 
 
 149 
 
 diameter of boiler - 71 . 1250 4800000 
 
 factor of safety = 6 1 . 0000 = twice thickness of plate 
 
 426. 75^0)4800000 . 0000 (112 Ibs. working pressure 
 4267500 
 
 5325000 
 4267500 
 
 10575000 
 8535000 
 
 2040000 
 
 Rule to find safe working pressure according to the U. S. Gov- 
 ernment rule is as follows : Multiply one sixth of the lowest tensile 
 strength found stamped on any plate by the thickness of same, 
 expressed in inches or decimal parts of same, and divide by the 
 radius or half of diameter expressed in inches. The result will 
 give pressure allowed for a single riveted boiler; when double 
 riveted add 20 per cent. This rule is based on the rivet and plate 
 section being equal and holes drilled. 
 
 Thickness 
 of plate 
 
 Diameter 
 of rivet 
 
 Pitch in 
 inches 
 
 Lap in 
 inches 
 
 Distance 
 between 
 rows 
 
 Efficiency 
 
 M 
 
 H 
 
 ^ 
 
 \l 
 
 1 
 
 iS- 
 
 69 
 
 72 
 
 M 
 
 H 
 
 2 % 
 
 111 
 
 li| 
 
 74 
 
 T 
 
 N 
 
 2ft 
 
 IM 
 
 1^ 
 
 68 
 
 ft 
 
 tt 
 
 
 
 1% 
 
 70 
 
 . A 
 
 
 2K 
 
 i J^ 
 
 1^| 
 
 72 
 
 || 
 
 M 
 
 
 iM 
 
 1 K 
 
 68 
 
 if 
 
 it 
 K 
 
 2% 
 
 JS 
 
 2 
 
 69 
 
 71 
 
 * 
 
 ^ 
 
 2 & 
 
 
 i j4 
 
 65 
 
 ft 
 
 K 
 
 2 
 
 il 
 
 2 2 
 
 67 
 
 7 
 
 
 3 _^. 
 
 
 
 70 
 
 \^ 
 
 K 
 
 2tt 
 
 ift 
 
 2 1 " 
 
 65 
 
 y>, 
 
 if 
 
 3 
 
 I'H 
 
 2 K 
 
 66 
 
 /^ 
 
 i 
 
 3 1^ 
 
 l^i 
 
 2^ 
 
 68 
 
 ft 
 
 g 
 
 15 
 
 ^ 
 
 2 
 
 63 
 65 
 
150 
 
 THE BOILER. 
 
 COMPUTING STRENGTH OF TRIPLE RIVETED LAP 
 
 JOINTS. 
 
 Causes for failure at joint. 
 
 1st. Resistance to shearing three rivets. 
 
 2nd. Resistance to tearing between three rivets. 
 
 3rd. Resistance to crushing in front of three rivets. 
 
 Assuming a boiler of dimensions and data as follows : 
 LEGEND: 
 
 T -thickness of plate == y % = . 375 
 TS = tensile strength = 55000 
 
 d -diameter of rivet = 13/16 = . 8125 
 
 A = area of rivet hole =13 X 16 = .5185 
 
 P =pitch of rivet = 3 J4 = 3 . 2500 
 SR = shearing resistance of rivets =38000 
 CS = crushing strength of rivet and plate = 95000 
 
 D = diameter of boiler = 60" 
 
 F = factor of safety = 5 
 
 First. Resistance to shearing of three rivets. 
 
 Rule to find strength of rivets in single shear : Multiply area 
 of rivet hole by number of rivets, and multiply this sum by the 
 shearing resistance of rivet material. 
 
 FORMULA: 
 
 Ax No. of rivets XSR = strength of rivets in single shear 
 EXAMPLE: 
 
 .5185 =area of rivet hole 
 3 = number of rivets 
 
 1.5555 
 
 38000 = shearing resistance of rivets 
 
 124440000 
 46665 
 
 59109.0000 
 59,109 Ibs. = strength of three rivets in single . c hear 
 
LAP JOINTS. 151 
 
 Second. Resistance to tearing of plate between three rivets. 
 
 Rule to find strength of net section of plate : From pitch of 
 rivets subtract diameter of rivet hole and multiply by thickness of 
 plate and multiply this sum by the tensile strength of plate. 
 
 FORMULA: 
 
 (P d) XTxTS= strength of net section of plate 
 EXAMPLE : 
 
 3 . 2500 -pitch of rivet 
 . 8125 = diameter of rivet hole 
 
 2.4375 
 
 .375 = thickness of plate 
 
 121875 
 170625 
 73125 
 
 9140625 
 
 55000 = tensile strength 
 
 45703125000 
 45703125 
 
 50273.4375000 
 50,273 ^strength of net section of plate 
 
 Third : Resistance to crushing in front of plate in front of three 
 rivets. 
 
 FORMULA: 
 
 dX3xTxCS= resistance to crushing in front of three rivets 
 
 EXAMPLE: 
 
 .8125 = diameter of rivet 
 3 = three rivets 
 
 2.4375 
 
 .375 = thickness of plate 
 
 121875 
 170625 
 73125 
 
 9140625 
 
 95000= crushing strength of rivet 
 and plate 
 
 4570 3125000 
 82265 625 
 
 86835.9375000 
 
 86,835 Ibs. = resistance to crushing of material 
 
152 THE BOILER. 
 
 Rule to find strength of solid plate : Multiply pitch of rivets by 
 thickness of plate and this sum by tensile strength of material. 
 
 FORMULA: 
 P XT XTS = strength of solid plate 
 
 EXAMPLE: 
 
 3. 2500 -pitch 
 
 .375 = thickness of solid plate 
 
 162500 
 227500 
 97500 
 
 1.2187500 
 
 55000 = tensile strength 
 
 6093 7500000 
 60937 500000 
 
 67031.2500000 
 67,031 Ibs. -strength of solid plate 
 
 Rule to find efficiency of this joint: Divide net section of plate 
 by strength of solid plate. 
 
 EXAMPLE: 
 
 50,273 =net section of plate 
 67,031 = strength of solid plate 
 
 67031) 50273 . 000 ( . 749 =efficiency 
 46921 7 
 
 3351 30 
 2681 24 
 
 670 060 
 603 279 
 
 66 781 
 
LAP JOINTS. 
 
 153 
 
 Rule to find safe working pressure from these calculations: 
 Multiply tensile strength of plate by efficiency of joint and multiply 
 this sum by twice thickness of plate ; divide this product by diameter 
 of boiler in inches multiplied by factor of safety. 
 
 EXAMPLE: 
 
 55000 = tensile strength of plate 
 . 749 = percentage of joint 
 
 495 000 
 2200 00 
 38500 
 
 41195.000 
 
 . 7 500 = twice thickness of plate 
 
 diam. of boiler = 60" 2059 7500 
 factor of safety = 5 28836 5 
 
 300)30896.23^(102.9 Ibs. working pressure 
 300 
 
 896 
 600 
 
 2962 
 2700 
 
 262 
 
 Thickness 
 of plate 
 
 Diameter 
 of rivet 
 
 I 
 I 
 
 1 
 
 14 
 
 \ 
 !ii 
 
 Pitch in 
 in inches 
 
 Lap in 
 in inches 
 
 14 
 
 Distance 
 
 between 
 
 rows 
 
 2 
 
 Efficiency 
 
 76 
 80 
 81 
 76 
 76 
 79 
 76 
 77 
 79 
 73 
 76 
 77 
 73 
 74 
 76 
 72 
 73 
 
CHAPTER VII. 
 
 BUTT JOINT DOUBLE STRAPPED AND DOUBLE 
 RIVETED. 
 
 Where butt straps are used in the construction of marine boilers, 
 the straps for single butt strapping shall in no case be less than 
 the thickness of the shell plates; and where double butt straps are 
 used, the thickness of each shall in no case be less than five-eighths 
 (^s) the thickness of the shell plates. 
 
 A rule to find thickness of butt straps is as follows : Multiply 
 the thickness of shell plate by factor 5 and this sum by the wide pitch 
 of rivets in inches minus diameter of one rivet ; divide this product by 
 the wide pitch minus two times diameter of rivet multiplied by 
 constant 8. 
 
 FORMULA: 
 TxFx(WP d) 
 
 WP (2Xd)xC 
 
 LEGEND: 
 
 = thickness of each butt strap 
 
 T = thickness of plate = ^ = 4375 
 d =diameter of rivet = % = . 8750 
 WP=wide pitch =6% =6. 7500 
 F=factor = 5 
 C= constant =8 
 
 154 
 
BUTT JOINTS. 155 
 
 EXAMPLE: 
 
 . 4375 = thickness of plate 
 5 = factor 
 
 2 . 1875 =5 times thickness 
 5.8750 6. 7 5 00= wide pitch 
 
 wide pitch = 6 . 7500 . 8750 =rivet diameter 
 
 twice rivet diam. = 1. 7500 1093750 
 
 153125 5.8750 
 
 5.0000 175000 
 constant = 8 109375 
 
 40 . 0W) 12 . 85150JW ( . 3212 = thickness of butt strap 
 12 = $ approximately 
 
 85 
 80 
 
 51 
 40 
 
 115 
 80 
 
 35 
 
 When joints have one strap, butt or lap, the rivets are in single 
 shear only. In triple riveted joints, double strap, the two inner rows 
 are in double shear and the outer in single shear. 
 
 Rule to find strength of a solid strip of plate or resistance to a 
 tensile strength : Multiply width of strip by thickness of plate and 
 this product by the tensile strength of material. 
 
 FORMULA: 
 
 WxTxTS = strength of solid plate 
 LEGEND: 
 
 W = width of strip =6.3750 
 T = thickness of plate = .4375 
 TS = tensile strength =60000 
 
 EXAMPLE: 
 
 6.3750=width of strip 
 .4375 = thickness of plate 
 
 318750 
 446250 
 191250 
 2 55000 
 
 2.78906250 
 
 60000 = tensile strength 
 
 1 67343. 
 167,343 Ibs. =strength of solid plate 
 
156 THE BOILER. 
 
 BUTT JOINT, DOUBLE STRAP AND DOUBLE RIVETED. 
 
 Possible causes for failure. 
 
 First. Resistance to tearing of plate at outer row of rivets. 
 
 Second. Resistance to shearing of two rivets in double shear and one in 
 
 single shear. 
 Third. Resistance to tearing of plate at inner row of rivets and shearing 
 
 one of the outer row single shear. 
 
 Fourth. Resistance to crushing in front of three rivets. 
 Fifth. Crushing in front of two rivets and shearing one rivet. 
 
 LEGEND: 
 
 T = thickness of plate = & = . 4375 
 dh =diameter of rivet hole = if = . 8125 
 D = diameter of boiler = 60" 
 
 p=pitchof rivets =4 ^ =4. 3750 
 TS 
 
 A S = tensile strength = 60000 
 
 A =area of rivet hole = if - . 5185 
 SS=shearing strength of rivet, single shear =38000 
 DS= " " " double " =70300 
 
 N = number of rows of rivets =2 
 CS = crushing strength of material =95000 
 
 F = factor of safety =-5 
 
 First. Resistance to tearing at outer row of rivets. 
 
 FORMULA: 
 (p dh) xTxTS =net section of plate 
 
 EXAMPLE: 
 
 4 . 3750 =pitch of rivet 
 . 8125 =diameter of rivet hole 
 
 3.5625 
 
 .4375 = thickness of plate 
 
 178125 
 249375 
 106875 
 1 42500 
 
 1.55859375 
 
 60000 = tensile strength 
 
 93,515 Ibs. = strength of net section of plate. 
 
 Second. The resistance to shearing two rivets in double shear and one in 
 single shear. 
 
 FORMULA: 
 A X N X DS + ( A X SS ) = total shearing strength of rivets 
 
BUTT JOINTS. 157 
 
 EXAMPLE: 
 
 .5185 =area of rivet hole 
 
 2 = number of rows of rivets 
 
 1.0370 
 
 70300 shearing strength 
 
 double shear 
 
 area of rivet = .5185 3111000 
 
 single shearing strength = 38000 72590 
 
 4148 0000 72901. J000 
 15555 19703 . -area multiplied by SS 
 
 19703. JW 92604 lbs.= total shearing strength 
 
 of rivets 
 
 Third. The resistance to tearing at inner row of rivets and shearing of one 
 rivet. 
 
 FORMULA: 
 (p 2dh) XTXTS+ (AxSS) = resistance to tearing at inner row 
 
 EXAMPLE: 
 
 4. 3750 -pitch of rivets 
 
 1 . 6250 =two diameters of rivet hole 
 
 2.7500 
 .4375 -thickness of plate 
 
 137500 
 192500 
 82500 
 1 10000 
 
 1.20312500 
 
 60000 tensile strength 
 
 72187.^0000000 
 
 19703 -area multiplied by SS 
 
 91890 Ibs. resistance to tearing at inner row 
 of rivets 
 
 Fourth. The resistance to crushing in front of three rivets. 
 
 FORMULA: 
 dh X 3 X T X CS = resistance to crushing 
 
158 THE BOILER. 
 
 EXAMPLE : 
 
 . 8125 =diameter of rivet 
 3 = three rivets 
 
 2.4375 
 .4375 = thickness of plate 
 
 121875 
 170625 
 73125 
 97500 
 
 1.06640625 
 
 9 5 000= crushing strength 
 
 5332 03125000 
 95976 5625 
 
 101308 .^9^/7^000 Ibs. = resistance to crushing strength 
 in front of three rivets 
 
 Fifth. The resistance to crush in front of two rivets and shearing of one rivet 
 
 FORMULA: 
 2xTxCS+ (AxSS) =resistance to crushing plate and shearing one rivet 
 
 EXAMPLE : 
 
 .4375 = thickness of plate 
 2 =two rivets 
 
 . 8750=twice thickness of plate 
 95000 = crushing strength 
 
 43750000 
 78750 
 
 83125.0000 
 
 19703 =area multiplied by SS 
 
 102828 Ibs. ^resistance to crushing plate and 
 shearing one rivet 
 
 Strength of solid plate. 
 
 FORMULA: 
 p xTxTS = strength of solid plate 
 
 EXAMPLE: 
 4.3750=pitch 
 .4375 =thickness of plate 
 
 218750 
 306250 
 131250 
 1 75000 
 
 1.91406250 
 
 60000= tensile strength 
 
 1 14843.^000000 Ibs. ^strength of solid plate 
 
BUTT JOINTS. 
 
 159 
 
 To find efficiency of joint from these computations : Divide weakest sec- 
 tion of plate by strength of solid plate. 
 
 EXAMPLE: 
 
 Weakest section of plate =91890 
 Strength of solid plate =114843 
 
 1 14843 ) 91890 . 00 ( . 80 ^efficiency of joint 
 91874 4 
 
 15 60 
 
 Rule to find safe working pressure from joint efficiency : Multi- 
 ply tensile strength of plate by joint efficiency and multiply that 
 product by twice the thickness of plate ; divide by diameter of boiler 
 multiplied by factor of safety. 
 
 FORMULA: 
 TSX%X(2XT) 
 
 =safe working pressure 
 DXF 
 
 EXAMPLE : 
 
 60000 =tensile strength 
 . 80 = efficiency, of joint 
 
 48000. ( 
 .8750 
 
 2400000 
 
 diameter of boiler = 60" 3360000 
 factor = 5 3840000 
 
 300) 42000. W*0 (140 Ibs. = working pressure 
 300 
 
 1200 
 1200 
 
 DOUBLE RIVETED BUTT JOINTS. 
 
 
 
 s 
 
 gw 
 
 C 51 
 
 Y6 m 
 
 X" 
 
 4% " 
 
 9 in 
 9% " 
 
 l^in 
 
 2K " 
 
 83 
 82.9 
 
 82 
 80 
 
160 THE BOILER. 
 
 BUTT JOINT DOUBLE STRAPPED TRIPLE RIVETED. 
 
 " 
 
 Rule to find diagonal pitch of rivets for a butt joint double strap 
 and triple riveted: 
 
 To the horizontal pitch multiplied by 6 add diameter of rivet 
 multiplied by 4 and divide result by 10. 
 
 FORMULA: 
 (HpxC6) + (dxC4) =diagonal pitch 
 
 10 
 
 LEGEND: 
 
 Hp = horizontal pitch =3.3750 
 d = diameter of rivet = . 8750 
 
 horizontal pitch = 3 . 3750 
 6 
 
 20.2500 
 3.5000 
 
 EXAMPLE :, 
 
 diameter of rivet = .8750 
 . 4 
 
 3.5000 
 
 10)23.7500(2.3750=diagonal pitch 
 20 
 
 37 
 30 
 
 75 
 70 
 
 50 
 50 
 
BUTT JOINTS. 161 
 
 Rule to find distance between inner rows of rivets in a butt joint, 
 double or triple riveted chain or zig zag form. Multiply 1 1 times 
 the pitch plus 8 times the rivet diameter by the pitch, plus 8 times 
 the rivet diameter ; extract square root of this product and divide the 
 sum by 10. 
 
 FORMULA: 
 
 distance between rows of rivets 
 
 10 
 
 LEGEND: 
 
 p = narrow pitch =3^=3.375 
 d = diameter of rivet = . 875 
 
 EXAMPLE: 
 
 3.375=narrow pitch 
 11=11 times 
 
 37.125 
 7.000 . 875= rivet diam. 
 
 44.125 
 
 10.375 7 . 000 = 8 times rivet diam. 
 
 220625 3.375 = narrow pitch 
 3 08875 7 . 000 = 8 times diam. rivet 
 
 13 2375 
 
 441 25 10.375 
 
 2)458.796875(21.419 
 
 41) 58 
 ) 41 
 
 424) 1779 10)21.419 
 
 | 16% 2.1419=2^ approximate dis- 
 
 4281) 8368 tanCG 
 
 ) 4281 
 
 42829) 408775 
 
 ) 385461 
 \ 
 
 ) 23314 
 
 Rule to find pitch of rivets in a -butt joint double strap and 
 triple riveted inner row : Multiply thickness of plate by 3.5 and 
 add 1^ of an inch to product. 
 
 LEGEND: FORMULA: 
 
 T=thickness of plate = ^ = .4375 TX3.5 + ! 5 /6=pitch 
 
 p=pitch 3.5=3.5000 
 1^=1.6250 
 
162 THE BOILER. 
 
 EXAMPLE: 
 
 .4375 = th*ickness of plate 
 3.5 
 
 21875 
 13125 
 
 1.53125 
 
 i.625o = 
 
 3.15625= 3& pitch 
 
 Rule to find plate percentage at wide pitch : From wide pitch 
 subtract diameter of rivet and divide this product by wide pitch of 
 rivet. 
 
 FORMULA : 
 
 WP d 
 
 = plate percentage 
 
 WP 
 
 LEGEND: 
 
 WP = wide pitch = 6 . 7500 
 
 d = rivet diameter = = . 93 75 
 
 EXAMPLE : 
 
 6 . 7500 =pitch of rivet 
 . 9375 =diameter of rivet 
 
 wide pitch =6.7500)5. 812500 (. 86 =plate .percentage at wide pitch 
 5 40000 
 
 412500 
 405000 
 
 7500 
 
 Rule to find percentage of plate at narrow pitch : From narrow 
 pitch subtract rivet diameter and divide this product by narrow 
 pitch. 
 
 FORMULA : 
 
 NP d 
 
 = plate percentage 
 NP 
 
 LEGEND: 
 
 NP= narrow pitch =3. 5 000 
 d = rivet diameter =|| = . 9375 
 
BUTT JOINTS. 163 
 
 EXAMPLE : 
 
 3 . 5000 = narrow pitch 
 .9375 rivet diameter 
 
 narrow pitch -3. 5000) 2. 562500 (.73 = plate percentage at nar- 
 2 45000 row pitch 
 
 112500 
 105000 
 
 7500 
 
 Rule to find safe working pressure on a boiler butt joint double 
 strap, triple riveted : Multiply tensile strength of material by the 
 lowest percentage of joint and this sum by twice the thickness of 
 plate ; divide by diameter of boiler multiplied by factor of saftey. 
 
 FORMULA: 
 TSX%X(Tx2) 
 
 DxF 
 LEGEND: 
 
 TS = tensile strength =60000 
 % = lowest percentage of joint =73% 
 
 T = thickness of plate = ^ = . 4375 
 
 D = diameter of boiler = 72" 
 
 F = factor of safety =5 
 
 EXAMPLE: 
 
 =safe working pressure 
 
 60000 = tensile strength 
 
 . 73 = lowest percentage of joint 
 
 180000 
 420000 
 
 43800.00 
 
 .8750=twice thickness of plate 
 
 219000000 
 
 boiler diam. = 72 30660000 
 factor = 5 35040000 
 
 360)38325. JWW (106 Ibs. working pressure 
 360 
 
 2325 
 2160 
 
 165 
 
164 
 
 THE BOILER. 
 TRIPLE RIVETED BUTT JOINTS. 
 
 o 
 
 ^-, c. 
 
 
 
 o's 
 
 & 
 f 1 
 
 1 
 
 Yf 
 \l 
 
 X 
 
 u 
 
 A 
 
 11 
 
 14 
 14 
 
 9% 
 LO 
 
 LO 
 11 
 
 16 
 
 16M 
 
 18 
 
 18 
 
 3M 
 3M 
 
 3% I 
 
 674 
 6M 
 
 2^ 
 
 87 
 86 
 88 
 88 
 87 
 87 
 86 
 86 
 86 
 85 
 84 
 
 COMPUTING STRENGTH OF A BUTT JOINT DOUBLE STRAP AND TRIPLE 
 
 RIVETED. 
 
 There are five causes for failure at a butt joint double strap 
 and triple riveted, as follows : 
 
 First. By tearing at outer row of rivets. 
 
 Second. By shearing of four rivets in double shear and one in single 
 shear. 
 
 Third. By the tearing at middle row of rivets and the shearing of one 
 rivet. 
 
 Fourth. By the crushing in front of four rivets and shearing of one rivet. 
 
 Fifth. By the crushing in front of five rivets, four through strap, the 
 fifth through inner covering of plate only. 
 
 LEGEND: 
 
 D = diameter of boiler = 72" 
 ID = internal diameter of boiler = 71 . 1250 
 
 F=factor = 5 
 TS = tensile strength = 60000 
 
 P = pressure 
 
 Pt = pitch inner row =3^=3.375 . ;i 
 
 Po =pitch outer row =6% =6. 750 
 SS = shearing strength of rivets =38000 
 CS = crushing resistance =95000 
 
 T ^thickness of plate = T V = . 4375 
 
 d ^diameter of rivet = % = . 8750 
 DH = diameter of rivet hole = jf = . 9375 
 
 A =area of rivet = . 6903 
 CP = cover plate or thickness of strap = . 3750 
 
BUTT JOINTS. 165 
 
 First. The failure by tearing at the outer row of rivets, the resistance is 
 found by the following rule: From pitch of rivet subtract the 
 diameter of rivet and multiply by thickness of plate and then multi- 
 ply by tensile strength of material. 
 
 FORMULA: 
 (Po DH) XTxTS =net section of plate 
 
 EXAMPLE: 
 
 6. 7 5 00= wide pitch 
 .9375 = diameter of rivet hole 
 
 5.8125 
 .4375 = thickness of plate 
 
 290625 
 406875 
 174375 
 2 32500 
 
 2.54296875 
 
 60000 = tensile strength of plate 
 
 152578. WWWW Ibs. -net section of plate 
 
 Second. Shearing of four rivets in double shear and one in single shear. 
 
 FORMULA: 
 
 A X N X DS + Id of SS = strength of rivets 
 N = number of rivets =4 
 for double shear 
 
 EXAMPLE: 
 
 . 6903 =area of f rivet 
 
 4 = number of rivets, double shear 
 
 area of rivet = . 6903 2.7612 
 
 single shearing re- = 38000 70300 = strength of rivets double shear 
 sistance 
 
 55224000 8283600 
 
 20709 193284 
 
 26231. &W 194112. 
 
 26231. = single shearing strength one 
 
 rivet 
 220343 . Ibs. -strength of rivets 
 
 Third. Tearing at middle row of rivets and shearing of one rivet, the resist- 
 ance is : 
 
 FORMULA: 
 
 (Po 2DH) XT XTS plus (A X SS) = resistance to tearing of plate at middle 
 
 row and shearing one rivet 
 
166 THE BOILER. 
 
 EXAMPLE: 
 
 6. 7 5 00= wide pitch 
 
 1.8750=2 diameters of rivet hole 
 
 4.8750 
 .4375 = thickness of plate 
 
 243750 
 341250 
 146250 
 1 95000 
 
 2.13281250 
 
 60000= tensile strength 
 
 127968. 10000000 
 26231. =shearing strength one rivet single 
 
 shear 
 
 154199. Ibs. = resistance to tearing at middle row 
 and shearing one rivet 
 
 Fourth. Crushing in front of four rivets and shearing of one rivet. 
 
 FORMULA: 
 
 (4DH XT xCS)plus (A XSS) = resistance to crushing in front of four rivets 
 
 and shearing one rivet 
 
 EXAMPLE: 
 
 3 . 7500 =four diameters of rivet hole 
 .4375 = thickness of plate 
 
 187500 
 262500 
 112500 
 1 50000 
 
 1.64062500 
 
 95000 = crushing strength of rivet 
 
 material 
 820312500000 
 14765625 
 
 155859.J 
 26231 = shearing strength one rivet single 
 
 shear 
 
 182090. Ibs. = resistance to crushing in front of 
 four rivets and shearing of one 
 
 Fifth. Crushing in front of five rivets, four thro ugh straps, the fifth through 
 inner cover plate only, the resistance is : 
 
 FORMULA: 
 
 (4DHXTXCS) plus(DHxCPxCS) = resistance to crushing of plate in 
 
 front of five rivets 
 
BUTT JOINTS. 167 
 
 EXAMPLE: 
 
 diameter of rivet hole = . 9375 3 . 7500 = four diameters of rivet hole 
 
 strap thickness = . 3750 . 4375 =thickness of plate 
 
 468750 187500 
 
 65625 262500 
 
 28125 112500 
 
 1 50000 
 
 crushing strength .35156250 
 
 of rivet = 95000 1.64062500 
 
 95000= crushing strength of 
 175781250000 rivet 
 316406250 820312500000 
 1476562500 
 
 33398. WWWKt 
 
 155859. 
 33398 
 
 189257 Ibs. ^crushing strain of plate in 
 front of five rivets 
 
 Rule to find strength of strip of plate at wide pitch. 
 
 FORMULA: 
 
 Po XT XTS =strength of plate at wide pitch 
 EXAMPLE: 
 
 6.7500=wide pitch 
 .4375 = thickness of plate 
 
 337500 
 472500 
 202500 
 2 70000 
 
 2.95312500 
 
 60000= tensile strength 
 
 177 18 7. 0000000 Ibs. = strength of strip of 
 plate at wide pitch 
 
 Rule to find efficiency of joint from these calculations. 
 
 LEGEND: 
 
 152578 = strength of net section of plate 
 177187 = strength of solid plate 
 
 EXAMPLE: 
 
 177187) 152578 . 00 ( . 86 ^efficiency of joint 
 141749 6 
 
 10828 40 
 10631 22 
 
 197 18 
 
168 THE BOILER. 
 
 Rule to find safe working pressure from efficiency of joint: 
 Multiply tensile strength of plate by percentage of joint; multiply 
 this sum by twice thickness of plate and divide product by diameter 
 multiplied by factor of safety. The quotient will be the safe work- 
 ing pressure of boiler. 
 
 FORMULA : 
 TSX%X(2XT) 
 IDXF 
 
 EXAMPLE: 
 
 =safe working pressure 
 
 60000 = tensile strength of plate 
 . 86 = percentage of joint 
 
 3600 00 
 48000 
 
 51600.00 
 
 .8750 = twice thickness of plate 
 
 internal diam. of 258 000000 
 
 boiler = 71.1250 3612 0000 
 factor of safety = 5 41280 000 
 
 355. 6250)45150. 000000 (126. 95 -safe working pressure 
 3556250 
 
 9587500 
 7112500 
 
 24750000 
 21337500 
 
 34125000 
 32006250 
 
 21187500 
 17781250 
 
 3406250 
 
BUTT JOINTS. 
 QUADRUPLE-RIVETED BUTT JOINT. 
 
 169 
 
 
 
 ; 
 
 
 :': 
 
 <) 
 
 
 
 (S) 
 
 ..:j 
 
 Computing strength of a quadruple-riveted butt joint. 
 Causes for possible failure in a butt joint double strap 
 quadruple riveted: 
 
 and 
 
 First. Tearing of plate through the line of rivets at outer row. 
 
 Second. Tearing of plate through line of rivets at se.cond outer row and 
 
 shearing of outer row of rivets. 
 Third. Failure of plate through second row of narrow pitch and shearing 
 
 of the two outer rows of rivets 
 Fourth. By shearing of all rivets. 
 
 LEGEND: 
 
 TS = tensile strength = 60000 
 
 SS shearing strength of rivets material =38000 
 
 CS = crushing strain of material =95000 
 
 T = thickness of plate = ^ = . 4375 
 
 D = diameter of boiler = 72" 
 
 d = diameter of rivets = ^f =.8125 
 DH = diameter of rivet hole = % = . 8750 
 
 A =area of rivets = % = . 6013 
 PN = narrow pitch = 4^=4. 062 5 
 PW=wide pitch =8^=8. 125 
 Po = outside pitch = 1634" = 16 . 2500 or width of strap 
 
 N = number of rivets 
 
 In connection with this problem it is assumed that the straps 
 or cover plates are three fourths (%) the thickness of shell plates. 
 Calculations will be made according to points of possible failures. 
 
