RETREATS SRO NS Re PC oo = REAR ERS Sa SN RS aS pres Ss PaaS a 5 Se eee a ry SEU EE ENS Ra ESTE Sere TEAMS LE ; SS oe SE SERN ase SuSE Reet erty ee ee ; SRO ee = 2 SN REE SS tes | Seow S Sees e ce Pe oe Sas : oe oe ae See : es SSeS 2 eB - SSS Se eebesesepe = ee a pare Me Be ua Br pe d ty ‘i ei hedge ree CE Ee eres Stee ny Seek Spe RRS Bonk eat ee RE Bie ore Sty Soreatetreet ir sere Bea apts Sener SS ee = Sep eter eerste ess Su ‘ : 3 Se scenes = ate tebe ee Ef restiricies i 5 eriron tenets SS Ss Sata aves . aie Garuell University Library Ithaca, New York FROM Cornell University Library TH 6631.H19 Plumbing fixture traps; an historical sta UII PLUMBING FIXTURE TRAPS An Historical, Statistical and Experimental Engineering Research on VENTED AND UNVENTED TRAPS BY A. E. HANSEN HYDRAULIC AND SANITARY ENGINEER 2 RECTOR STREET, NEW YORK PRICE TWO DOLLARS Copyright 1921 by A. E. HANSEN PRINTED IN THE UNITED STATES OF AMERICA BY HARPER & BROTHERS DEDICATION To those, who by the skill of their brains or their hands, endeavor to uphold the present high standards of plumbing design and thus aid in the up-building of the health and com- fort of the American people, this book is respectfully dedicated. FOREWORD The subject of plumbine traps is one which closely touches every modern American home, more intimately perhaps than most people realize, These devices are Intended to intervene securely, permanently, and unfailingly between the foulness of the sewer on one side and the sweetness of the home on the other. Anything, which threatens to weaken or destroy this barrier, must be shunned and condemned. There is no half-way security; absence of complete security means danger. lt is hoped that this book will be used as a reference by those whose duty it is to prepare or administer plumbing codes, and to design, specify, or install plumbing systems. THE AUTHOR PLUMBING FIXTURE TRAPS AN HISTORICAL, STATISTICAL AND EXPERIMENTAL ENGINEERING RESEARCH ON VENTED AND UNVENTED TRAPS UCH consideration and study has been given, much guess work has been at- tached to, and many opinions have been advanced with regard to the subject of non-vented, anti-siphon, non-siphoning or re- sealing traps, on their power of resisting siphonage and back pressure, and on their self-cleansing action, all as compared with the corresponding qualities of the vented bent tube or 4% S traps. On this subject a great difference is to be noted in the plumbing regulations of the vari- ous cities and states; numerous tests have been reported; and inventors have found the field of anti-siphon traps apparently most fruitful. It seemed advisable, therefore, to collect data of historical, statistical, experimental and engineering interest, to combine these with the results of experiments made under my direction, to draw certain conclusions from the entire available information, and to pre- sent the same for the information of those in- terested in this particular branch of science, especially architects, sanitary engineers, plumb- crs, and officials of states and municipalities having jurisdiction in plumbing work. HISTORICAL In about 1840 the first plumbing fixtures were introduced in Professor Longfellow’s home in Cambridge, Mass. They included water closets and a kitchen sink. The his- torian fails to state what attempts were made to exclude sewer air, described as “Effluvia,” from the professor’s house. In 1856 Charles H. Bush was granted a U. S. patent for improvements to the “Bell stench trap”; the application states: “The in- ventor does not claim as new in themselves, the perforated, plate or grating, and bell or cup with surrounding chamber and central exit pipe, arranged as described to form in combination a stench trap for sinks, as such is old and commonly known as the “Bell stench trap.” This “Bell stench trap” was an ordinary bell trap, placed directly against the bottom of the kitchen sink underneath its strainer outlet. In 1860 Alfred Carson, of New York, intro- duced an improvement on the Bell trap by attaching a miniature septic tank with a hang- ing baffle to the underside of a plumbing fix- ture. W. E. Hatfield, of Newark, appears to de- serve the questionable credit of first applying in 1862 the principle of a counterweighted flap valve, enclosed within a tight box, to the waste pipe of a plumbing fixture, which was modified in 1868 by F. H. Williams by the substitution of a spring operated concave disk. In 1872 Thomas Smith, of New York, intro- duced a hinged valve trap mechanism designed to “check wind blasts from blowing up from the sewer.” During the years 1872 to 1875, the bent pipe trap, now designated as the %4 S or S trap, seems to have made its first appearance, but who originated its use or adapted it from the old English “D” trap is not stated in any of the works which I have been able to consult. I find, however, that 1875 was the year in which the first definite recommendations were made to provide such traps with vent pipes. The 1875 to ’76 report of the Board of Health of the City of Brooklyn states that “Running traps for basins, sinks and tubs are unsafe and should never be used without a vent pipe from their highest point to the open air.” Colonel George E. Waring also recognized in 1878 the necessity of venting traps as well as waste pipes, by saying: “Such traps as are needed may be placed so close to the outlets which they guard that the length of intervening pipe shall be too little for the decomposition of its sliming to be noticeable. Every waste pipe may be venti- lated through its whole length from the soil pipe to the trap, that is by carrying an air pipe from the side of the house into the trap pipe a little above the water seal, and another pipe leading from the top of the receiver up alongside of the soil pipe out at the roof. This will secure a circulation of air at a point where it is very much needed and will much lessen the danger which we have to apprehend from kitchen sink and water closet traps as at present arranged.” It is interesting to note that in the same year Col. Waring obtained a patent on a modi- fied % S trap with enlarged outlet body con- taining a float designed to prevent entrance of sewer air, very similar in construction to de- signs patented about 5 years earlier. In 1873 Patrick W. Doherty patented a “stench trap” very similar to that used by the U. S. Housing Corporation during the recent war and now manufactured by the Sanitary Company of America, under the name of the “Saaco Anti-Siphon Trap.” In 1875 Ludwig Brandeis, of Brooklyn, de- veloped and obtained a patent on enlarging the body, but retaining the shape of the S trap. Many additional patents were issued under the names of: “Stench, Fluid, Plumbers’, Sewer Gas, Waste Pipe,” traps since 1874, among which the following few may call for special mention: Chas. W. Garland, San Francisco, Cal., 1874 and 1876. B. P. Bowers, Cleveland, Ohio, 1877. George E. Waring, Jr., New York City, 1878. Ludwig Brandeis, Brooklyn, Paragon Trap, 1878. Frank E. Cudell, 1878, 1886, 1896, 1912. Joseph Bennor, Philadelphia, Pa., 1880 (first Mercury Seal Trap). Frederick N. DuBois, New York, 1882. J. Pickering Putnam, Boston, Mass., 1884 (2 patents), 1887, 1897 and 1905. Samuel S. Hellyer, Lon- don, England, 1884. Hiram T. Bush, Detroit, Mich., Assignor to Ideal Mfg. Co., 1893. Leon- ard D. Hosford, Brooklyn, 1897. Albert S. PLUMBING FIXTURE TRAPS Newton, Providence, R. I., 1898, 1907. George Cody, New York, .Assignor to Louis Munziger, New York, 1904. (This trap is not the one now known as the “Geco” trap, but consisted of an S trap with enlarged cylindrical outlet leg, containing a baffle in front of the outlet pipe. The patentee claimed this trap to be “non-siphonable and self-scouring.’”) Among others are: Henry J. Luff, Cleveland, Ohio, 1908. George Cody, New York, March 24, 1910. (This trap is now sold under the name of “Geco.” It is described in the patent application as an “automatic anti-siphon self- scouring trap, having an inlet at the bottom and a horizontally extending outflow connec- tion from the top, the outer wall of the trap being extended inwardly at its junction with the outflow connection, and inclined continu- ously downward from said junction so as to form a combined cut-off lip and return water- shed when the trap is siphoning.”) Since 1910 there have been issued about five patents on anti-siphon traps each year to various applicants, which are, however, less important than those mentioned above, for the purposes of this treatise. In 1879, on August 26th, a patent was is- sued to John McCloskey under No. 218,891 on improvements to sewer pipe connections, which covered the system of back-venting. McCloskey, being apparently of an aggressive disposition, took steps immediately to collect the royalty from D. P. Barhydt, for using back vents in his residence at 23 E. 41st street, New York, and suggested through his attor- ney, Frank J. Dupignac, of the Equitable Building, 120 Broadway, that he should settle for the sum of $50 per line of pipe used. Mr. Barhydt, undaunted, referred the matter to the Sanitary Engineer, now the Engineering News-Record, who had their patent attorney, J. N. McIntire, investigate the patem. Mr. McIntire reported that in his opinion no one could be enjoined under the patent from the use of a venting system as then commonly em- ployed, and that the patent was perfectly in- valid. Another suit was brought by McCloskey against a householder on 54th street, James H. Young, for the use of his “patented venting system.” It seems that the patentee had been employed as a journeyman plumber by Henry McGuckin, master plumber of 951 6th avenue, in the installation of the work during the sum- PLUMBING FIXTURE TRAPS mer of 1879, just prior to the issuance of his patent. Mr. Young refused to pay, and suit was brought in the U. S. Circuit Court, South- ern District of New York; Betts, Atterbury and Betts were the defendant’s attorneys and they retained Edward S. Philbrick, C.E., of Boston, Mass., as expert. Mr. Philbrick proved that he had used the venting system in 1875 in Brookline, Mass., and again in 1876 in the home of Dwight Fos- ter, 18 Chestnut street, Boston, Mass. Mr. Philbrick testified that he had been unable to find in the patent any point or combination which he as an engineer had not previously practised. ; The plaintiff finally withdrew the suit and paid the cost of the Court. It appears from the available literature, that in about 1880 the question was first raised seriously, whether anti-siphon traps could safely supplant vented traps of the %4- S or S pattern. During this year Geo. E. Waring applied to the then existing National Board of Health for an appropriation for experimenting on trap siphonage. This was granted, and the work was carried on with some degree of thorough- ness between June 6 and December 22, 1881, as stated by Col. Waring. Col. Waring goes on to say: “Subsequently I reported my results to the National Board of Health, and the report was put in type for publication in the ‘Bulletin.’ The publication was postponed for a time be- cause the results shown and the deductions drawn were not in accordance with the theories on which the prescriptions of several Boards of Health had been based.” In these experiments Wm. Paul Gerhard assisted Col. Waring. The experiments, as described by Col. Waring, “in the interest of chronological exactness” in the “Sanitary En- gineer” of November 2, 1882, and stated by him to have been under the immediate super- vision of his assistant, William Paul Gerhard, C.E., were made in two different series. In series No. 1, the traps selected for test were attached with a “putty” joint to the end of a 14-inch lead waste pipe connected into a 4x 2 Y of the 4inch cast iron soil pipe stack. The waste pipe was provided with three vent branches located at intermedi- ate distances between the trap and the stack; w the vent branches could be opened or closed at will. The soil stack was about 15% feet high and extended at its foot by a bend and a 4inch horizontal or inclined line. About 9 feet above the 4 x 2 Y branch was placed a bathtub with a 2-inch outlet and a 1%-inch lead waste pipe, discharging °80 gallons from the tub in about 80 seconds through a 4 x 2 Y into the 4-inch stack at some distance, which is not shown, but prob- ably about 7 or 8 feet, above the lower 4x 2 Y. Still further up the stack, possibly a foot or so, although this is not stated in the records, a 4 x 4 Y was inserted, which received 214 gallons discharges from a funnel through a “Pan Water Closet” with a 4-inch lead trap having about l-inch seal. The rate of discharge is not given. The top of the soil pipe was provided with a flap valve used to close the stack wholly or partially. Also a 4-inch tinned iron pipe about 54 feet long with four bends was inserted at times into the top of the open 4-inch soil stack to provide additional length of stack. Five types of traps, namely the ordinary 14-inch S trap with seals varying from 3-inch to 5-inch, and made of glass; the Bowers trap having a ball floated against the inlet end; the Garland trap having a ball resting on the inlet by gravity; the Brandeis “Paragon” trap having an enlarged rectangular body, and the Nicholson mercury seal trap, were intended to be tested. The Cudell trap, another gravity ball trap, “arrived too late for trial,” but “‘it seemed to be the same as the Garland trap.” With the soil stack and vent branches closed, all the traps were completely siphoned, when only the bathtub full of water was discharged. With the soil stack closed, and one vent open, the maximum loss of seal of the S trap was 1 inch. The other traps were not experi- mented with. With the valve on top of the soil pipe %- inch open all around, the S trap lost 14-inch water seal, when the bath and water closet were discharged simultaneously. Under the same conditions the two ball valve traps lost no water; the others were not tested. With the soil pipe open at the top and one of the vents open, the S trap and the two ball valve traps lost no water seal; the other traps were not