 First. Tearing of plate through the line of rivets at outer row, 
 
 FORMULA: 
 Po d = section of plate to resist tearing 
 
170 THE BOILER. 
 
 EXAMPLE: 
 
 16 . 2500 =outside pitch 
 
 .8750 = diameter of rivet hole 
 
 15 . 3750 ^section of plate to resist tearing 
 less diameter of rivet 
 
 To calculate the efficiency of a joint it will be necessary to find out strength 
 of solid plate in strip calculated. 
 
 16. 2500 =pitch outside row 
 . 4375 = thickness of plate 
 
 812500 
 1137500 
 487500 
 650000 
 
 7.10937500 
 
 60000= tensile strength 
 
 426562 .00000000 Ibs. ^strength of solid plate 
 at point of calculation. 
 
 Second. Tearing of plate at line of rivets next to outer row. 
 
 FORMULA: 
 
 (Po 2DH) XTxTS + SS of Id = resistance to tearing of plate at line of 2d 
 
 outer row 
 
 EXAMPLE: 
 
 16 . 2500 = outer pitch or width of strip 
 1. 7500 =two diameters of rivet hole 
 
 14.5000 
 
 .4375 = thickness of plate 
 
 725000 
 1015000 
 435000 
 580000 
 
 6.34375000 
 
 60000 = tensile strength of plate 
 
 380625.00000000 
 
 380625 =lbs. resistance to tearing of plate at second outer row 
 22849 ^strength of the one rivet in outer row 
 
 403474 =lbs. resistance at that part of joint 
 
 Third. Failure of plate through second row of rivets in narrow pitch and 
 shearing of the two outer rows of rivets. 
 
 FORMULA: 
 (Po 4DH) XTxTS + SSof 3d =lbs. resistance in width of strip 
 
BUTT JOINTS. 171 
 
 EXAMPLE: 
 
 .6013 =area of one rivet 16. 2500 = width of strip of plate outer row 
 
 38000 = shearing strength 3 . 5000 = diameter of four rivet hole 
 
 of rivet 
 
 48104000 12.7500 
 18039 .4375 = thickness of plate 
 
 22849.4000 637500 
 
 3 =three. rivets 892500 
 
 382500 
 68548.2000 510000 
 
 5.57812500 
 
 60000= tensile strength 
 
 334687. 
 68548 ^shearing strength of three rivets in 
 
 outer rows 
 
 403235 =lbs. resistance through net section 
 of plate 
 
 Fourth. Point of possible failure by shearing of all rivets. There being 
 three rivets in single shear and eight in double shear. 
 
 FORMULA : 
 
 AxSSxN = single shear + N in double shear = shearing strength of rivets in 
 
 joint 
 EXAMPLE: 
 
 . 6013 =area of % rivet 
 
 38000 ^shearing strength in single 
 
 shear 
 48104000 
 18038 
 
 22849.4000 
 
 3 = number of rivets in single shear 
 
 68548 . 2000 = shearing strength of 3 rivets in 
 
 single shear 
 . 6013 =area of % rivet 
 
 70300 = shearing strength in double shear 
 
 1803900 
 420910 
 
 42271.3900 
 
 8 = number of rivets 
 
 338171 
 
 Add this latter product to the sum of three rivets in single shear, which 
 gives the total shearing strength of rivets in joint. 
 
 68548 =shearing strength of 3 rivets in single shear 
 338171 =shearing strength of 8 rivets in double shear 
 
 406719 Ibs. =total shearing strength of rivets in joint 
 
172 THE BOILER. 
 
 To get the efficiency of joint at this point : Divide resistance of net sec- 
 tion of plate by strength of solid plate. 
 
 EXAMPLE: 
 
 403235 = resistance through net section of plate 
 426562 =strength of solid plate 
 
 426562) 403235. 000 (. 945 =per cent, of efficiency 
 3839058 
 
 1932920 
 1706248 
 
 2266720 
 2132810 
 
 133910 
 
 Rule to find safe working pressure for boiler from these calculations: 
 Multiply tensile strength by lowest percentage and by twice thickness of 
 plate; divide this product by diameter multiplied by factor of safety. 
 
 FORMULA: 
 TSX%X2T 
 
 DXF 
 EXAMPLE: 
 
 = safe working pressure 
 
 60000 = tensile strength 
 . 945 = lowest percentage of joint 
 
 300000 
 240000 
 540000 
 
 56700.000 
 
 . 8750 = twice thickness of plate 
 
 2835000000 
 
 diam. of boiler = 72" 396900000 
 factor of safety = 5 453600000 
 
 360)49612. 5000000 (137. 8=lbs. safe workingpres- 
 360 sure 
 
 1361 
 1080 
 
 2812 
 2520 
 
 2925 
 2880 
 
 45 
 
BUTT JOINTS. 173 
 
 Butt straps or cover plates of a quadruple riveted joint. 
 Possible causes for failure of butt straps. 
 
 First. Both straps breaking across the inner row of rivets. 
 
 Second. The plate and inner strap breaking through line of next to inner 
 row of rivets. 
 
 Third. The inner strap breaking through the inner row of rivets and shear- 
 ing rivets. 
 
 Fourth. The outer strap breaking through the inside row of rivets and shear- 
 ing of rivets. 
 
 LEGEND: 
 
 DH -diameter of rivet hole = % = . 8750 
 TS = tensile strength - 60000 
 Po -outer pitch = 16 . 2500 
 T = thickness of strap = . 3750 
 
 First possible cause. Both straps breaking across the inner row of rivets. 
 
 FORMULA. 
 
 (Po 4DH) XT XN XTS = tensile strength of two straps 
 EXAMPLE: 
 
 16. 2 5 00 -outer pitch 
 3. 5000 =four rivet hole diameters 
 
 12.7500 
 
 . 3750 -thickness of strap 
 
 6375000 
 892500 
 3 82500 
 
 4. 78125000 -square inches of material at 
 
 2 straps (point of possible fracture 
 
 9. 56250000 -total number of square inches 
 60000 -tensile strength 
 
 573750.00P00000 Ibs. -tensile strength of the two straps 
 Showing strength of straps section stronger than plate section. 
 
 Second. Point of possible failure the resistance to fracture at this point 
 is greater than first possible cause. 
 
 Third. Possible cause for failure by breaking of strap through line of rive; 
 holes at inner row. 
 
 FORMULA: 
 
 (Po 4DH) XT XTS + (N X SS) -total resistance to tear plate and shear 
 
 rivets. 
 
1/4 THE BOILER. 
 
 EXAMPLE : 
 
 16. 2500 -outer pitch 
 3 . 5000 =four rivet hole diameters 
 
 12.7500 
 
 . 3750 = thickness of plate 
 
 6375000 
 892500 
 3 82500 
 
 4.78125000 
 
 60000 = tensile strength 
 
 182792 = rivet strength 
 
 469667 Ibs. = resistance to tear plate and shear 
 
 rivets 
 
 22849 shearing resistance single shear of 7 / 8 rivets 
 8 number of rivets 
 
 182792 
 
 Fourth. Point of possible failure same as third point. 
 
 These calculations show the straps resistance to strain exceeds the shell 
 plate. 
 
CHAPTER VIII. 
 
 SAFE WORKING STEAM PRESSURE OF BOILERS. 
 
 AS PRESCRIBED BY THE BOARD OF SUPERVISING INSPECTORS OF STEAM 
 VESSELS OF THE UNITED STATES. 
 
 The working- steam pressure of a boiler shell is determined by 
 the following rule : 
 
 Multiply one-sixth (1-6) of the lowest tensile strength, found 
 stamped on any plate in the cylindrical shell, by the thickness ex- 
 pressed in inches or parts of an inch, of the thinnest plate in the 
 same cylindrical shell, and divide by the radius or half diameter 
 also expressed in inches and the sum will be the pressure allow- 
 able per square inch of surface for single riveting, to which add 
 20 per cent, for double riveting when all the holes have been fairly 
 drilled and no part of the hole has been punched. 
 
 EXAMPLE. 
 
 A boiler 36 inches in diameter, ]/ inch in thickness, tensile 
 strength 60,000 pounds, resolves itself into the following : 
 
 1/6 of 60000 = 10000 X . 25 =2500 
 
 = 138 . 88 working steam pressure allowable 
 18 
 
 for single riveting; for double riveting and drilled holes, 20 per cent, added 
 = 166.65, this being the pressure allowable by the United States Marine 
 Inspectors. 
 
 On the following pages find tables of pressure allowed on 
 various sizes of boiler shells for 50,000, 55,000 and 60,000 pounds 
 tensile strength plates ; also a table which simplifies the calculation. 
 Steel plate having a tensile strength of 60,000 pounds is almost 
 universally used by builders of both stationary and marine boilers. 
 
 175 
 
176 
 
 THE BOILER. 
 
 fi fe 
 
 a I! 
 
 
 20 per 
 cent ad- 
 ditional. 
 
 10 co oo TH <M LO co co <N .- 
 
 
 
 OO-^OS'^'HCOOCOt^CO i-HCOO'<*<i-NOOO'<*'N * CS CO CO Ci* 
 COLOCOOOO5--iCO**L01~ CO^COt^COO'-HCO'-fcO (M COLO CD I- 
 
 II 
 
 <N i-H> CO i-< CO OO * LO CO CO <N 
 
 LO .-I O O LO OS LO 00 00 O r4 OS <N LO 
 
 i-HCDCfciNOOIXNCOCDCO 
 
 ;^! 
 
 T-H <N Tf< LO LO l~ OS O --H CO O 0-1 CO Tt< >O CO 00 040 H O'-'C^COTl 
 
 Ill 
 
 ss 
 
 
 
 
 (NCOLOCOl>OSOi-lCOTt< i-HCO^LOCDOOOSO(MCO rH C4 CO >O IQ 
 
 T-(^-lrH^-I^^H(N<N(M<N l-li-<i-li-li-lr-lrH(N(N(M i-lr-li-HrHi-l 
 
 'If 
 
 00 (M LO t^ rJH CO I> GO I-H CO LO LO 00 CM ** 
 
 COLOOiOOOCO^cOtMCO l> (M LO (N LOOOC 
 
 (^Hr^^H^KM ^^221^2^(22 ^S^^S^H^S^S ^SSr 1 ^ 
 
 Is 
 'If 
 
 a^ o 
 o fl+3 
 M o'S 
 
 >'- 
 ^H (M rt 10 10 t^ O5 O iH < 
 
 Tt<COO5C 
 
 OC CO CO i- 
 
 i < i i O OS ^"< 
 
 ooosoo^ 
 
 CO M rt< 1-1 (NCOCO 
 
 (M O5 LO C OC 
 
 :s?o 
 
 :lw 
 
 (MO3COCOCOCO 
 
 2 
 
 CM COCOCOCO COLO i-HOSOOOOCOI 
 
 i i LO 00 >-H CO 00 (N LO GO IN OOOt>CDcO- 
 
 il 
 
 l-O 
 
 t^- (M lO 
 
 OOi-HCOiOcOOi'-HCOlOt- 
 r-IO1<NCN(M<MCOCOCOCO 
 
 lO LO LO LO 
 
 CM LO t- (N HO l> 
 
 c-HCOLOt^ 00'-lCOLOCOOS'-iCOLOI> OO^COLO< 
 ^H(N(N(N( 
 
 S a3 
 
 all 
 
 1 
 
THE STEAM BOILER. 
 
 177 
 
 a 
 
 .3 ar 
 Q"<B, 
 
 n' 
 
 CO CO CO O ** 1C 00 OS t- CO 
 OS CO CD OS O Tf' 00 OS 01 GO 
 
 Jn,_i_i_i,-ii-i,Hc5Ol 
 
 01 01 OS CO iC OJ ^ CO CO JC 
 
 "*' t-i os oi 06 co' d d co' oo 
 
 1C OS CO 01 1C CO OC OS >C -f 
 
 W* l '-iOOCO^'M'<t'^t^ 
 
 -r re osc X> t~ i^c; co oo - n 
 
 
 iCCOCOCO-^t^OOt-I^O 
 OS C "M CC * iC CO t^ OS 
 
 cooo 01 x i- ^ w os 
 os o ^ 01 01 5 ic co r 
 
 o -"So" 
 
 20 per 
 ent ad- 
 itional 
 
 ^ Ol rC * ic 1 - X 55 ~ Ol 
 
 1 I^H^-l^i-l^-lr-li-IOlOl 
 
 ^ O5 OS 1C <N (M ~H <M * 
 
 05 CO OS CO OS OS CD 1C 00 OS 
 
 1C 00 Os' - CO CO CO CO t-' i-H 
 
 O'-KM'^'fcD 
 
 i ^COTt<iCOt^O300O5< 
 ^-i O -i 01 CO * 1C CO t- 00 ( 
 
 Ol >C 01 OS GO OS * i-O '-ii CO 1C CO OS OS COO 01 
 
 PH to 
 
 ,; I h-i-i 
 
 ^ 8 SI 
 
 01 O * w 00 i-i * OS i-C 
 OlTt"i-CCO'^OOOOOTf< t^-OSCO> 
 
 S^ 71 "^ 10 !-^ 00 ^? 2^I2 : 
 
 r-ososososos 
 
 LC rf CO CO T* * OS O 
 Tj< 1C CO <-* W O O * 
 
 >C O -^ CO 00 <- O1 O OS O 
 
 ^'-'co^ioicr^ 
 
 00 1^ 1C TjJ 00 O O t^ >C CO 
 
 t-OOOSOOOlCOCO-^lC 
 
 S5 
 
 CO^ h-CD'^OlTt< CO 
 OSOl-^iC'-iCSOlOlTt'OO 
 
 1C CD 1C ^ OS Ol CO -< O ^4 
 OOOSO I "H CO 't C t- 
 
 
 OlOSCOCOOH^.TttOlOSLC 
 t^ CO CO CO CO O 1C iC Tf rj- 
 
 oor^ic-^oooct^-icco 'tco^osco'C'*--<< 
 
 - Tt< oo co >c ^ r^ 01 
 
 CO0100rt<COl^COOCO01 
 
 i-I O t>-' 1C OS O Os' CO CO CO 
 t-OOOOOSOS'-i'-iOlCOTf 
 
 SI 
 
 "= 
 
 00 (NIC SO 
 
 O 00 1-1 CO >O 
 
 00 00 1> O 00 
 
 co Tf ic co r^ 
 
 CO 00 '-< <M OS OS O 
 
 '-i'-'CO-'tf'^f'Cl-- 
 
 1C Ol COO 
 
 ' ~* o od co co c co oi co 
 
 OOOSOO'-IOICO'^'CCO 
 
 % 
 
 2 
 
 
 
 p osxoo 
 
 ^CrfOOOOO 
 
 XOO Oc2eO'toOCOOO So 
 
 CO C Ol O Ol i 
 
 t^-CDCOO^^CCOOSCDiC 
 
 cor-xososO'-i'-ioico 
 
 C01OSCOOOXrt<^HO 
 COI>I>XOSOO' IO1CO 
 
 '-^.2 
 li 
 
 oicor? 
 
 X CO C CO CO t^ t- 
 
 i c *' oi co 06 1^ ic co co 
 
 XOSOO' i Ol CO "* C 
 
 CO CO 01 00 t^ 01 1C CO 
 CO 01 O t-' ^ CO 01 OS CD CD 
 
 >C t^- ^H t-^ Ol 
 
 o x co co J^ x t-' co' '-I d 
 
 t^- 1- X OS OS O <-H Ol COrf 
 
 O^T-^OICO S t t 
 
 ^ l^ Ol X CO CO X 
 
 CDcDt^XXOSOOT^Ol 
 
 OS 
 1C C 
 
 OO'C'-iOO'-'Ot^COOSt^ 
 iCCDt-t^OOOSOSOO'-H 
 
 SSI 
 
 Ha 
 
 OS'-i 
 (NCO 
 
 tCNiM(M(M(NCOCOCOCO 
 
 1C O 
 
 t^ Ol 1C 
 
 00<-<COCCOOS'-ICOCI > - 
 I-H0101010101COCOCOCO 
 
 s 
 .2fe : 
 
 Q-8. 
 
178 
 
 THE BOILER. 
 
 S!3 
 
 all 
 
 
 12 
 
 ~ 
 
 COOOOI>00 O5C5(MCOfO(MIMO5COO5 COOCt^COOSC^lCOOlt^O 
 
 COO'-*'*-* Tta>MOCOCOOOO5CCO5 LOCOO<MOiCCi^ 
 
 t^OOO05rt*OWi-iT-<^ t^.t^t^CD'-iiO'OCOCO'* C5O5t~-^CMMO5*O 
 
 C5 O i C^l JO iO CD t- 00 O5 00 O5 O 1 -M rC -f 'O CO t- I- 00 O5 C ?1 rC X * i 
 
 .-J w ?C ' O 
 Oi * !N 
 
 'M^-Olt^ 
 
 I-OCOCCT-C 
 
 Ot^OCXCSO <M7C 
 
 OOO^^ 
 O'Ot^OC 
 
 1 'OO>-OOSOXXO I-H O OS X C^l iO O iM < i M COC>lOX<NTl<CO^r^h- 
 OS C rH <M IM jo O 10 CD X XO5C5O W CO * OCD l-OC OS OS O <N <N W 
 
 t>- qo O (N OC 
 
 t^iO CO 
 
 S*2 
 
 8.2 . 
 
 OJ 
 
 11 
 
 COiOGO 1-1 i5 00 COCO 
 (N(N(NCClCOCOCO^^rt< 
 
 iOTf<MOT<<O>O<NOO 
 t-000500-KMCO^O 
 
 lOJO t^>O OOCOC5 
 
 'OOS'OOrO'MOrC'GO'-' 
 
 '-'OO'OlMiOiO'MOC^fO 
 
 JOt-OCX0500-lM 
 
 <NC5--'MTt 
 't^-KM'MiM 
 
 CCfOOSiOX 
 iCC!CCt-l- 
 
 Is 
 
 1 CJO 
 
 [*2 
 
 v ei a 
 
 o^'S 
 
 IMCOC^i-HOOOGOOiOO IO'^'-<O5CO'O^(NO3O QCCOrOO'^'OfOOt^O 
 OOOSO-^'-KMrO-^iOCO t-XOSOSO'-iiMCOCO'O CCt^XOSOSO^C-l^rC 
 
 rt* l> X OS OS 1-1 LI (M ^1 X OS 
 
 T^ t^ i 1 1C C^l ^ O C^ CO X iO OS 
 
 OSt^OO'lCOt^'C(NO5X (NOSCO 
 
 COt-XO3OSOi-N<MCO COcOt- 
 
 X^OS^IM^OCOX^ Tt*O3(MiO(MCOt-O3<NOS O5OSC^1OCOC:O3CDO3 
 COiO<OOOaSi-iCO-*iOt> r-OSCOCOCOCOOOSfO^ ^OSOCOCCCO^OSCOOS 
 
 >LOCO^LOX^--*(M(M 
 
 (M OS --0 CO C CO rf OS CO - 
 
 (N^COCO'* 
 t^-rfi O CO OS 
 
 =-s; 
 
 S'l-^oo^jooopeooiodi^ i>Ttiocoosxiooco^ >M x co cs !M c co i r^ * ^coxcoco 
 t-t^XXOSO^H i(N OCOt-t-t^XOSOO'-i id'COCOl-XXaiCTSO TfiOiCCOCO 
 
 t^Tj<ot^ooscO'-iX'O (NXcoos^cco-Hr-Tf r^MooccocO'cox-* coxcor-o 
 
 OtOb-t^OOOOOSOOrH lOOCOcOt-XXOSOSO TftiOiOtCCOt^t-XXOS ^^lOiCCO 
 
 20 per 
 ent ad 
 itiona 
 
 ThOSCOCOCOCO^ 
 
 uj 
 
 I 
 
 <N O ^(Nf-r-iOSO CO(N OiO XCO 
 
 i-iOiOt- CDIXNXOOS iO(N-Ot^CSO" 
 
 gi-a 
 
 .-H<N<M<M<M<MCOCOCOCO T-i(N(N<N<N(MCO 
 
 - 
 
 Xi-iCOiOcO 
 ^HlM<NC^(N 
 
 sfe 
 
 .23- 
 
 ?*s-5 
 
 
THE STEAM BOILER. 
 
 179 
 
 .ass's 
 
 21J5 
 
 01 rC S i^ rC r-i ^ * CO CO 
 
 h- "C 01 CS rO * 01 X iC **' 
 
 COI-XXCSO ' Oire 
 
 OS ~ '- 01 CO ~ CO CS CO CS CC CS X t- CO CO 01 CC 01 CO 
 
 "*C5COrCCOCO^CSCOCS O OS CC^J<t--l^- CCO 
 
 01 CS CO CC CO CO rf 05 CO * X * ^-' t^ C5 OS CO 01 X CO 
 
 CO CO t~ X X OS O C 01 iC CO t- t- X X OS O O ' 
 
 ; o -^ oi >~ re o >o ^ x 
 
 /oi oixrecioioco^^t^-^ 
 
 >^ iC '-CO CO I- X XC-. CIO 
 
 iC O iC O Ol O5 <C OS * O 
 
 Tficiccococot-r-xcs 
 
 ! *-?"3 
 
 i m 
 
 i. 
 
 c ~ 
 
 20 
 
 en 
 dit 
 
 : -.o o) CT. 01 -t re x x o oi x -^ x x cs re 
 ! t^ cs cs 01 i ic co cc c t- 1 01 x 01 01 c: -H 
 
 st-r^i-xasoo^-i ccocor^t-xxcicso 
 
 iC CCOICO 
 >C 00 CO 04 ^H 
 
 XXC5CSO 
 
 
 ^^Ic!cJcoSf2t-o6 
 
 t-oio ^cec5-*t^-<co cs 01 r- x * * oi ic 
 oics^dcc^oocc'xic cs ^ o >c x o ~i cc --' x 
 
 Ol Ol Ol iC X CO Tf iC 
 
 00 CC 01 ~* i-C 00 CC CO i-C CO 
 
 c ^' co -- cc d co' o ic ' 
 * ic ic co cc i- r- x x cs 
 
 >^Tj< OCCOt^ Ir- 
 
 C S ccos-^os'C 
 PH i t^t-XXOs 
 
 os !" V5 ?J ~ U '2 ^' ?- ^ 
 
 ^! Hx^ ^"^js^-s^ J~ :C '* X^'" v lc: 2c "-5ZJ2F 
 
 ^-iceccox 
 r^ oi cc -' co 
 
 -* CO -H i * 
 ^-'l--X^X'H 
 
 "So 
 
 w 
 
 ^ J. "^ CS Ol OS -^ 
 
 p| *-**: 
 
 _ -^ -s i 01 x 01 1-- ce 
 - =^ I i-i-xxcs 
 
 ^^iccore t- 
 
 S^ 
 
 8S8SS 
 
 
 k 
 
 iC iC 1C iC 
 
 t^- CM 1C l^- Ol iC 
 
 ir 
 
180 
 
 THE BOILER. 
 
 is 
 
 .s 
 
 .IS 
 
 ; *s 
 
 L-S2 
 
 .1 
 
 20 per 
 cent ad- 
 ditional. 
 
 's-S 
 
 ^ 
 
 IM a; ^3 
 
 o a'-S 
 
 <N 
 
 111 
 
 H c'n 
 
 IMOOSOO'Oi KMOCD 
 
 iC ^H iC O CO O >O C 10 ^ 
 ^iO>O?DCOl^t--OOiX)O5 
 
 1-1 O5 <N 00 >O Ol h- O5 00 
 COCOC5Tft^^iOTt<O5CC 
 
 i iO I-H 00 O i-i iO > i (M 
 
 fe 
 
 il 
 
 
THE STEAM BOILER. 
 
 181 
 
 The following rules and tables are from a commercial rating and 
 only approximate. 
 
 STANDARD STEAM BOILER MEAUSUREMENTS. 
 
 HORIZONTAL TUBULAR. 
 
 Based on 12 square feet of heating surface to a horse power. 
 A Commercial Rating. 
 
 
 Size. 
 
 
 Thick- 
 ness. 
 
 Boiler with 
 
 Hand Holes. 
 
 Boiler with Man Holes. 
 
 .2 
 
 Z j~ 
 J 'fi 
 
 "2 
 ffi 
 
 Size of 
 Dome. 
 
 Tubes 
 No. 
 
 Dia. 
 
 Heat. 
 Surf, 
 sq. ft. 
 
 Horse 
 Power 
 
 Tubes 
 No. 
 
 Heating. 
 Surf. 
 Dia. sq. ft. 
 
 Horse 
 Power. 
 
 30 
 
 6 y 
 
 3^ 
 
 16x20 
 
 19 
 
 2 i^ 
 
 106 
 
 9 
 
 
 
 
 30 
 
 8 J 
 
 iMI " 
 
 16x20 
 
 19 
 
 2 % 
 
 141 
 
 12 
 
 
 
 
 
 
 
 
 38 
 
 2 % 
 
 256 
 
 21 
 
 
 
 
 36 
 
 8 M 
 
 M 
 
 18x20 
 
 28 
 
 3 
 
 226 
 
 19 
 
 
 
 
 
 
 
 
 25 
 
 3 % 
 
 234 
 
 20 
 
 
 
 
 
 
 
 
 38 
 
 2/4 
 
 311 
 
 26 
 
 
 
 
 36 
 
 10 K 
 
 3^ 
 
 18x20 
 
 28 
 
 3 
 
 283 
 
 24 
 
 
 
 
 
 
 
 
 25 
 
 3Y2 
 
 292 
 
 24 
 
 
 
 
 42 
 
 10 M 
 
 % 
 
 20x24 
 
 38 
 
 3 
 
 372 
 
 31 
 
 
 
 
 
 
 
 
 34 
 
 3% 
 
 385 
 
 32 
 
 
 
 
 42 
 
 12 M 
 
 % 
 
 20x24 
 
 38 
 
 3 
 
 446 
 
 37 
 
 
 
 
 
 
 
 
 34 
 
 3 H} 
 
 462 
 
 39 
 
 
 
 
 42 
 
 14 ^ 
 
 N 
 
 20x24 
 
 38 
 
 3 
 
 520 
 
 43 
 
 
 
 
 
 
 
 
 34 
 
 3 ^2 
 
 539 
 
 45 
 
 
 
 
 42 
 
 16 M 
 
 % 
 
 20x24 
 
 38 
 
 3 
 
 595 
 
 43 
 
 
 
 
 
 
 
 
 34 
 
 3 Yz 
 
 616 
 
 51 
 
 
 
 
 44 
 
 12 M 
 
 % 
 
 24x24 
 
 48 
 
 3 
 
 544 
 
 45 
 
 
 
 
 
 
 
 
 38 
 
 
 510 
 
 43 
 
 
 
 
 44 
 
 14 K 
 
 3% 
 
 24x24 
 
 48 
 
 3 2 
 
 635 
 
 53 
 
 
 
 
 
 
 
 
 38 
 
 
 491 
 
 41 
 
 
 
 
 43 
 
 12 A 
 
 A 
 
 24x24 
 
 58 
 
 3 2 
 
 647 
 
 54 
 
 50 
 
 3 572 
 
 48 
 
 
 
 
 
 50 
 
 
 651 
 
 54 
 
 34 
 
 3M 475 
 
 40 
 
 48 
 
 14 A 
 
 A 
 
 24x24 
 
 58 
 
 3 
 
 755 
 
 63 
 
 50 
 
 3 667 
 
 55 
 
 
 
 
 
 50 
 
 3 Y% 
 
 759 
 
 63 
 
 34 
 
 3 1 A 547 
 
 46 
 
 48 
 
 16 A 
 
 A 
 
 24x24 
 
 58 
 
 3 
 
 862 
 
 72 
 
 50 
 
 3 762 
 
 64 
 
 
 
 
 
 50 
 
 3 y% 
 
 867 
 
 72 
 
 34 
 
 3Y Z 633 
 
 53 
 
 48 
 
 18 A 
 
 A 
 
 24x24 
 
 58 
 
 3 
 
 970 
 
 81 
 
 50 
 
 3 857 
 
 71 
 
 
 
 
 
 50 
 
 3 /4 
 
 976 
 
 81 
 
 34 
 
 3Y Z 712 
 
 59 
 
 
 
 
 
 71 
 
 3 
 
 912 
 
 76 
 
 59 
 
 3 780 
 
 65 
 
 54 
 
 14 A 
 
 i^ 
 
 30x30 
 
 56 
 
 3 ^2 
 
 851 
 
 71 
 
 48 
 
 3 Y% 748 
 
 62 
 
 
 
 
 
 43 
 
 4 
 
 763 
 
 64 
 
 40 
 
 4 719 
 
 60 
 
 
 
 
 
 71 
 
 3 
 
 1042 
 
 87 
 
 59 
 
 3 891 
 
 74 
 
 54 
 
 16 A 
 
 H 
 
 30x30 
 
 56 
 
 3 ^2 
 
 972 
 
 81 
 
 48 
 
 3Y Z 855 
 
 71 
 
 
 
 
 
 43 
 
 4 
 
 802 
 
 67 
 
 40 
 
 4 821 
 
 68 
 
 The above table is based on rule for ascertaining Heating Surface. 
 