tested. With the soil pipe lengthened 54 feet, open ‘at the end, and no vent, water closet and bath- tub discharging simultaneously, the S trap lost 42-inch seal, the Paragon trap 14-inch; other traps were not tested. Under the same conditions, with the vent open, no loss of seal occurred in any trap; all traps were tested in this test. The second series of tests were made to de- termine if the flow of one fixture, such as a bathtub, would siphon the trap of another fix- ture, such as a basin, connected to the same waste pipe. In these tests a 14-inch lead waste pipe with a bathtub at its upper end was connected into the 4 x 2 Y used in the previous series for the connection of the traps under test. The 14-inch bath waste received a 1%-inch branch to which the various traps were connected for test, while the bathtub was being discharged. It was found that, whether the 4-inch soil stack was open or closed at the top made no difference; the un- vented S and Paragon traps were siphoned while the ball valve traps retained a sufficient water seal. The mercury seal trap was not tested. All of the experiments were made with the 2-inch funnel-shaped bath outlet, which was then changed to 1%4-inch and produced the same results. In his deductions, Col. Waring states that the opening of the 4-inch soil pipe at the top practically prevents suction in the soil pipe, even when the upper part of the pipe is 70 feet in length; that the siphoning of even unvented %4-S traps having more than 1 inch of seal need not be apprehended, if each fixture wastes by an independent outlet to a branch of a 4-inch soil pipe open at the top; that, if one fixture waste is connected as a branch to another fixture waste pipe, discharging into a soil stack, the discharge of the latter fixture may nearly or quite break the seal of an S trap on the former, unless of unusual depth; that under such conditions the seal of traps with balls, tested by him was not broken; that under the same conditions the trap with an enlarged body tested by him was not superior to the ordinary S trap. He drew the general conclusion that the separate ventilation of traps, where the main soil pipe is 4inch in diameter and open at the top, is unnecessary, especially “as it is always simpler and much less expensive to carry each waste independently to a branch of the soil pipe.” However much Col. Waring may have been searching for the truth, it is impossible to PLUMBING FIXTURE TRAPS grant that he found it, as will be readily seen in the light of present-day knowledge. No plumbing code of any city, however slack, would today approve of a system of plumbing with a 4-inch soil stack open at the top ex- tending 70 feet above the highest fixture, and receiving by individual branch wastes the dis- charges from unvented fixture traps of the %4- S or S pattern. They would insist on either vented traps of the S or 14-S pattern or on the installation of such anti-siphon traps as they might consider proper. Even those who ad- vocate the use of anti-siphon traps in place of vented traps of the S pattern would concede that unvented S or 14-S traps would be unsafe under such conditions. The Colonel’s suggestion that each fixture be connected by a separate waste pipe into the soil pipe stack, is impracticable for reasons of building construction. It is fair to conclude from the deductions made by Col. Waring that, where it is impos- sible to provide individual waste pipes to the soil stack from each fixture, and where it be- comes necessary therefore to use the same branch waste pipe for two or more fixtures, the only alternative is the use of traps with a floating or gravity ball or similar device. Nearly all standard plumbing codes and all reputable sanitary engineers will prohibit, in the light of present knowledge, the use of traps with balls or similar mechanical devices. Hence I am satisfied that experience has proven Col. Waring’s conclusions to be erro- neous in two particulars, to say the least. I do not believe that Col. Waring drew in- tentionally any conclusions favoring ball traps, but it is the fact that he was the patentee of a trap containing a mechanical device of a similar type. A comparison made between the siphonage resisting qualities of the vented S trap and the unvented anti-siphon traps in the Waring tests shows that the former could not be siphoned even with the soil stack completely closed at the roof, while the latter, even those with the ball valves, failed completely under the same conditions. So far as I am able to ascertain, the Na- tional Board of Health, for whom the tests had been conducted, never published “Col. Waring’s report. In 1882, S. S. Hellyer, of London, England, conducted an interesting series of trap siphon- age experiments, which are described in the PLUMBING FIXTURE TRAPS Sanitary Engineer, issue of August 17, 1882, Vol. VI. These tests were made with 1%4- inch, 2-inch, 3-inch and 3%-inch stacks, slop sinks, baths, lavatories and water closets, and with %-S, Bowers, Anti-D, Anti-D Narrow Band, Helmet and Eclipse traps. The experiments were very comprehensive and made with fixtures on three floors, the total height of stacks varying between 37 and 70 feet. The vent pipes were controlled by valves. Mr. Hellyer, whose experiments are referrd to by Dr. Wm. Paul Gerhard in his “Sanitary Engineering of Buildings,” as care- ful and valuable, concludes that, ‘“‘Where tiers of traps of any description are fixed upon one main pipe, for receiving discharges from water closets, slop sinks, baths, quick waste lavatories, etc., each individual trap or branch must be ventilated, if the traps upon the pip- ing are to maintain their seals intact.” It is obvious that the conclusions drawn by Mr. Hellyer are diametrically opposed to those drawn by Col. Waring, and it is interesting to note that Dr. Gerhard,* who conducted the Waring tests, considers the Hellyer tests as “careful and valuable.” Attention is called to the fact that Mr. Hellyer held an English patent on the Anti-D trap since March 25, 1880, and the American patent on the same trap was issued to him on October 10, 1884, two years after his tests re- ferred to above. In 1882 Messrs. Ernest W. Bowditch, C.E., and Edward S. Philbrick, C.E., of Boston, were retained by the National Board of Health to “conduct sundry experiments, to test the efficacy of various styles of traps used upon house drains under the varying circumstances and conditions to which they are subject in ordinary use, especially with a view to ascer- tain the liability of such traps to lose their water seal by siphon action.” These experi- ments were conducted in the Mechanics Hall, Boston, Mass. The apparatus consisted of vertical typical 2-inch and 4-inch stacks, extending 57%4 feet above the basement floor, with branches in the basement and on the floors above, and having the upper end open 8 feet 3 inches above the upper floor. The stacks extended down to a point 2 feet above the basement floor, from which they turned to a slope of 2 feet in 32 feet. The 2-inch stack was connected into the 4-inch at a distance of 51% feet from the bend along the horizontal run. A 4-inch run- vl ning trap and fresh air inlet were provided at the end of the 4-inch line. Fixtures, including water closets, bathtub and slop hopper, were connected and dis- charged into stacks on various floors; branches were provided for attaching the traps under tests; trap vent pipes were installed in the shape of pipe coils laid on the floor, and the traps tested were the S, the Adee, Cudell, Bowers and pot or round trap. The tests are described in detail in Vol. VI, 1882, August 31, issue of the Sanitary Engineer. Among the conclusions drawn by Messrs. Philbrick and Bowditch were the following: “The ordinary S trap alone with ample air vent is therefore recommended for use under water closets, and also for all other fixtures, when its proper ventilation can be secured within reasonable limits of expense. The proper size and length of such vent pipes must be largely a matter of judgment. “Whenever branch inlets are connected to a line of waste or soil pipe that is vertical or approaching that direction, above which branches other fixtures are used for discharg- ing water into the same main, there is great risk of losing water from the traps attached to such branches, whenever the upper fixtures are used. No form of trap has come to our attention without special air vent which is not likely to lose water seal under such circum- stances, even when the top of waste or soil pipe is open, except those which, like the round trap, are objectionable for retaining filth. The writer has seen them so far en- cumbered with grease as to lose most of those advantages and the ability to retain water seal. We can, therefore, recommend with less reservation the use of a well-ventilated S trap, wherever the vent pipe can be applied without unreasonable cost. The best and most simple remedy for the siphoning of traps, in most cases, is undoubtedly to be found in the in- troduction of air at the normal pressure at the crown of the trap. “There is still another risk arising from change of air pressure in drains besides that of siphoning traps. The latter is the result of lack of pressure, while an excess of pres- sure is also to be avoided.” Experiments made by the investigators are cited, which resulted in the forcible eiection of “water and foul drain air” from a base- ment trap. The National Board of Health, to whom the report was made, had as its members the surgeon-general of the U. S. Army, the medi- cal director of the U. S. Navy, the solicitor general, medical representatives of the U. S. Marine Hospital Service and of the Army and Navy, and seven physicians in private practice from New York, Boston, Washington, Chicago, Memphis, etc. In 1884, J. Pickering Putnam, architect, of Boston, Mass., claims to have been retained by the Boston City Board of Health to experi- ment and report on trap siphonage and evap- oration. His report, as published in the 1911 edition of his book, “Plumbing and House- hold Sanitation,” is signed by himself and by L. Frederick Rice. The same report, signed by both, appeared also in the American Archis tect and Building News of June 7, 1884. Henry C. Meyer, the well-known editor of the Sanitary Engineer, who was always vitally interested in all matters pertaining to sanita- tion and public health, reviewed the report in the August 7th issue of 1884, as follows: “The paper relates at length a series of experiments made upon traps of various pat- terns with the author’s deductions. As the deductions are at variance with those arrived at by E, S. Philbrick, member of the Ameri- can Society of Civil Engineers, and E. W. Bowditch, published in these columns in the report of these gentlemen to the National Board of Health, and as it tends to show the practice of ventilating traps to be a great mis- take, we have taken some pains to inquire into the nature of the investigation and the amount of weight to be attached to the de- ductions. “We find that Mr. Rice was not known by the Boston Board of Health to have taken part in the investigation, nor did this Board employ Mr. Putnam for that purpose. The idea originated apparently with Mr. Putnam, who, it seems, had invented and patented a new device for a trap and wished to test its merits as compared with other traps. He therefore applied to the Boston Board of Health, stating that he wished to make some experiments, but without mentioning that he had a patent of his own, and asked for aid in defraying the expense of necessary apparatus. The Board, wishing to make certain tests as to the efficiency of “bottle” or “pot” traps, offered aid to a limited extent for the sake of getting further information on this particular sub- ject and no other, but the Board, not being PLUMBING FIXTURE TRAPS personally acquainted. with Mr. Putnam, told him that the experiments must all be con- ducted in the presence of Mr. Philbrick and Mr. Bowditch. “These gentlemen were therefore notified and were present at a portion of the tests. But after the first test, which they witnessed, they were convinced that the apparatus used was not a fair type of ordinary good prac- tice, and so informed Mr. Putnam. Mr. Phil- brick also wrote him under date of January 18, 1884: “It seems to me that it is a very plain case that there is no practicable risk of having your new trap or either of the larger sizes of the Bottle trap lose their seal by siphon ac- tion, while new and clean, or in any condition which they are not likely to be subjected to in actual use. This being admitted, it does not seem to me of any use or of interest to the public in any way to continue the experi- ments in that line. In short, since we do not regard the loss of water seal in these traps when clean as their’ weak point, why trouble ourselves any more on such remote possibili- ties? Neither do I think it possible, by any series of laboratory tests, to develop the weak points in this class of traps, because I con- sider that weak point to be their liability to collect filth, with the several evils indirectly arising from such results. “I think, however, that the loss of trap water by evaporation is an important subject for investigation, and will try to get up a pro- gram for that with Mr. Bowditch as requested. “(Signed) Edward S. Philbrick.” “The Putnam report to the Boston Board of Health was submitted to Mr. Philbrick with request that they should sign it, which they declined to do for the reason that they con- sidered that his deductions were not war- ranted by the results. The chairman of the Board was surprised to find that the re- port presented in a prominent manner the patent traps of Mr. Putnam, of which he had never heard when agreeing to assist him with money, and advised Mr. Putnam to omit all mention of that device. _ This suggestion was not adopted, however. “Now, while Mr. Putnam is respected so far as we can learn, as an honest and upright man, we regret that such an_ investigation, which might in the hands of a man without the bias of self-interest, have produced re- sults of more value, should have been com- PLUMBING FIXTURE TRAPS mitted to any one who had an axe to grind for himself in the same connection. This cer- tainly would not have happened if the Board of Health had understood the fact that Mr. Putnam had a patent trap which he wished to test and bring into notice. The deductions of Mr. Putnam concerning inefficiency of ordi- nary vented S traps to resist loss of water by siphon action seemed to be vitiated by the fact that the apparatus he employed does not fairly represent ordinary practice. The com- bination is as follows: “A vertical soil pipe over 70 feet in height without crook or offset to break the fall; near the top a Plunger water closet having a charge of 4% gallons; 40 feet below this point a 4 x 4 Y branch, the inserted hub of which was capped and in the cap a 14-inch waste pipe inserted, to the end of which the traps to be tested were successively applied. The fall of 4% gallons passed the Y branch with such high velocity that a considerable vacuum was produced. The water seal of 144-inch S trap was broken after three suc- cessive discharges, although trap was pro- vided with 14-inch vent 17 feet long. A single discharge of the water closet, while the bath waste was running, on the same floor, broke the seal of the same trap when the same vent was attached.” “Mr. Putnam used a 4x4 Y branch capped, in which cap a small waste was inserted. This peculiar joint increased the siphoning power of a passing column of water some four fold, if not more, above what it would have been with a 4x2 Y. The power of a charge falling in the vertical pipe, to disturb the water in any trap attached to the branch, past which it tushes, depends on the following elements: 1. The volume of water passing such branch orifice. 2. Its velocity. 3. Size of side opening on branch. 4. The cubic capacity of the branch itself below the trap. “Tt is evident to any one who has watched such an apparatus in operation that the power to disturb the water in the trap on the branch waste arises not from the vacuum in the ver- tical pipe above the falling water, for the effect is made manifest before this mass of water seven feet or more in length has com- pletely passed the opening and before the time has elapsed to establish communication between the air in the branch waste and that above the falling charge of water. The effect is certain- ly due to the air which was previously in the branch being forcibly torn out by the water which rushes past it. This action is certainly just in proportion to the size of the side open- ing in the vertical pipe, and this is 4 times as large in a 4x4 Y as it is in a 4x2 Y. But the amount of disturbance of the trap water de- pends not only on the degree of vacuum pro- duced below it, but also on the volume or cubic capacity of the chamber in which such vacuum exists, 7. e., on the quantity of air which it is necessary to force through the trap to supply the vacuum and establish an equilibrium. “The criticisms we have made tend to show the importance of having all investigations of natural laws conducted by thoroughly edu- cated physicists who are quite independent of a basis of self-interest; for, however candid a man may try to be, human nature is known to be too fallible and nature’s laws too ob- scure to be fathomed by any but the most independent investigators.” It is unnecessary for me to further question Mr. Putnam’s report. Mr. Meyer performed this task at considerable length, as shown by the foregoing quotations from his periodical. I believe, however, that before passing on to further tests, it is pertinent to look into Mr. Putnam’s general scientific mental attitude on sanitary questions, as revealed in his writings. I am not surprised to find in his book pre- viously referred to, published as recently as 1911 and entitled “Plumbing and Household Sanitation,” that he is the inventor of and devotes a whole chapter of 24 pages to the description of a cast iron pipe joint made tight with ‘“‘a composition which has about the consistency of fresh putty when in the condi- tion used by glaziers, with three very impor- tant other qualities, the first being a perma- nent plasticity due to the combination in the substance of a special form of non drying oil, etc.” I find further that “sunlight is hostile to disease germs, but modern science has demon- strated that germs are, as we have seen, equally hostile to sewers and plumbing pipes, so that it is now known to be no longer re- quired for bathrooms.” Also on the same subject: “Proper artificial lighting is actually preferable.” But the worst of all: “In its fresh state sewage forms a useful food for fish.” The master plumbers of Boston, it would seem, were not satisfied with the tests and report by the patentee of the Sanitas trap, any more than Messrs. Philbrick and Bow- ditch or the Boston City Board of Health, for in 1885 they decided to experiment on their own hook under the auspices of the Board of Health and under the direction of a com- mittee of the association, of which J. O. Sisson was chairman. The tests seem to have been made in the Pierce block in Worcester, Mass. The ap- paratus consisted of a vertical 2-inch pipe, about 50 feet long, with a horizontal discharge pipe, 14 feet long, at its bottom to the sewer. The top of the 2-inch vertical pipe was con- nected into the bottom of a tank of such’ size that 2% inches of water in depth amounted to 5 gallons. The 2-inch tank outlet was fitted with a 2-inch hand operated flush valve. A 2-inch Y branch was inserted in the 2-inch vertical pipe at a point 14 feet 3 inches below the tank bottom. To this Y the traps to be tested were attached by a threaded nipple, which had a valved ventilating connection with a 1%4-inch clear circular opening ex- tended with 10 feet of 114-inch vent pipe. The traps tested were the Sanitas, Bowers, Cudell, Bennor, Bottle, Round and S traps. The tests applied consisted of successive 5- gallon flushes from the tank without refilling the traps. With the Vent Connection Closed—The Cudell, Bowers and Bennor traps were com- pletely unsealed after the first discharge. The Bottle trap, 2%4 inches diameter, 7 inches high, with 3% inches depth of seal, was unsealed by the third flush. The Sanitas trap had only a total of % gill of water and only 6 drachms left above the seal after the third flush. The Round trap, 5% inches diameter, 9 inches high, with 4% inches depth of seal, holding 244 quarts, retained 16 ounces of water above the seal after 15 or 20 flushes. With the Vent Connection Open—The S trap water seal was not disturbed. The above-mentioned tests are described fully in the Sanitary Engineer of September 10, 1885. It is interesting to note that J. Pickering Putnam claims in his book ‘‘Plumb- ing and Household Sanitation,” page 258, 1911 edition, that the seal of the S trap was “broken when ventilated through the 14-inch vent next the soil pipe.” Mr. Putnam should have known that he was PLUMBING FIXTURE TRAPS in error, since he wrote on the same subject in September, 1885, to the Sanitary Engineer, the editor of which, Chas. F. Wingate, replied to him under date of October 1, 1885, calling his attention to the fact that the test report was correct, it having been furnished him by the chairman of the testing committee. In 1886, Wm. E. Hoyt, C.E., S.B., chief engi- neer of the Buffalo, Rochester and Pittsburgh R. R. Company, delivered an address on house- hold sanitation before the Rochester Academy of Sciences, in which he described tests on trap siphonage made by J. Pickering Putnam at the Massachusetts Institute of Technology in Boston. The testing apparatus was unique and ingeniously designed, unquestionably favoring the siphonage of vented traps. It was constructed, as described and shown in a cut in Mr. Putnam’s much mentioned book, of a 4inch soil and 2-inch vent pipe stack, the former having connected to it two water clos- ets and about 10 feet lower a Y branch to which the waste pipe was attached with the S trap to be tested. Each of the two stacks were about 90 feet long made up of coils of six vertical loops of about 15 feet each with return bends at the end of each loop. The end of the 2-inch vent coil was connected into the 4-inch soil pipe coil at about its middle point by means of an inverted 4x2 Y, so that the inrushing air had to pass around this very sharp turn and in addition through 10 feet of small vent pipe of unknown size, 90 feet of 2- inch vent pipe, 45 feet of 4-inch pipe, six 2- inch return bends, one 2-inch quarter bend, three 4-inch return bends and one 2-inch quar- ter bend. The “inverted” Y branch produced, of course, a faulty installation, since it practi- cally forced the 2-inch venting system to at- tempt to draw its supply of air from the 4 inch soil pipe between this Y and the water closets, in which the air was already rarefied by the water closet discharges. What sane man, attempting to design a reasonably good plumbing system, would re-connect a 2-inch vent stack into a 4-inch soil stack by means of a 4x2 Y branch with the branch pointing downward? This is not all. The S trap under test had its inlet pipe connected into the 2-inch vent stack, that is, it was vented on the house side. No other vent was provided from either’ the waste or the trap. No wonder that the trap could be easily siphoned. PLUMBING FIXTURE TRAPS Nothing could have been done which would have more positively produced siphonage of the S trap than this, and which would have tended to mislead any but those thoroughly acquainted with the science of venting. In December, 1886, Glenn Brown, architect, of Washington, D. C., read before the Ameri- can Institute of Architects at its 20th annual convention a paper, describing a series of tests made on anti-siphon and S traps at the Museum of Hygiene, U. S. Navy Department, Washington, D. C. In his introductory re- marks he says the following: “The experiments on trap siphonage made by S. S. Hellyer, of London, and similar ex- periments conducted by Philbrick and Bow- ditch, of Boston, clearly proved the utility of trap ventilation. The reports of Geo. E. War- ing, of Newport, and J. Pickering Putnam, of Boston, as clearly (apparently) proved the uselessness of such ventilation. In the prep- aration of a work on Plumbing I found this conflict of authorities very perplexing. In fact, it was impossible for any one to form a definite conclusion on the efficiency or inefh- ciency of trap ventilation without actual ex- periment. “The difficulty and object to be attained were laid before Dr. J. Mills Browne, medical director, U. S. Navy, in charge of the Museum of Hygiene at that time. Upon consulting with the Surgeon General of the Navy, the subject was thought of sufficient importance to have a system of iron and lead pipes with fixtures erected outside of the Museum Build- ing. With these pipes I have conducted ex- periments from the fall of 1885 to the present time as opportunity would permit. The waste and vent pipes are of the sizes used and ar- ranged as in common practice. The traps, on which the tests were made, were selected so as to cover the different kinds in the market, both mechanical and non-mechanical. The apparatus is so arranged that fixtures can be subjected to a strain equal to what they would receive in actual use, as well as strains more severe than they would have to withstand, ex- cept in unusual contingencies. “The points of inspection and for attach- ment of traps, are platforms located on first, second, third and fourth stories, as shown in drawing attached. By this arrangement the effect of water discharged from varying heights can be thoroughly tested in their relation to different stories of a building. There is a marked change in the effect produced in dif- ferent stories of a building by a discharge of water from the same point. “The main stack is of 4-inch extra heavy cast iron, starting at a connection with the sewer and running thence a distance of 32 feet horizontally, and 42 feet vertically to a point above the roof of the building. In the second story there is an auxiliary stack of 4 inch lead pipe connected with the iron pipe and running to a point above the roof. Both of the iron and lead pipes have running traps and fresh air inlets near their point of com- mencement with valves and screw plugs, by which they can be partially or completely closed as desired. By means of a Y branch the system can be made to empty into the sewer without passing these running traps. Kither outlet can be used at pleasure, both being governed by gate valves. “Two stacks of 3-inch vent pipe, one of iron and the other of lead, run vertically from the second story to the roof, thence horizontally along the roof. By means of plugs and valves, the lengths of vents may be varied from a few feet to 42 feet and openings from 0 to 3 inches. The outlets in both soil and vent pipes are so arranged that traps from 14-inch to 4-inch can be attached at pleasure, all outlets not in use being cut off by gate valves or screw plugs. “Siphonage caused by the discharge of water through the trap itself from a fixture above has been found of very little conse- quence. Siphonage rarely takes place; the water passing over the long arm of the siphon rarely fills the pipe so as to cause the neces- sary vacuum. When it does take place, the trap fills by drainage from the fixture above. Back pressure which comes from sewers would never force the seal of the trap in a house plumbed according to modern practice, the fresh air inlet and the top of the soil pipe being always left open. “The greatest danger arises from the dis- charge of large bodies of water down long vertical 4-inch pipes. This column acts to a certain extent like a piston, compressing air in front of it, and creating a vacuum behind. The air rushing in to fill the vacuum, forces or drains the water from the trap into the soil pipe, while compressed air finds its easiest mode of escape through the traps below the point of discharge, even when there is a fresh air opening between the running trap and the house. Although water in