 A commercial rating of boiler horse power is obtained by the 
 following rule : 
 
 Add to two-thirds of boiler shell area, tube area and the 
 area of one head (this will compensate for tubes holes in both) and 
 
182 
 
 THE BOILER. 
 
 divide product by unit of H. P. according to type of boiler. (See 
 table.) 
 
 FORMULA: 
 SA + TA + AH 
 
 LEGEND: 
 
 SA = shell area 
 TA =tube area 
 AH =area of head 
 60" =boiler diameter 
 16' = length 
 
 46 4" tubes 
 
 HP unit =12 sq. ft. 
 
 diameter of head = 
 
 HP 
 
 HP unit 
 
 EXAMPLE: 
 
 3 . 1416 = circumference of one inch 
 60" = diameter of boiler 
 
 60" 
 60 
 
 188.4960 
 
 192" = length of boiler 
 
 area of one inch = 
 
 3769920 
 16964640 
 
 3600 1884960 
 .7854 
 
 3)36191. 2320 =area of boiler shell 
 
 14400 
 18000 
 28800 
 25200 
 
 12063 . 7440 
 2 
 
 area head =2827 . 4400 
 
 24127 . 4880 = % of boiler shell area 
 2827 . 4400 =area of one head 
 
 26954.9280 
 110986. 4448 =tube area 
 
 inches per square ft. = 144) 137941 . 3 72M (957 . 9 =square feet of heating 
 
 1296 surface 
 
 834 
 720 
 
 3. 1416=circumferenceof lin. 1141 calculating 12 square 
 
 4"= tube diameter 1008 ft. per HP = 12)957. 9(79. 8 -HP 
 84 
 
 12.5664 
 
 192" =length of tube 
 
 251328 
 1130976 
 125664 
 
 1333 
 1296 
 
 37 
 
 117 
 108 
 
 99 
 96 
 
 2412 . 7488 = heating surface one tube 
 46 tubes 
 
 144764928 
 96509952 
 
 110986.4448 =tube area 
 
THE STEAM BOILER. 
 
 183 
 
 Heating surface proper means any portion of the boiler where 
 heat is applied to one side of the plate, and water on the other. 
 
 The heating surface of a round furnace and tubes is figured by 
 their internal diameter, water tubes and external fired surfaces 
 are measured by their outside diameter, this latter being the surface 
 heated must necessarily be considered as effective heating surface. 
 
 The heating surface of boilers can readily be obtained from the 
 following table : In the case of horizontal tubular bricked in boilers, 
 two-thirds of the boiler shell, the whole of the tube surface, and the 
 front and rear head deducting area of tubes and surface above water- 
 line is figured as effective heating surface. 
 
 Diameter of boiler, 
 
 
 
 
 
 
 
 
 
 
 
 
 
 inches 
 
 26 
 
 28 
 
 30 
 
 32 
 
 34 
 
 36 
 
 38 
 
 40 
 
 42 
 
 44 
 
 46 
 
 48 
 
 Two-thirds of the 
 
 
 
 
 
 
 
 
 
 
 
 
 
 heating surface of 
 
 
 
 
 
 
 
 
 
 
 
 
 
 shell per foot of 
 
 
 
 
 
 
 
 
 
 
 
 
 
 length 
 
 4.54 
 
 4.89 
 
 5 . 24 
 
 5.59 
 
 5.93 
 
 6.29 
 
 6.G3I 6.98 
 
 7.331 7.68 
 
 8.03 
 
 8.38 
 
 Diameter of boiler, 
 
 
 
 
 
 
 
 
 
 
 
 
 inches 
 
 50 
 
 52 
 
 54 
 
 5G 
 
 58 
 
 GO 
 
 62 
 
 64 
 
 66 
 
 68 
 
 70 
 
 72 
 
 Two-thirds of the 
 
 l 
 
 
 
 
 
 
 
 
 
 
 
 heating surface of 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 shell per foot of I 
 
 
 
 
 
 
 
 
 I 
 
 
 length |8.73 
 
 9.08 
 
 9.42 
 
 9.77110.12 
 
 10.47110 82 
 
 11.17111.52 
 
 11 .87112.22 
 
 12.57 
 
 TYPES OF BOILERS AND ESTIMATED GRATE TO HEATING SURFACE PER 
 HORSE POWER. 
 
 Types. 
 
 Square feet of 
 Heating Surface 
 per horse power. 
 
 Square feet of 
 Heating Surface 
 to one foot of grate . 
 
 Cylinder 
 
 6 to 10 
 
 12 to 15 
 
 Flue . 
 
 8 to 12 
 
 20 to 25 
 
 Horizontal Tubular 
 Water Tube 
 Vertical 
 
 12 to 14 
 11 to 12 
 10 to 12 
 
 25 to 35 
 35 to 40 
 25 to 30 
 
 Internal Fired 
 
 12 to 15 
 
 50 to 100 
 
 RATIO GRATE SURFACE TO HORSE POWER. 
 
 Type of Boiler. 
 
 Ratio. 
 
 HT 4 to 6 
 
 WT 3 
 
 Loco .02 " 6 
 
 Marine. . . . 12 
 
 HEATING SURFACE RATIO TO GRATE SURFACE. 
 
 HT 40 to 50 
 
 WT 34 " 65 
 
 Loco , 30 " 34 
 
 Marine . .28 " 32 
 
184 
 
 THE BOILER. 
 
 COAL AND GRATE. 
 
 The average consumption of coal for steam boilers is 12 pounds 
 per hour for each square foot of grate surface. 
 
 Western coals, having a large amount of sulphur, require more 
 space in furnace and more air. 
 
 Rule to find area of grate for a given boiler: 
 
 Divide pounds of water to be evaporated per hour by number of 
 pounds of water evaporated multiplied by number of pounds of coal 
 burned per hour per square foot of grate. 
 
 FORMULA: 
 number of Ibs. of water evaporated per hour 
 
 water in Ibs. evap. X per Ibs. of coal per hour 
 LEGEND: EXAMPLE: 
 
 'area of grate 
 
 2400 =lbs. of water to be 
 
 evaporated 
 12 =lbs. of coal per square 
 
 foot of grate 
 9 =lbs. of water 
 
 108)2400 (22 square feet of grate required 
 216 
 
 240 
 216 
 
 24 12 Ibs. of coal per sq. ft. of grate 
 9 Ibs. of water per Ibs. of coal 
 
 108 Ibs. of water evaporated per 
 sq. foot of grate 
 
 TABLE FOR PRESSED STEEL BOILER LUGS. 
 
 Iron rivets have a shearing strength of 38000 Ibs. 
 Steel " " 45000 " 
 
 See tables for boiler weights and rivet strength. 
 
 Diameter 
 of boiler, 
 inches. 
 
 Height of 
 base of 
 lug above 
 center of 
 boiler. 
 
 Width of 
 lug. 
 
 Length of 
 lug pro- 
 jection. 
 
 Height 
 of lug 
 on 
 boiler. 
 
 Thick- 
 ness. 
 
 Weight, 
 Ibs. 
 
 30 
 
 1 
 
 7 
 
 7 
 
 7 
 
 A 
 
 6 
 
 36 
 
 2 
 
 7 
 
 7 
 
 7 
 
 M 
 
 8 
 
 42 
 
 2j^ 
 
 8 
 
 8 
 
 8 
 
 L/ 
 
 10 Vo 
 
 48 
 
 3^ 
 
 8 
 
 8 
 
 8 
 
 & 
 
 14 
 
 54 
 
 
 10 
 
 10 
 
 10 
 
 & 
 
 20^ 
 
 60 
 
 4^ 
 
 10 
 
 10 
 
 10 
 
 3/ 
 
 23 
 
 66 
 
 4L/ 
 
 12 
 
 12 
 
 12 
 
 ^8 
 
 35 
 
 72 
 
 5 
 
 12 
 
 12 
 
 12 
 
 
 40 
 
 78 
 
 6 
 
 12 
 
 12 
 
 12 
 
 iHi 
 
 45 
 
 84 
 
 7 
 
 12 
 
 12 
 
 12 
 
 * 
 
 50 
 
THE STEAM BOILER. 
 
 185 
 
 WEIGHT OF HORIZONTAL TUBULAR BOILERS FOR 125 LBS. STEAM PRESSURE 
 COMPLETE WITH FITTINGS FULL OF WATER. 
 
 Diameter of 
 boiler, inches 
 Length in feet . . 
 Weight full of 
 water 
 
 36 
 
 8 
 
 6,100 
 
 36 
 10 
 
 7,600 
 
 42 
 10 
 
 9,500 
 
 42 
 12 
 
 10,600 
 
 44 
 12 
 
 11,600 
 
 48 
 12 
 
 13,400 
 
 50 
 13 
 
 14,300 
 
 54 
 13 
 
 15,400 
 
 54 
 15 
 
 17,900 
 
 60 
 14 
 
 20,900 
 
 60 
 15 
 
 24,900 
 
 
 Diameter of 
 boiler, inches . 
 Length in feet 
 Weight full of 
 water 
 
 60 
 16 
 
 27,300 
 
 66 
 16 
 
 30,400 
 
 66 
 16 
 
 35,100 
 
 72 
 16 
 
 40,100 
 
 72 
 18 
 
 44,100 
 
 78 
 18 
 
 48,100 
 
 78 
 20 
 
 56,100 
 
 84 
 18 
 
 55,100 
 
 84 
 20 
 
 67,100 
 
 90 
 18 
 
 65,100 
 
 90 
 20 
 
 75,100 
 
 DIRECTIONS FOR SETTING BOILERS. 
 
 Make the excavation to a depth suitable to ground that boiler is 
 to rest upon not less than 24 inches. Build foundation walls at least 
 12" wider than walls to floor level, fronts to rest upon two courses 
 of brick above the floor level. Set boiler in place and block it up 
 three or four inches higher than it is to remain, the back side of 
 front to set back four inches from front edge of brick work. Carry 
 up the side and end walls to the proper height for the resting place 
 of brackets (if boiler has brackets place rollers between plates and 
 lugs) leaving space so that walls will not be pushed out of place by 
 expansion of boiler. (Some engineers prefer an air space in setting 
 side and end walls, as a nonconductor of heat.) The walls should 
 be tied together by headers and run every eighteen inches. The 
 headers from outside walls should touch those of inner wall and not 
 be tied together. Fire brick in the furnace should be laid with a 
 course of headers every six courses so that the wall can easily be 
 taken out and repaired at any time when necessary. The rear con- 
 nection or back arch should be lined with fire brick, the ends of arch 
 resting on side walls and the arch of such radius to permit of easy 
 access to tubes at rear head. A space of one inch should be left 
 between rear end of boiler and inside of arch so that the expansion 
 of boiler will not affect brick work and should be so arranged that 
 it can be removed without injury to walls. It is preferable when cov- 
 ering a boiler to do so with magnesia, as it is light, a non-conductor 
 and will give evidence of any leakage at a local point by discoloration 
 or becoming soft, not like the brick covered boiler that may have 
 leakage many feet from point of steam issuing. If brick is to be 
 used a two inch space should be left between boiler and brick work. 
 
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THE STEAM BOILER. 
 
 187 
 
 
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188 
 
 THE BOILER. 
 
 MATERIALS FOR BRICKWORK OF REGULAR TUBULAR BOILERS. 
 SINGLE SETTING. 
 
 Boilers. 
 
 Common 
 Brick. 
 
 Fire 
 Brick. 
 
 Sand, 
 bushels 
 
 Cement, 
 barrels. 
 
 Fire 
 Clay, 
 Ibs. 
 
 Lime, 
 barrels. 
 
 30 inches x 8 feet 
 
 5200 
 
 320 
 
 42 
 
 5 
 
 192 
 
 2 
 
 30 " x 10 " 
 
 5800 
 
 320 
 
 46 
 
 53^ 
 
 192 
 
 2M 
 
 36 " x 8 " 
 
 6200 
 
 480 
 
 50 
 
 6 
 
 288 
 
 2^ 
 
 36 " x 9 " 
 
 6600 
 
 480 
 
 53 
 
 63^ 
 
 288 
 
 2% 
 
 36 " x 10 " 
 
 7000 
 
 480 
 
 56 
 
 7 
 
 288 
 
 
 36 " x 12 " 
 
 7800 
 
 480 
 
 62 
 
 8 
 
 288 
 
 3M 
 
 42 " x 10 " 
 
 10000 
 
 720 
 
 80 
 
 10 
 
 432 
 
 4 
 
 42 " x 12 " 
 
 10800 
 
 720 
 
 86 
 
 11 
 
 432 
 
 4K 
 
 42 " x 14 " 
 
 11600 
 
 720 
 
 92 
 
 11M 
 
 432 
 
 ^A 
 
 42 " x 16 " 
 
 12400 
 
 720 
 
 99 
 
 12^ 
 
 432 
 
 5 
 
 48 " x 10 " 
 
 12500 
 
 980 
 
 100 
 
 12H 
 
 590 
 
 5M 
 
 48 " x 12 " 
 
 13200 
 
 980 
 
 108 
 
 13 H 
 
 590 
 
 53^ 
 
 48 " x 14 " 
 
 14200 
 
 980 
 
 116 
 
 143^ 
 
 590 
 
 5M 
 
 48 " x 16 " 
 54 " x 12 " 
 
 15200 
 13800 
 
 980 
 1150 
 
 124 
 108 
 
 153^ 
 13M 
 
 590 
 690 
 
 6 
 
 $ 1 A 
 
 54 " x 14 " 
 
 14900 
 
 1150 
 
 117 
 
 15 
 
 690 
 
 6 
 
 54 " x 16 " 
 
 16000 
 
 1150 
 
 126 
 
 16 
 
 690 
 
 6M 
 
 60 " x 10 " 
 
 13500 
 
 1280 
 
 108 
 
 133^ 
 
 768 
 
 53^ 
 
 60 " x 12 " 
 
 14800 
 
 1280 
 
 118 
 
 14M 
 
 768 
 
 6 
 
 60 " x 14 " 
 
 16100 
 
 1280 
 
 128 
 
 16 
 
 768 
 
 6^ 
 
 60 " x 16 " 
 
 17400 
 
 1280 
 
 140 
 
 173^ 
 
 768 
 
 7 
 
 60 " x 18 " 
 
 18700 
 
 1280 
 
 148 
 
 ISM 
 
 768 
 
 7^ 
 
 66 " x 16 " 
 
 19700 
 
 1400 
 
 157 
 
 19% 
 
 840 
 
 8 
 
 72 x 16 
 
 20800 
 
 1550 
 
 166 
 
 20M 
 
 930 
 
 8K 
 
 TWO BOILERS IN A BATTERY. 
 
 30 inches x 8 feet 
 
 8900 
 
 640 
 
 70 
 
 9 
 
 384 
 
 33^ 
 
 30 " x 10 " 
 
 9600 
 
 640 
 
 76 
 
 93^ 
 
 384 
 
 4 
 
 36 " x 8 " 
 
 10500 
 
 960 
 
 84 
 
 103/6 
 
 576 
 
 4M 
 
 36 " x 9 " 
 
 11100 
 
 960 
 
 88 
 
 11 
 
 576 
 
 4^ 
 
 36 " x 10 " 
 
 11800 
 
 960 
 
 95 
 
 12 
 
 576 
 
 4% 
 
 36 " x 12 " 
 
 13000 
 
 960 
 
 104 
 
 13 
 
 576 
 
 5M 
 
 42 " x 10 " 
 
 17500 
 
 1440 
 
 140 
 
 17H 
 
 864 
 
 7 
 
 42 " x 12 " 
 
 18600 
 
 1440 
 
 148 
 
 18^ 
 
 864 
 
 73^ 
 
 42 " x 14 " 
 
 19900 
 
 1440 
 
 159 
 
 20 
 
 864 
 
 8 
 
 42 " x 16 " 
 
 21200 
 
 1440 
 
 168 
 
 21 
 
 864 
 
 8K 
 
 48 " x 10 " 
 
 21400 
 
 1960 
 
 170 
 
 21H 
 
 1180 
 
 8M 
 
 48 " x 12 " 
 
 22300 
 
 1960 
 
 178 
 
 22 y 3 
 
 1180 
 
 9 
 
 48 " x 14 " 
 
 23900 
 
 1960 
 
 190 
 
 24 
 
 1180 
 
 9^ 
 
 48 " x 16 " 
 
 25100 
 
 1960 
 
 200 
 
 25 
 
 1180 
 
 10 
 
 54 " x 12 " 
 
 23300 
 
 2300 
 
 186 
 
 233^ 
 
 1380 
 
 934 
 
 54 " x 14 " 
 
 24800 
 
 2300 
 
 198 
 
 25 
 
 1380 
 
 10 
 
 54 " x 16 " 
 
 26300 
 
 2300 
 
 210 
 
 263^ 
 
 1380 
 
 103^ 
 
 60 " x 10 " 
 
 22600 
 
 2560 
 
 180 
 
 22^ 
 
 1536 
 
 9 
 
 60 " x 12 " 
 
 24800 
 
 2560 
 
 198 
 
 25 
 
 1536 
 
 10 
 
 60 " x 14 " 
 
 26800 
 
 2560 
 
 214 
 
 27 
 
 1536 
 
 10M 
 
 60 " x 16 " 
 
 28900 
 
 2560 
 
 230 
 
 29 
 
 1536 
 
 ii-H 
 
 60 " x 18 " 
 
 31000 
 
 2560 
 
 248 
 
 31 
 
 1536 
 
 123^ 
 
 66 " x 16 " 
 
 33100 
 
 2800 
 
 264 
 
 33 
 
 1680 
 
 13H 
 
 72 " x 16 (< 
 
 34000 
 
 3100 
 
 272 
 
 34 
 
 1860 
 
 13M 
 
THE STEAM BOILER. 189 
 
 In connection with boiler setting the following information will 
 be useful : 
 
 One barrel of lime will lay 800 brick. 
 
 Two barrels of lime will lay one perch rubble stone. 
 
 To every barrel of lime estimate about ^ yards of good sand 
 for brick work. 
 
 One and one quarter barrels of cement and three quarters 
 yard of sand will lay 100 feet of rubble stone. 
 
 Rule to find number of brick required: Multiply the number 
 of cubic feet by 22.5. 
 
 The cubic feet is found by multiplying length by height, then 
 by thickness. 
 
 Bricks are usually made 8" X 4" X 2" requiring 27 bricks to 
 make a cubic foot without mortar, the latter is estimated to fill one 
 sixth of space. 
 
 CHIMNEYS AND STACKS. 
 
 The use for chimneys is necessary in many plants and main- 
 tained at great expense of heat units varying as high as 30 per 
 cent of fuel. The necessity arises from following causes, viz. : cost 
 of installing modern methods and the necessity for a chimney to 
 carry off obnoxious gases. 
 
 The main object is to obtain air supply for combustion of fuel. 
 Areas for chimneys are calculated from grate area, coal burned in 
 a certain time and usually a ratio of 8 to 1. 
 
 The temperatures of gases escaping up a chimney will depend 
 on the material and distance from boilers the higher the tem- 
 perature the greater the velocity. 
 
 The weight of air necessary for fuels varies, hence the necessity 
 for computing for the maximum amount. 
 
 The volume of air is proportional to its temperature ; 24 pounds 
 of air at the mean of the atmosphere temperature is 300 cubic 
 feet and at a temperature of 550 degrees F is twice as great. 
 
 Rule to find the volume of one pound of air under atmospheric 
 pressure for a given temperature: Divide the absolute temperature 
 
190 THE BOILER. 
 
 of air by x the constant 40 ; the result gives the volume in cubic feet 
 nearly. 
 
 LEGEND: EXAMPLE: 
 
 Temp, of atmosphere 80 40)80 (2 = volume of one pound in cubic feet 
 
 Constant 40 80 
 
 The intensity of draft is independent of the area of the flue 
 but is proportional to the difference in weight of two columns of 
 air of equal base, one internal and one external. The difference 
 in temperatures between the volume escaping from the inside and 
 the atmosphere increases the draft as the difference between the 
 temperature increases. 
 
 The atmospheric pressure or draft is estimated by the height of 
 an equivalent column of water. 
 
 CONSIDERATIONS GOVERNING THE HEIGHT OF A 
 
 CHIMNEY. 
 
 It must be high enough to give the required intensity of draft 
 at an economical flue temperature, and to be well above the surround- 
 ing objects; increased capacity is much more cheaply gained by 
 increasing the area, it being cheaper to build nearer the ground, and 
 the capacity increases with the square of the diameter and only as 
 the square root of the height. If of brick the height should not 
 exceed ten or eleven times the base, on account of stability. 
 
 Rule to find the difference in pressure to be expected between the 
 inside and outside of a chimney for a given height and temperature : 
 Divide 39 by the absolute (actual temperature Fahrenheit plus 461) 
 temperature of the outside air; again, divide 40 by the absolute 
 average temperature of the gases in the stack; subtract the latter 
 from the former quotient, multiply the remainder by the height of 
 the chimney in feet, and divide by 5.2; the final quotient will be 
 the draft in inches in water. 
 
 The following table will give the draft power in inches of water 
 for chimneys of specific height basing the temperature as follows : 
 
 Escaping gases 552 degrees F. 
 
 Atmospheric temperature 62 degrees F. 
 
THE STEAM BOILER. 
 
 191 
 
 Height of 
 Chimney 
 
 Draft Power 
 in Inches 
 
 Theoretical velocity in feet 
 per second. 
 
 in Feet. 
 
 of Water. 
 
 Cold Air 
 
 Hot Gases 
 
 
 
 Entering. 
 
 Escaping. 
 
 10 
 
 .073 
 
 17.8 
 
 35.6 
 
 20 
 
 .146 
 
 25.3 
 
 50.6 
 
 30 
 
 .219 
 
 31.0 
 
 62.0 
 
 40 
 
 .292 
 
 35.7 
 
 71.4 
 
 50 
 
 .365 
 
 40.0 
 
 80.0 
 
 60 
 
 .438 
 
 43.8 
 
 87.6 
 
 70 
 
 .511 
 
 47.3 
 
 94.6 
 
 80 
 
 .585 
 
 50.6 
 
 101.2 
 
 90 
 
 .657 
 
 53.7 
 
 107.4 
 
 100 
 
 .730 
 
 56.5 
 
 113.0 
 
 120 
 
 .876 
 
 62.0 
 
 124.0 
 
 150 
 
 1.095 
 
 69.3 
 
 138.6 
 
 175 
 
 1.277 
 
 74.8 
 
 149.6 
 
 200 
 
 1.460 
 
 80.0 
 
 160.0 
 
 Draft required depends largely on quality and nature of fuel 
 and rate of combustion ; it is least for wood and free burning fuels 
 and greatest for fine coal; for slack coal draft equivalent to 1J4 
 inches of water is necessary. 
 
 In designing height of chimney it is the aim to provide for an 
 excess of demands and regulate by dampejs to amount required. 
 
 Increasing height will increase the flow of escaping gases. 
 
 AREA OF CHIMNEY WHEN HORSE POWER IS GIVEN. 
 
 Three horse power per square foot of grate surface. 
 
 Rule. Divide 'the horse power by 3.33 times the square root ot 
 the height. The quotient will be the required effective area in 
 square feet. To the diameter or length of side required to give 
 this area add two inches to compensate for friction. 
 
 HORSE POWER OF A GIVEN CHIMNEY. 
 
 Rule. From the area in square feet subtract .6 of the square 
 root of that area and multiply the remainder by the square root of 
 the height and by 3.33. 
 
 Or: 
 
 Multiply the area in square inches by the square root of the 
 height in feet and divide by 40. The quotient will be the horse 
 power. 
 
192 
 
 THE BOILER. 
 
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 .^ 
 
 
 
THE STEAM BOILER. 
 Following is a table by Professor Trowbridge : 
 
 193 
 
 Height in feet. 
 
 Pounds of Coal burned 
 per hour per square 
 foot of section of 
 chimney. 
 
 Pounds of Coal burned 
 per hour per square 
 foot, the ratio of grate to 
 chimney be. ing 8 to 1. 
 
 20 
 
 60 
 
 7.5 
 
 25 
 
 68 
 
 8.5 
 
 30 
 
 76 
 
 9.5 
 
 35 
 
 84 
 
 10.5 
 
 40 
 
 93 
 
 11.6 
 
 45 
 
 99 
 
 12.4 
 
 50 
 
 105 
 
 13.1 
 
 55 
 
 111 
 
 13.8 
 
 60 
 
 116 
 
 14.5 
 
 65 
 
 121 
 
 15.1 
 
 70 
 
 126 
 
 15.8 
 
 75 
 
 131 
 
 16.4 
 
 80 
 
 135 
 
 16.9 
 
 85 
 
 139 
 
 17.4 
 
 90 
 
 144 
 
 18.0 
 
 95 
 
 148 
 
 18.5 
 
 100 
 
 152 
 
 19.0 
 
 105 
 
 156 
 
 19.5 
 
 110 
 
 160 
 
 20.0 
 
 CHIMNEYS. 
 
 Area of chimney for given height and number of square feet 
 of grate surface connected. 
 
 Rule. Multiply the number of square feet of grate surface by 
 120, and divide by the square root of the height. The quotient will 
 be the required cross section in square inches. See table. 
 
194 
 
 THE BOILER. 
 
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THE STEAM BOILER. 
 
 195 
 
 PROPORTIONS OF SELF-SUPPORTING STEEL STACKS. 
 
 
 
 
 
 
 
 
 Diameter 
 
 
 
 
 
 
 "o 
 
 & 
 
 J 
 
 .5-5 
 
 _ b 
 
 "o 
 
 Diameter 
 
 at Top of 
 
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 15 c 
 
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 at Base. 
 
 Bell 
 
 at Top of 
 
 t/3 , .2 
 
 
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 ^ 
 
 
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 U 
 
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 100 
 
 30 
 
 70 
 
 0.41 
 
 0.25 
 
 30 
 
 7 
 
 6 
 
 4 
 
 6 
 
 3 
 
 4 
 
 20.6 
 
 4500 
 
 3500 
 
 7.1 
 
 115 
 
 30- 
 
 90 
 
 0.53 
 
 0.28 
 
 34 
 
 8 
 
 6 
 
 4 
 
 8 
 
 3 
 
 4 
 
 29.5 
 
 5000 
 
 5000 
 
 10.0 
 
 130 
 
 30 
 
 110 
 
 . 65 
 
 0.32 
 
 38 
 
 9 
 
 
 
 4 
 
 9 
 
 3 
 
 4 
 
 40.0 
 
 7000 
 
 6500 
 
 13.0 
 
 125 
 
 33 
 
 70 
 
 0.41 
 
 0.31 
 
 36 
 
 7 
 
 4 
 
 4 
 
 9 
 
 3 
 
 7 
 
 25.0 
 
 5000 
 
 4500 
 
 8.8 
 
 140 
 
 33 
 
 90 
 
 ).53 
 
 0.35 
 
 42 
 
 8 
 
 3 
 
 5 
 
 
 
 3 
 
 7 
 
 34.5 
 
 6000 
 
 5500 
 
 11.0 
 
 160 
 
 33 
 
 110 
 
 ).65 
 
 0.40 
 
 46 
 
 9 
 
 3 
 
 5 
 
 2 
 
 3 
 
 7 
 
 46.0 
 
 7500 
 
 7000 
 
 14.1 
 
 150 
 
 36 
 
 70 
 
 0.41 
 
 0.37 
 
 44 
 
 7 
 
 7 
 
 5 
 
 
 
 3 
 
 10 
 
 29.6 
 
 5000 
 
 5000 
 
 9.6 
 
 175 
 
 36 
 
 90 
 
 0.53 
 
 0.44 
 
 52 
 
 s 
 
 6 
 
 5 
 
 2 
 
 3 
 
 10 
 
 40.0 
 
 7000 
 
 6000 
 
 11.6 
 
 200 
 
 36 
 
 110 
 
 0.65 
 
 0.50 
 
 58 
 
 9 
 
 6 
 
 5 
 
 4 
 
 3 
 
 10 
 
 52.5 
 
 8000 
 
 8000 
 
 15.0 
 
 250 
 
 42 
 
 90 
 
 0.53 
 
 0.62 
 
 74 
 
 8 
 
 9 
 
 5 
 
 6 
 
 4 
 
 4 
 
 32.1 
 
 7500 
 
 6000 
 
 12.3 
 
 275 
 
 42 
 
 110 
 
 0.65 
 
 0.68 
 
 80 
 
 9 
 
 3 
 
 5 
 
 8 
 
 4 
 
 4 
 
 46.0 
 
 9000 
 
 8000 
 
 16.2 
 
 300 
 
 42 130 
 
 0.76 
 
 0.75 
 
 92 
 
 10 
 
 9 
 
 6 
 
 2 
 
 4 
 
 4 
 
 63.3 
 
 10500 
 
 11000 
 
 20.2 
 
 350 
 
 48 
 
 90 
 
 ).53 
 
 0.87 
 
 104 
 
 9 
 
 2 
 
 6 
 
 5 
 
 4 
 
 10 
 
 40.0 
 
 8000 
 
 7000 
 
 13.6 
 
 375 
 
 48 
 
 110 
 
 0.65 
 
 0.93 
 
 110 
 
 9 
 
 9 
 
 6 
 
 9 
 
 4 
 
 10 
 
 56.0 
 
 10000 
 
 9000 
 
 18.1 
 
 400 
 
 48 
 
 130 
 
 0.76 
 
 1.00 
 
 118 
 
 11 
 
 4 
 
 6 
 
 8 
 
 4 
 
 10 
 
 75.7 
 
 12000 
 
 12000 
 
 21.8 
 
 430 
 
 54 
 
 90 
 
 0.53 
 
 1.07 
 
 126 
 
 9 
 
 8 
 
 6 
 
 6 
 
 5 
 
 4 
 
 52.6 
 
 9000 
 
 7500 
 
 15.3 
 
 470 
 
 54 
 
 110 
 
 0.65 
 
 1.17 
 
 138 
 
 10 
 
 8 
 
 6 
 
 8 
 
 5 
 
 4 
 
 71.9 
 
 11000 
 
 10000 
 
 20.1 
 
 510 
 
 54 
 
 130 
 
 0.76 
 
 1.27 
 
 150 
 
 11 
 
 9 
 
 7 
 
 2 
 
 5 
 
 4 
 
 94.7 
 
 13000 
 
 13000 
 
 24.0 
 
 580 
 
 60 
 
 100 
 
 ).59 
 
 1.45 
 
 170 
 
 10 
 
 6 
 
 7 
 
 
 
 5 
 
 10 
 
 67.3 
 
 11000 
 
 8000 
 
 18.5 
 
 675 
 
 60 
 
 125 
 
 0.73 
 
 1.62 
 
 190 
 
 12 
 
 
 
 7 
 
 8 
 
 5 
 
 10 
 
 97.0 
 
 14000 
 
 13000 
 
 24.7 
 
 700 
 
 60 
 
 150 
 
 0.87 
 
 1.75 
 
 206 
 
 13 
 
 2 
 
 7 
 
 9 
 
 5 
 
 10 
 
 122.0 
 
 17000 
 
 17000 
 
 31.9 
 
 700 
 
 66 
 
 100 
 
 ).59 
 
 1.75 
 
 206 
 
 11 
 
 
 
 7 
 
 6 
 
 6 
 
 4 
 
 80.0 
 
 12000 
 
 9000 
 
 20.8 
 
 800 
 
 66 
 
 125 
 
 0.73 
 
 2 00 
 
 234 
 
 12 
 
 6 
 
 8 
 
 2 
 
 6 
 
 4 
 
 105.0 
 
 15000 
 
 15000 
 
 26.3 
 
 900 
 
 66 
 
 150 
 
 0.87 
 
 2.25 
 
 264 
 
 13 
 
 8 
 
 8 
 
 4 
 
 6 
 
 4 
 
 135 . 
 