case of back pres- 10 sure is drawn up into the pipe or fixture above the trap and then returns to the trap, the sewer air passes into the house. “The majority of experiments have been made to test the power of the traps to resist siphonage and back pressure produced by the column of water passing down the vertical pipes. The question of first importance is: Does ventilation protect the seal of traps in ordinary use? This question is answered by the following experiments, in all of which the vent pipes were open, and a positive effort was made to break the seal of the trap.” Any one interested in the detail experiments is referred to the Sanitary Engineer, Vol. 15, December 11, 1886, which says of the in- vestigation : “Such disinterested work as is here re- ported is very creditable. Moreover, it is of value, since the investigations were evidently conducted to get at the real facts; no unusual conditions were arranged, and no misleading conclusions are drawn. As was to have been expected, the results of Philbrick and Bow- ditch in their investigation for the National Board of Health have again been reached. Mr. Brown, like Messrs. Philbrick and Bow- ditch, had no commercial interests to serve by securing special results; consequently his ex- periments were fairly and intelligently con- ducted and his conclusions are entitled to consideration.” Mr. Brown states in his recapitulation: “T conclude. Traps, when properly vented, are not siphonable. It has been asserted that, when the vent is placed on the crown of the trap, in time it becomes choked by refuse matter adhering to the surface. In these ex- periments the vent has been put in different positions and it makes no difference in its effectiveness, as long as it is between the trap and the vertical soil pipe. With a little care the Y can be so placed and shaped that the matter passing through the pipe would not adhere to the vent.” J. Pickering Putnam dismisses Mr. Brown’s tests in his previously mentioned book with the words: “Another illustration of trap testing ap- paratus, upon which interesting experiments on siphonage have been made, is given in Fig. 263. This apparatus was used at the Museum of Hygiene, U. S. Navy Department, at Wash- ington, and they showed substantially the same results as the experiments already de- PLUMBING FIXTURE TRAPS scribed.” The author fails to even mention the name of the investigator. So far as I am able to ascertain facts with regard to conditions in New York City be- tween 1880 and 1890, I find that the first “Law and Regulations Governing the Plumb- ing and Drainage of All Buildings Hereafter Erected,” were enacted by the New York City Health Department on April 3, 1883, on au- thorization by the State Legislature in Chapter 450, Laws of 1881, passed June 4, 1881. Great credit is due to Dr. Charles F. Chand- ler, who was president of the New York City Board of Health from 1873 to 1884, inclusive. The regulations provided that “Traps must be protected from siphonage, and the waste pipes leading from them ventilated by a special air pipe, in no case less than 2 inches in diameter for water closet traps, and 114 inches for other traps”; also “That every water closet, urinal, sink, basin, washtray, bath and every tub or set of tubs must be separately and effectively trapped.” No particular type of trap seems to have been prescribed. While no record appears to be available of the tests on which these regulations had been based, I consulted Dr. Chandler personally to ascertain what steps had been taken by him in this respect prior to the preparation of the “code.” Dr. Chandler, who is perhaps in these days better known as Professor Chandler of Columbia University, told me that he had, as president of the Board of Health, obtained an appropriation from the city for experimental plumbing tests, and that he had caused to be installed an actual plumbing system in the New York City Board of Health office in the eighties for testing purposes, which system, he said, was fitted with glass traps. He concluded from his experiments that the protection of the health of the people of New York City demanded the back-venting of each fixture trap. Professor Chandler expressed it as his opinion that the general introduc- tion of unvented anti-siphon traps in New York City would be most unfortunate and ill-considered, because of their tendency to foul, their subsequent loss of siphonage re- sisting qualities, the danger of back pressure with resulting “blowing” of traps, in plumbing systems without back air pipes, and the in- creasing menace of pipe corrosion which will necessarily follow the decrease in pipe ventila- tion. Tests of anti-siphon traps have been made PLUMBING FIXTURE TRAPS or witnessed by the chief plumbing inspectors of various cities, but they have, as a rule, not been published. I have made inquiry by cor- respondence with the chief plumbing inspec- tors of about 185 cities in this country exceed- ing 35,000 population as estimated from the U. S. Census, what, if any, trap tests had been made or witnessed by them. Ninety replies were received, of which 16 were afhrmative, the balance negative. Out of these 16, there are 13 which, apparently because of the test results, prohibit the general use of unvented anti-siphon traps, namely: Newark, N. J.; Elizabeth, N. J.; Elmira, N. Y.; Altoona, Pa.; Worcester, Mass.; Akron, Ohio; Cleveland, Ohio; Chicago, Ill.; Washington, D. C.; Davenport, Iowa; Oakland, Cal.; San Antonio, Texas, and Portland, Ore., with a total re- ported population of about 5,925,000 people. The three cities, in which tests were re- ported to have been made, and which now per- mit the use of certain unvented anti-siphon traps, but also under restrictions as to dis- tance from the soil or waste stack, are: Hol- yoke, Mass.; Springfield, Mass., and Richmond, Va., with a total reported population of only about 365,000 people. The anti-siphon traps which were approved on the basis of the tests in one or more of the three cities mentioned are: The Connolly, Dome or Drum, Newton, Sanitas, McAuliffe, Positive, Radcliffe, Imco, Wolverine, Hajoca, Monarch, Femco, Paragon and Novis. While the city of Springfield, Mass., ap- proved 13 different anti-siphon traps for use, the chief plumbing inspector, Frank W. Tower, states that the experience in Springfield with 10 of the approved traps has been so unsatis- factory that their use has been discontinued. It should be noted that the “Geco” trap, which the Board of Standards and Appeals has approved for use in New York City, is not included in the traps which were approved by the three cities named. It would be too lengthy to describe in de- tail all of the tests reported to me to have been made or witnessed by the chief plumbing inspectors of the 16 cities, but the tests made for Chicago, Ill.; Davenport, Iowa; Washing- ton, D. C.; Cleveland, Ohio; Elmira, N. Y.; Richmond, Va.; Springfield and Holyoke, Mass., are of particular interest, and are there- fore hereinafter briefly explained. In addition thereto, tests made for the students of the In- ternational Correspondence School at Scran- 11 ton, under the direction of T. N. Thomson, consulting engineer, also one he observed in Wilkesbarre, Pa., should be briefly referred to. The city of Rochester, N. Y., has also, perhaps more extensively than other cities of its size, conducted tests on anti-siphon traps which will be considered more in detail hereafter. Chicago, Ill. tests reported from memory by Thomas J. Claffy, assistant sanitary inspec- tor. Tests were made in 1906 under the super- vision of Chief Sanitary Inspector Perry L. Hedrich on the following traps: Sanitas, Clow, Whiteford, L. Wolff Mfg. Co. “A tank containing at least 15 gallons of water was connected to a vertical 14-inch waste pipe with a quick opening valve near the bottom of the tank. About 10 feet below the tank a 114-inch tee was placed to which the traps to be tested were connected. A ver- tical extension of about 20 feet was connected to this tee and emptied into a trough below. The trap was filled with water to the level of its outlet and the depth of the seal measured. By opening the valve wide and emptying the tank, the vacuum was formed in a long waste pipe and the loss of trap seal varied from 5%- inch to 1%4-inch. Repeated discharges from the tank lowered the trap seal to almost the vanishing point in some traps.” Richmond, Va., reported by Thomas M. Landers, chief plumbing inspector: “The first anti-siphon trap that was tested was a New- ton trap, manufactured by the Providence Steam Trap Co., of Providence, R. I., about 20 years ago. This trap was tested at their factory in Providence at that time under my personal inspection. “As a description of the test made, I will say that there was a large tank erected on the roof of the building and elevated with a capac- ity of, say, about 75 gallons, filled with water. Connected to the bottom of the tank was a 14-inch iron pipe, say about 40 or 50 feet in length, extending to the yard below. To the best of my memory. the pipe ran across the roof of the building some distance, with 2 ells, to get to the outside of the building, and thence down the side of the building to the yard below. About two feet below the bottom of the tank was inserted a quick opening valve with lever handle. About a foot or so below the valve there was installed a Y branch, and into this was screwed a 114-inch Newton P trap with a Mica window soldered to the por- tion of the trap on the outside that holds its seal. The quick opening valve was then opened full, and the pressure of water from the tank flowed through the pipe, and the effect of the action of the water seal on the trap was watched. It was found, after several tests of this kind were made, that the seal was not broken, and it was impossible to break the seal. Naturally, in testing an anti-siphon trap, some of the water seal may be lost in making the test. In fact, all I have ever tested, would lose a little of the seal, but not sufficient to break it. “This is a description of how our first trap was tested out, and all the other traps that the Plumbers’ Examining Board and myself have approved, were tested in a manner similar to that, but they were all tested here in this city of Richmond.” Davenport, Iowa. Tests reported by Otto Meinert, inspector of plumbing, as follows: “One of the tests was made by installing a line of 14-inch pipe, connecting a lavatory on the first floor and on the second floor, and filling the bowls with water and discharging them at the same time, and both of the traps siphoned, using the Bowers anti-siphon trap. “Another time a 114-inch pipe was used and the same result occurred. On another occa- sion I connected an anti-siphon trap to a bath- tub and filled same with water, and when it was discharged the trap had siphoned. “In another case, a sink was installed with one of these traps, which was 14 feet from a 2-inch vent stack going through the roof on a one-story building, and when the sink was filled with water this trap siphoned. This would always happen on wash days, and from all of these experiences I am more than satis- fied that there is nothing like the pipe traps which are vented.” Washington, D. C. Tests reported by A. R. McGonegal, inspector of plumbing, office of the Engineer Commissioner of the District of Columbia, as follows: It is perhaps regret- table that we have kept no record of tests of anti-siphon traps, but the idea we had in mind was two fold: “1. Not to have a written record which might crop up some time to embarrass the manufacturer of a trap that failed, and “2. In case one did pass, not to have a written record which might be availed of for advertising purposes. Therefore, each trap was tested when submitted, usually in the PLUMBING FIXTURE TRAPS presence of the manufacturer’s representative, and he was told of its failure there. “The majority of the tests were made through the medium of an old tank and a 1%4- inch galvanized pipe with a full opening valve (throttle type), a 114-inch long turn recessed TY, 5 feet below the tank for connection of the trap, and 30 feet of 14-inch galvanized pipe straight down with a free opening at the bottom. The normal test consisted of three intermittent discharges of five seconds each, and any trap which failed to have half he regulation seal requirement (7%-inch) left, was not passed. Two makes came pretty near passing, and at the request of their makers they were tested over and over again, but their average remained slightly under 44-inch, therefore all were classed as failures. No tests or conditions were made or created rela- tive to back pressure. “For a short period, instead of the apparatus described above, we availed ourselves of the proximity of an air compression plant, and used a reducing valve and a direct blow of air on the fixture opening of the trap of 14% pounds, for 5 seconds, and the results were about the same as with the other. “I realize that there are occasions when it is an impossibility both financially and practi- cally to obtain a vent for a fixture found to be necessary, such as a basin in a barber shop in a many storied fireproof building, and a resealing trap is the remedy, if some compe- tent official could designate the manner of its connection so as to be assured of its air relief by two or more different lines, but even then their use is questionable.” Cleveland, Ohio. Tests reported by Chas. A. Rainger, chief inspector of plumbing, as follows: “Some recent tests were made under the supervision of Henry J. Luff at the Case School of Applied Science, consisting of a 10- foot leg with a quick-acting valve on the ex- treme lower end, the trap being attached to the upper end, and the whole line and trap filled with water and discharged by opening the valve. “These tests I kept no record of, as I con- sidered that they were of no value, because of the fact that there was no discharge of water through the trap, but simply a discharge of water contained in the trap and line. The discharge line in this case was semi-vertical.” Elmira, N. Y. Tests reported by Edgar