 18000 
 
 20000 
 
 34.4 
 
 950 
 
 72 
 
 125 
 
 0.65 
 
 2.37 
 
 280 
 
 13 
 
 
 
 8 
 
 8 
 
 6 
 
 10 
 
 90.0 
 
 16000 
 
 11000 
 
 27.2 
 
 1050 
 
 72 
 
 150 
 
 0.87 
 
 2.67 
 
 310 
 
 14 
 
 2 
 
 8 
 
 9 
 
 6 
 
 10 
 
 113.0 
 
 20000 
 
 19000 
 
 38.8 
 
 1150 
 
 72 
 
 175 
 
 1.03 
 
 2.87 
 
 326 
 
 15 
 
 3 
 
 9 
 
 
 
 6 
 
 10 
 
 155.0 
 
 23000 
 
 26000 
 
 42.3 
 
 1150 
 
 78 
 
 1 25 
 
 0.65 
 
 2.87 
 
 326 
 
 13 
 
 6 
 
 9 
 
 2 
 
 7 
 
 4 
 
 105.0 
 
 17000 
 
 18000 
 
 30.0 
 
 1250 
 
 78 
 
 150 
 
 0.87 
 
 3.12 
 
 368 
 
 14 
 
 8 
 
 9 
 
 4 
 
 7 
 
 4 
 
 141.0 
 
 21000 
 
 24000 
 
 38.9 
 
 1350 
 
 78 
 
 175 
 
 1.03 
 
 3.37 
 
 396 
 
 15 
 
 9 
 
 9 
 
 6 
 
 7 
 
 4 
 
 185.0 
 
 24000 
 
 29000 
 
 45.0 
 
 1400 
 
 84 
 
 130 
 
 0.76 
 
 3.50 
 
 412 
 
 14 
 
 
 
 9 
 
 8 
 
 7 
 
 10 
 
 116.0 
 
 19000 
 
 21000 
 
 33.8 
 
 1550 
 
 84 
 
 It).', 
 
 0.97 
 
 3.87 
 
 456 
 
 15 
 
 4 
 
 9 
 
 9 
 
 7 
 
 10 
 
 161.0 
 
 25000 
 
 28000 
 
 44.7 
 
 1700 
 
 84 
 
 200 
 
 1.18 
 
 4.25 
 
 500 
 
 16 
 
 9 
 
 10 
 
 
 
 7 
 
 10 
 
 217.0 
 
 30000 
 
 34000 
 
 54.3 
 
 1800 
 
 96 
 
 140 
 
 0.82 
 
 4.501 530 
 
 15 
 
 4 
 
 10 
 
 8 
 
 8 
 
 10 
 
 140.0 
 
 24000 
 
 25000 
 
 42.4 
 
 2100 
 
 96 
 
 180 
 
 1.06 
 
 5.25 
 
 620 
 
 17 
 
 
 
 10 
 
 9 
 
 8 
 
 10 
 
 200.0 
 
 30000 
 
 31000 
 
 52.9 
 
 2300 
 
 96 
 
 );() 
 
 1.30 
 
 5.75 
 
 676 
 
 18 
 
 8 
 
 11 
 
 
 
 8 
 
 10 
 
 273.0 
 
 37000 
 
 42000 
 
 65.3 
 
 2400 
 
 108 
 
 150 
 
 0.87 
 
 6.00 
 
 706 
 
 16 
 
 9 
 
 11 
 
 9 
 
 9 
 
 10 
 
 175.0 
 
 28000 
 
 31000 
 
 49.9 
 
 2700 
 
 108 
 
 190 
 
 1.12 
 
 6.75 
 
 794 
 
 18 
 
 6 
 
 12 
 
 
 
 9 
 
 10 
 
 242.0 
 
 35000 
 
 37000 
 
 62.3 
 
 3000 
 
 108 
 
 240 
 
 1.41 
 
 7.50 
 
 882 
 
 20 
 
 6 
 
 12 
 
 2 
 
 9 
 
 10 
 
 325.0 
 
 45000 
 
 48000 
 
 89.0 
 
 3000 
 
 120 
 
 150 
 
 0.87 
 
 7.50 
 
 882 
 
 17 
 
 9 
 
 12 
 
 9 
 
 10 
 
 10 
 
 262.0 
 
 31000 
 
 35000 
 
 53.9 
 
 3500 
 
 120 
 
 200 
 
 1.18 
 
 8.75 
 
 1030 
 
 19 
 
 9 
 
 13 
 
 
 
 10 
 
 10 
 
 304.0 
 
 40000 
 
 47000 
 
 71.0 
 
 3900 
 
 120 
 
 250 
 
 1.48 
 
 9.75 
 
 1148 
 
 21 
 
 9 
 
 13 
 
 2 
 
 10 
 
 10 
 
 400.0 
 
 51000 
 
 60000 
 
 94.8 
 
 4200 
 
 132 
 
 200 
 
 1.18 
 
 10.50 
 
 1236 
 
 20 
 
 9 
 
 14 
 
 
 
 11 
 
 10 
 
 294.0 
 
 45000 
 
 50000 
 
 77.2 
 
 4700 
 
 132 
 
 250 
 
 1.48 
 
 11.75 
 
 1382 
 
 23 
 
 4 
 
 14 
 
 4 
 
 11 
 
 10 
 
 400.0 
 
 56000 
 
 62000 
 
 100.5 
 
 5200 
 
 132 
 
 300 
 
 1.67|13.00 
 
 1528 
 
 25 
 
 
 
 14 
 
 8 
 
 11 
 
 10 
 
 530.0 
 
 67000 
 
 75000 
 
 140.7 
 
196 THE BOILER. 
 
 SMOKE STACKS. 
 APPROXIMATE WEIGHT IN POUNDS OF ONE FOOT OF STACK. 
 
 Diameter, 
 inches. 
 
 THICKNESS OF MATERIAL. 
 
 No. 16. 
 
 No. 14. 
 
 No. 12. 
 
 No. 10. 
 
 No. 8. 
 
 Weight. 
 
 Weight. 
 
 Weight. 
 
 Weight. 
 
 Weight. 
 
 10 
 
 8 
 
 10 
 
 13 
 
 16 
 
 \9 
 
 12 
 
 9 
 
 12 
 
 14 
 
 19 
 
 23 
 
 14 
 
 11 
 
 14 
 
 16 
 
 22 
 
 27 
 
 16 
 
 12 
 
 16 
 
 20 
 
 25 
 
 31 
 
 18 
 
 14 
 
 18 
 
 23 
 
 28 
 
 35 
 
 20 
 
 15 
 
 19 
 
 25 
 
 31 
 
 38 
 
 22 
 
 17 
 
 21 
 
 28 
 
 34 
 
 42 
 
 24 
 
 18 
 
 23 
 
 30 
 
 36 
 
 45 
 
 26 
 
 19 
 
 24 
 
 32 
 
 40 
 
 48 
 
 28 
 
 21 
 
 26 
 
 35 
 
 43 
 
 52 
 
 30 
 
 22 
 
 28 
 
 37 
 
 46 
 
 56 
 
 32 
 
 23 
 
 30 
 
 39 
 
 48 
 
 58 
 
 34 
 
 24 
 
 31 
 
 41 
 
 50 
 
 60 
 
 36 
 
 26 
 
 32 
 
 43 
 
 .52 
 
 63 
 
 38 
 
 27 
 
 34 
 
 44 
 
 54 
 
 66 
 
 40 
 
 29 
 
 36 
 
 47 
 
 57 
 
 70 
 
 42 
 
 31 
 
 38 
 
 49 
 
 60 
 
 74 
 
 44 
 
 33 
 
 41 
 
 54 
 
 66 
 
 81 
 
 48 
 
 35 
 
 45 
 
 59 
 
 72 
 
 89 
 
 54 
 
 38 
 
 48 
 
 64 
 
 82 
 
 97 
 
 60 
 
 42 
 
 53 
 
 71 
 
 90 
 
 108 
 
 66 
 
 45 
 
 59 
 
 77 
 
 98 
 
 117 
 
 72 
 
 '51 
 
 65 
 
 86 
 
 110 
 
 131 
 
 78 
 
 58 
 
 74 
 
 98 
 
 120 
 
 150 
 
 84 
 
 62 
 
 80 
 
 105 
 
 130 
 
 160 
 
 96 
 
 72 
 
 92 
 
 130 
 
 148 
 
 180 
 
THE STEAM BOILER. 
 
 197 
 
 I * 
 
 I 
 
 
 
 rfH 00 10 05 -CO CO - 
 
 CO O Oi t^ NjfN? !^ O S rvi ^ 
 
 M os co co -S*> n Jj M ^ 1 
 
 OO O5 O ^H 
 
 I-H ^H IQ 
 
 es 
 s . 
 he 
 
 of shell, inches . 
 shell, inches 
 ubes, inches. . 
 2-inch tubes . 
 f shell, inches 
 of heads, inche 
 urnace, inches 
 f furnace, inc 
 rface, square f 
 r safety-valve 
 -off, inches .. 
 
 12 
 
 5 i oc 
 
 B - 
 
 Is! 
 
 |co 
 
 : ji|j||*i 
 . _ .j i . 
 
 
 .2 S '' 
 
 
 1 
 
198 
 
 THE BOILER. 
 
 CAPACITIES OF BOILERS FOR Low PRESSURE STEAM HEATING APPARATUS. 
 
 Boiler Surface, 
 square feet. 
 
 Total Direct Radiation, 
 square feet. 
 
 Direct Radiation 
 per square foot of 
 Boiler Surface. 
 
 40 
 
 168 
 
 4.20 
 
 50 
 
 218 
 
 4.36 
 
 60 
 
 272 
 
 4.53 
 
 80 
 
 384 
 
 4.80 
 
 100 
 
 504 
 
 5.04 
 
 120 
 
 626 
 
 5.21 
 
 140 
 
 752 
 
 5.37 
 
 152 
 
 830 
 
 5.46 
 
 172 
 
 962 
 
 5.60 
 
 194 
 
 1114 
 
 5.74 
 
 211 
 
 1232 
 
 5.84 
 
 252 
 
 1522 
 
 6.04 
 
 292 
 
 1816 
 
 6.21 
 
 295 
 
 1840 
 
 6.23 
 
 347 
 
 2240 
 
 6.45 
 
 399 
 
 2642 
 
 6.62 
 
 421 
 
 2820 
 
 6.69 
 
 482 
 
 3321 
 
 6.89 
 
 541 
 
 3818 
 
 7.05 
 
 580 
 
 4247 
 
 7.37 
 
 720 
 
 6210 
 
 8.46 
 
 The quantities of radiation in the above table are exclusive of all piping. 
 One square foot of indirect requires the same boiler capacity as 1^ 
 square feet of direct radiation. 
 
 TO DETERMINE THE SIZE OF STEAM PIPE MAINS FOR VARYING 
 RADIATION. 
 
 For every 100 square feet of radiating surface, allow the area 
 of a one-inch pipe (.7854 square inches). 
 
 LIST OF SIZES OF STEAM MAINS. 
 
 Radiation, 
 
 square feet. 
 
 One Pipe Work, 
 inches. 
 
 Two Pipe Work, inches. 
 
 40 t 
 
 o 50 
 
 1 
 
 MX Y 
 
 100 
 
 125 
 
 m 
 
 1 x M 
 
 125 
 
 250 
 
 m 
 
 iMxi 
 
 250 
 
 400 
 
 2 
 
 i^xi M 
 
 400 
 
 650 
 
 2^ 
 
 2 xl^ 
 
 650 
 
 900 
 
 3 
 
 2^x2 
 
 900 
 
 1250 
 
 3^ 
 
 3 x2^ 
 
 1250 
 
 1600 
 
 4 
 
 3^x3 
 
 1600 
 
 2050 
 
 4^ 
 
 4 x3^ 
 
 2050 
 
 2500 
 
 
 4^x4 
 
 2500 
 
 3600 
 
 6 
 
 5 x4^ 
 
 3600 
 
 5000 
 
 7 
 
 6 x5 
 
 5000 
 
 6500 
 
 8 
 
 7 x6 
 
 6500 
 
 8100 
 
 9 
 
 8 x6 
 
 8100 
 
 10000 
 
 10 
 
 9 x6 
 
THE STEAM BOILER. 
 
 199 
 
 Under ordinary conditions, one square foot of direct radiation 
 surface will heat approximately in: 
 
 Bath-room ............................................ 
 
 Living-room .......................................... 
 
 Living-room, exposures, ordinary amount of glass ........... 
 
 Halls ............................................ 50 to 
 
 Sleeping rooms ................................... 55 " 
 
 School-rooms ... .................................. 60 " 
 
 Churches and auditoriums of large cubic contents and 
 
 with high ceilings ............................. 65 
 
 Factories and work-shops 
 
 75 
 
 40 cubic feet. 
 
 50 " 
 
 60 " 
 
 70 
 
 70 
 
 80 
 
 100 
 150 
 
 CAPACITIES OF BOILERS FOR HOT WATER HEATING APPARATUS. 
 
 Boiler Surface, 
 square feet. 
 
 Total Direct Radiation, 
 square feet. 
 
 Direct Radiation 
 per square foot of 
 boiler surface. 
 
 20 
 
 110 
 
 5.50 
 
 30 
 
 181 
 
 6.03 
 
 40 
 
 257 
 
 6.42 
 
 50 
 
 338 
 
 6.76 
 
 60 
 
 425 
 
 7.08 
 
 70 
 
 512 
 
 7.46 
 
 80 
 
 603 
 
 7.54 
 
 90 
 
 695 
 
 7.72 
 
 100 
 
 792 
 
 7.92 
 
 120 
 
 991 
 
 8.26 
 
 140 
 
 1198 
 
 8.56 
 
 159 
 
 1400 
 
 8.80 
 
 199 
 
 1842 
 
 9.25 
 
 225 
 
 2142 
 
 9.52 
 
 279 
 
 2788 
 
 9.99 
 
 323 
 
 3332 
 
 10.31 
 
 372 
 
 3976 
 
 10.68 
 
 453 
 
 5065 
 
 11.18 
 
 517 
 
 5938 
 
 11.48 
 
 The quantities of radiation in the above table are exclusive of all 
 
 piping- 
 One square foot of indirect requires the same boiler capacity as 
 \Y-2. square feet of direct radiation. 
 
CHAPTER IX. 
 
 SAFETY VALVES. 
 
 A safety valve should have area sufficient for the escape of 
 steam with rapidity to prevent the raising of steam to exceed 10 
 per cent of pressure allowed and calculations should be from a 
 standard, the maximum water that could be evaporated per pounds 
 of fuel- 
 Any spring-loaded safety valve constructed so as to give an 
 increased lift by the operation of steam, after being raised from 
 its seat, or any spring-loaded safety valve constructed in any other 
 manner so as to give an effective area equal to that of the afore- 
 mentioned spring-loaded safety valve, may be used in lieu of the 
 common lever-weighted valve on all boilers on steam vessels, and 
 each spring-loaded valve shall be supplied with a lever that will raise 
 the valve from its seat a distance of not less than that equal to 
 one-eighth of the diameter of the valve opening; but in no case 
 shall any spring-loaded safety valve be used in lieu of the lever- 
 weighted safety valve without first having been approved by the 
 Board of Supervising Inspectors. 
 
 The valves shall be so arranged that each boiler shall have at 
 least one separate safety valve, unless the arrangement is such as 
 to preclude the possibility of shutting off the communication of any 
 boiler with the safety valve or valves employed. This arrangement 
 shall also apply to lock-up safety valves when they are employed. 
 
 The use of two safety valves may be allowed on any boiler, 
 provided the combined area of such valves is equal to that required 
 by rule for one such valve. Whenever the area of a safety valve, 
 as found by the rule of this section will be greater than that cor- 
 
 200 
 
TESTS AND INSPECTION. 201 
 
 responding to 6 inches in diameter, two or more safety valves, the 
 combined area of which shall be equal at least to the area required, 
 must be used. 
 
 EXAMPLES: 
 Boiler pressure =75 pounds per square inch (gauge ) . 
 
 2 furnaces: Grate surface =2x5 feet 6 inches long X 3 feet wide = 
 33 square feet. 
 
 Water evaporated per pound of coal = 8 pounds. 
 
 Coal burned per square foot grate surface per hour = 12^ pounds. 
 
 Evaporation per square foot grate surface per hour = 8X12^ =100 Ibs. 
 
 Hence W = 100 and gauge pressure =75 pounds. 
 
 From table the corresponding value of a is .230 square inches. 
 
 Therefore area of safety valve =33 X.23 =7.59 square inches. 
 
 For which the diameter is 3^ inches nearly. 
 
 Boiler pressure =215 pounds. 
 
 6 furnaces: Grate surface =6X5 feet 6 inches long X 3 feet 4 inches 
 wide =110 square feet. 
 
 Water evaporated per pound coal = 10 pounds. 
 
 Coal burned per square foot grate surface per hour = 30 pounds. 
 
 Evaporation per square foot grate surface per hour = 10 X 30 =300 Ibs. 
 
 Hence W =300, gauge pressure =215, and a =.270 (from table). 
 
 Therefore area of safety valve = 110 X. 270 =29.7 square inches, which 
 is too large for one valve. Use two. 
 29.7 
 
 = 14.85 square inches. Diameter = 4 % inches. 
 
 Rule to determine the area of a safety valve for boiler using oil 
 as fuel or for boilers designed for any evaporation per hour : 
 
 Divide the total number of pounds of water evaporated per hour 
 by any number of pounds of water evaporated per square foot of 
 grate surface per hour (W) taken from, and within the limits of, 
 the table. This will give the equivalent number of square feet of 
 grate surface for boiler for estimating the area of valve. Then 
 apply the table as in previous examples. 
 
 The areas of all safety valves on boilers contracted for or the 
 construction of which commenced on or after June 1, 1904, shall be 
 determined in accordance with the following formula and table : 
 
202 THE BOILER. 
 
 EXAMPLE. 
 
 Required the area of a safety valve for a boiler using oil as fuel, 
 designed to evaporate 8,000 pounds of water per hour, at 175 
 pounds gauge pressure. 
 
 Make W=200. 
 8,000 
 
 = 40, the equivalent grate surface, in square feet. 
 200 
 
 For gauge pre:sure = 175 pounds and W=200 from table, a =.218 
 square inch. .218x40=8.72 square inches, the total area of safety valve 
 required for this boiler, for which the diameter is 3jf square inches nearly. 
 
 From which formula the areas required per square foot of grate 
 surface in the following table are found by assuming the different 
 values of W and P. 
 
 The figures (a) in table multiplied by square feet of grate 
 surface give the area of safety valve or valves required. 
 
 When these calculations result in an odd size of safety valve, use 
 next larger standard size. 
 
TESTS AND INSPECTION. 
 
 203 
 
 r (W) = pounds water eva 
 rface per hour. 
 
 pounds per square foot of grate surface per h 
 X pounds coal burned per square foot grate 
 
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204 
 
 THE BOILER. 
 
 er hour (W) ^pounds wate 
 te surface per hour. 
 
 square foot of grate surfac 
 l burned per square foot g 
 
 n po 
 X po 
 
 5O50000l^t^COC 
 (M C^l iM (M C^ <M W &\ ^1 
 
 r^ <M CO ^ CD 7-1 1^. 00 O5 LO T-I t~ 
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 13 
 
TESTS AND INSPECTION. 205 
 
 Rule to find area of pop safety valve computed from grate sur- 
 face, water evaporation and pressure : Multiply constant .2074 by 
 water evaporated per pound of coal per hour and divide by working- 
 pressure ; this gives area of safety valve per square foot of grate 
 surface. Multiplying this result by total .grate surface gives re- 
 quired area of safety valve for furnace grate area. 
 
 FORMULA: 
 .2074XW 
 
 =area of safety valve per square foot of grate area 
 
 LEGEND: 
 
 C= constant = .2074 
 W = pounds of water evaporated per square foot of grate surface per hour 
 
 8 pounds of water per pound of coal. 
 
 P=absolute pressure plus 15 pounds atmospheric pressure =90 pounds. 
 G = grate surface =30 feet. 
 Coal burned per square foot of grate per hour = 12.5 pounds. 
 
 EXAMPLE: 
 
 Ibs. of coal burned per square 
 
 foot of grate per hour = 12.5 
 
 water evaporated = 8 
 
 100.0 
 
 .2074= constant 
 
 100 =lbs. of water evap. per hour 
 
 working pressure =90)20. 7400 (. 2304 =area of valve per 1 
 
 18 square foot of grate 
 
 2 74 
 2 70 
 
 400 
 360 
 
 40 
 
 . 2304 =area of valve %j "" 
 
 30 = total square feet of grate surface 
 
 6 . 9120 =3" diameter valve required 
 
206 THE BOILER. 
 
 REQUIREMENTS IN CONSTRUCTION OF LEVER-SAFETY VALVES. 
 
 All the points of bearing on lever must be in the same plane. 
 
 The distance of the fulcrum must in no case be less than the 
 diameter of the valve opening. 
 
 The length of the lever should not exceed the distance of the 
 fulcrum multiplied by ten. 
 
 The width of the bearings of the fulcrum must not be less than 
 three-fourths of 1 inch. 
 
 The length of the fulcrum link should not be less than 4 inches. 
 
 In all cases the weight must be adjusted on the lever to the 
 pressure of steam allowed in each case by a correct steam gauge 
 attached to the boiler. The weight must then be securely fastened 
 in its position and the lever marked for the purpose of facilitating 
 the replacing of the weight should it be necessary to remove the 
 same, and in no case shall a line or any other device be attached to 
 the lever or weight except in such manner as will enable the 
 engineer to raise the valve from its seat. 
 
 When safety valve is blown off always note pressure on gauge ; 
 if there is a difference, seek the cause and adjust the gauge or valve 
 until they are as intended. 
 
 The lever safety valve, while being very extensively used, is not 
 perfect in action or operation, in not seating itself until pressure has 
 been reduced considerable below point it is set at. 
 
 The following rules are used in determining values, viz. : 
 pressure, length of lever and weight of ball. 
 
 Rule to find weight of ball when pressure, length of lever and 
 area of valve is known : Multiply pressure in pounds by area of 
 valve in inches and multiply this product by distance of valve center 
 to fulcrum ; subtract weight of lever from this product and divide 
 sum by length of lever. 
 
 LEGEND: 
 
 Va = valve area = 12 . 5664 =4" valve 
 
 L=length of lever = 30" 
 W = weight of lever =20 Ibs. 
 
 d = distance valve center to fulcrum =4" 
 
 P = pressure =100 Ibs. 
 
 FORMULA: 
 
 PxVaXd W 
 
 = weight required for ball 
 
TESTS AND INSPECTION. 207 
 
 EXAMPLE: 
 
 12.5664 4" valve area 
 100 = pressure 
 
 1256.6400 
 
 4= distance valve center to ful- 
 
 crum 
 
 5026.5600 
 
 20. == weight of lever 
 
 length of lever =30") 5006. 5600 (166. 8853 or 167 Ibs. nearly 
 30 weight of ball 
 
 200 
 180 
 
 206 
 180 
 
 265 
 240 
 
 256 
 240 
 
 160 
 150 
 
 100 
 90 
 
 10 
 
 Rule to find length of lever when pressure and weight of ball 
 and area of valve is given: Multiply area of valve by pressure in 
 pounds and by distance of center of valve to fulcrum ; to this product 
 add weight of lever ; divide by weight of ball. 
 
 FORMULA: 
 VaXPXd + W 
 
 = length of lever 
 Wt 
 
 EXAMPLE 
 Wt= weight of ball = 166. 8853 Ibs. 
 
 12 . 5664 = valve area 
 
 100 =lbs. pressure 
 
 1256.6400 
 
 4" = valve center to fulcrum 
 
 5026.5600 
 
 20. = weight of lever 
 
 weight of ball -166. 8853)5046. 5600 (30 =length of lever 
 5006 559 
 
 40 0010 
 
208 THE BOILER. 
 
 Rule to find pressure a safety valve will blow off at when weight 
 of ball, length of lever and distance of valve center to fulcrum are 
 known: Multiply weight of ball by length of lever, add weight of 
 lever to this and divide by valve area multiplied by distance of valve 
 center to fulcrum ; the quotient will be pressure in pounds. 
 
 FORMULA: 
 WtXL + W 
 
 = pressure 
 VaXd 
 
 EXAMPLE : 
 166 . 8853 = weight of ball 
 
 30" = length of lever 
 
 valve area =12. 5664 5006.5590 
 
 distance == 4" 20. = weight of lever 
 
 50 . 2656) 5026 .55900 (99 . 9 or 100 pounds 
 
 4523 904 pressure nearly 
 
 502 6550 
 452 3904 
 
 50 26460 
 45 23904 
 
 5 02556 
 
 Extracts from U. S. Government rules and regulations, pre- 
 scribed by the Board of Supervising Inspectors, as amended Janu- 
 ary, 1907: 
 
 " No engineer's license shall be issued hereafter or grade in- 
 creased except upon. written examination, which written examination 
 shall be placed on file as records of the office of the inspectors 
 issuing said license. When any person makes application for license 
 it shall be the duty of local inspectors to give the applicant the 
 required examination as soon as practicable." 
 
 CLASSIFICATION -OF ENGINEERS. 
 
 CHIEF. 
 
 Chief engineer of ocean steamers. 
 
 Chief engineer of condensing lake, bay and sound steamers. 
 
 Chief engineer of noncondensing lake, bay and sound steamers. 
 
 Chief engineer of condensing river steamers. 
 
 Chief engineer of noncondensing river steamers. 
 
TESTS AND INSPECTION. 209 
 
 Any person holding" chief engineer's license shall be permitted 
 to act as first assistant on any steamer of double the tonnage of 
 same class named in said chief's license. 
 
 Engineers of all classifications may be allowed to pursue their 
 profession upon all waters of the United States in the class for 
 which they are licensed. 
 
 FIRST ASSISTANT. 
 
 First assistant engineer of ocean steamers. 
 
 First assistant engineer of condensing lake, bay and sound 
 steamers. 
 
 First assistant engineer of noncondensing lake, bay and sound 
 steamers. 
 
 First assistant engineer of condensing river steamers. 
 
 First assistant engineer of noncondensing river steamers. 
 
 Engineers of lake, bay and sound steamers, who have actually 
 performed the duties of engineer for a period of three years, shall 
 be entitled to examination for engineer of ocean steamers, applicant 
 to be examined in the use of salt water, method employed in regu- 
 lating the density of the water in boilers, the application of the 
 hydrometer in determining the density of sea water and the prin- 
 ciple of constructing the instrument ; and shall be granted such 
 grade as the inspectors having jurisdiction on the Great Lakes 'and 
 seaboard may find him competent to fill. 
 
 Any assistant engineer of steamers of 1,500 gross tons and over, 
 having had actual service in that position for one year, may, if the 
 local inspectors, in their judgment, deem it advisable, have his 
 license indorsed to act as chief engineer on lake, bay, sound, or river 
 steamers of 750 gross tons or under. 
 
 Any person having had a first assistant engineer's license for two 
 years and having had two years' experience as second assistant 
 engineer, shall be eligible for examination for chief engineer's 
 license. 
 
 SECOND ASSISTANT. 
 
 Second assistant engineer of ocean steamers. 
 
 Second assistant engineer of condensing lake, bay and sound 
 steamers. 
 
 Second assistant engineer of noncondensing lake, bay and sound 
 steamers. 
 
210 THE BOILER. 
 
 Second assistant engineer of condensing river steamers. 
 
 Any person having had a second assistant engineer's license 
 for two years and having had two years' experience as third 
 assistant engineer, shall be eligible for examination for first assistant 
 engineer's license. 
 
 THIRD ASSISTANT. 
 
 Third assistant engineer of ocean steamers. 
 
 Third assistant engineer of condensing lake, bay and sound 
 steamers. 
 
 First, second, and third assistant engineers may act as such on 
 any steamer of the grade of which they hold license, or as such 
 assistant engineer on any steamer of a lower grade than those 
 to which they hold a license. 
 
 Any person having a third assistant engineer's license for two 
 years and having had two years' experience as oiler or water tender 
 since receiving said license, shall be eligible for examination for 
 second assistant engineer's license. 
 
 Inspectors may designate upon the certificate of any chief or 
 assistant engineer the tonnage of the vessel on which he may act. 
 
 Any assistant engineer may act as engineer in charge on steam- 
 ers of 100 tons and under. In all cases where an assistant engineer 
 is permitted to act as engineer in charge, the inspectors shall so 
 state on the face of his certificate of license without further ex- 
 amination. 
 
 It shall be the duty of an engineer when he assumes charge 
 of the boilers and machinery of a steamer to forthwith thoroughly 
 examine the same and if he finds any part thereof in bad condition, 
 caused by neglect or inattention on the part of his predecessor, he 
 shall immediately report the facts to the master, owner, or agent 
 and to the local inspectors of the district, who shall thereupon in- 
 vestigate the matter and if the former engineer has been culpably 
 derelict of his duty, they shall suspend or revoke his license. 
 
 Before making general repairs to a boiler of a steam vessel the 
 engineer in charge of such steamer shall report, in writing, the 
 nature of such repairs to the local inspector of the district wherein 
 such repairs are to be made. 
 
 And it shall be the duty of all engineers when an accident 
 occurs to the boilers or machinery in their charge tending to render 
 
TESTS AND INSPECTION. 211 
 
 the further use of such boilers or machinery unsafe until repairs 
 are made, or when, by reason of ordinary wear, such boilers or 
 machinery have become so unsafe, to report the same to the local 
 inspectors immediately upon the arrival of the vessel at the first port 
 reached subsequent to the accident, or after the discovery of such 
 unsafe condition by said engineer. 
 
 Whenever a steamer meets with an accident involving loss of 
 life or damage to property, it shall be the duty of the licensed 
 officers of any such steamer to report the same in writing and in 
 person without delay to the nearest board: Provided, That when 
 from distance it may be inconvenient to report in person it may 
 be done in writing only and the report sworn to before any person 
 authorized to administer oaths. 
 
 No person shall receive an original license as engineer or assist- 
 ant engineer (except for special license on small pleasure steamers 
 and ferryboats of 10 tons and under, sawmill boats, pile drivers, 
 boats exclusively engaged as fishing boats and other similar small 
 vessels) who has not served at least three years in the engineer's 
 department of a steam vessel, a portion of which experience must 
 have been obtained within the three years next preceding the 
 application. 
 
 Provided, That any person who has served three years as ap- 
 prentice to the machinist trade in a marine, stationary, or locomotive 
 engine works, and any person who has served for a period of not 
 less than three years as a locomotive or stationary engineer, and 
 any. person graduated as a mechanical engineer from a duly recog- 
 nized school of technology, may be licensed to serve as an engineer 
 of steam vessels after having had not less than one year's experi- 
 ence in the engine department of steam vessels, a portion of which 
 experience must have been obtained within the three years preced- 
 ing his application ; which fact must be verified by the certificate, in 
 writing, of the licensed engineer or master under whom the appli- 
 cant has served, said certificate to be filed with the application of 
 the candidate; and no person shall receive license as above, except 
 for special license, who is not able to determine the weight necessary 
 to be placed on the lever of a safety valve (the diameter of valve, 
 length of lever, distance from center of valve to fulcrum, weight 
 of lever and weight of valve and stem being known) to with- 
 
212 THE BOILER. 
 
 stand any given pressure of steam in a boiler, or who is not 
 able to figure and determine the strain brought on the braces of a 
 boiler with a given pressure of steam, the position and distance apart 
 of braces being known, such knowledge to be determined by an 
 examination in writing, and the report of examination filed with the 
 application in the office of the local inspectors, and no engineer or 
 assistant engineer now holding a license shall have the grade of the 
 same raised without possessing the above qualifications. No origi- 
 nal license shall be granted any engineer or assistant engineer who 
 can not read and write and does not understand the plain rules of 
 arithmetic. 
 
 Any person may be licensed as engineer (on Form 2130^) 
 [New Form 880] on vessels propelled by gas, fluid, naphtha, or 
 electric motors, of 15 gross tons or over, engaged in commerce, if 
 in the judgment of the inspectors, after due examination in writing, 
 he be found duly qualified to take charge of the machinery of 
 vessels so propelled. 
 
 Any person holding a license as engineer of steam vessels, de- 
 siring to act as engineer of motor vessels, must appear before a 
 board of local inspectors for examination as to his knowledge of 
 the machinery of such motor vessels, and if found qualified shall 
 be licensed as engineer of motor vessels. Form 878, special license 
 to engineers, shall be issued only to engineers in charge of vessels 
 of 10 tons and under. All other licenses to engineers shall be 
 issued on Forms 876 and 877, according to grades specified in this 
 section. 
 
 INSPECTING BOILERS. 
 
 The necessity of care in inspecting steam boilers is apparent 
 when the amount of power stored up while the boiler is in commis- 
 sion is known as an illustration: a common sized boiler 60" X 
 16' has 38923square inches, and carrying a pressure of 100 pounds, 
 has 1946 tons of energy. With strains of expansion and contrac- 
 tion not equal all over but varying, and limits to the extreme 
 (i. e.) the temperature of fire in furnace to that of parts furthest 
 from it, and furthermore when considering that 85% of the boiler 
 is concealed this by design or principle of installation the 
 
TESTS AND INSPECTION. 213 
 
 necessity of vigilance can be realized, especially when the causes of 
 failure and defects are numerous, viz. : 
 
 Material, 
 
 Design, 
 
 Construction, 
 
 Appliances, 
 
 Fuel, 
 
 Feed Water, 
 
 Settings, and 
 
 Management and Care. 
 
 The hydrostatic test is a method not very satisfactory but often 
 necessary when access to parts is impossible, or where a design 
 of boiler has flat surface and notice of bulging or elongation must 
 be noted before and after pressure ; it is necessary when notes of 
 bracing are to be taken and when there are any minor defects such 
 as leaks at rivets or caulking so they can be remedied before more 
 serious results follow. When a hydrostatic test is made of boilers 
 that are accessible, braces and such joints that are weaker than the 
 original plates' tensile strength, must be inspected carefully for any 
 distortions or leaks due to riveting, welds or defective flanges and 
 hidden defects may give evidence of their presence. 
 
 INSPECTIONS. 
 
 There are internal and external inspections, both essential in 
 determining the boiler's safety; for to determine the safe working 
 pressures, an internal inspection is absolutely necessary. 
 
 The conditions for this latter examination are as follows : The 
 boiler must be cool, water out (this is supposing the boiler has been 
 in commission), ashes and soot removed, the mud only washed out of 
 boiler (it is well to avoid excessive pump pressure when washing 
 out until inspection is made), this so as not to destroy or wash off 
 any evidence of leaks that might be at points inaccessible to view 
 from the outside, but would be in evidence at a point inside, for 
 deposits or precipitation in suspension would collect at point where 
 leakage was, thus giving evidence of leaks that could not be seen 
 from outside ; this, of course, applies to boilers of size and design 
 accessible. A thorough examination must be made of all parts of 
 boiler accessible ; sounding plates where possible over fire or in 
 
214 THE BOILER. 
 
 furnace ; and parts where not possible over fire or in furnace to see 
 or sound, symptoms that would deceive the eye, can, at times, be 
 detected by the sense of touch; flanges and junction of pipes at 
 boilers must be examined, for threads are an initial fracture, and by 
 the pipe or boiler expanding much undue strain results and often 
 causes breaking off of pipe. The tubes at rear and front heads 
 being thin, are often a source of annoyance ; examine seams and 
 rivets for leakage and cracks; see that openings to outlets are free 
 from obstructions ; sound braces ; examine flanges, seams and rivets 
 internally, the condition as to incrustation, corrosion, pitting, and 
 when in doubt, give a hydrostatic test; this would reveal any weak- 
 ness and leaks impossible to see, or defects developed by closing 
 down the boiler, resulting in contraction. An inspection and sound- 
 ing of braces should follow the hydrostatic test. Stay bolts must be 
 sounded when type of boiler is braced by them. 
 
 The first thing, look at or for the water level, then the steam 
 pressure; view the furnace, tube sheets, crown sheets and sides in 
 internal fired boilers and bottom and furnace walls in external fired 
 boilers, looking at back head from rear doors for leakage; (the 
 doors at rear end were designed for access to back head and 
 to view when the boilers were in commission) the blow-off, and 
 as much of the bottom as possible; brick work; examine the blow 
 off pipe; if it is hot outside of valve it is evidence of leakage at 
 valve (this unless some drips or other steam outlets are connected 
 into same blow-off pipe). A leaky blow-off valve is a source of 
 danger, waste of fuel and energy; the danger lies in the fact that 
 the precipitates will collect at a point where there is leakage and 
 as the blow-off pipe part of it is exposed to heat one can realize 
 there is danger by burning of blow-off pipe. 
 
 The outside of brick settings should be examined for fissures 
 or cracks caused by expanding of boiler and excessive heat. These 
 cracks admit cold air, quantity governed by size and draft. These 
 are the cause of much loss of energy, certainly a waste of fuel, 
 and at expense of life or boiler. 
 
 Examine the feed appliances ; test the steam gauge ; following 
 this up by firing up of boiler to point of safe working pressure, then 
 the setting of valve if necessary. When the steam gauge is taken off. 
 blow out the pipe and be sure it is clear, for oftentimes these pipes 
 
TESTS AND INSPECTION. 215 
 
 are neglected, and if there is a syphon or trap for condensation, this 
 latter will generate corrosion and liable to stop up stop-cock, if nol; 
 the pipe. 
 
 Management and care must be considered, as we have measured 
 the safe working pressure by design, material and construction. 
 The best of man's work would be trivial in th^ hands of an 
 ignorant boiler attendant, and the only factor for safety in such 
 cases would be to keep the boilers cold. Again, the inspector must 
 bear in mind that those in power to hire attendants are oftentimes 
 those whose knowledge of the requirements necessary, for men and 
 duties is very limited. 
 
 Fuel should be considered by the inspector, for in these days of 
 coal as fuel it must be remembered that the more sulphur in the 
 fuel, the quicker crystallization will develop in the plates. 
 
 Quality of feed water, its temperature and point of admission 
 should be looked after; for these are elements that will, in a meas- 
 ure, give evidence of what one expects. 
 
 POINTS TO CONSIDER WHEN INSPECTING BOILERS. 
 
 Evidence of excessive firing; piping of boilers for best effect to 
 allow for expansion; avoid rigidity; pipe of sufficient strength for 
 high pressures; deterioration from leakage; corrosion from sul- 
 phuric action soot and moisture develops sulphuric acid. Remember 
 that 75 per cent of the boiler is concealed either by the design or set- 
 tings and much depends on viewing and examining the minimum por- 
 tion ; that a large amount of energy is stored up in the boiler when 
 in commission ; for instance, a boiler 60" X 16' at 100 pounds 
 pressure has approximately 1946" tons of energy stored in it. This 
 suggests reasons for thought. There is lamination or blisters and 
 bagging of plates to look for, or to be expected. See that water 
 columns are properly connected and convenient to try at all times; 
 that the safety valve is of sufficient size and operative ; that blow- 
 pipes are of proper size and protected ; that the feed water ap- 
 pliances are ample and more than one to feed boiler ; that the 
 feed water enters at a suitable place ; that the check and stop valves 
 are connected and placed a reasonable distance from boiler ; that the 
 boiler (if externally fired) is properly set for heat distribution; 
 that the grates are not too close to the boiler (bottom), for space 
 is necessary for combustion and conductivity of heat. Do not for- 
 
216 THE BOILER. 
 
 get that it is a human being who is in charge of the boiler and 
 that it is human to err. This will impress the inspector that if 
 the man in -charge knew as much as he does, the inspector's services 
 would not be necessary. It also qualifies the old adage, "No man 
 is the best judge of his own work or actions." 
 
 % THE SAFE WORKING PRESSURE. 
 
 Years ago the Lloyds of Europe adopted a rule to govern the 
 safe working by pressure, viz. : One sixth of the tensile strength 
 of plate, multiplied by thickness of the plate, and divided by the 
 radius ; and for years this rule was used universally. It was the 
 supposition that the plate and rivet strength would be near equal 
 and construction the best, 20 per cent was added for double riveted 
 longitudinal seam. At that time low pressures were the rule, con- 
 sequently security or safety was reasonably expected ; but when 
 other factors came to be considered, different types of engines that 
 required higher pressures and fuel became a prime factor, along 
 with space, the demand for higher pressure became apparent and 
 something more than the old time design and construction of boilers 
 had to be considered. The weakest point had to be strengthened, 
 necessitating butt joints, drilled holes, modern flanging, braces and 
 bracing, larger plates and less joints, abandonment of cast iron for 
 man holes and openings. Boiler making tools and machinery had to 
 keep pace, thus the advancement made in the craft necessitates some 
 more definite rules to govern us in the allowing of a safe working 
 pressure. The factor of six, as formerly used, was, no doubt, little 
 enough when iron plates, short and narrow, were used ; chipping 
 done by hand, i. e., the grooving by same ; punched holes ; 
 the drift pin and designing of seams. Thus it was absolutely 
 necessary for a large factor of safety ; but as stated, boiler con- 
 struction to-day is modern and complies to the demand for high 
 pressures. We are too advanced to use such a large safety 
 factor as 6. It is true there are the extremes, but there are things 
 that must be considered in this matter of safety factor, viz., design ; 
 tensile strength ; thickness of plate ; diameter of hole ; diameter and 
 pitch of rivet; shearing strength of rivet; diameter of boiler; 
 bracing; lowest percentage of seam. It might be carried further 
 to be more definite, by considering the boiler's use ; if boiler would 
 
TESTS AND INSPECTION. 217 
 
 be forced ; if loads would vary ; type of engine ; if the boiler would 
 be used for power or heating only. 
 
 It would not be consistent to lay clown any specified rule to 
 govern all cases. It may be that the boiler would deteriorate faster 
 in one location than another. This, of course, would be a local 
 consideration, but in these days of modern ideas, designs and con- 
 struction, a factor of four would be ample to cover all differences in 
 construction and material. 
 
 Prepare for inspection by having ashes and deposits removed 
 from under boiler and ash pits, tubes cleaned and soot removed. 
 
 Allow boiler and setting time to cool off gradually, open gauge- 
 cocks before letting water run out. Leave dampers open and 
 furnace door closed. 
 
 Wash boiler out and have same as dry as possible. 
 
 Take steam gauges down for testing. 
 
 Steam gauges should be connected with a union between stop 
 cock and gauge, so that the latter can be taken off syphon or pipe 
 without disturbing threads that would alter position when connect- 
 ing gauge again. It is advisable, when having gauges tested, to 
 raise steam and note point of blowing off, and adjust safety valve 
 if necessary. 
 
 If a hydrostatic test is to be made have pump and piping con- 
 nected and the hydrostatic test applied to a pressure equal to the 
 proportions of 150 pounds to 100 pounds working pressure. 
 
 The U. S. Government makes annual inspections and tests and 
 all mandates are carried out to the letter. 
 
 Testing of plates, piping and material must fill all requirements, 
 or condemnation or rejection follows. Boilers and appliances must 
 be approved before installing and put into commission. 
 
 Some of the requirements are as follows : 
 
 CAST STEEL AND CAST IRON. 
 
 No cast steel or cast iron subject to pressure shall be allowed 
 to be used 4n boilers or the pipes connected thereto, except as de- 
 scribed as follows: 
 
 Cast iron or cast steel may be used in the construction of man- 
 hole and hand-hole plates, valves and cocks, water columns, flanges, 
 saddles, ells, tees, crosses or manifolds when such flanges, saddles, 
 
218 THE BOILER. 
 
 ells, tees, crosses, valves and cocks, or manifolds are bolted or 
 riveted directly to the boiler and the valves or cocks ; also, casings 
 of slip joints in pipes : Provided, however, that the material shall 
 be of the best grade and of suitable thickness and uniform section 
 for the pressure allowed on boilers. 
 
 FEED WATER. 
 
 The feed water shall not be admitted into any boiler at a temper- 
 ature less than 100 F., and no marine boiler shall be used with- 
 out having proper auxiliary appliances for supplying said boilers 
 with water in addition to the usual mode employed. 
 
 NAME PLATES. 
 
 There shall be fastened to each boiler a plate containing the 
 name of the manufacturer of the material, the place where manu- 
 factured, the tensile strength, the name of the builder of the boiler, 
 when and where built. 
 
 FUSIBLE PLUGS. 
 
 Every boiler, other than boilers of the water-tube type, shall 
 have at least one fusible plug as described below. Plugs shall be 
 made of a bronze casing filled with good Banca tin from end to 
 end. The manufacturers of fusible plugs shall stamp their name 
 or initials thereon for identification and shall file with the local in- 
 spectors a certificate, duly sworn to, that such plugs are filled with 
 Banca tin. 
 
 Fusible plugs, except as otherwise provided, shall have an ex- 
 ternal diameter of not less than three-fourths of an inch pipe tap, 
 and the Banca tin shall be at least one-half of an inch in diameter 
 at the smallest end and shall have a larger diameter at the center 
 or at the opposite end of the plug. 
 
 Fusible plugs, when used in the tubes of upright boilers, shall 
 have an external diameter of not less than three-eighths of 
 an inch pipe tap, and the Banca tin shall be at least one- fourth of 
 an inch in diameter at the smaller end and shall have a greater 
 diameter at the opposite end of the plug: Provided, however, that 
 all plugs used in boilers carrying a steam pressure exceeding 150 
 pounds to the square inch may be reduced at the smaller end of 
 the Banca tin to five-sixteenths of an inch in diameter. 
 
 Externally heated cylindrical boilers, with flues, shall have one 
 
TESTS AND INSPECTION. 219 
 
 plug inserted in one flue and also one plug inserted in shell of 
 each boiler, immediately below the' fire line and not less than 4 
 feet from the front end : Provided, however, that when such 
 flues are not more than 6 inches in diameter a fusible plug of not 
 less diameter than three-eighths-inch pipe tap may be used in such 
 flues. 
 
 Other shell boilers, except especially provided for, shall have 
 one plug inserted in the crown sheet of the back connection. 
 
 Vertical tubular boilers shall have one plug inserted in one 
 of the tubes at least 2 inches below the lowest gauge cock, but 
 in boilers having a cone top the plug shall be inserted in the upper 
 tube sheet. 
 
 All plugs shall be inserted so that the small end of the Banca 
 tin shall be exposed to the fire. 
 
 It shall be the duty of the inspector at each annual inspection 
 to see that the plugs are in good condition. 
 
 GAUGE COCKS AND WATER GLASS. 
 
 All boilers shall be supplied with one reliable water gauge and 
 three gauge cocks in each boiler: Provided, that when the gauge 
 glass and gauge cocks are connected to the boilers by a water 
 column there must be an additional gauge cock inserted in the 
 head or shell of boiler. The lower gauge cock in boilers more 
 than 48 inches in diameter shall not be less than 4 inches from 
 the top of the flues or tubes. In boilers less than 48 inches in 
 diameter the lower gauge cock shall not be less than 2y 2 inches 
 above the top of the flues or tubes. A gauge glass shall be con- 
 sidered a reliable water gauge, and a float such as used on western 
 river steamers shall be considered on such boilers as a reliable 
 water gauge. 
 
 In vertical boilers or boilers of the water-tube type the location 
 of the lowest gauge cock shall be determined by the local inspectors. 
 
 Boilers known as flash boilers constructed of a continuous coil 
 of pipe or series of coils of pipes under three-fourths inch in diam- 
 eter, whose construction has been approved by the Board of Super- 
 vising Inspectors, shall not be required to be supplied with gauge 
 cocks or low- water gauges. 
 
220 THE BOILER. 
 
 DRILLING TO DETERMINE THICKNESS. 
 
 Any boiler ten years old or more shall, at the first annual 
 inspection thereafter, be drilled at points near the water line and 
 at bottom of shell of boiler, or such other points as the local in- 
 spectors may direct, to determine the thickness of such material 
 at those points ; and the steam pressures allowed shall be gov- 
 erned by such ascertained thickness and the general condition of 
 the boiler. 
 
 HYDROSTATIC PRESSURE. 
 
 The hydrostatic pressure applied must be in the proportion 
 of 150 pounds to the square inch to 100 pounds to the square inch 
 of the steam pressure allowed and the inspector, after applying 
 the hydrostatic test, must thoroughly examine every part of the 
 boiler. 
 
 In applying the hydrostatic test to boilers with a steam chimney, 
 the test gauge should be applied to the water line of such boilers. 
 
 All coil and pipe boilers hereafter made, when such boiler is 
 completed and ready for inspection, must be subjected at the first 
 inspection to a hydrostatic pressure double that of the steam pres- 
 sure allowed in the certificate of inspection. 
 
 The use of malleable-iron or cast-steel manifolds, tees, return 
 bends or elbows in the construction of pipe generators shall be 
 allowed and the pressure of steam shall not be restricted to less 
 than one-half the hydrostatic pressure applied to pipe generators 
 unless a weakness should develop under such test as would render 
 it unsafe in the judgment of the inspector making such inspection. 
 
 DRUMS AND HEADS. 
 
 All drums attached to coil, pipe, sectional or water-tube boilers 
 not already in use or actually contracted for, to be built for use 
 on a steam vessel and its building commenced at or before the 
 date of the approval of this rule, shall be required to have the 
 heads of wrought iron or steel or cast steel flanged and substan- 
 tially riveted to the drums or secured by bolts and nuts of equal 
 strength with rivets, in all cases where the diameters of such drums 
 exceed 6 inches. 
 
 Drums and water cylinders constructed with a bumped head 
 at each or either end, (any opening in the shell or heads to be 
 
TESTS AND INSPECTION. 221 
 
 reinforced as required by the rules of the Board, the circumferen- 
 tial and horizontal seams to be welded and properly annealed 
 after such welding is completed), when tested with a hydrostatic 
 pressure at least double the amount of the steam pressure allowed 
 may be used for marine purposes. 
 
 PIPES. 
 
 COPPER. 
 
 All copper pipe subject to pressure shall be flanged over or 
 outward to a depth of not less than twice the thickness of the 
 material in the pipe and such flanging shall be made to a radius 
 not to exceed the thickness of the pipe. On boilers whose con- 
 struction was commenced after June 30, 1905, no bend will be 
 allowed in copper pipe of which the radius is less than one and 
 one-half times the diameter of the pipe and such pipe must be 
 so led and flanges so placed that they may be readily taken down if 
 required. Such pipes must be protected by iron casings when run 
 through coal bunkers and must be clear of the coal chutes. 
 
 The flanges of all copper steam pipes over 3 inches in diam- 
 eter shall be made of brass or bronze composition, forged iron or 
 steel, or open-hearth steel castings and shall be securely brazed or 
 riveted to the pipe : Provided, however, that when such pipes are 
 properly formed with a taper through the flange, such taper being 
 fully reinforced, the riveting or brazing may be dispensed with : 
 And provided, also, that when the pipe has been expanded by 
 proper and capable machinery into grooved flanges and the pipe 
 flared out at the ends to an angle of approximately 20, said angle 
 to be taken in the direction of the length of the pipe and having 
 a depth of flare equal to at least one and one-half times the thick- 
 ness of the material in the pipe, said riveting or brazing may be 
 dispensed with. Where copper pipes are expanded into or riveted 
 to 4 flanges it will be necessary for the pipes with their flanges at- 
 tached to withstand a hydrostatic pressure of two and one-half 
 times the boiler pressure. 
 
 Flanges must be of sufficient thickness and must be fitted with 
 such number of good and substantial bolts to make the joints at 
 least equal in strength to all other parts of the pipe. 
 
 Any form of joint that will add to the safety or increase the 
 
222 THE BOILER. 
 
 strength of flange and pipe connections over those provided for 
 by this rule, will be allowed on any and all classes of steam pipe. 
 
 WATER TUBE AND COIL BOILERS. 
 
 Blue prints or drawings of coil boilers and of other boilers, with 
 their specifications, submitted to the Board of Supervising In- 
 spectors for approval under section 4429, Revised Statutes of the 
 United States, must be in duplicate before action thereon will be 
 taken by the Board, with a view of approving the same ; one set 
 to be filed with the records of the Board of Supervising Inspectors 
 and the other with the records of the supervising inspector of the 
 district where the manufacturer of the boiler is located. 
 
 Rule to find the working pressure allowable on cylindrical shells 
 of water tube or coil boilers, when such shells have a row or rows of 
 pipes or tubes inserted therein : From pitch of holes subtract diame- 
 ter of pipe, then multiply by thickness of plate and one-sixth of 
 tensile strength. Divide this product by pitch of holes multiplied by 
 radius. 
 
 FORMULA: 
 p d XT X 1/6 of TS 
 
 pXR 
 LEGEND: 
 
 = pressure 
 
 p= pitch =1" 
 d = diameter of pipe = 1" 
 T = thickness of plate = K?" 
 TS= tensile strength =60000 
 R = radius = 10" 
 
 EXAMPLE: 
 
 2 = pitch 
 
 1 = diameter of pipe 
 
 1 
 
 . 5 = thickness of plate 
 
 pitch = 2" .5 
 radius =10" 10000 = one-sixth of tensile strength of 
 
 plate 
 
 20) 5000 . (250 pounds pressure allowed 
 40 
 
 100 
 100 
 
CHAPTER X. 
 
 FEED WATER HEATING AND PURIFICATION. 
 
 While boiler designing, construction and setting have received 
 the thought and attention of many prominent specialists of this 
 age, this for security against the high pressures necessary to meet 
 the demands of modern engines and that factor, fuel, it is apparent 
 even to the layman that the feed water for steam boilers must be 
 a factor worthy of much consideration, for it means life of boiler 
 and efficiency of same this under varying conditions even to those 
 who have free fuel and best of water. Various appliances and 
 methods are employed to obtain the best possible results from feed 
 water, for the latter is one of the primaries for disaster and expense 
 in operation. Many well designed and well constructed boilers 
 have been condemned on this account. Reputations that have been 
 built on years of experience and study have been affected by local 
 influences bad feed water. 
 
 Instances can be cited where boilers designed and made by the 
 most progressive boiler makers have been condemned and only 
 material and construction given by the operators as a cause for 
 failures or reduced condition. Feed water is the initial factor in 
 the steam plant. To install the best designed and constructed boiler 
 from the best of material and subject the same to bad feed water, 
 failure of seams or plate are the results expected. 
 
 In some localities incrustation and deposits from water are un- 
 known this where matter which is soluble in land strata are 
 absent but these locations are very few to the major part of this 
 country. Hence the necessity for an appliance a vital adjunct 
 to the steam plant i. e., a feed water purifier. 
 
 Many and varied are the appliances now used for this purpose ; 
 it would seem that each one has its advocates and no doubt its 
 niche, or suitable place. They all aim to obtain the best possible 
 results, but many fail to accomplish the maximum effect. 
 
 223 
 
224 THE BOILER. 
 
 A brief description of types mostly in use may be interesting 
 or at least give some food for thought. Possibly future discussions 
 may change views and show that present convictions are wrong. 
 Such subjects are almost inexhaustible and when analyzed they can 
 be made subjects of much merit and of great interest to those whose 
 lives are devoted to steam engineering. For instance, analyzing the 
 boiler, we. find : 
 
 Material. 
 
 Design. 
 
 Construction. 
 
 Settings. 
 
 Appliances. 
 
 Management and care, and 
 
 Feed water. . 
 
 It is the latter which I will attempt to digest, not in material 
 value order, or on personal judgment, but as they suggest themselves 
 to the mind when reviewing this subject. A brief description of 
 types in use are : 
 
 1. Auxiliary pipes. 
 
 2. Water backs. 
 
 3. Pipes in uptakes. 
 
 4. Closed heaters. 
 
 5. Boxes or receptacles in boilers. 
 
 6. Live steam heaters. 
 
 7. Open heaters. 
 
 There is no question but that any or all of these types have 
 some merit in some particular place or under some conditions. 
 
 I will take them up in individual order and try to point out their 
 degree of usefulness, or advantages, one over the other. 
 
 In order to obtain the best values, we must look for require- 
 ments, they must be known ; then put them in valued order. 
 