E. Kroul, inspector of plumbing, Board of Health, PLUMBING FIXTURE TRAPS as follows: “The test made here a number of years ago consisted of an oil barrel placed on the roof of a four-story building; connected to same was a 2-inch pipe running down the rear of the building with a connection left at the first floor for connecting the different traps; above the said connection a quick opening valve was placed and below the connection the pipe was continued down about 10 or 12 feet. The water from the barrel was given a good start down the pipe and then the valve was closed quickly, and no unvented trap could stand the test.” The Elmira plumbing code now recognizes separate back-venting for all fixture traps only, except in unusual instances. Wilkesbarre, Pa. Anti-siphon trap tests were made for this city and witnessed by T. N. Thomson, consulting engineer, Scranton, Pa., and chief of the staff of instructors in plumbing of the International Correspondence Schools at Scranton. In these tests Mr. Thom- son states: “The trap was first connected into the side of a vertical waste pipe open at top and bottom. In this erection the trap was sub- jected only to siphonic action and performed its function well. But when an elbow was screwed on the base of the stack and several feet of horizontal waste pipe were added, this small addition was enough to reverse the test from siphonic to compression. The falling water entirely filled the horizontal waste line at base of stack, thereby preventing the com- ptessed air from escaping at the water outlet. It therefore forced the water seal of the anti- siphon trap then under test, and blew a spray high in the air of the room. The results so caused precluded, I believe, the adoption of the anti-siphon traps by the city.” Scranton, Pa. International Correspondence School. T. N. Thomson reports that he ob- served that, during heavy rainfalls, when the house sewer was running practically full and the fresh air inlet thereby closed, the air, which was sucked into the leader and forcibly driven down by the falling water column, forced its way into the house, when the traps were not thoroughly ventilated. Rochester, N. Y. While I endeavored to obtain the required information about the Rochester trap tests direct by correspondence, I failed to do so. It was therefore necessary for me to seek it elsewhere, and I was fortu- nate in obtaining it from Albert Webster, C.E., of New York City. Mr. Webster per- 13 mitted me to copy the complete information about the Rochester tests from two blueprints which had been furnished him, I understand, direct by the Rochester Examining Board, and which I also understand to be authentic and official test records. From these blueprints I gather the following information: In 1908 the Examining Board of Plumbers of the City of Rochester, N. Y., which at that time consisted of Frederick E. Fladd, presi- dent; Thomas A. Morgan; Joseph F. Mon- aghan; Edwin A. Fisher, city engineer, ex- oficio member; Frank DuMond, chief inspec- tor of plumbing, and J. Alfred O’Kane, clerk, conducted a series of siphonage tests on anti- siphon traps. The apparatus consisted of a 50-gallon tank, 10 feet above a cut-off in a 1%-inch iron pipe; 2 feet below this cut-off the traps were attached, and from the trap down to the drain was 35 feet. The tests were “5 seconds each alternating.” The “velocity of water was 18 feet per second.” The results of the tests are shown in Table A. In 1913 the Examining Board of Plumbers of the City of Rochester conducted another series of tests on other anti-siphon traps with an apparatus quite similar to that described above, except that the distance from the tank to the quick-opening gate valve is recorded as 8 feet 9 inches and from the latter to the drain as 32 feet. The record shows that the 1%-inch pipe discharged into a vertical 4-inch drain connection and that the trap connection was made to the side of the stack by means of a Y branch and 45-degree elbow. The results of the tests are shown in Table B. In connection with these Rochester tests, I desire to direct attention especially to the recorded velocity of flow, namely, 18 feet per second, which is equivalent to a rate of dis- charge of about 99 gallons per minute. I point out this most important fact for the reason that in my tests at 366 W. Broadway, New York City, as will be hereafter shown, the 144-inch Cody (Geco) trap, which in the Rochester tests retained a l-inch seal, was completely and permanently siphoned under practically the same rate of flow, namely about 75 gallons per minute. Furthermore, in our tests, this trap was connected to a 3-inch waste stack instead of a 14-inch, and the 3- inch was wide open at the top, whereas the top of the 144-inch Rochester stack was closed by its direct connection into the bottom of the tank and the quick-closing gate valve. 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Holyoke, Mass. These tests are reported by F. L. Avery, inspector of plumbing, to have been made in 1903 to 1905 as follows: “An 80-gallon tank with quick-opening valve was installed with 114-inch pipe and 60 feet drop as per sketch. This test resulted in the siphonage of all the traps, but while the water seal was lowered, several of the traps retained a seal from %-inch to 1%4-inch, and repeated tests failed to lower the seals. “Later a 90-degree ell was placed at the bot- tom of the riser with a length of pipe (about 18 feet) installed with a pitch of 14-inch per foot. The back pressure in lower trap was very pronounced, but trap still retained a par- tial seal even after repeated tests. “Again a test was made, the top of stack was extended about 6 feet and left open, and four sinks were installed to traps as per sketch. Paper was put over strainers and all sinks filled to top and let off at proper times. After repeated tests there was no appreciable lower- ing of the seals of the non-siphon traps ap- proved by this department.” The sketch referred to by Mr. Avery shows that in the first series of tests, the 1%4-inch pipe was a straight vertical line without offset, connected at its top into the bottom of the 80- gallon tank. No measurements are given on the sketch to indicate the distances of the quick-opening valve and the trap from each other or from the tank. In the third series of tests the sketch shows the four sink branch wastes to have been spaced 15 feet apart, but does not indicate the exact location of the quick-opening valve and the upper branch waste, with reference to the tank bottom, nor that of the lowest sink waste branch with reference to the 90-degree elbow at the foot of the stack. No information was given to show the rate of flushing employed during the tests. While back pressure was developed in some of the tests, to a “very pronounced” degree, the serious danger of such occurrences does not seem to have made a deep impression on those who witnessed the tests, judging from Mr. Avery’s report. It has been so definitely proven that bacteria are carried in atomized sewage, such as occurs in the blowing of traps, 15 that it should be by no means disregarded or slighted. There is a question whether the sewage blowing back into a fixture, such as a lavatory or a sink, or into a room through a water closet, may not contain small amounts at least of the discharges from the fixtures above, which might well carry fecal matter or urine, if these fixtures happen to be water closets or urinals. It is unfortunate that the Holyoke tests, similar to those in Rochester and elsewhere, were made with a 114-inch pipe stack which, at least according to the New York City plumbing code, is not used in actual practice. The absence of any information on the rates of flushing and the lengths of flushing periods makes it practically impossible to express any real opinion on the value of the siphonage tests. Springfield, Mass. The tests were made under the supervision of Frank W. Tower, chief plumbing inspector, from 1897 to 1914, inclusive. Mr. Tower gives the following information: The tests were limited to siphonage resist- ance and no tests were applied to determine resistance to back pressure. Traps were at- tached to a branch of a vertical 114-inch pipe connected at its top into the bottom of a flush tank, and tested under a 30-foot fall with three successive 12-second pulls of the tank valve, without refilling traps. The trap waste branch was formed by a threaded T-Y drainage fitting which was located about 6 inches below the tank valve. The latter was placed 18 inches below the bottom of the tank. The actual distance from the branch waste connection to the foot of the stack was 29 feet 8 inches; the tank had a capacity of 17% gallons and was discharged at a rate of about 75 gallons per minute. The tank valve was a 114-inch wheel compression type valve. The records supplied by Mr. Tower show the following results of seal left in traps after three flushes: Wolverine, 14/16-inch; Sanitas, 13/16-inch; Dome or Drum, 12/16-inch; Con- nolly, 12/16-inch; Femco, 12/16-inch; New- ton, 11/16-inch; McAuliffe, 10/16-inch; Posi- tive, 10/16-inch; Imco, 10/16-inch; Hajoca, No. 10, 10/16; Monarch, 10/16-inch; Para- gon, 8/16-inch; Radcliffe, 8/16-inch; Bowers, 2/16-inch; Cudell, 0; Clean Sweep, 0; King, 0; Centrifugal, 0. In general the Rochester and Springfield 16 tests were fairly similar, except that the Rochester distances from tank to valve, from valve to trap branch, and from trap branch to foot of stack were greater, that the Springfield flushes were of 12 seconds duration and 75 gallons per minute rate against 5 seconds duration and about 100 gallons rate in Rochester. Neither the Rochester nor the Springfield tests were made under conditions which are in any way similar to those existing in actual plumbing systems. Aside from the all-impor- tant fact that they were made on clean, in- stead of fouled traps, the use of an 1%4-inch vertical waste stack, closed at its top, intro- duces conditions which do not exist in good plumbing practice. Therefore it does not appear to me that any value whatever attaches to the tests, ex- cept only that of determining the relative siphonage resisting qualities of anti-siphon traps, when compared with each other, but not that of determining the value of unvented anti-siphon traps under actual conditions of use. It is of special interest to note as reported to me by Mr. Tower, that since 1917 the use of seven of the thirteen previously approved anti-siphon traps, namely, the Connolly, New- ton, Sanitas, McAuliffe, Positive, Radcliffe and Femco has been discontinued, and that the traps now approved are the Dome or Drum, Imco, Wolverine, Hajoca No. 10, Mon- arch and Paragon. It appears therefore that the tendency in Springfield is to gradually abolish the use of unvented anti-siphon traps. Bridgeport, Conn. During the recent war the U. S. Housing Corporation installed in some of its developments plumbing systems with unvented traps of a type similar to the old-fashioned Drum or Bottle trap. Among these developments the most notable were the apartment buildings of the “Black Rock” and the “Mill Green” groups at Bridgeport, Conn. In view of doubts cast by the city of Bridge- port on the safety of plumbing work contain- ing these unvented traps, a committee was appointed in 1919 by the U. S. Housing Cor- poration and, I understand, was liberally paid by it to undertake an investigation and cer- tain tests of, and make a preliminary report on the quality and character of plumbing work as designed and installed by its own clients, who had consistently defended it there- tofore. A final report was never rendered to PLUMBING FIXTURE TRAPS my knowledge, for the committee realized that such final report could not be made in view of the fact that its work had not been completed; indeed, it recommended that addi- tional tests and experiments should be made, which, however, it has, unfortunately, never been authorized to make. The buildings are now occupied and it is highly improbable that this important investigation, which might have been most valuable, will ever be carried to a conclusion. The city of Bridgeport was forced, I under- stand, by threat of a law suit to allow the plumbing systems to remain, on the ground of a technicality in the wording of its original formal permit, which was intended to be lim- ited to the war emergency duration, but was by a fluke left open for an unlimited period. It would be futile to attempt in this report a description of incompleted tests. Suffice it to say that the committee, consisting of Albert L. Webster, consulting engineer, New York City, chairman; Dr. Wm. Paul Gerhard, con- sulting engineer, New York City, secretary; Chas. S. Ball, chief inspector, Division of Sani- tation, Department of Health, Chicago; Nel- son S. Thompson, chief mechanical engineer, Supervising Architect’s Office, Washington, D. C., and J. W. McCarthy, plumbing con- tractor, Washington, D. C., prepared, at the request of its clients, a preliminary report which was so thoroughly limited by qualifica- tions and restrictions, and in addition thereto recommended the need of further tests and experiments, that no broad conclusions can be drawn therefrom on the merits or weak- nesses of unvented anti-siphon traps. Neither do I believe from conversations held with the chairman of the committee, that he would underwrite any conclusions of this kind. Existing Conditions in Cities of the United States —Before proceeding to the tests made in New York City, during 1918-1919, which are so intimately connected with our own investi- gations, it would seem proper and pertinent to review briefly the present conditions in other cities of this country with regard to the general use of unvented anti-siphon and vented bent tube or 14-S traps. To this end I wrote to the chief plumbing inspectors of those cities in this country outside of New York City, which were recorded in the “Stan- dard Diary” of 1919 as having in 1916 an esti- mated population of over 35,000 inhabitants: there were 185 such cities listed. A total of PLUMBING FIXTURE TRAPS 107 replies were received