 The heater and purifier must have some of these requirements. 
 There is much variance with each type, no two alike, when units of 
 measurement are taken. Quotations of prices are based on indi- 
 vidual units of measurement and, like the different types of boilers, 
 are rated on a given quantity of heating surface ranging from 6 to 
 15 square feet this irrespective of plate thickness, grate surface, 
 fuel or draft. It is the same with the heaters and so-called purifiers. 
 
MISCELLANEOUS. 225 
 
 1. AUXILIARY PIPES. 
 
 These are connected to boiler, water and steam connections. 
 They simply make additional heating surface and have very little 
 merit otherwise. They are not to be recommended for either effi- 
 ciency, safety or economy. They are short-lived, a menace to se- 
 curity, subject to incrustation and fracture due to expansion and 
 contraction; impossible to clean, making, oftentimes, long and 
 serious delays. It is like courting disaster to apply these to a 
 boiler. 
 
 2. WATER BACKS. 
 
 These are usually placed back of boiler, top of setting, or in 
 front of or at sides of furnace and shapes are either cylindrical or 
 flat. They are supposed to act in a dual capacity feed water 
 heater and form an arch or a part of the furnace. It cannot be 
 said that there is any fuel economy. They are a part of the boiler 
 and absorb furnace heat. They have boiler pressure, and are no 
 prevention against solids in suspension going into boiler. They 
 often become incrustated, necessitating repairs, and when one con- 
 siders the difference in temperature in such a short space, between 
 parts exposed to fire and boiler room, expectations can be realized. 
 The tempering of water by heat before going to boiler, as in case 
 of injectors, is the only point of merit they have. The cylinder 
 type may have some advantages strength of form and being more 
 accessible to clean. The flat type offers little in that respect. The 
 latter are more costly, owing to the flange and the bracing by stay 
 bolts. Again, either type has the disadvantage of adding weight 
 on settings or walls. The latter are expensive items in keeping up 
 the boiler plant. 
 
 3. PIPES IN UPTAKE. 
 
 This application for heating feed water has sometimes primary 
 benefits in the way of economy, due to absorbing heat from escaping 
 gases. But this is largely a guess and it is a question if they are 
 often or long economical, for the heat escaping up the stack or 
 uptake is a large factor, in fact very necessary and essential when 
 natural draft is depended on, and supply limited ; for to reduce this 
 temperature means less oxygen to fuel. 
 
226 THE BOILER. 
 
 In some places, and under some conditions, there may be some 
 economy, but in the average plant, none. Incrustated pipes, solids 
 in suspension forced into boilers, fractures, delays in removal or 
 cleaning, can be expected. This type cannot be considered a profit- 
 able investment even in plants where induced draft is used, unless 
 water is purified before going through same. 
 
 4. CLOSED HEATERS. 
 
 Water or steam tubes or pipes, return bends, corrugated or 
 straight, coils, with and without setting chambers. 
 
 These appliances are made in varying forms, the aim being to 
 obtain heat from exhaust steam in non-condensing plants, but it is 
 futile to expect anything like purification of feed water from this 
 type. No matter what design they are, their value is limited to that 
 of heating to some extent, the feed water then at a low temperature. 
 They have pressure in excess of the boiler, this owing to the neces- 
 sity of lifting check valve or overcoming weight of water and pres- 
 sure in boiler. The exhaust steam temperature must be. conducted 
 through plate pipes, coils or tubes, there being no chance for precipi- 
 tation other than light solids, such as magnesia this owing to lack of 
 temperature imparted by exhaust and the existing pressure in heater, 
 even with back pressure on engine, for to precipitate other solids 
 the temperature must be increased with pressure obtained in heater. 
 For instance, if pressure was 100 pounds, the temperature necessary 
 would be 338 F., but at atmospheric pressure it would be 212 F. 
 Then what chances could there be even with back pressure when 
 the heat must be conducted through plate? Should light solids be 
 precipitated these would be forced into boiler. Again, this type or 
 class of heater is hard if not almost impossible to clean. Thus, 
 should any solids be in suspension and collect, when the attempt is 
 made to clean exhaust pipes must be disconnected and those of 
 water or steam tube type are difficult for access. 
 
 Those with a so-called setting chamber have very little effect 
 from settling, for these have a continuous circulation when feed 
 water passes through. Hence settling is impossible when pumps 
 would be stopped ; then the only amount of settling would be equal 
 to that which volume of water at that time would hold. 
 
 One argument used in its favor, as heard, is that "only one 
 
MISCELLANEOUS. 227 
 
 pump is required." This apparently is enough to convince the lay- 
 man that to select this type is wise. Some of these closed heaters 
 may have individual merit. For instance, the return bend expands 
 on one end that is, it is free to do so. Then the corrugated tube 
 has additional heating surface and prevents leaking at ends, expan- 
 sion and contraction being taken up by the corrugations. But in 
 this form of heater, condensation is usually lost with its purity and 
 heat units. This heater is fast being relegated to one place in the 
 power plant, and that place is the condensing one. Its position 
 being between the engine, cylinder and injection water. Its value, 
 besides giving some heat, is to prevent condensation of steam in 
 cylinder by the injection water. 
 
 5. THE BOX OR RECEPTACLE THAT IS PLACED IN THE BOILER. 
 
 This idea of a feed water heater and purifier is not new. It 
 is old and has been tried and found wanting. These may be ob- 
 tained in any shape, or to be put or placed in any part of boiler, 
 on top of tubes or under same. That does not prevent results from 
 being the same. Though feeding impure water into a box having 
 holes or slots, it is a fact the water must find its level, must flow 
 to that point where steam globules are formed and then ascend 
 into space to diffuse. Precipitation does not occur at the instant 
 of contact with heat. Even if it did these receptacles are only 
 settling pans and the perforations are limited this to confine water 
 inside as long as possible and to aid precipitation. Danger is 
 courted, for should those openings become stopped up danger from 
 low water is the result. If these boxes are open then the solids 
 will find their way to all parts of boiler this through circulation. 
 These boxes obstruct steam passages, retard circulation and make 
 internal inspections impossible. The price involved in these would 
 bo far better invested in something to prevent solids from going into 
 boiler or in aiding to purify feed water before going into boilers, 
 this being done now in modern plants. 
 
 6. THE LIVE STEAM HEATER AND PURIFIER. 
 
 The live steam purifier, like all other contrivances and appliances 
 for bettering the condition of boilers and increasing efficiency and 
 reducing the hazard and risk in steam boilers, has its advocates. 
 
228 THE BOILER. 
 
 Much has been claimed for it. Like preceding types it no doubt 
 has some features that might at least appear commendable. But, 
 however, claims are one thing, effects, results and investments are 
 others. The name is somewhat misleading. Its value ceases as an 
 investment when cost and maintenance are experienced. While ad- 
 mitting that it would have one factor, that of precipitation of solids 
 that were held in solution by boiler pressure temperature, this does 
 not alone insure purity of water or establish it as a purifier, for 
 two results are necessary for purification of feed water viz. : 
 precipitation and filtering. 
 
 The pans used are settling surfaces for some of the solids that 
 will settle, but much goes into boiler through gravity circulation. 
 The live steam heaters are selected for only one action precipita- 
 tion and this at the expense of condensation, they being in a 
 position at a considerable distance from water line to grate surface. 
 Some argue that if only some of the solids are prevented from going 
 into boiler, the value of the live steam heater must be considered 
 with fuel saving and efficiency gained, this offsetting the condensa- 
 tion. But there are points of disadvantages. The added hazard, 
 being subjected to the full boiler pressure, has additional energy 
 stored in it. They are placed much higher than boiler water 
 line, access to clean difficult, involve much expense for installation, 
 special frame support and floor. When points of advantages are 
 taken into consideration and weighed with the disadvantages, care 
 should be taken when selection of a feed water purifier is to be 
 made. 
 
 7. THE OPEN HEATER AND PURIFIER. 
 
 Feed water purification is a possibility and this is when open 
 type of feed water heater and purifier is used, (this is only when 
 care and reason are exercised in selection), and this can be done 
 with minimum loss of furnace heat. It is practically the solution 
 solved when the elements and requirements are adjusted and propor- 
 tions are .proper, viz., time and temperature. 
 
 Where a lack of temperature fails time must be increased. 
 Additional body of water will represent time. 
 
 This appliance is open to the atmosphere. The feed water supply 
 comes in contact with the exhaust steam or steam used for tern- 
 
MISCELLANEOUS. 229 
 
 perature necessary for precipitation. It will produce a partial 
 vacuum on engine when exhaust steam is used. Precipitation occurs 
 at lowest possible temperature, 15 to 20 per cent of pure water being 
 gained by condensation. There are some open heaters that are so 
 constructed that precipitation is expected at instant of contact of 
 steam and water. Others have so limited a supply of water that no 
 time for action is allowed. In some cases a few strokes of the 
 pump takes all the water out. Others, while they have a copious 
 supply of water, the filtering material is such that it separates, thus 
 leaving water with its solids in suspension free to go to pump, then 
 to the boiler. Others, again, have no facilities for cleaning the filter, 
 unless at expense of closing down or putting cold water into boilers. 
 Most of these are simply receivers, heaters or condensers. They 
 cannot be termed feed water purifiers. 
 
 A few suggestions on selection may be in order. Conditions 
 must be observed. First, quality of water to be used ; this will de- 
 termine the filtering^ surface, but the main requirements are : high 
 temperature, large body of water, large amount of filtering surface, 
 easy to clean. 
 
 The two elements, time and temperature, are necessary. 
 
 Points to be considered in selecting slow filtering filter acces- 
 sible to clean when in use, filtering material and adjustment of 
 same against derangement. 
 
 When filtering is operative, deposits will collect on filtering ma- 
 terial, thus the necessity of some way fo clean off same at any time. 
 
 There is the greatest of economy in heating feed water by 
 exhaust steam, even when the latter is used for heating purposes. 
 In this age we are resorting to chemistry as a positive aid in water 
 purification. 
 
230 
 
 THE BOILER. 
 
 H 
 
 * g 
 
 J, 1 
 
 S I 
 
 oo oo oo oo oo oo oo oo oo oo o* o^ ^ o^ ^ ^ ^ o^ ^ ^ ^ o o 
 
 OO OO OO OO OO OO OO OO OO O^ ^ ^ O^ O** O^i ^ ^ ^ O> O^i O O O 
 
 10 ro ' * O ^ t^ 
 CO 
 
 IP 
 
 1-1 6*0 
 
 H 
 
 o o o o o o o 
 
 i I CO CO CO CO CO CO 
 
 o 
 
 T3 y, 
 
 II 
 
 rt C 
 
 tf> oJ 
 
 C/3 flj 
 
 OJ C- 
 
 
 bJO ^ C^ 
 
 C .*3 % ' 
 
 ^tf V 
 
 B ^o 
 
 D ^2 W 
 
 o 8H 
 
 VH 
 
 a 
 
MISCELLANEOUS. 231 
 
 FORMULA: 
 
 FT OT X C = percentage 
 FT = final temperature = 209 
 OT = original temperature =60 
 C = constant = . 0864 
 
 EXAMPLE: 
 
 209 = final temperature 
 60 = original temperature 
 
 149 = difference of temperature 
 . 0864 = column constant 
 
 596 
 894 
 1192 
 
 12 . 8736 = 12 9/10 per cent, nearly 
 
 PUMPS AND TANKS. 
 
 The efficiency of a pump varies with the type, size, lift, elevation, 
 temperature of water and friction. The steam pump is flexible as 
 regards capacity, a few revolutions faster or slower will greatly 
 increase or diminish the quantity delivered, the maximum efficiency 
 depending on details as to size and connection and locating pump. 
 Hot water cannot be lifted by suction, as its vapor destroys the 
 necessary vacuum, hence the necessity to have the hot water flow 
 to the pump. When long suction pipes are used it will be necessary 
 to have a larger size than with shorter distances, this to allow for 
 friction which might prevent adequate supply to pump. Use as few 
 elbows and sharp bends and valves as possible; avoid traps or air 
 pockets in pipe ; suction pipes should be absolutely air tight. A 
 vacuum chamber should be placed on the opposite side of the pump 
 from where suction enters and a foot valve will be found advantage- 
 ous and desirable, the latter if its location is such that it can be 
 drained when necessary. The valve insures quick starting of pump 
 by keeping suction pipe filled with water. A priming pipe will be 
 convenient when chambers are to be filled to enable pump to start 
 quickly. In starting a pump under pressure it oftentimes happens 
 that the pump will not discharge the water while the pressure is 
 
232 THE BOILER. 
 
 resting on the discharge valve, for the reason that the air in pump 
 cylinders is not discharged, but only compressed by the motion of 
 plungers, then it is necessary to expel air from pump and suction 
 pipe. This can be done by placing a check valve in the discharge 
 pipe near the pump and opening an air vent on the discharge be- 
 tween pump and check, or on a valve chamber on top. 
 
 A relief valve is desirable, to prevent damage which might occur 
 by obstruction in discharge line, thus increasing pressure on pump in 
 excess of that which pump was designed for. 
 
 Sometimes a pump when first started will deliver a good stream 
 of water, which gradually diminishes in volume until it stops entirely. 
 One reason for this is leak in suction pipes or stuffing box of pump, 
 or, when suction primer is used, in the hand pump stuffing 
 box. Another reason might be that the* pump lowers the suction 
 supply, thus increasing the lift until there is not sufficient speed 
 for the elevation. If the pump works indifferently, delivering a 
 stream obviously too small, it is generally because the pump was 
 not properly primed and some air remains in the top part of pump 
 shell. Unless primed by steam ejector the pet cock or plug found 
 on top of pump shell should always be open while priming, and the 
 pump must not be started until water flows out of same. 
 
 A pump with horizontal top discharge and short length of dis- 
 charge pipe is sometimes difficult to start, especially if suction lift 
 is high, owing to the fact that the water is thrown out of the pump 
 shell before the water in suction pipe has got fairly started, thus 
 allowing air to rush back into the pump. If the pump is to work 
 under this condition it is better to use a pump with a vertical dis- 
 charge and deliver through an elbow, or else lead the discharge pipe 
 upward for a short distance so as to keep a slight pressure or head 
 on the pump, and after priming as high as possible start quickly. 
 
 There is generally nothing gained by running above the proper 
 speed required for a given elevation. 
 
MISCELLANEOUS. 233 
 
 To find the theoretical horse power required to elevate water, 
 multiply the gallons pumped per minute by the head in feet and by 
 8.33 (weight of one gallon of water) and divide product by 33,000. 
 This will be only approximate. 
 
 LEGEND: EXAMPLE: 
 
 800 = gallons per minute 800 gallons per minute 
 
 20 =feet elevation 20 =feet elevation 
 
 8.33 = weight of one gallon of water 
 
 16000 
 8 . 33 = weight of one gallon of 
 
 water 
 48000 
 48000 
 128000 
 
 33000)133280.000(4.038 H. P. required 
 132000 
 
 1280 00 
 990 00 
 
 290 000 
 264 000 
 
 26 000 
 
 Ordinarily pumps will elevate water 50 to 60 feet, and if specially 
 built in regard to strength, could elevate 100 feet, depending on 
 speed. 
 
 THEORETICAL STEAM CONSUMPTION. 
 
 AT A PISTON TRAVEL OF 100 FEET PER MINUTE. 
 
 For use with this table, the effective piston travel is only that 
 portion of the total travel during which the steam valve is open. 
 Thus, if an engine is running 400 feet per minute, and cutting off 
 at T/2 stroke, its effective travel will be 200 feet, and its theoretical 
 steam consumption will be 200 divided by 100 multiplied by the 
 amount given in the table for its cylinder diameter and steam 
 
234 
 
 THE BOILER. 
 
 pressure. The actual consumption exceeds the theoretical by 25 
 per cent to 50 per cent. 
 
 *o ^ 
 
 Q'lS 
 
 11 
 
 -L- C 
 
 INITIAL STEAM PRESSURE 
 
 o.S 
 
 = ">> 
 
 s? 
 
 60 
 
 70 
 
 80 
 
 90 
 
 100 
 
 110 
 
 120 
 
 130 
 
 140 150 
 
 go 
 
 uS 
 
 STEAM CONSUMPTION IN POUNDS PER HOUR 
 
 8 
 
 34.9 
 
 365 
 
 410 
 
 455 
 
 500 
 
 540 
 
 585 
 
 630 
 
 670 
 
 720 
 
 760 
 
 9 
 
 44.3 
 
 465 
 
 507 
 
 575 
 
 630 
 
 690 
 
 740 
 
 800 
 
 855 
 
 920 
 
 964 
 
 10 
 
 54.5 
 
 570 
 
 640 
 
 710 
 
 780 
 
 845 
 
 915 
 
 985 
 
 1050 
 
 1125 
 
 1185 
 
 11 
 
 66 
 
 690 
 
 770 
 
 860 
 
 940 
 
 1020 
 
 1110 
 
 1190 
 
 1270 
 
 1360 
 
 1435 
 
 12 
 
 78.5 
 
 820 
 
 920 
 
 1020 
 
 1120 
 
 1220 
 
 1320 
 
 1420 
 
 1520 
 
 1620 
 
 1710 
 
 14 
 
 107 
 
 1120 
 
 1250 
 
 1390 
 
 1530 
 
 1660 
 
 1800 
 
 1940 
 
 2070 
 
 2210 
 
 2330 
 
 16 
 
 139.6 
 
 1460 
 
 1625 
 
 1810 
 
 2000 
 
 2160 
 
 2350 
 
 2530 
 
 2700 
 
 2880 
 
 3040 
 
 18 
 
 176.7 
 
 1850 
 
 2070 
 
 2290 
 
 2530 
 
 2750 
 
 2970 
 
 3200 
 
 3420 
 
 3650 
 
 3850 
 
 20 
 
 218.2 
 
 2290 
 
 2550 
 
 2840 
 
 3120 
 
 3380 
 
 3660 
 
 3950 
 
 4200 
 
 4500 
 
 4750 
 
 22 
 
 264 
 
 2760 
 
 3090 
 
 3430 
 
 3760 
 
 4100 
 
 4430 
 
 4780 
 
 5090 
 
 5440 
 
 5750 
 
 24 
 
 314 
 
 3290 
 
 3660 
 
 4070 
 
 4490 
 
 4860 
 
 5270 
 
 5680 
 
 6060 
 
 6480 
 
 6820 
 
 26 
 
 369 
 
 3870 
 
 4310 
 
 4800 
 
 5270 
 
 5720 
 
 6200 
 
 6680 
 
 7110 
 
 7600 
 
 8020 
 
 28 
 
 428 
 
 4490 
 
 5000 
 
 5560 
 
 6110 
 
 6650 
 
 7190 
 
 7750 
 
 8260 
 
 8820 
 
 9310 
 
 30 
 
 491 
 
 5160 
 
 5750 
 
 6390 
 
 7010 
 
 7610 
 
 8250 
 
 8880 
 
 9490 
 
 10120 
 
 10680 
 
 EXAMPLE: To determine the steam consumption of a 12 and 
 18 X 12 X 18 Duplex Compound Pump : Piston speed 85 feet per 
 minute : Initial Steam pressure 100 pounds. 
 
 Since the pump is duplex and since live steam enters the high 
 pressure cylinders only, the theoretical consumption would be double 
 that of a single 12" cylinder ; or at 100 feet piston speed, 1220 X 2 - 
 2440 pounds per hour. 
 
 Theoretical consumption at 85 feet piston speed, 2440 X .85 = 
 2074 pounds per hour. 
 
 The actual steam consumption exceeds the theoretical by 20 per 
 cent to 50 per cent. 
 
 The mean pressure of the atmosphere is usually estimated at 14.7 
 pounds per square inch, so that with a perfect vacuum it will sustain 
 a column of mercury 29.9 inches, or a column of water 33.9 feet 
 high at sea level. 
 
 To determine the proportion between the steam and the pump 
 cylinder, multiply the given area of the pump cylinder by the 
 resistance on the pump in pounds per square inch, and divide the 
 product by the available pressure of steam in pounds per square 
 inch. The product equals the area of the steam cylinder. To this 
 
MISCELLANEOUS. 235 
 
 must be added an extra area to overcome the friction, which is 
 usually taken at 25 per cent. 
 
 The resistance of friction in the flow of water through pipes of 
 uniform diameter is independent of the pressure and increase directly 
 as the length and the square of the velocity of the flow, and 
 inversely as the diameter of the pipe. With wooden pipes the fric- 
 tion is 1.75 times greater than in metallic. Doubling the diameter 
 increases the capacity four times. 
 
 To determine the velocity in feet per minute necessary to dis- 
 charge a given volume of water in a given time, multiply the number 
 of cubic feet of water by 144 and divide the product by the area 
 of the pipe in inches. 
 
 To determine the area of a required pipe, the volume and velocity 
 of water being given, mulptily the number of cubic feet of water 
 by 144 and divide the product by the velocity in feet per minute. 
 
 To find the diameter of pump plungers to pump a given 
 quantity of water at 100 feet piston speed per minute, divide the 
 number of gallons by 4, then extract the square root, and the result 
 will be the diameter in inches of the plungers. 
 
 To find the number of gallons delivered per minute by a single 
 double-acting pump at 100 feet piston speed per minute, square 
 the diameters of the plungers, then multiply by 4. 
 
 The area 'of the steam piston, multiplied by the steam pressure, 
 gives the total amount of pressure that can be exerted. The area 
 of the water piston, multiplied by the pressure of water per square 
 inch, gives the resistance. A margin must be made between the 
 power and resistance. 
 
 CAPACITY OF PUMPS AT 100 FEET PISTON SPEED. 
 
 A travel of 100 feet piston speed per minute is considered prac- 
 tical and is accepted as standard speed. Slow speed for boiler 
 feeding is recommended. No set rule can be given to cover all 
 conditions. In Fire Pumps, where the largest quantity of water is 
 required, the speed may exceed 200 feet per minute. 
 
236 
 
 THE BOILER. 
 
 THEORETICAL CAPACITY OF PUMPS AT 100 FEET SPEED OF 
 PISTON OR PLUNGER. 
 
 Diameter 
 of Pump 
 or Plunger 
 in Inches 
 
 U. S. GALLONS PER 
 
 Diameter 
 of Pump 
 or Plunger 
 in Inches 
 
 U. S. GALLONS PER 
 
 Minute 
 
 Hour 
 
 24 Hours 
 
 Minute 
 
 Hour 
 
 24 Hours 
 
 1 
 
 4.07 
 
 244.7 
 
 5875 
 
 14% 
 
 828 
 
 49704 
 
 1192896 
 
 1% 
 
 6.37 
 
 382.5 
 
 9180 
 
 143 / 2 
 
 858 
 
 51468 
 
 1235232 
 
 1;L/ 
 
 9.18 
 
 550.8 
 
 13219 
 
 14% 
 
 887 
 
 53256 
 
 1278144 
 
 1% 
 
 12.49 
 
 749 
 
 17992 
 
 15 
 
 918 
 
 55070 
 
 1321915 
 
 2 
 
 16.31 
 
 979 
 
 23500 
 
 15% 
 
 949 
 
 56928 
 
 1366272 
 
 2% 
 
 20.6 
 
 1239 
 
 28180 
 
 
 980 
 
 58800 
 
 1411200 
 
 
 25.5 
 
 1530 
 
 36720 
 
 15% 
 
 1012 
 
 60720 
 
 1457280 
 
 2% 
 
 30.8 
 
 1851 
 
 44424 
 
 16 
 
 1044 
 
 62668 
 
 1504046 
 
 
 36.7 
 
 2203 
 
 52878 
 
 16 M 
 
 1077 
 
 64638 
 
 1551312 
 
 3% 
 
 43.1 
 
 2586 
 
 62064 
 
 
 1110 
 
 66642 
 
 1599408 
 
 
 49.9 
 
 2998 
 
 71971 
 
 16% 
 
 1144 
 
 68676 
 
 1648224 
 
 3% 
 
 57.3 
 
 3442 
 
 82619 
 
 17 
 
 1179 
 
 70752 
 
 1698048 
 
 4 
 
 65.2 
 
 3916 
 
 94002 
 
 17% 
 
 1214 
 
 72840 
 
 1748160 
 
 4% 
 
 73.7 
 
 4422 
 
 106128 
 
 
 1249 
 
 74964 
 
 1799136 
 
 
 82.6 
 
 4957 
 
 118971 
 
 17% 
 
 1285 
 
 77124 
 
 1850976 
 
 4% 
 
 92 
 
 5523 
 
 132552 
 
 18 
 
 1322 
 
 79314 
 
 1903550 
 
 
 102 
 
 6120 
 
 146880 
 
 18% 
 
 1359 
 
 81528 
 
 1956672 
 
 5M 
 
 112 
 
 6745 
 
 161934 
 
 
 1396 
 
 83778 
 
 2010672 
 
 
 123 
 
 7404 
 
 177696 
 
 18% 
 
 1434 
 
 86060 
 
 2065449 
 
 5% 
 
 134 
 
 8093 
 
 194248 
 
 19 
 
 1473 
 
 88368 
 
 2120832 
 
 6 
 
 146 
 
 8812 
 
 211511 
 
 19% 
 
 1511 
 
 90660 
 
 2175840 
 
 6M 
 
 159 
 
 9562 
 
 229500 
 
 19//> 
 
 1552 
 
 93120 
 
 2234880 
 
 63^ 
 
 172 
 
 10344 
 
 248256 
 
 19% 
 
 1590 
 
 95400 
 
 2289600 
 
 
 185 
 
 11152 
 
 267660 
 
 20 
 
 1632 
 
 97920 
 
 2350080 
 
 7 4 
 
 200 
 
 11995 
 
 287884 
 
 20% 
 
 1673 
 
 100380 
 
 2409120 
 
 7% 
 
 214 
 
 12867 
 
 308808 
 
 20^ 
 
 1714 
 
 102840 
 
 2468160 
 
 
 229 
 
 13769 
 
 330478 
 
 20% 
 
 1756 
 
 105396 
 
 2529504 
 
 7% 
 
 245 
 
 14700 
 
 352300 
 
 21 
 
 1799 
 
 107952 
 
 2590848 
 
 8 
 
 261 
 
 15667 
 
 376011 
 
 21% 
 
 1842 
 
 110538 
 
 2652912 
 
 8% 
 
 277 
 
 16660 
 
 399852 
 
 213^ 
 
 1886 
 
 113154 
 
 2715696 
 
 
 294 
 
 17688 
 
 424512 
 
 21% 
 
 1930 
 
 115800 
 
 2779200 
 
 8% 
 
 312 
 
 18741 
 
 449978 
 
 22 
 
 1974 
 
 118482 
 
 2843568 
 
 9 
 
 330 
 
 19828 
 
 475887 
 
 22% 
 
 2020 
 
 121194 
 
 2908656 
 
 
 349 
 
 20944 
 
 502668 
 
 22^ 
 
 2065 
 
 123924 
 
 2974176 
 
 91^ 
 
 368 
 
 22092 
 
 530208 
 
 22% 
 
 2111 
 
 126696 
 
 3040704 
 
 9% 
 
 388 
 
 23280 
 
 558720 
 
 23 
 
 2158 
 
 129492 
 
 3107808 
 
 10 
 
 408 
 
 24480 
 
 587518 
 
 23 % 
 
 2205 
 
 132324 
 
 3175776 
 
 10% 
 
 428 
 
 25716 
 
 617184 
 
 233^ 
 
 2253 
 
 135186 
 
 3244464 
 
 
 449 
 
 26989 
 
 647789 
 
 23% 
 
 2301 
 
 138078 
 
 3313872 
 
 10% 
 
 471 
 
 28290 
 
 678960 
 
 24 
 
 2349 
 
 140958 
 
 3382992 
 
 11 
 
 493 - 
 
 29616 
 
 710784 
 
 24% 
 
 2399 
 
 143952 
 
 3454848 
 
 11% 
 
 516 
 
 30986 
 
 743677 
 
 243^ 
 
 2449 
 
 146958 
 
 3526992 
 
 
 539 
 
 32374 
 
 776993 
 
 24% 
 
 2499 
 
 149952 
 
 3598848 
 
 11% 
 
 564 
 
 33795 
 
 811080 
 
 25 
 
 2550 
 
 152994 
 
 3671856 
 
 12 
 
 587 
 
 35251 
 
 846046 
 
 253^ 
 
 2653 
 
 159179 
 
 3820300 
 
 12% 
 
 612 
 
 36735 
 
 881640 
 
 26 
 
 2758 
 
 165484 
 
 3971630 
 
 
 637 
 
 38250 
 
 918000 
 
 263^ 
 
 2865 
 
 171908 
 
 4125800 
 
 12% 
 
 663 
 
 39816 
 
 955584 
 
 27 
 
 2974 
 
 178457 
 
 4282967 
 
 13 
 
 689 
 
 41370 
 
 992880 
 
 273^ 
 
 3085 
 
 185130 
 
 4443125 
 
 13% 
 
 716 
 
 42972 
 
 1031328 
 
 28 
 
 3199 
 
 191922 
 
 4606125 
 
 
 743 
 
 44610 
 
 1070640 
 
 28K 
 
 3314 
 
 198838 
 
 4772118 
 
 13% 
 
 771 
 
 46278 
 
 1110672 
 
 29 
 
 3431 
 
 205876 
 
 4941028 
 
 14 
 
 799 
 
 47980 
 
 1151536 
 
 30 
 
 3672 
 
 220320 
 
 5287675 
 
 For practical purposes, deduct 
 deliver its theoretical capacity. 
 
 10 per cent, as no pump will 
 
MISCELLANEOUS. 
 