to the inquiries, most of which were accompanied by a copy of the plumbing code. Tabulations shown in Table C have been prepared from the material gathered in this manner. It must be freely admitted that the tables fail to show the conditions in the seventy- eight following cities, to whose chief plumbing inspectors inquiries were also sent, but from whom no replies or plumbing codes were re- ceived: Amsterdam, N. Y.; Atlantic City, N. J.; Augusta, Ga.; Baltimore, Md.; Binghamton, N. Y.; Boston, Mass.; Buffalo, N. Y.; Butte, Mont.; Camden, N. J.; Charleston, S. C.; Charlotte, N. C.; Chattanooga, Tenn.; Chester, Pa.; Dallas, Tex.; Dubuque, Ia.; East Orange, N. J.; El Paso, Tex.; Erie, Pa.; Evansville, Ind.; Everett, Wash.; Fall River, Mass.; Fitch- burg, Mass.; Fort Worth, Tex.; Grand Rapids, Mich.; Hamilton, Ohio; Harrisburg, Pa.; Haverill, Mass.; Hoboken, N. J.; Huntington, W. Va.; Jackson, Mich.; Joliet, Il.; Kala- mazoo, Mich.; Knoxville, Tenn.; Lancaster, Pa.; Lansing, Mich.; Lexington, Ky.; Man- chester, N. H.; McKeesport, Pa.; Mobile, Ala.; Mt. Vernon, N. Y.; New Castle, Pa.; New Rochelle, N. Y.; Norfolk, Va.; Oklahoma City, Okla.; Oshkosh, Wis.; Passaic, N. J.; Pawtucket, R. I.; Peoria, Il.; Perth Amboy, N. J.; Portland, Me.; Portsmouth, Va.; Provi- dence, R. I.; Reading, Pa.; Roanoke, Va.; Sacramento, Cal.; Saginaw, Mich.; St. Joseph. Mo.; St. Paul, Minn.; Scranton, Pa.; Sioux City, Ia.; Somerville, Mass.; South Bend, Ind.; Springfield, Ill.; Springfield, Ohio; Superior, Wis.; Syracuse, N. Y.; Taunton, Mass.; Topeka, Kan.; Troy, N. Y.; West Hoboken. N. J.; Wheeling, W. Va.; Wilkes-Barre, Pa.; Wilmington, Del.; Yonkers, N. Y.; York, Pa.; Youngstown, Ohio. The total population of the cities to which inquiries were sent, as given by the 1916 cen- sus estimates and the replies was approxi- mately 29,900,000; that of the cities answering the inquiries, 22,963,000. Therefore, while authentic information is available from only about 58 per cent of the total cities, it covers about 77 per cent of their population. An analysis of the returns shows the fol- lowing facts: 1. In 81 per cent of the number, and in 84 per cent of the population of the cities, un- vented anti-siphon traps are not permitted for 17 general use in new buildings. 2. In about 40 per cent of this number and about 24 per cent of this population, anti- siphon traps are not allowed, whether vented or unvented, for general use in new buildings. 3. In about 4 per cent of the number, and in about 4 per cent of the population of the cities from which information is available, are unvented anti-siphon traps permitted for general use, but with decided limitations. 4. In about 17 per cent of the number, and in about 11 per cent of the population of the cities, is the general use of unvented anti- siphon traps permitted. 5. In these cities, in which unvented anti- siphon traps are permitted, the maximum al- lowable distances from the traps to the soil or waste stacks varies from 18 inches to 25 feet; in the case of Macon, Ga., there is no extreme limit. 6. In not a single city, except New York, is only one anti-siphon trap reported approved to the exclusion of all others. 7. In not a single city is the 1% inch to 2 inch Geco trap approved by the Board of Standards and Appeals of New York City, re- ported as approved or in use. Opinions of Plumbing Officials of Other Cities About the “Geco Trap.’—Since the reports show that the “Geco” trap has not been approved by any other city in this coun- try, I had an accurate actual size sectional drawing prepared in my office and had blue- prints sent to the chief plumbing inspectors of those cities in which the reports showed the use of anti-siphon traps, whether vented or unvented, permissible. It was my purpose to ascertain, if possible, the opinions of these officials about the design of this trap. A blueprint like those forwarded to the city officials is shown in this connection. To their inquiries I received the following replies, all of which are herewith transmitted with the permission of their writers: 1. R. E. Nelson, Salt Lake City, Utah: “Our code requires all traps to be vented either on the crown or in the rough, but your trap may be used when vent pipes cannot be - installed.” 2. Inspector of plumbing, Holyoke, Mass., name withheld by request: “The writer is of the opinion that this trap would retain a water seal under any conditions to be met with in ordinary plumbing. The principles of the re- duced inlet with slightly enlarged outlet, the TABLE C a eee eee eeeeeeeeeoooaaoaooooooaaaaaaaaaeaeaeaEeeG_OOOoeaaw@a@a@=@=®=~=~ooNnuee””yS Cities Which Permit Unvented Anti-Siphon Traps for General Use. State Ga. Ga. Ta. Ky. Mass. Mass. Mass. Mich. Mich. Mich. N. J. N. Y. N. Y. Pa. R, I. Tenn. Va. dy City Macon Savannah Cedar Rapids Covington Holyoke Pittsfield Springfield Flint Bay City Detroit Trenton Niagara Falls Rochester Schenectady Allentown Woonsocket Memphis Richmond Population 69,000 85,000 50,000 57,000 72,000 43,000 130,000 35,000 45,000 1,000,000 115,000 65,000 250.000 100,000 85.000 # 45,000 224,000 163,000 Maximum Distance Approved Anti-Siphon Remarks From Stack Without Traps Vent ins Unlimited Positive Hajoca Newton McAuliffe Not stated Haines-Jones Cadbury Co. No, 22 Deep Seal 5 ft. for bathtubs Drum and laundry trays All fixture traps except drum traps used for bathtubs and laundry trays, and: ex- cept anti-siphon traps for barber shop lavatories and drinking fountains must be. vented, eee. Unvented anti-siphon traps limited to sinks. urinals and wash stands with no other fixtures on stack. 3 ft. Not stated 4 ft. 12 ft. 12 ft. Not stated Clean Sweep Barrel Drum Imco Wolverine Hajoca No. 10 Monet 8 ft. for lav.; 10 Dae ft. for bath; 25 ft. Marvel for sink; 25 ft. for Boosey washtray 3 ft. Clean Sweep Centrifugal Marvel Drum Any which do not de- pend on mechanical parts or internal parti- tions to maintain seal of trap Clark Hajoca “Any good non-siphon trap.” 8 ft. 15 ft. Not stated No anti-siphon traps officially approved, but those named are generally used. 8 ft. Dumond-Baker Cudelt Hajoca Wolverine Simplex American Pin Co. Elgin Brass Co. Shiler Buckeye Am. San. Mfg, Co. Monarch Imco deneca Public Safety Selo Oldfield Newton | Wolff Sanitas Sanito Clean Sweep Public Safety McAuliffe Woodward McAuliffe- Wanger Wolverine Centrifugal Iron Drum, partition ttern Hajoca Bath No. 10 and 20 All traps which passed the tests in Not stated Rochester are accepted in Schenectady . Monarch Hajoca Lavatory Any kind Not stated; to be ap- proved by the Inspect- or of Plumbing No specia! make Newton Monarch Hajoca Sanitas Wolverine Novis Hajoca Slop Sink According to condi- tions 15 ft. 18 ft. 16 ft. All anti-siphon traps named can be used for sinks and basins only, not for baths. a II. Cities Which Permit Unvented Anti-Siphon Traps for General, But Not Limited Use in New Work. State mW. Ind. Ohio City Decatur Indianapolis Cincinnati Population 45,000 272,000 450,000 Remarks < : Drum traps used without vents under kitchen sinks and bath tubs, under certain con- ditions. | 7 i-si S must be vented ‘‘where it shall be deerned necessary, onl shan ‘taps may be used without venting, where lines of wastes are used exclu- sively for kitchen sinks, urinals and washstand only, in such events the pipes must be increased in size, for instance not more than 4 sinks or urinals or 6 washstands to a ,3-inch, and not more than 7 sinks or urinals or 10 washstands to a 4-inch pipe “Under certain conditions’’ Newton and Centrifugal traps are permitted III. Cities in Which Non-Vented Anti-Siphon Traps Are Not Permitted for General Use in New Work. State Ala. Cal. Cal. Cal. Cal. Cal. Colo. Conn. Conn. Conn. Conn. Fila. Ga. Tl. Ind. Ta. Ta. Kan. Kan. La. Mass. Mass. Mass. Mass. Mass. Mass. -Mass. Mass. Mass. Mass. Mass. Minn. Mo. Mo. Mo. Neb. Neb. N. N. N. N. Midd Ht 8 N. Y. N. ¥ Ohio Ohio City — Birmingham Berkeley Los Angeles Oakland Pasadena San_ Francisco Pueblo Bridgeport Hartford New Britain Waterbury Jacksonville Atlanta Chicago Terre Haute Des Moines Waterloo Kansas City Wichita New Orleans Brockton Cambridge Chelsea Everett Lawrence Lowell Lynn Malden Quincy Salem Worcester Duluth Kansas City St. Louis Springfield Lincoln Omaha Bayonne Newark Paterson Albany Auburn Elmira Jamestown Utica Akron Cleveland Population 182,000 60,000 750,000 265,000 60,000 464,000 60,000 200,000 140,000 65,000 100,000 100,000 180,000 2,750,000 66,000 102,000 38,000 97,000 70,000 372,000 7TU,00U 115,000 43,000 40,000 110,000 113,000 102,000 51,000 55,000 46,000 200,000 110,000 400,000 850,000 45,000 55,000 280,000 75,000 450,000 135,000 125,000 46,000 50.000 46,000 95,000 200,000 900,000 Remarks No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented drum or any other form of anti-siphon traps may be used only where it is impracticable on account of structural features to vent traps. No anti-siphon traps allowed with or without vents, except in old buildings on 1st floor, and not in sleeping rooms. Anti-S8iphon traps not encouraged. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps alttowed only when it is impracticable to vent fixtures, such as bar wastes, or fixtures installed in center of room; deep seal drum traps are then used. No other anti-siphon trap is approved. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps (McAuliffe and Monarch) may be used only in case of re pair work when impossible to do otherwise. : No anti-siphon traps allowed without vents except where impracticable to vent: trap in additions to old work or where fixture is away from wall. No anti-siphon traps allowed with or without vents except by special permit. Sanitas, Clow, Whiteford and L. Wolff Mfg. Co. anti-siphon traps can be used only where a special permit is tssued, and in no case can an unvented anti-sipnon trap be placed more than 5 feet from its soil or waste stack connection. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Tee anti-siphon traps are allowed only in certain cases and under certain cone itions. No unvented anti-siphon traps allowed. ‘‘Ideal’’ traps approved if vented. No unvented anti-siphon traps allowed except where back venting Is impossible. No unvented anti-siphon traps allowed except where back venting is mmpossible. Unvented anti-siphon traps (McAuliffe and Monarch) may be used only in old build- ings, if vents unduly cut up the building. Unvented anti-siphon traps may be used only in very rare instances. Unvented anti-siphon traps of any make permitted for replacements in old buildings only, where plumbing was done before plumbing laws were adopted. No unvented anti-siphon traps allowed, except that any trap for upper fixtures within 2 feet from stack need not be vented. ase anti-siphon traps allowed only on temporary fixtures under some circum- stances. No unvented anti-siphon traps allowed: except in old buildings where venting is im- possible and trap not over 3 feet from stack. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps permitted on old work only; approved trap is McAuliffe, manufactured by F. W. Webb Co., Boston. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed, except in ‘‘some instances.”’ Bower, Wolverine, and Clean Sweep anti-siphon. traps allowed without vent only. where it is net practicable to re-vent. No anti-siphon traps are permitted where backventing is possible. No unvented anti-siphon traps allowed. Unvented ‘Clarke’ anti-siphon traps permitted only for basins in barber shops er for dentist chairs where fixtures are owned by the tenants. No unvented anti-siphon traps allowed. Unvented anti-siphon traps (‘‘the general type’'’) may be used on old work and in cases where basin is placed in center of floor as in barber shops. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps of the style of the Baker traps may be tised if impracticable to install a vent or for other good reasons on approval of Inspector. No anti-siphon traps allowed without vents, except that under certain restricted condi- tions centrifugal action traps may be used. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. allowed Ceili aoa BI III. Cities in Which Non-Vented Anti-Siphon Traps Are Not Permitted for General Use in New Work. Cal. Cal. Cal. Colo. Conn. Conn. Conn. Conn. Fila. Ga. Til. Ind. Ta. Kan. Kan. Mass. Mass. Mass. Mass. Mass. Mass. -Mass. Mass. Mass. Mass. Mass. Minn. Mo. Mo. Mo. Neb. xy AAA Az Hiding 4 i Ohio Ohio Ohio Ohio Ohio Ohio Ore.- Penn. Penn. Penn. Tenn. Tex. Utah vt Wash. Iv. State a et —_———————————————————— City — Birmingham Berkeley Los Angeles Oakland Pasadena San_ Francisco Pueblo Bridgeport Hartford New Britain Waterbury Jacksonville Atlanta Chicago Terre Haute Des Moines Waterloo Kansas City Wichita New Orleans Brockton Cambridge Chelsea Everett Lawrence Lowell Lynn Malden Quincy Salem Worcester Duluth Kansas City St. Louis Springfield Lincoln Omaha Bayonne Newark Paterson Albany Auburn Elmira Jamestown Utica Akron Cleveland Columbus Dayton Lorain Toledo Portland Johnstown Philadelphia Pittsburgh Nashville Houston Salt Lake City Burlington Seattle City San Diego San Jose Denver Washington, , Miami Tampa E. St. Louis Quincy Rockford Davenport Louisville New Bedford Newton Minneapolis Elizabeth Jersey City Canton Muskggee Altoona Galveston San Antonio Tacoma Racine Milwaukee Population 182,000 60,000 750,000 265,000 60,000 464,000 60,000 200,000 140,000 65,000 100,000 100,000 180,000 2,750,000 66,000 102,000 38,000 97,000 70,000 372,000 7U,0UU 115,000 43,000 40,000 110,000 113,000 102,000 51,000 55,000 46,000 200,000 110,000 400,000 850,000 45,000 55,000 280,000 75,000 450,000 135,000 125,000 46,000 50.000 46,000 95,000 200,000 900,000 260,000 175,000 50,000 192.000 308,000 90,000 2,000,000 580,000 150,000 175,000 150,000 22°000 400,000 Population 90,000 50,000 300,000 365,000 * 40,000 60,000 90,000 45,000 75,000 72,000 300,000 115,000 45,000 400,000 100,000 310,000 100,000 40,000 65,000 50,000 200.000 125,000 50.000 600,000 Remarks No unvented anti-siphon traps allowed. No unvented anti-siphon traps ollowed. Unvented drum or any other form of anti-siphon traps may be used only where it is impracticable on account of structural features to vent traps. No anti-siphon traps allowed with or without vents, except in old buildings on Ist floor, and not in sleeping rooms. Anti-Siphon traps not encouraged. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps altowed only when it is impracticable to vent fixtures, such as bar wastes, or fixtures installed in center of room; deep seal drum traps are then used. No other anti-siphon trap is approved. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps (McAuliffe and Monarch) may be used only in case of re pair work when impossible to do otherwise. No anti-siphon traps allowed without vents except where impracticable to vent: trap in additions to old work or where fixture is away from wall. No anti-siphon traps allowed with or without vents except by special permit. Sanitas, Clow, Whiteford and Ll. Wolff Mfg. Co. anti-skhphon traps can be used only wnere a special permit is issued, and in no case can an unvented anti-siphon trap be placed more than 5 feet from its soil or waste stack connection. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps are allowed only in certain cases and under certain cone itions. No unvented anti-siphon traps allowed. ‘‘Ideal’’ traps approved if vented. No unvented anti-siphon traps allowed except where back venting !s impossible. No unvented anti-siphon traps allowed except where back venting is impossible. Unvented anti-siphon traps (McAuliffe and Monarch) may be used only in old build- ings, if vents unduly cut up the building. Unvented anti-siphon traps may be used only in very rare instances. Unvented anti-siphon traps of any make permitted for replacements in old buildings only, where plumbing was done before plumbing laws were adopted. No unvented anti-siphon traps allowed, except that any trap for upper fixtures within 2 feet from stack need not be vented. Unvented anti-siphon traps allowed only on temporary fixtures under some circum- stances. No unvented anti-siphon traps allowed: except in old buildings where venting is im- possible and trap not over 3 feet from stack. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps permitted on old work only; approved trap is McAuliffe, manufactured by F. W. Webb Co., Boston. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed, except in ‘‘some instances.” Bower, Wolverine, and Clean Sweep anti-siphon. traps allowed without vent only. where it is net vracticable to re-vent. No anti-siphon traps are permitted where backventing is possible. No unvented anti-siphon traps allowed. Unvented ‘‘Clarke” anti-siphon traps permitted only for basins in barber shops er for dentist chairs where fixtures are owned by the tenants. No unvented anti-siphon traps allowed. Unvented anti-siphon traps (‘‘the general type’) may be used on old work and in cases where basin is placed in center of floor as in barber shops. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. Unvented anti-siphon traps of the style of the Baker traps may be tsed if impracticable to install a vent or for other good reasons on approval of Inspector. No anti-siphon traps allowed without vents, except that under certain restricted condi- tions centrifugal action traps may be used. No unvented anti-siphon traps allowed. unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed, except for photograph galleries, restaurant sinks and wash basins in barber shops. No unvented anti-siphon traps allowed. No unvented anti-siphon traps allowed. ° Aha? No unvented anti-siphon traps allowed except in old buildings, where venting is im- possible. : ake . . Unvented anti-siphon traps allowed only by special permission of inspector, who specifies type of trap to be used. No unvented anti-siphon traps except that drum traps may be used where venting is im- possible. No unvented anti-siphon traps allowed. : No unvented anti-siphon traps allowed except by permission of inspector. 3 No anti-siphon trap without vent allowed except by special permission, where vent in- stallation is impossible. bar sinks, Cities Which Do Not Permit Any Anti-Siphon Traps Whether Vented or Un-Vented for General Use in New Work. Remarks No anti-siphon traps allowed with or without venting. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. ‘‘All anti-siphon traps which have been submitted as such have failed to pass a test; about 50 such traps have b@en sub- mitted and tested.” No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. 3 ‘3 Vented or unvented anti-siphon traps not allowed except “‘by special permit only. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. z No vented or unvented anti-siphon traps allowed except where vents are impossible of installation. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. é No vented or unvented anti-siphon traps allowed except under certain conditions. No vented or unvented anti-siphon traps allowed. No vented or unvented anti-siphon traps allowed. PLUMBING FIXTURE TRAPS partitions acting as baffle or retarding rings and the enlarged bowl allows for a great dis- placement of water with large refill, and while under severe conditions the seal of trap would be lowered, I am of the opinion that with the refill there would always be a partial seal of sufficient depth to retard all sewer air. “There might be an objection that this trap would easily stop up at partition near the inlet end, but with the submerged cleanout directly under, it is easily cleaned and has the advan- tage of keeping the stoppage in trap rather than some imaccessible point.” 3. Thos. M. Landers, chief plumbing inspec- tor, Richmond, Va.: “I will say that I am familiar with the characteristics or principles in the print of the trap that you sent me, for it is either the Sanito trap, made by The J. L. Mott Co., New York City, or its duplicate. I must say it is a very excellent trap and has given entire satisfaction.” 4. Inspector of plumbing, Bay City, Mich., name withheld by request: “I certainly would allow such a trap to be used for kitchen sinks, for I think it is as safe as any trap we are using.” 5. A. W. Young, plumbing inspector, Oma- ha, Neb.: “On old work where it is impos- sible to vent, we permit the use of anti-siphon traps, if they are approved by this department. The design of trap you submit would be per- mitted to be used where anti-siphon traps have to be used.” 6. E. F. LaForce, inspector of plumbing, Schenectady, N. Y.: “We have rejected several traps because the inlet, outlet or cleanouts are too small, and this trap seems to have sev- eral of these faults.” 7. Plumbing inspector, St. Louis, Mo., name withheld by request: “I am not willing to ap- prove same for general use in plumbing work.” 8. Thos. J. Claffy, assistant sanitary inspec- tor, Chicago, Ill.: ‘This trap has been given some consideration in the past by this office, and we are convinced that it is much like other anti-siphon traps in that it has some re-sealing features, but is not proof against back pres- sure in an unvented plumbing system. “We are convinced also that it can be si- phoned so as to lose nearly all of its seal, but aside from that, we believe that it is open to more serious objections. The body of the trap is so enlarged that the course of the stream of water flowing through it is broken, the speed of the stream slowed up considerably, and the 19 scouring action which obtains in the ordinary half S or P trap is almost entirely lost. “Experience teaches us that if this trap were used generally under sinks and similar plumb- ing fixtures through which greasy wastes are discharged, that in a comparatively short time the waterway through the body of the trap would become so filled with grease as to reduce the bore to the same size as the smallest open- ing into the trap, which would be approximate- ly l-inch. We would then have nothing but a long P trap without any of the re-sealing or anti-siphon qualities claimed, and with a large body of foul, greasy, putrid wastes on the interior. Such traps as this will not be ap- proved in this city. “The tendency now in sanitary engineering and plumbing practice is to get away from the more complicated forms of traps with their long water travel and irregularities and to stick to the simple, straight, smooth bore P or 34 S trap which has the easiest waterway, the smoothest flow and the greatest scouring action.” 9. W. T. Galloway, supervisor of plumbing, Kansas City, Mo.: “Not willing to approve trap for general use, unless same is to be vented.” 10. Wm. J. Jackley, chief inspector of plumbing, Dayton, Ohio: “It would have to be back-aired or vented.” 11. J. J. Kimley, inspector of plumbing, Quincy, Mass.: “I cannot allow the use of it without a back vent.” 12. Peter P. Griffin, plumbing inspector, Salem, Mass.: “The writer will have to with- hold further endorsement.” 13. A. R..McGonegal, inspector of plumb- ing, Washington, D. C.: “I believe it good practice to require that in every conceivable condition of service a trap shall maintain a safe seal, that it shall not have any cast par- tition between any two parts of the trap which may in even remote possibility have a sand hole, shrinkage crack or split capable of leak- age of gas or water in such manner that the efficiency of the seal can by any manner be destroyed or even seriously affected; and that it shall have no deflector capable of so direct- ing the flow of waste that there is any possi- bility of any of it falling or being directed back into the stream of waste. “This office would not approve a trap con- structed as per blueprint, even though it main- tained a seal, on account of the features of cast partition and deflector mentioned above. This 20 letter is not only my official opinion, but my personal one also.” 14. Edgar E. Kroul, inspector of jlumbing, Elmira, N. Y.: “I would not approve of any trap containing the features as shown on the above-mentioned blueprint. The trap on the blueprint has too great an amount of watez and depth of seal to be self-scouring despite its contour, except under a greater pressure than would actually occur in ordinary usage, and no trap with an 1%-inch outlet should have passages cut down to 1-inch.” 15. F. W. Cloutier, chief plumbing inspec- tor, Minneapolis, Minn.: “I would not approve for use in this city an anti-siphon trap such as shown in the blueprint, as I do not consider it designed along practical lines.” 16. Adolph Anderson, building inspector, Duluth, Minn.: “Our ordinance provides for a certain minimum size waste pipe from fixtures. A trap is part of such waste pipe and it follows from a legal point of view that the minimum area of these passages should not be smaller than minimum size of waste pipes allowed. Furthermore, our building code provides that all plumbing fixture traps must be properly vented. Therefore, we must rule that these traps when no provisions are made for venting same, are not allowed in this city.” 17. John Campbell, plumbing inspector, Paterson, N. J.: “We would beg to be excused at this time from making any comment on the construction of this type of anti-siphon trap, either favorable or unfavorable, for the reason that we have not seen its operation for any length of time in general use.” 18. J. F. Dowd, chief sanitary inspector, Cincinnati, Ohio: “Permit me to say that we would not allow the use of this trap in our city for several reasons: “First. The inlet side of the trap must be the same as the outlet. “Second. Partition at ‘A’ would not be per- mitted. “Third. Partition at ‘B’ would not be per- mitted, as our law does not permit the use of partitions in traps. “Fourth. ‘C’ would have to be at least 11%4- inch opening. “Fifth. ‘D’ would also have to be a 11-inch opening; in other words, our code does not permit the trap to be decreased in any part of the bore; it must be the same bore as the out- let side of the trap.” 19, John F. Smith, plumbing inspector, PLUMBING FIXTURE TRAPS Jamestown, N. Y.: “We do not use anything but the centrifugal action pattern.” 20. F. W. Connolly, chief plumbing inspec- tor, Rochester, N. Y.: “The Board does not ap- prove of traps having partitions.” 21. Winfield S. Reed, supervisor of house drainage, Philadelphia, Pa.: “I beg to say that I am personally opposed to any trap that has ary restriction in the interior of the appliance. “The obvious intent and purpose of a waste connection is to remove sewage. It is unques- tionably good practice to remove it from the fixtures as rapidly as possible. With this end 1/2" IRON PIPE THREAD CLEANOUT Cross Sectional Diagram of the “Geco” Anti- Siphon Trap in view, certain size of pipes are designated and required specifically for the fixture to be drained. I am therefore of the opinion that it would be decidedly inconsistent to designate the size of a waste pipe 14-inch in diameter and a trap of similar size, and then restrict the area of the interior at certain points, which no doubt would have a retarding influence on the discharge. Again I question the effect it would have on the scouring of the trap, which occurs in a trap of uniform diameter. “In view of the foregoing, therefore, I should not approve of the use of the trap referred to.” 22. Chas. A. Rainger, chief inspector of plumbing, Cleveland, Ohio: “This trap posi- tively would not be allowed in Cleveland, as it PLUMBING FIXTURE TRAPS conflicts with several sections of our code; one being that there is a material reduction of the Pipe area in the direction of the flow and zn- other being that the cleanout must be same size as the largest area of the trap. I also note in the construction of the trap that it has what we would term a concealed interior partition, which in case of defect, would greatly reduce the seal. “T do not believe that this trap has many good features to recommend it, and certainly not any that would commend it as a proper fixture trap to install without proper venting.” 