 237 
 
 FRICTION Loss IN POUNDS PRESSURE. 
 
 For each 100 feet of length, in different size, clean iron pipes, discharging 
 given quantities of water per minute. 
 
 SIZES OF PIPES INSIDE DIAMETER. 
 
 3-S 
 
 I 
 
 
 
 i 
 
 ! 
 
 
 1 i i 
 
 16 in. 
 
 18 in. 
 
 OS 
 
 5 
 
 10 
 15 
 20 
 25 
 30 
 35 
 40 
 45 
 50 
 75 
 100 
 125 
 150 
 175 
 200 
 250 
 300 
 350 
 400 
 450 
 500 
 750 
 1000 
 1250 
 1500 
 1750 
 2000 
 2250 
 2500 
 3000 
 3500 
 4000 
 4500 
 5000 
 
 fin. 
 
 3.3 
 
 13.0 
 28.7 
 50.4 
 78.0 
 
 1 in. 
 
 0.84 
 3.16 
 6.98 
 12.3 
 19.0 
 27.5 
 37 
 
 liin. 
 
 0.31 
 1.05 
 2.38 
 4.07 
 6.40 
 9.15 
 19 4 
 
 Hm. 
 
 0.12 
 0.47 
 0.97 
 1.66 
 2.62 
 3.75 
 5 05 
 
 2 in. 
 
 6!i2 
 ' 6!i2 
 
 oioi 
 
 2^ in. 
 
 3 in. 
 
 4 in. 
 
 6 in. 
 
 Sin. 
 
 10 in. 
 
 12in. 
 
 14 in. 
 
 
 
 
 
 ..,.. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 0.21 
 
 1.10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 48.0 
 
 16.1 
 20 2 
 
 6.52 
 
 8 15 
 
 1.60 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 24.9 
 56 1 
 
 10.0 
 22 4 
 
 2.44 
 5 32 
 
 0.81 
 1 80 
 
 0.35 
 74 
 
 0.09 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 39.0 
 
 9.46 
 14 9 
 
 7.20 
 4 89 
 
 1.31 
 1 99 
 
 0.33 
 
 0.05 
 
 
 
 
 
 
 
 
 
 
 
 
 
 21.2 
 28.1 
 37.5 
 
 7.0 
 9.46 
 12.47 
 19.66 
 28.06 
 
 2.85 
 3.85 
 5.02 
 7.76 
 11.2 
 15.2 
 19 5 
 
 0.69 
 
 0.10 
 
 
 
 
 
 
 1.22 
 1.89 
 2.66 
 3.65 
 4 73 
 
 0.17 
 0.26 
 0.37 
 0.50 
 66 
 
 '6!67 
 0.09 
 0.12 
 16 
 
 '6.03 
 0.04 
 0.05 
 08 
 
 6.6 i 
 
 6'.02 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 '.'.'.'.'. 
 
 : : : : : 
 
 '.'.'.'.'. 
 
 ..... 
 
 '. ... '. 
 
 
 25.0 
 30.8 
 
 6.0.1 
 7.43 
 
 0.81 
 0.96 
 2.21 
 3.88 
 
 0.20 
 0.25 
 0.53 
 9.94 
 1 46 
 
 0.07 
 0.09 
 0.18 
 0.32 
 49 
 
 0.03 
 0.04 
 0.08 
 0.13 
 20 
 
 6.'6i7 
 6.062 
 
 6.009 
 6.036 
 
 6.005 
 6.020 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 2.09 
 
 0.70 
 95 
 
 0.29 
 38 
 
 0.135 
 
 0.071 
 
 0.040 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1.23 
 
 0.49 
 63 
 
 0.234 
 
 0.123 
 
 0.071 
 
 
 
 
 
 
 
 
 
 ...... 
 
 ::;:: 
 
 
 0.77 
 1.11 
 
 0.362 
 0.515 
 0.697 
 0.910 
 
 0.188 
 0.267 
 0.365 
 0.472 
 0.593 
 0.730 
 
 0.107 
 0.150 
 0.204 
 0.263 
 0.333 
 0.408 
 
 
 
 
 
 
 
 
 
 ;:;:: 
 
 
 
 
 
 
 
 
 
 . . .' . '. 
 
 
 
 
 
 i 
 
 I 
 
 
 
 
238 
 
 THE BOILER. 
 
 PH 
 
 s 
 
 03 
 0) 
 
 
 
 0* 
 
 CN O 
 
 o pi 
 
 }0 
 
 cq t^ xo u-i t^. (f\ OO O 
 
 ^t- "I !>. ^ r-H VO CO O t^ ^O ^O * OO rH U") 
 
 0> 
 ^CM^^CSJi-HCyiOOOOOTfOrOOO PH 
 
 
 
 B 
 
 r^ 00 u-> 00 t^ <N ro O <N 00 00 CN 
 
 PH 
 i-H i I rH <NJ <V) T}- 
 
 'o 
 
 1 
 
 in Tt- ro i-H O Tj- vo CO i l 
 
 C-> CO 10 CM O ^ Ch ^1 00 g 
 
 i? 
 
 03 
 
 00 ::::::::::::: 
 
 ^>00 , 
 
 g 
 
 t^ (N O CN 00 00 <N 
 rt- cy> O fO 00 vO 1> 
 
 i 1 1 i ro ^- >-o r^ c^ 
 o o 01 vo o 
 
 C<] ro ** vo <T> 
 
MISCELLANEOUS. 
 SIZES FOR BOILER FEED PUMPS. 
 
 239 
 
 Diameter of 
 Strain Cylinder 
 
 Diam. of 
 Water 
 Cylinder 
 
 Stroke 
 
 Horse Power 
 Boilers 
 
 Steam 
 Pipe 
 
 Exhaust 
 Pipe 
 
 Suction 
 Pipe 
 
 Discharge 
 Pipe 
 
 zy>" 
 
 2M" 
 
 4" 
 
 30 to 40 
 
 H" 
 
 MT 
 
 1" 
 
 " 
 
 4^ 
 
 2^ 
 
 4 
 
 80 to 100 
 
 y?, 
 
 M 
 
 2 
 
 1M 
 
 5^ 
 
 3^ 
 
 5 
 
 140 to 160 
 
 H 
 
 1M 
 
 2^ 
 
 1H 
 
 When long suction is required use larger suction pipe. Ordi- 
 narily allowance for boiler feeding is to deliver 1 cubic foot or 
 7y 2 gallons of water per horse power. 
 
240 
 
 THE BOILER. 
 
 M 
 
 OTS 
 
 8 o 
 
 ^g 
 
 r W 
 
 I? 
 
 bX) oJ 
 
 o3 
 o w 
 
 i i ,O 
 
 O , ,; 
 
 'jfi 
 
 O)^,-, 
 WJH o3 
 
 ^ CO 
 
 O oo 
 
 rOiJ^t^oO 
 xo ^-O ^o 10 *o VD vo vo vo vO 
 
 rH ^ rH i t O O^ I>* 10 ro ~H 
 i-HC<irO'^->0 1 ^v)t^oO<^ 
 
 oj ^ C 
 ^5 <U O 
 o <u o 
 
 
 
 i lr- li li li li li ii i 
 
 
 ^^ vo O ^O O 
 
 O ^O O *-O O ^-O O *O O 
 
MISCELLANEOUS. 
 
 241 
 
 . <u 
 ^w > 
 
 -d ^ 
 c o 
 
 rt >> 
 
 ll 
 
 bo "to 
 ' ^ 
 
 CO 
 
 - 
 
 le 
 el 
 
 o3 <U 
 CT & 
 
 CO W 
 
 w. 'd 
 
 , 
 
 *S 
 
 s 1 
 
 .W 
 
 1) _C) 
 C 4J 
 
 1 * 
 PH 
 
 , ri 
 
 
 
 
 * 
 
 CSJCOCNCNeNC^C^CNCSCSirorOrororO 
 
 ro t^ rH rj- 1^ ^n 
 Tf OO rO t^. r-H VO 
 
 OO OO OO CTi CTi O O 
 
 8S 
 - 
 
 
 
 OOOOO 
 
 xov^iOxr)Xoir>vr>vOvOO>OvO'OvO'sOvOvO. 
 
 c 
 oV^ 
 
 ^ 
 
242 
 
 THE BOILER. 
 
MISCELLANEOUS. 
 
 243 
 
 Rule to find pressure of water head : Multiply constant .434 
 by number of feet of head. 
 
 EXAMPLE: 
 
 . 434 = constant 
 45 =feet head 
 
 2170 
 1736 
 
 19. 530 ^pressure or 19^ Ibs. approxi- 
 mately 
 
 TANKS. 
 
 Rule to find capacity of round tank : Square diameter in inches 
 and multiply sum by .7854, then by height in inches ; divide this 
 product by 231. This gives capacity in gallons. 
 FORMULA : 
 
 D 2 x.7854xh 
 
 = capacity of round tank 
 231 
 LEGEND: 
 
 D = diameter of tank = 60" 
 h = height of tank =60" 
 231 cubic inches in one gallon 
 
 EXAMPLE: 
 
 60" = diameter of tank 
 60 
 
 3600 = diameter squared 
 .7854 
 
 14400 
 18000 
 28800 
 25200 
 
 2827.4400 
 
 60 = height 
 
 231) 169646 . 4000 (734 . 4 gallons capacity 
 1617 
 
 794 
 693 
 
 1016 
 924 
 
 924 
 924 
 
244 
 
 THE BOILER. 
 
 U. S. GALLONS IN ROUND TANKS. 
 
 For 1 Foot in Depth. 
 
 Dia. 
 of 
 Tanks. 
 
 1 No. 
 U. S. 
 Gals. 
 
 Cubic Ft. 
 and Area 
 in sq. ft 
 
 Dia. 
 of 
 Tanks. 
 
 No. 
 U. S. 
 Gals. 
 
 Cubic Ft. 
 ami Area 
 in sq. ft. 
 
 Dia. 
 of 
 Tanks. 
 
 No. 
 U. S. 
 Gals. 
 
 Cubic Ft. 
 and Area 
 in sq. ft. 
 
 ft. 
 
 in 
 
 ft. 
 
 in. 
 
 ft. 
 
 in. 
 
 1 
 
 
 5.87 
 
 .785 
 
 5 
 
 8 
 
 188.66 
 
 25.22 
 
 19 
 
 
 2120.90 
 
 283 53 
 
 1 
 
 1 
 
 6.89 
 
 .922 
 
 5 
 
 9 
 
 194.25 
 
 25.97 
 
 19 
 
 3 
 
 2177.10 
 
 291 .04 
 
 1 
 
 2 
 
 8. 
 
 1.069 
 
 5 
 
 10 
 
 199.92 
 
 26.73 
 
 19 
 
 6 
 
 2234 
 
 298 . 65 
 
 1 
 
 3 
 
 9.18 
 
 1.227 
 
 5 
 
 11 
 
 205.67 
 
 27.49 
 
 19 
 
 9 
 
 2291.70 
 
 306 . 25 
 
 1 
 
 4 
 
 10.44 
 
 1.396 
 
 6 
 
 
 211.51 
 
 28.27 
 
 20 
 
 
 2350 10 
 
 314.16 
 
 1 
 
 5 
 
 11.79 
 
 1 . 576 
 
 6 
 
 3 
 
 229.50 
 
 30 . 68 
 
 20 
 
 3 
 
 2409 . 20 
 
 322 '. 06 
 
 1 
 
 6 
 
 13.22 
 
 1.767 
 
 6 
 
 6 
 
 248 . 23 
 
 33.18 
 
 20 
 
 6 
 
 2469.10 
 
 330 . 06 
 
 1 
 1 
 
 7 
 8 
 
 14.73 
 16.32 
 
 1.989 
 
 2.182 
 
 6 
 7 
 
 9 
 
 267 . 69 
 
 287 . 88 
 
 35 . 78 
 
 38.48 
 
 20 
 21 
 
 9 
 
 2529 . 60 
 2591. 
 
 338.16 
 346 . 36 
 
 1 
 
 9 
 
 17.99 
 
 2.405 
 
 7 
 
 3 
 
 308.81 
 
 41.28 
 
 21 
 
 3 
 
 2653. 
 
 354 (}(*, 
 
 1 
 1 
 2 
 2 
 
 2 
 
 10 
 11 
 
 1 
 2 
 
 17.95 
 21.58 
 23.50 
 25.50 
 
 27.58 
 
 2.460 
 2.885 
 3.142 
 3.409 
 3 . 687 
 
 7 
 7 
 8 
 8 
 8 
 
 6 
 9 
 
 3 
 
 6 
 
 330.48 
 352 . 88 
 376.01 
 399 . 88 
 424.48 
 
 44.18 
 47.17 
 50.27 
 53 . 46 
 56.75 
 
 21 
 21 
 22 
 22 
 22 
 
 6 
 9 
 
 3 
 
 6 
 
 2715.80 
 2779.30 
 2843 . 60 
 2908 . 60 
 2974.30 
 
 363.' 05 
 371.54 
 380 . 1 3 
 388.82 
 397.61 
 
 2 
 
 3 
 
 29.74 
 
 3.976 
 
 8 
 
 9 
 
 449 . 82 
 
 60.13 
 
 22 
 
 9 
 
 3040 . 80 
 
 406 . 49 
 
 2 
 
 4 
 
 31.99 
 
 4 . 276 
 
 9 
 
 
 475.89 
 
 63.62 
 
 23 
 
 
 3108. 
 
 415 48 
 
 2 
 2 
 
 5 
 6 
 
 34.31 
 36 . 72 
 
 4.587 
 4.909 
 
 9 
 9 
 
 3 
 
 6 
 
 502 . 70 
 530 . 24 
 
 67.20 
 70.88 
 
 23 
 23 
 
 3 
 6 
 
 3179.90 
 3244 60 
 
 424 '56 
 433 . 74 
 
 2 
 
 7 
 
 39.21 
 
 5.241 
 
 9 
 
 9 
 
 558.51 
 
 74.66 
 
 23 
 
 9 
 
 3314. 
 
 443' 01 
 
 2 
 
 8 
 
 41 .78 
 
 5.585 
 
 10 
 
 
 587 . 52 
 
 78.54 
 
 24 
 
 
 3384 10 
 
 452.39 
 
 2 
 
 9 
 
 44.43 
 
 5.940 
 
 10 
 
 3 
 
 617.26 
 
 82.52 
 
 24 
 
 3 
 
 3455. 
 
 461 .86 
 
 2 
 
 10 
 
 47.16 
 
 6 . 305 
 
 10 
 
 6 
 
 640 . 74 
 
 86.59 
 
 24 
 
 6 
 
 3526 60 
 
 471.44 
 
 2 
 
 11 
 
 49.98 
 
 6.681 
 
 10 
 
 9 
 
 678 . 95 
 
 90.76 
 
 24 
 
 9 
 
 3598.90 
 
 481 .11 
 
 3 
 
 
 52.88. 
 
 7.609 
 
 11 
 
 710.90 
 
 95.03 
 
 25 
 
 
 3672 . 
 
 490.87 
 
 3 
 
 1 
 
 55.86 
 
 7.467 
 
 11 
 
 3 
 
 743.58 1 99.40 
 
 25 
 
 3 
 
 3745.80 
 
 500 . 74 
 
 3 
 
 2 
 
 58.92 7.876 
 
 11 
 
 6 | 766.99 1 103.87 
 
 25 
 
 6 
 
 3820 . 30 
 
 510 71 
 
 3 
 
 3 
 
 62.06 
 
 8.296 
 
 11 
 
 9 
 
 811.14 
 
 108 . 43 
 
 25 
 
 9 I 3895.60 
 
 520.77 
 
 3 
 
 4 
 
 65.28 
 
 8.727 
 
 12 
 
 
 846 . 03 
 
 113.10 
 
 26 
 
 
 3971.60 
 
 530 . 93 
 
 3 
 
 5 
 
 68.58 
 
 9.168 
 
 12 
 
 3 
 
 881.65 
 
 117.86 
 
 26 
 
 3 
 
 4048 . 40 
 
 541.19 
 
 3 
 
 6 
 
 71 .97 
 
 9.261 
 
 12 
 
 6 
 
 918. 
 
 122.72 
 
 26 
 
 6 
 
 4125.90 
 
 551 .55 
 
 3 
 
 7 
 
 75.44 
 
 10.085 
 
 12 
 
 9 
 
 955.09 
 
 127.68 
 
 26 
 
 9 
 
 4204.10 
 
 562 
 
 3 
 
 8 
 
 78.99 
 
 10.559 
 
 13 
 
 
 992.91 
 
 132.73 
 
 27 
 
 
 4283. 
 
 572.66 
 
 3 
 
 9 
 
 82.62 
 
 11.045 
 
 13 
 
 3 
 
 1031.50 
 
 137.89 
 
 27 
 
 3 
 
 4362.70 
 
 583.21 
 
 3 
 
 10 
 
 86.33 
 
 11.541 
 
 13 
 
 6 
 
 1070.80 
 
 143.14 
 
 27 
 
 6 
 
 4443 . 10 
 
 593.96 
 
 3 
 
 11 
 
 90.13 
 
 12.048 
 
 13 
 
 9 
 
 1110.80 
 
 148.49 
 
 27 
 
 9 
 
 4524.30 
 
 604.81 
 
 4 
 
 
 94. 
 
 12.566 
 
 14 
 
 
 1151.50 
 
 153.94 
 
 28 
 
 
 4606 . 20 
 
 615.75 
 
 4 
 
 1 
 
 97.96 
 
 13.095 
 
 14 
 
 3 
 
 1193.0 
 
 159.48 
 
 28 
 
 3 
 
 4688.80 
 
 626.80 
 
 4 
 
 2 
 
 102. 
 
 13.635 
 
 14 
 
 6 
 
 1235.30 
 
 165.13 
 
 28 
 
 6 
 
 4772.10 
 
 637.94 
 
 4 
 
 3 
 
 106.12 
 
 14.186 
 
 14 
 
 9 
 
 1278.20 
 
 170.87 
 
 28 
 
 9 
 
 4856 . 20 
 
 649. 18 
 
 4 
 
 4 
 
 110.32 
 
 14.748 
 
 15 
 
 
 1321.90 
 
 176.71 
 
 29 
 
 
 4941. 
 
 660 52 
 
 4 
 
 5 
 
 114.61 
 
 15.321 
 
 15 
 
 3 
 
 1366.40 
 
 182.65 
 
 29 
 
 3 
 
 5026 . 60 
 
 671.96 
 
 4 
 
 6 
 
 118.97 
 
 15.90 
 
 15 
 
 6 
 
 1411.50 
 
 188.69 
 
 29 
 
 6 
 
 5112.90 
 
 683 . 49 
 
 4 
 
 7 
 
 123.42 
 
 16.50 
 
 15 
 
 9 
 
 1457.40 
 
 194.83 
 
 29 
 
 9 
 
 5199.90 695.13 
 
 4 
 
 8 
 
 127.95 
 
 17.10 
 
 16 
 
 
 1504.10 
 
 201.06 
 
 30 
 
 
 5287.70 1 706.86 
 
 4 
 
 9 
 
 132.56 
 
 17.72 
 
 16 
 
 3 
 
 1551.40 
 
 207 . 39 
 
 30 
 
 3 
 
 5376.20 
 
 718.69 
 
 4 
 
 10 
 
 137.25 
 
 18.35 
 
 16 
 
 6 
 
 1599.50 
 
 213.82 
 
 30 
 
 6 
 
 5465 . 40 
 
 730 . 62 
 
 4 
 
 11 
 
 142.02 
 
 18.99 
 
 16 
 
 9 
 
 1648.40 
 
 220.35 
 
 30 
 
 9 
 
 5555 . 40 
 
 742 . 64 
 
 5 
 
 
 146.88 
 
 19.63 
 
 17 
 
 
 1697.90 
 
 226.98 
 
 31 
 
 
 5646.10 
 
 754.77 
 
 5 
 
 1 
 
 151.82 
 
 20.29 
 
 17 
 
 3 
 
 1748.20 
 
 233.71 
 
 31 
 
 3 
 
 5737.50 
 
 766 . 99 
 
 5 
 
 2 
 
 156.83 
 
 20.97 
 
 17 
 
 6 
 
 1799.30 
 
 240.53 
 
 31 
 
 6 
 
 5829 . 70 
 
 779.31 
 
 5 
 
 3 
 
 161.93 
 
 21.65 
 
 17 
 
 9 
 
 1851.10 
 
 247.45 
 
 31 
 
 9 
 
 5922.60 
 
 791.73 
 
 5 
 
 4 
 
 167.12 
 
 22.34 
 
 18 
 
 
 1903.60 
 
 254.47 
 
 32 
 
 
 6016.20 
 
 804 . 25 
 
 5 
 
 5 
 
 172.38 
 
 23.04 
 
 18 
 
 3 
 
 1956.80 
 
 261.59 
 
 32 
 
 3 
 
 6110.60 
 
 816.86 
 
 5 
 
 6 
 
 177.72 
 
 23 . 76 
 
 18 6 
 
 2010.80 
 
 268.80 
 
 32 
 
 6 
 
 6205 . 70 
 
 829 . 58 
 
 5 
 
 7 183.15 
 
 24.48 
 
 18 9 2065.50 
 
 276.12 
 
 32 
 
 9 
 
 6301.50 
 
 842 . 39 
 
 3iy 2 Gallons equals 1 Barrel. 
 
 To find the capacity of Tanks greater than the largest given in 
 the table, look in the table for a Tank of one-half of the given size 
 and multiply its capacity by 4, or one of one-third its size and mul- 
 tiply its capacity by 9, etc. 
 
MISCELLANEOUS. 
 
 245 
 
 STEEL TANK DIMENSIONS. 
 
 Diameter, 
 Feet. 
 
 Height, 
 Feet. 
 
 Thickness, 
 Shell, 
 Inches. 
 
 Thickness, 
 Head, 
 Inches. 
 
 Size, 
 Angle Iron, 
 Inches. 
 
 Weight, 
 Lbs. 
 
 3 
 
 2y 2 
 
 t 
 
 A 
 
 1^ 
 
 300 
 
 3 
 
 3 
 
 
 fk 
 
 ji2 
 
 385 
 
 4 
 
 3 
 
 A 
 
 A 
 
 l/^ 
 
 475 
 
 4 
 
 4 
 
 3 
 
 _3_ 
 
 1 ^ 
 
 585 
 
 43^*? 
 
 4 
 
 ^L 
 
 ^ 
 
 1^ 
 
 670 
 
 4^/9 
 
 41^ 
 
 T^ 
 
 ~re 
 
 1^ 
 
 730 
 
 5 
 
 4^1 
 
 TG 
 
 M 
 
 2 
 
 885 
 
 5 
 
 5 
 
 TS 
 
 M 
 
 2 
 
 955 
 
 sy> 
 
 5 
 
 rs 
 
 M 
 
 2 
 
 1065 
 
 5 12 
 
 $y> 
 
 JL- 
 
 
 2 
 
 1135 
 
 6 
 
 51^ 
 
 / 
 
 M 
 
 2 
 
 1600 
 
 6 
 
 6 
 
 / 
 
 / 
 
 2 
 
 1700 
 
 7 
 
 6 
 
 M 
 
 M 
 
 2 
 
 2100 
 
 7 
 
 7 
 
 M 
 
 M 
 
 2 
 
 2350 
 
 8 
 
 7 
 
 
 / 
 
 2^ 
 
 2800 
 
 8 
 
 o 
 
 / 
 
 M 
 
 2^i 
 
 3000 
 
 9 
 
 8 
 
 M 
 
 M 
 
 2^ 
 
 3730 
 
 9 
 
 9 
 
 
 /4 
 
 2V^ 
 
 4060 
 
 10 
 
 9 
 
 A 
 
 tk 
 
 2^ 
 
 4965 
 
 10 
 
 9 
 
 A 
 
 A 
 
 2J^ 
 
 5400 
 
 10 
 
 10 
 
 A 
 
 A 
 
 2X 
 
 585 
 
 12 
 
 10 
 
 A 
 
 JL 
 
 2 Vi> 
 
 7250 
 
 12 
 
 12 \ S 
 
 A 
 
 2^1 
 
 8300 
 
246 
 
 THE BOILER. 
 
 
 i-H * t O CO CD 
 
 1 
 
 - * 1 CO O **< 
 t~000 i 
 
 v-| r-H i-H (M (M G^ CO CO CO CO ^ T* ^ " 
 
 CDO'^t l OO(McOO^* ( GOC^COO' 1 ^ 
 
 ^cocq SS cor^^I ^Sc5SSct-2S 
 
 <M r~ co TJH os 
 
 o I-H t^ co o co IM oo Tt< o r- co os ic <M 
 
 CO CO O5 CD CO O5 CD (>4 O5 CO CM O5 kO C^l O5 
 
 c^cc^SSc^c^t^S^SS 
 
 OJ iO C5 C^l iO OO I-H "^ OO I-H "Tf t>- 
 ,-H H *-i C^ <M CS| CO CO CO -^ -^ ^ i 
 
 
 
 as 
 
 
 t>. i 
 !> <M 
 
 C^CO-<*i->*iiOl 
 O C^l -5t< CO OO 
 
 OO *O IM O5 CO CO O 
 
 OCNI 
 
 ^ t co 
 
MISCELLANEOUS. 247 
 
 Rule to find capacity of a square tank : Divide cubic inches of 
 tank by 231. The sum will be the number of gallons. 
 
 EXAMPLE: 
 
 Tank 60" X 60" X 60" 
 
 60" width 
 60" long 
 
 3600 
 
 60= height 
 
 gallons in cubic foot 231)216000 ( =935 gallons capacity 
 2079 
 
 810 
 693 
 
 1170 
 1155 
 
 15 
 
 Rule to find weight of water in same tank : Multiply the number 
 of gallons by 8.33 (this is weight of one gallon of water). This 
 sum will be weight in pounds. 
 
 EXAMPLE: 
 
 935 = gallons 
 8 . 33 = weight of one gallon of water 
 
 28 05 
 280 5 
 7480 
 
 7788 . 55 = weight of water in pounds 
 
248 THE BOILER. 
 
 WATER. 
 
 One U. S. gallon equals 231 cubic inches. 
 One U. S. gallon equals .133 cubic feet. 
 One U. S. gallon equals 8.33 pounds. 
 One U. S. gallon equals .83 imperial gallon. 
 
 One imperial gallon equals 277.274 cubic inches. 
 
 One imperial gallon equals .16 cubic feet. 
 
 One imperial gallon equals 10 pounds. 
 
 One imperial gallon equals 1.2 U. S. gallon. 
 
 One cubic inch of water equals .03607 pound. 
 
 One cubic inch of water equals .003607 imperial gallon. 
 
 One cubic inch of water equals .004329 U. S. gallon. 
 
 One cubic foot of water equals 6.23 imperial gallons. 
 
 One cubic foot of water equals 7.48 U. S. gallons. 
 
 One cubic foot of water equals 62.321 pounds. 
 
 One cubic foot of water equals .028 ton. 
 
 One pound of water equals 27.72 cubic inches. 
 One pound of water equals .10 imperial gallon. 
 One pound of water equals .12005 U. S. gallon. 
 
 One ton of water equals 35.98 cubic feet. 
 One ton of water equals 224 imperial gallons. 
 One ton of water equals 268.8 U. S. gallons. 
 
 A column of water 1 foot high equals .433 pounds pressure 
 per square inch. 
 
 A pressure of 1 pound per square inch equals 2.31 feet of water 
 in height. 
 
 A pressure of 1 ounce per square inch equals .144 feet of water 
 in height. 
 
MISCELLANEOUS. 
 
 249 
 
 O> * CS-O-'MrPiO-OCCCCOCCOOOiMt^ 
 
 -tH (M <M -co -MMM M Tt Tji Tf* >O LO CO CO 
 
 _P_, . . p C: O O ' O O O O O O O O O O 
 
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 -CO <3> TjH -143 -COOOO5 - i M O C5 00 t^ rH i!? 
 
 i i i-t 'M *M *M ^) M CO fO M CC * ** iO IO 
 
 - C-'3^eOMO5TjHOO*iaC'<J<Oi>O--'l^MMOaOOO'NOOTt<00*tCO 
 E ^H ,-< ,-1 ,-H ,-H ,-! ,-* ^H -H r^'N'N'N'N'M'M'MM'M'M'NMM... , 
 
 ~U - ^U- M 00 M 00 M 00 M p M p M p ^_ ^_ rt| Ti< Tf T*< Tj| CO CD CO 00 00 
 i^-t ... 
 
 iQOWMO*HOO'^OOMI^e*OON-<OOOOeOOT!iOT< 
 
 o '" 
 x: 
 
 ^ 
 
 oo; 
 a w 
 
 P5 
 
 o 
 
 w 
 
 <-i CO LO t - 00 C iN M O OS X C iM rf CO 00 C <M O 
 
 M 1C t^ p ^H Tf co 00 O (M * t- p .-i M iO 00 O (M >O t- p *-* M CO 00 O <M * p 00 ^- CC O t- M p p ^ p 00 "- 1 * CO C TJ< 
 
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 MH OOO>^MTt<Ol^OCO'^MTt<COl^O5O^MLOcOOOO>'--iC v lTt<Ol^OOO5'-*^'* | iOl>XT-J^t^O^10000COTt<Ttif'l 
 
 Tf 
 
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 CL 4 OcDt^QOOlO T ~ | C v l'>lT^T^iOcOI^OOO3O'^ 
 
 ro VbOOOO94eO^>Q<Ot^OOAQ* l ^C4ViO 
 
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 III 
 
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 O t 00 d> O ^ CO ^ ^CO t 00 06 O ^ (N ^^ g b- 00 Q i^ ^ CO t^ 00 OS O * 00 Q * Q<O N 00 ^ 
 
 i i I-H ^H ^H r-l T-I ^H i-H ^H rt (M <M C-l 'M C-l C^l 'M <M 7-1 'M M rC CO CO M TO M JC CO ?O Tt* Tf "* Tf< TJH IO LO CO CO t^ t^ 00 
 
250 THE BOILER. 
 
 Rule to find length of belt : Add together the diameter in inches 
 of the two pulleys ; divide this by 2 and multiply the quotient by con- 
 stant 3^4 (3.25) ; to this add twice the distance in inches between the 
 centers of shaft ; the result will give length of belt approximately. 
 
 FORMULA: 
 
 /2D\ 
 
 ( ~2~) XC+ (2xd) = length of belt 
 
 LEGEND: 
 
 D = diameter of pulleys =30" 
 20" 
 
 C= constant =3.25 
 d = distance between shaft centers = 10' = 120' 
 
 EXAMPLE: 
 
 30" and 
 
 20 = pulley diameters 
 
 2)50 
 
 25 
 3 . 25 = constant 
 
 1 25 
 5 
 75 
 
 twice distance 81.25 
 
 between centers of shaft =240. 
 
 321.25" = length of belt 
 
 THE USE OF BELTING. 
 
 The ultimate strength of a single belt one inch in width and 
 one-quarter inch thick is about 750 pounds, but from the weaken- 
 ing effect of the several methods of joining, the ends not more 
 than 200 pounds .per inch in width should be depended upon for 
 ultimate strain. 
 
 Belts will transmit a force of about 55 pounds for every inch 
 in width, and taking the average thickness of belts at one-sixth 
 of an inch, this means a strain of 330 pounds per square inch of 
 section. 
 
 The horse power of a laced belt becomes a maximum at a speed 
 of 87.41 feet per second, or 5,245 feet per minute, or considerably 
 over a mile a minute. 
 
MISCELLANEOUS. 251 
 
 One good method for lacing" a belt is to punch the holes in two 
 rows and zigzag, thus a six-inch belt would have seven holes, 
 four nearest the end. The first row should be about three-quarters 
 of an inch from the end of the belt and about the same from the 
 sides. On the larger belts the distance would be somewhat in- 
 creased. Begin the lacing in the center of the belt and lace both 
 ways; keep the ends of the belt in line and the tension on both 
 ends of the lace the same. The lacing should not be crossed on 
 the side of the belt that runs next the pulley, so that the lacing 
 on that side will be parallel with the edges of the belt, while on 
 the other side it will be at an angle. Loose belts can be run on 
 less power it takes to drive that belt, and in order to run the 
 belt loose it must be in good order ; so taking care of belts means 
 less fuel for power and longer life to the belts. 
 
 Do not use any belt dressing that will make the belt stick to 
 the pulley. The use of a little good oil occasionally, such as 
 neat's-foot, to keep the leather soft and pliable, will give the very 
 best results. 
 
 RULES FOR PULLEY SPEED CALCULATION. 
 
 Rule to find size of a pulley for a main line shaft, if the speed 
 of shaft and diameter of pulley on the counter shafts are given: 
 Multiply the diameter in inches of pulley on counter shafts by 
 speed and divide by the revolution of the main shaft; the sum will 
 be the diameter of the pulley. 
 
 EXAMPLE: 
 
 Main shaft 150 revolutions per minute; to drive a 15" pulley 350 revo- 
 lutions per minute what will be the diameter of pulley on main shaft ? 
 
 15" diameter pulley counter shaft 
 350 revolution of counter shaft 
 
 750 
 
 45 
 
 150)5250(35" diameter of pulley for main 
 450 line 
 
 750 
 750 
 
252 THE BOILER. 
 
 To find size of a pulley for counter shaft when revolutions of 
 pulley on main shaft are given : Multiply diameter in inches of 
 driving pulley by the revolutions of the main shaft and divide 
 by the speed required on counter line. 
 
 EXAMPLE: 
 
 35" diameter of pulley main shaft 
 150 revolution main shaft 
 
 1750 
 35 
 
 revolution counter shaft 350) 5250 (15" pulley for counter line 
 
 350 
 
 1750 
 1750 
 
 To find speed of counter shaft when revolutions of the main 
 shaft and size of pulleys are known : 
 
 Multiply the revolutions of main shaft by the diameter in inches 
 of the pulley and divide by the diameter in inches of the pulley 
 on counter shaft. 
 
 EXAMPLE: 
 
 > - V 
 
 35" pulley main shaft 
 150 revolutions 
 
 1750 
 35 
 
 diameter pulley, counter shaft 15)5250 (350 revolution of counter shaft 
 
 45 
 
 75 
 75 
 
 Slip of belt, also thickness of same, will vary the revolutions 
 some. 
 
MISCELLANEOUS. 
 HORSE POWER SHAFTING TRANSMISSION 
 
 253 
 
 Diameter of 
 Shaft in Inches 
 
 REVOLUTIONS PER MINUTE. 
 
 100 
 
 125 
 
 150 
 
 175 
 
 200 | 225 
 
 250 
 
 300 
 
 350 
 
 400 
 
 ,8::::::::::::: 
 
 HORSE POWER. 
 
 1.2 
 2.4 
 , 4.3 
 6.7 
 10.0 
 14.3 
 19.5 
 26.0 
 33.8 
 43.0 
 53.6 
 65.9 
 80.0 
 113.9 
 156.3 
 
 1.4 
 3.1 
 5.3 
 8.4 
 12.5 
 17.8 
 24.4 
 32.5 
 42.2 
 53.6 
 67.0 
 82.4 
 100.0 
 142.4 
 195.3 
 
 1.7 
 3.7 
 6.4 
 10.1 
 15.0 
 21.4 
 29.3 
 39.0 
 50.6 
 64.4 
 79.4 
 97.9 
 120.0 
 170.8 
 234.4 
 
 2.1 
 4.3 
 7.4 
 11.7 
 17.5 
 24.9 
 34.1 
 43.5 
 59.1 
 75.1 
 93.8 
 115.4 
 140.0 
 199.3 
 273.4 
 
 2.4 
 4.9 
 8.5 
 13.4 
 20.0 
 28.5 
 39.0 
 52.0 
 67.5 
 85.8 
 107.2 
 121.8 
 160.0 
 227.8 
 312.5 
 
 2.6 
 5.5 
 9.5 
 15.1 
 22.5 
 32.1 
 44.1 
 58.5 
 75.9 
 96.6 
 120.1 
 148.3 
 180.0 
 256.2 
 351.5 
 
 3.1 
 6.1 
 10.5 
 16.7 
 25.0 
 35.6 
 48.7 
 65.0 
 84.4 
 107.3 
 134.0 
 164.8 
 200.0 
 284.7 
 390.6 
 
 3.6 
 7.3 
 12.7 
 20.1 
 30.0 
 42.7 
 58.5 
 78.0 
 101.3 
 128.7 
 158.8 
 195.7 
 240.0 
 341.7 
 468.7 
 
 4.3 
 
 8.5 
 14.8 
 23.4 
 35.0 
 49.8 
 68.2 
 87.0 
 118.2 
 150.3 
 187.6 
 230.7 
 280 
 398.6 
 546.8 
 
 5.0 
 9.7 
 16.9 
 26.8 
 40.0 
 57.0 
 78.0 
 104.0 
 135.0 
 171.6 
 214.4 
 243.6 
 320.0 
 455.6 
 625.0 
 
 }jj 
 
 2J- 
 
 *>j 5. 
 
 > 1 1 
 
 4j|: .::::::::::: 
 
 The following- table gives the maximum permissable distances 
 between bearings of continuous shafts: 
 
 Diameterof shaft in inches 
 
 Distance between 
 wrought iron 
 
 Bearings in feet 
 steel 
 
 1 
 
 12.27 
 
 12.61 
 
 2 
 
 15.46 
 
 15.89 
 
 3 
 
 17.7 
 
 18.19 
 
 4 
 
 19.48 
 
 20.02 
 
 5 
 
 20.99 
 
 21.57 
 
 6 
 
 22.3 
 
 22.92 
 
 7 
 
 23.48 
 
 24.13 
 
 8 
 
 24.55 
 
 25.23 
 
 9 
 
 25.53 
 
 26.24 
 
 10 
 
 26.4 
 
 27.18 
 
 The length of a bearing is usually given as three times the 
 diameter of the shaft in inches. The distance between bearings 
 are also given as three times diameter, the product being expressed 
 in feet. 
 
 Rule to find diameter of a shaft. Multiply the horse power 
 to be transmitted by the constant 100 for wrought iron ; divide 
 the product by the number of revolutions per minute and extract 
 the cube root of quotient ; this sum will give safe diameter of shaft- 
 ing. For steel use constant 62.5. 
 
 Rule to find diameter of shafts as second movers, transmitting 
 power through long lines. Use preceding rule, using constant 50 
 for wrought iron and 31.5 for steel. 
 
254 THE BOILER. 
 
 Rule to find diameter for counter shafting well supported by 
 bearings at short distances. Use preceding rules with constant 
 33 for wrought iron and 21 for steel. 
 
 Rule to find horse power a given shaft will transmit. Multiply 
 the cube of the diameter by the revolutions per minute and divide 
 the product by 100. 
 
 For SECOND MOVERS Multiply the cube of the diameter by 
 twice the revolutions and divide the product by 100. 
 
 For THIRD MOVERS Multiply the cube of the diameter by 
 three times the revolutions and divide by 100. 
 
 Approximately a one inch shaft will transmit at 100 revolutions 
 1 horse power as first mover, 2 horse power as second mover, and 
 3 horse power as third mover, the power transmitted with safety 
 will vary in proportion as to the speed and as the cube of the 
 diameter. 
 
 RULES FOR STEAM BOILERS. 
 
 See that water-level has not fallen, and examine joints and 
 seams to detect leakage, and furnaces for evidence of bulging. 
 
 Blow through water gages ; open blow-off cock to remove sedi- 
 ment.; try safety valve to insure free action; raise dampers to clear 
 flues of explosive gases ; and stir up fire, heating boiler and setting 
 slowly. 
 
 In case of low water, immediately cover the fires with ashes, 
 or, if no ashes are at hand, use fresh coal, and close ash-pit doors. 
 Don't turn on the feed under any circumstances, nor tamper with 
 nor open the safety valve. Let the steam outlets remain as they 
 are. 
 
 Close throttle and keep closed long enough to show true level 
 of water. If that level is sufficiently high, feeding and blowing 
 will usually suffice to correct the evil. In case of violent foaming, 
 caused by dirty water, or change from salt to fresh, or vice versa, 
 in addition to the action above stated, check draft and cover fires 
 with fresh coal. 
 
 In preparing to get up steam after boilers have been open, or 
 
MISCELLANEOUS. 255 
 
 out of service, great care should be exercised in making- the man 
 and hand-hole joints. Safety valve should then be opened, and 
 blocked open, and the necessary supply of water run in or pumped 
 into the boilers until it shows at second guage in tubular and 
 locomotive boilers ; a higher level is advisable in vertical tubulars 
 as a protection to the top end of the tubes. After this is done fuel 
 may be placed upon the grate, dampers opened, and fires started. 
 If chimney or stack is cold and does not draw properly, burn some 
 oily waste or light kindling at the base. Start fires in ample time 
 so it will not be necessary to force them unduly. When steam 
 issues from the safety valve, lower it carefully to its seat and note 
 pressure and action of steam gauge. 
 
 If there are other boilers in operation, and stop valves are to 
 be opened to place boilers in connection with others on a steam 
 pipe line, watch those recently fired up until pressure is up to that 
 of the other boilers to which they are to be connected ; and, when 
 that pressure is attained open the stop-valves very slowly and care- 
 fully. 
 
 Never feed cold water into a boiler as it is injurious to the 
 plates and liable to spring the seams and cause them to leak. A 
 good feed water heater should be used ; they not only save early 
 repairs on the boiler but effect a great saving in the consumption 
 of coal. 
 
 Boilers should be blown off, a little at least, once or twice a 
 day, and the water should be entirely blown off at least once every 
 two weeks, depending on the nature of the feed water. Never 
 blow out a boiler while it is too hot as the arch plates, flues and 
 braces retain heat enough to bake the deposits of mud into a hard 
 scale that becomes firmly attached to their surface. With the walls 
 and arches too hot while blowing off, the plates are liable to injury. 
 Always allow the setting to cool down before emptying completely 
 as the scale and mud will then be quite soft and can easily be 
 washed out with a hose. 
 
 If necessary to blow down, allow the boilers to become cool 
 before filling again. Cold water pumped into hot boilers is very 
 injurious from sudden contraction. 
 
 Care should be taken that no water comes in contact with the 
 exterior of the boiler, either from leaky joints or other causes. 
 
256 THE BOILER. 
 
 In tubular boilers the hand holes should be often opened, and 
 all deposits removed, and fire-plates carefully cleaned. 
 
 Keep the boiler clean internally and externally and thoroughly 
 examine plates and seams at frequent intervals, especially those in 
 contact with setting or exposed to direct action of fire. 
 
 Always raise steam slowly and never light fire until water shows 
 in gauge glasses. Keep furnace walls in good condition and well 
 pointed up. Allow boiler and brick work to cool before emptying 
 boiler. Prevent oil and greasy matter from entering boiler, as 
 same lead to serious inefficiency and to dangerous heating of plates. 
 
 Mud drums should be given careful attention and cleaned and 
 inspected regularly just the same as the boiler. 
 
 Try the safety valves cautiously and often, as they are liable 
 to become fast in their seats and useless for the purpose intended. 
 If the valve is of the lever type, do not load it with additional 
 weights. The safety valve is set to blow off at a certain pressure 
 and should blow off when the steam gauge registers this pressure ; 
 if it does not, one or the other is wrong and should be corrected. 
 
 When a blister appears there must be no delay in having it 
 carefully examined, and trimmed or patched, as the case may 
 require. 
 
 Particular care should be taken to keep sheets and parts of 
 boilers exposed to the fire perfectly clean ; also all tubes, flues 
 and connections well swept. This is particularly necessary where 
 wood or soft coal is used for fuel. 
 
 See that proper water-level is maintained. Keep water gauge 
 classes clean and passages clear, by trying gauges frequently. 
 (Lack of proper attention to water gauges leads to more accidents 
 than any other cause.) 
 
 Maintain a fire of even thickness, free from holes and clear of 
 ashes and clinkers. (The proper thickness of fire increases with 
 the hardness and size of coal and with the strength of draft.) 
 Regulate fire and draft and feed to meet demands for steam, keep- 
 ing water level constant to avoid priming or burning of plates. 
 Ash pits are to be kept clear to avoid burning grate bars and to 
 prevent loss of draft and efficiency. 
 
 Never attempt to stop a leak or tighten a joint when boiler is 
 
MISCELLANEOUS. 257 
 
 under high pressure. Never cut in a boiler with a battery until 
 its pressure is equal to that of the battery. 
 
 Before banking fires run water to proper level, which note, and 
 see that the steam pipe drains are open and in working order. 
 
 Water in ash pit has an effect of clinkering, and this varies 
 with the amount of sulphur and iron pyrites and ash in fuel, thus 
 choking up air spaces in grate effecting the life of same. Again 
 the moisture mixing with sulphur has the corrosive effect on boiler 
 and "tubes; it also has a cooling effect which detracts from com- 
 bustion, and volatile gases escape unconsumed. 
 
 NOTES. 
 
 Slight leakage at joints causes grooving. 
 
 Covering of boiler and steam pipes saves fuel and increases 
 efficiency. 
 
 A boiler showing pulsations of engine gives evidence of being 
 too small for duty. 
 
 Fly wheels should not have a greater speed than one mile per 
 minute to be safe. 
 
 Globe valves should always be so placed in steam pipes that 
 their stems are nearly horizontal. 
 
 Stack should drain inside for reasons appearance as 
 stacks are in use, most of the time, the advantage of having drain- 
 age outside is not to be weighed with the advantage of draining 
 inside and appearance. 
 
258 
 
 THE BOILER. 
 KNOTS AND MILES. 
 
 Knts 
 
 Miles 
 
 Knts 
 
 Miles 
 
 Knts 
 
 Miles 
 
 Knts 
 
 Miles 
 
 Knts 
 
 Miles 
 
 1.00 
 
 1.1515 
 
 6.00 
 
 6.9091 
 
 11.00 
 
 12.6667 
 
 16.00 
 
 18.4242 
 
 21.00 
 
 24.1818 
 
 1.25 
 
 1.4394 
 
 6.25 
 
 7.1970 
 
 11.25 
 
 12.9545 
 
 16.25 
 
 18.7121 
 
 21.25 
 
 24.4697 
 
 1.50 
 
 1.7273 
 
 6.50 
 
 7.4848 
 
 11.50 
 
 13.2424 
 
 16.50 
 
 19.0000 
 
 21.50 
 
 24.7576 
 
 1.75 
 
 2.0152 
 
 6.75 
 
 7.7727 
 
 11.75 
 
 13.5303 
 
 16.75 
 
 19.2879 
 
 21.75 
 
 25.0455 
 
 2.00 
 
 2.3030 
 
 7.00 
 
 8.0606 
 
 12.00 
 
 13.8182 
 
 17.00 
 
 19.5758 
 
 22.00 
 
 25.3333 
 
 2.25 
 
 2.5909 
 
 7.25 
 
 8.3485 
 
 12.25 
 
 14.1061 
 
 17.25 
 
 19.8636 
 
 22.25 
 
 25.6212 
 
 2.50 
 
 2.8788 
 
 7.50 
 
 8.6364 
 
 12.50 
 
 14.3939 
 
 17.50 
 
 20.1515 
 
 22.50 
 
 25.9091 
 
 2.75 
 
 3.1667 
 
 7.75 
 
 8.9242 
 
 12.75 
 
 14.6818 
 
 17.75 
 
 20.4394 
 
 22.75 
 
 26.1970 
 
 3.00 
 
 3.4545 
 
 8.00 
 
 9.2121 
 
 13.00 
 
 14.9697 
 
 18.00 
 
 20.7273 
 
 23.00 
 
 26.4848 
 
 3-25 
 
 3.7424 
 
 8.25 
 
 9.5000 
 
 13.25 
 
 15.2576 
 
 18.25 
 
 21.0152 
 
 23.25 
 
 26.7727 
 
 3.50 
 
 4.0303 
 
 8.50 
 
 9.7879 
 
 13.50 
 
 15.5455 
 
 18.50 
 
 21.3030 
 
 23.50 
 
 27.0606 
 
 3.75 
 
 4.3182 
 
 8.75 
 
 10.0758 
 
 13.75 
 
 15.8333 
 
 18.75 
 
 21.5909 
 
 23.75 
 
 27.3485 
 
 4.00 
 
 4.6061 
 
 9.00 
 
 10.3636 
 
 14.00 
 
 16.1212 
 
 19.00 
 
 21.8788 
 
 24.00 
 
 27.6364 
 
 4.25 
 
 4.8939 
 
 9.25 
 
 10.6515 
 
 14.25 
 
 16.4091 
 
 19.25 
 
 22.1667 
 
 24.25 
 
 27.9242 
 
 4.50 
 
 5.1818 
 
 9.50 
 
 10.9394 
 
 14.50 
 
 16.6970 
 
 19.50 
 
 22.4545 
 
 24.50 
 
 28.2121 
 
 4.75 
 
 5.4697 
 
 9.75 
 
 11.2273 
 
 14.75 
 
 16.9848 
 
 19.75 
 
 22.7424 
 
 24.75 
 
 28.5000 
 
 5.00 
 
 5.7576 
 
 10.00 
 
 11.5152 
 
 15.00 
 
 17.2727 
 
 20.00 
 
 23.0303 
 
 25.00 
 
 28.7879 
 
 5.25 
 
 6.0455 
 
 10.25 
 
 11.8030 
 
 15.25 
 
 17.5606 
 
 20.25 
 
 23.3182 
 
 25.25 
 
 29.0758 
 
 5.50 
 
 6.3333 
 
 10.50 
 
 12.0909 
 
 15.50 
 
 17.8485 
 
 20.50 
 
 23.6061 
 
 25.50 
 
 29.3636 
 
 5.75 
 
 6.6212 
 
 10.75 
 
 12.3788 
 
 15.75 
 
 18.1364 
 
 20.75 
 
 23.8939 
 
 25.75 
 
 29.6515 
 
 TABLE 'SHOWING KNOTS REDUCED TO MILES. 
 
 A nautical mile or knot is 6,080.27 feet. 
 
CONTENTS 
 
 CHAPTER I. PAGE 
 
 MATERIALS 5 
 
 CHAPTER II. 
 SELECTION OF BOILER . ... 18 
 
 CHAPTER III. 
 BOILER CONSTRUCTION ... . . -. . 35 
 
 CHAPTER IV. 
 BRACES AND REINFORCEMENT . . . . . . . 69 
 
 CHAPTER V. 
 FURNACES, FLUES AND U. S. RULES. /- . ... 106 
 
 CHAPTER VI. 
 LAP JOINT RULES . . . . . . . . 126 
 
 CHAPTER VII. 
 BUTT JOINT RULES . . . . . . . .154 
 
 CHAPTER VIII. 
 THE STEAM BOILER ........ 175 
 
 CHAPTER IX. 
 INSPECTIONS ......... 200 
 
 CHAPTER X. 
 MISCELLANEOUS 223 
 
 259 
 
INDEX 
 
 Adamson furnace rules ; 120 to 122, 125 
 
 Angle irons, sizes and weights, table 55 
 
 B 
 
 Belting, tables and rules 249 to 251 
 
 Boilers, construction 35 to 67 
 
 " designing 6, 16, 17 
 
 ". U. S. Government requirements 218 
 
 " selection 18 
 
 " hot water, rules and tables 159 
 
 " standard measurements 181, 182 
 
 heating, low pressure 198 
 
 " verticle, specifications, tables 197 
 
 weights, table of 185 
 
 " water tube or coil, rules 221, 222 
 
 Boiler room, rules and notes 254 to 257 
 
 Braces, measurements and weights 52 
 
 " number for standard boilers, table 53 
 
 " number, and rule to find 90 
 
 rods, rule to find working pressures 94 
 
 " and bracing, material 69. 70 
 
 socket bolts, rules to find pressure 125 
 
 formed 94 
 
 Butt Joints 154 to 172 
 
 Brown Furnaces 117 
 
 c 
 
 Channel steel, size and weight, table 56 
 
 Chimneys and stacks, rules and tables 189 to 196 
 
 Circles, rules for calculations, segments 20 to 23, 88, 89 
 
 " tables of areas and circumference 24, 25 
 
 Cones, rules 118, 119 
 
 Collapsing pressures, furnaces, rule to find 113 to 116, 123. 124, 126 
 
 Curved surfaces, rule 95 
 
 260 
 
INDEX. 261 
 
 Dome plate 48 
 
 Drills, table of sizes 61 
 
 *Drums and Heads, U. S. Government requirements 220 
 
 E 
 
 Engines, power 18, 19, 31 
 
 " types, efficiencies, table 20 
 
 Engineers, marine, classification 208 to 212 
 
 qualifications and duties 208 to 212 
 
 F 
 
 Feed water, heaters and heating 223 to 229 
 
 " admission 217 
 
 heating, tables and rules 230. 231 
 
 Flanges, diameters, sizes for pipes 58 
 
 Furnaces 105 
 
 plain, rules and tables 108 to 112, 120 
 
 Morrison, rules 113, 114, 121 
 
 " U. S. Government, rules and tables 108 to 112 
 
 Purvis, rules 117, 121 
 
 " verticle, rules 121 
 
 " Leeds Suspension, rules 116 
 
 Brown , 117, 121 
 
 Flues and furnaces 106, 108, 109 
 
 plain, rules . .110 to 122 
 
 G 
 
 Gauge cocks and water glass 219 
 
 Girders, rules .99, 103 
 
 Grate surface, rules and tables - 183, 184 
 
 H 
 
 Heads, flat 85 
 
 cast iron, rule 88 
 
 " convex, rule 86 
 
 " concaved 87 
 
 boiler, diameter and weights, table , 40 to 42 
 
 Heating surface, ratios, tables 183. 198 
 
 " surface, rule to find 50 
 
 Horse power, tables and rules 26, 27, 28, 181, 182 
 
 Hydrostatic test . 220 
 
262 THE BOILER. 
 
 I beams, sizes and weights 55 
 
 Iron, cast, composition, tables of properties 7 217 
 
 wrought g 
 
 cast, balls, diameter and weight, table 55 
 
 Inspections, U. S. Government rules 106 to 122, 219 
 
 of boilers 212 to 222 
 
 J 
 
 Joints, lap, single riveted, rules 127 to 137 
 
 lap, single riveted, table of efficiencies 137 
 
 lap, double riveted, rules . . 138 to 149 
 
 lap, double riveted, table of efficiencies 149 
 
 lap, triple riveted, rules 150 to 153 
 
 lap, triple riveted, table of efficiencies 153 
 
 butt, double strapped, double riveted, rules 154 to 159 
 
 butt, double strapped, double riveted, table of efficiencies 159 
 
 butt, double strapped, triple riveted, rules 160 to 168 
 
 butt, double strapped, triple riveted, table of efficiencies 164 
 
 butt, double strapped, quadruple riveted 169 to 174 
 
 butt, double strapped, quadruple riveted, table of efficiencies 172 
 
 K 
 
 Knots and miles 258 
 
 L 
 
 Lap joints 127 to 153 
 
 M 
 
 Materials . . 5 to 16 
 
 U. S. Govt. inspection, selection, tests 11. 106, 107 
 
 Metals, weights and table of ' 53 to 55 
 
 Morrison furnace 113 t o 121 
 
 N 
 
 Notes on boiler room, rules, etc ; 254 to 257 
 
 P 
 
 Pipe, steam, heating, radiation, table 198, 221 
 
 expansion and radiation, table 58 
 
 and piping 56 
 
 steam, gas, water, dimensions, table 59 
 
INDEX. 263 
 
 Pipe, rules to find thickness of 57 
 
 friction loss in discharge, table 237 
 
 " discharge at nozzle, table 240 
 
 Plates, steel, rules and tables 6, 9, 10, 11, 43 to 48 
 
 Pressures, U. S. Govt. rules, shells 175 
 
 U. S. Govt. tables 176 to 180 
 
 water heads, tables and rules ' 241, 242, 243 
 
 U. S. Govt. requirements 222 
 
 Pump, rules 231 
 
 tables, notes 234, 235 
 
 " capacities 236 
 
 piping table 237 
 
 " elevation of water 238 
 
 " feed, size, table 239 
 
 Pulleys, rules for calculations 251, 252 
 
 Purvis Furnace 251, 252 
 
 R 
 
 Reinforcement of openings, rules 103 to 105 
 
 Rivets and Riveting, table 1 36 to 39 
 
 *' shearing strength of 38, 39, 68 
 
 Rods, braces, rules 94 
 
 Rules, for calculating circles 20, 88 
 
 " mensuration 20, 23 
 
 S 
 
 Safety valve, rules and tables 200 to 207 
 
 Settings, boiler 185, 186 
 
 " measurements 186, 187 
 
 materials for 188, 189 
 
 Shafting, rules and tables 253, 254 
 
 Shearing strength of rivets 38, 39, 68 
 
 Socket bolt rules 125 
 
 Steam boiler notes 254 to 257 
 
 notes 28, 32 
 
 pressures, temperature and tables 29 
 
 Steel, flat, weight per foot, table 62, 63 
 
 round, square, weights, table 61, 62 
 
 " cast 217 
 
 Stay bolts, sizes and threads of same 60 
 
 " bolts, strain, areas, bracing of 71, 84 
 
264 THE BOILER. 
 
 Tables, decimals, circumferences, areas 24 to 26 
 
 pressures and temperature 29 
 
 " weights and size of boiler heads 40 
 
 I beams 56 
 
 " sizes, threads, flanges 58 
 
 flat steel, sizes and weights 63 
 
 " metals, weights 63, 64 
 
 Birmingham and U. S. standards, gauges 53, 54, 63, 64 
 
 " rivets 37 
 
 shearing strength of rivets 38, 39 
 
 circumference, areas and decimals 24, 25. 26 
 
 areas of circular arcs 91 to 93 
 
 horse power boilers 176 to 181 
 
 weights of boilers 185 
 
 " chimneys and stacks 191, 195 
 
 for safety valves 202, 203 
 
 Tanks, capacities, tables and rules 244 to 247 
 
 Taps and drills 61, 62 
 
 Testing, boiler plate, drilling 219, 222 
 
 Thermometer, rules and tables 32, 33, 34 
 
 Tube, rules and tables, standard sizes 49 to 51 
 
 plates, rule to find pressures 96 to 98 
 
 4< plates, thickness 97 
 
 plates, compressive strain 98, 101, 124 
 
 U 
 
 U. S. Government rules, tables, pressures 175 to 180 
 
 V 
 
 Verticle boiler, table of specifications 197 
 
 w 
 
 Water tube and coil boiler requirements 221, 222 
 
 pressure tables and rules 241, 242, 243 
 
 " measurement, notes 248 
 
 :BR^ 
 
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