23. Chas. A. Hallgring, chief plumbing in- spector, Newark, N. J.: “We do not approve of any trap which is less than 1% inches in diameter. “Traps with interior chamber or mechanism are prohibited. The trap which you show with its reduced diameter and baffle partition I would consider a violation of our code and would not approve its use.” 24. Arthur C. Shaver, inspector of plumbing, Pasadena, Cal.: “Personally I would not ap- prove the New York pattern for general use 21 in plumbing work without taking the same pre- cautions that would be necessary with an ordi- nary % Strap. Partition is more or less an un- known quantity. With a concealed partition of this kind there is always the possibility of a poor casting, and a whole or a part of the par- tition omitted. The centrifugal motion of the water in the trap, caused by partitions A and B, will cause lint, string, hair and other foreign substances to be rolled into a ball, and in time close the trap entirely. I have seen this happen many times when the so-called centrifugal trap was used in connection with the laundry tray or lavatory. When the New York trap is new and clean it will withstand siphonic action, or re-seal itself under ordinary conditions, but in my opinion with continuous use, the trap will foul and have no more siphonic qualities than the ordinary % S trap.” 25. Thomas N. Thomson, consulting engi- neer, Scranton, Pa., and former director of plumbing course, International Correspondence School: “The projecting partition A being con- cealed, is of a character that is subject to sus- picion. It may be cast with a blow-hole Cities Which Would Permit the Geco Trap Without Venting for General Use Name Population Holyokes Mass: sit. soicamna eerie es 72,000 Richmond): Vas asc. can sw ena aencnen 163.000 Bay City, Mich» (23 225) needless on 45,000 Total (sieve ins sie saartn Saaeek ae ee 280.000 Cities Which Would Permit the Geco Trap with Venting Only Name Population Springfield, Mass. ................... 130,000 Kansas::CitysMoe. & rocc a eadennaae o03 400.000 Dayton, Ohio: asics na deknedeeces 175,000 Oiincys Mass: 4.04 een seed 55,000 Duluth Minn: swat anasceieiutacs sen 110,000 Pasadena; Gals iseeccnseateeucetnes: 60,000 Total. scsesaceaes ia es caeicns ous es 930.000 Cities Which Would Permit the Geco Trap Without Venting for Emergency Only Name Population Salt Thake: Gity;- Utah oscb.5..s Rte vee & | aa vege Te o | 8 | SG ~ t | i HP ts | eee TRL S { i iO) Pett | THRE Bh | | i Iwate 1/09 7o dor ym Einuedy, | f uw } + fee f Set Eee i: Seer + Ise yeaa LY | PO/ dae BOAPG ISNT | | SPLOIAD 7, PUES BOIDY DENT iv r or S o ST o/ 2 o 7 | SnEuIITEHtETHT | ta Peer t eG Fe ai f 1 { f i YWEDRLS (109 40 doy 4a b6uluadg 2 RB YUYEY [P2Q. 42 SPY; PLUMBING FIXTURE TRAPS | Discharae Cecrad, We Tt Qpening ot Jap of Sal! rack a sub iL fel Discharge Faryad ia) Dischame Ee 17 (4) Consecutive Tests of 5 Seconds’ Duration of 1¥-Inch Hydric Trap with Various Rates of Discharge and Sizes of Opening at Top of Soil Stack air through it; and no plumbing system hav- ing such small trap seals would withstand even a ridiculously lax smoke test. It will be noted further that the least severe conditions under which the Geco trap seal was destroyed were those having a 1-5/16-inch soil pipe aperture and a 150 gallon per minute flushing rate; the U. S. Housing Corporation trap yielded under the still less severe con- dition of a 4-inch stack opening and a 150 gal- lon per minute flushing rate; the vented %S trap seal was broken only with a 9/16-inch siack opening and a 300 gallon per minute flushing rate. A few words should be said at this point about the degree of severity of the tests to which the traps were subjected. To me they ac not appear as excessively severe, but in- tensely practical, for the following reasons: 1. The flushing rate of 150 gallons per minute (equivalent to 244 gallons per second) represents the simultaneous discharge rate of only 2 siphon jet or siphon action water closets, supplied with the usual type of flush valves which operate at a rate of about 1 gal- lon per second. The actual rate of discharge from a water closet into the soil pipe exceeds the inflow rate of 1 gallon per second into the water closet bowl, since the latter dis- charges during its action not only the inflow, but in addition thereto its own contents. The outflow is thereby increased over the inflow rate by about % gallon per second, and the maximum simultaneous discharge rate of two water closets becomes actually 2% gallons per second. 2. The decrease in area by hoar frost of a 4-inch soil pipe to an opening 1 5/16-inch 46 PLUMBING FIXTURE TRAPS diameter may reasonably be expected after stantly allowed by all of our able men and extended cold weather periods. prescribed by all of our progressive cities. 3. Since the traps tested were in new and Plumbing pipes and fittings, their sizes, the thoroughly clean condition their siphonage methods of joining them, are all in excess of resisting strength was at its maximum. It is their actual needs; every able architect, engi- decreased materially by fouling of the traps in neer and health official will agree that the use, and due allowances must therefore be water and smoke tests of plumbing work are made in any similar test of clean traps to pro- most essential to secure goo work, and yet no vide for this future weakness of traps after soil, waste or vent pipe system is ever exposed fouling. There are no records available to to anywhere near the water or sewer air pres- show the degree of loss in siphonage resist- sire in actual practice, to which it is exposed ing power of traps by fouling, so that no defi. in this official preliminary water test. nite estimate can be made of the proper in- It is a matter of wisdom always and invari- crease in testing requirements. ably to provide for a factor of safety, and it is 4. No engineering structures are generally tully as necessary to keep sewer air from en- considered as being properly or competently tering the building throuzh a siphoned trap aesigned unless they have a factor of safety as it is through leaky pipe joints, for both are which is usually not Jess than 1.5 nor more — unsanitary. than 4. I need not go into the fields of struc- 5. It was established that under the testing tural engineering to show this fact; in plumb- conditions as described to have existed at 366 ing engineering high factors of safety are con- W. Broadway, the breaking load of the 114- Popening at Too pt Sei, razon | | | } | PB" Opening at Yop of Sel/ Stack | t | é pa SS § i [ais 3 t fetta 3 son %. 5 | ; 2 i < gS + 2 & [eas =! fe Je |S | i f fe } peace rrr : t t Ss | | | Laschange Peryad in Seconas| ) t 1 } = 4a i { 5 t | | } 3 b t i { 1 1 i pees f LW Opentrg at Tap of Saif Steck | | 1 t %° Opehing at the of Soh ; = t eeitebes - i ; pa f } =f $ 4 | Fess | ~ as. + Leen § f ; g Mee a : & \ & iste lag oe i a + ao 1 $e ated ms aos z 4 5 N a Bee 2 \ ‘ eae < \ S. 7 t— — a Fae ® ae 3 © % Bott eases = $e £ re Abas - + ss t es $ Fe St. + es + { = Hs { f tows. 4 ae dered Sh ees Discharge rerild in Sedanae * | Aerio ia (5) Consecutive Tests of 5 Seconds’ Duration of 1%-Inch Wolverine Trap with Various Rates of Discharge and Sizes of Opening at Top of Soil Stack | PLUMBING FIXTURE TRAPS 47 a 44 wn “Opening ar Tap of Sas/ Srach. LB 9p oF oneiiag, i ‘nena | || gprs oseri7g, | : ete ar Bataan |) discharge Aeriog in Seconas | (a Hi Opening at Tan of Sol Srack, & * 2 “aches ef Seal Retained, Ne (6) Consecutive Tests of 5 Seconds’ Duration of 1¥-Inch Monarch Trap with Various Rates of Discharge and Sizes of Opening at Top of Soil Stack inch half S trap, vented by a 1%-inch con- tinuous vent, occurred with a 9/16-inch stack epening and a 300 gallons per minute flush- rate. No anti-siphon trap has developed this strength within even reasonable limits. The %S vented trap has been and is now ac- cepted country-wide as the standard require- rient; no article offered in substitution can lope to successfully compete with it, unless it proves itself equally as strong in the most vital essential, namely, power of resistance to siphonage. 6. The depth of seal of the anti-siphon tcaps exceeds that of the %S trap tested under identical conditions with one exception, the Cudell trap. Generally, this excess is quite large, as for instance in the U. S. Housing Corporation trap by 61 per cent and in the Geco trap by about 90 per cent. It is well known that an increase in depth of seal of a trap will increase its resistance to siphonage. Hence, if the vented % S trap had lad the same depth of seal as the anti-siphon traps tested, the results would have been more comparative as to actual siphonage resisting rower of the two types of traps. For this reason I have prepared a series of curves, presented on the following pages, as Charts 12 to 21, which show a comparison of the percentage losses of seal of each of the anti-siphon traps with the vented % S trap. ing Each chart refers to only one of the anti-siphon traps, and the percentage losses of this trap are shown in full lines, while those of the vented 4S traps are indicated in dash lines. Referring to chart 12 which shows the com- parison of the percentage losses of seal of the Geco trap with the vented %S trap, it will be found that this chart is divided into 4 sets of curves, each set covering one of the four rates of flushes used in the tests. In each set are plotted the curves representing the per- centag® losses of seal with the different sizes of stack openings, one curve being for each size opening, and each curve being designated with the size of opening for which it repre- sents the test results. Bearing in mind that the full line repre- sents always the anti-siphon trap and the dash the 4% S trap seal losses, it is apparent at a glance that, wherever the dotted % S trap line for any particular size stack opening is on the left of the full anti-siphon trap line for the same size stack opening, the vented 4S trap had a smaller percentage loss of seal than the anti-siphon trap, and vice versa. Further, on the left of each set of curves will be found the words, “Discharge Period in Seconds,” which is divided into 5, 10 and 15-second periods and represents the three successive flushes of 5 seconds each. As a concrete example, to determine the compara- 48 tive percentage losses of seals of the vented 45S and the Geco traps, when the discharge rate was 2% gallons per second (150 gallons per minute) and the stack opening above the roof was 1-5/16 inches, at the completion of the first, second and third 5-second flushing periods. The procedure is as follows: In the upper right of chart 12, covering the Geco trap, note the given rate of discharge of 244 g.p.s. for the series of curves marked 1-5/16-inch opening. On the left of the set of curves note “Dis- charge Period in Seconds,” for the 5, 10 and 15-second periods. To determine the percentage seal loss of the 44S trap after the first 5-sccond flush, read horizontally along the 5-second line to its intersection with the dash line marked 1-5/l6-inch opening, then downward, and read off the percentage loss of seal of the %42S trap to be twenty-two per cent. Continue again along the 5-second horizon- tal line to the right to its intersection with the full curve marked 1-5/l6-inch opening and read downward, giving the percentage loss of seal of the Geco trap as eighty-eight per cent. To determine the losses after the 2nd and f PLUMBING FIXTURE TRAPS 3rd flushes, read horizontally along the 10 and 15-second lines respectively, until they inter- sect the same curves. Note the following losses to have taken place in the various tests: After 2nd flush, 1% S trap, 27%; Geco trap, 9214%. After 3rd flush, 4%S trap, 27%%%; Geco trap, 944%. The percentage losses of other traps may be determined in a similarly easy way from the charts Nos. 12 to 21. It would lead to unwarranted lengthy tables to attempt a tabu- lation of the percentage losses of all traps, but table H gives these losses for the Geco, U. S. Housing Corporation and 4% S vented traps. From this table it is at once apparent, as it is from the curves, that the percentage losses of seal of the two anti-siphon traps were far in excess of those of the vented % S traps, so far indeed in many instances, that their in- herent weakness to siphonage, inch for inch of depth of seal when compared with the 44S trap, becomes striking and beyond doubt con- vincing. No better proof can possibly be asked than this to show the comparative inherent weak- ness of the anti-siphon type and the inherent strength of the % S vented type of traps. (7) Consecutive Tests of 5 Seconds’ Duration of 1%-Inch Cudell Trap with Various Rates of Discharge and Sizes of Opening at Top of Soil Stack PLUMBING FIXTURE TRAPS It is interesting to note from the table that in general the tests showed greater percentage losses of seal of the U. S. Housing Corpora- tion trap than of the Geco trap. It would seem therefore that the design of the former produces less resistance to siphonage, inch for inch of depth of seal, than the latter; but even the latter proved its practical worthlessness in comparison with the % S vented trap, when it lost 100 per cent of its deep seal of 4% inches as shown in the table, as against the % S trap only 25 per cent. of its shallow seal of 2% inches; the U. S. Housing Corporation trap made, as stated above, a still worse demon- stration, as shown in the table, when it lost 100 per cent. of its seal against twenty- two per cent. loss of the One-half S trap. Throughout the tests, the recorded trap seal percentage losses of the anti-siphon traps run as high as 15 times those of the vented trap seal losses. This same general condition obtained in the comparison of the percentage of trap seal losses of all of the anti-siphon traps, some showing at times slightly greater strength, at times even much greater weakness. I am satisfied that the tests showed the ab- solute incapability of the anti-siphon traps to adjust themselves to the strain of meeting the conditions of actual service; they lacked the resiliency required to fill the vacuum created in the pipe lines, without spilling their seals to the danger point. Neither can this be wondered at; water is unyielding and objects to being compressed and expanded, whereas air, supplied through the vent connection of the 1% S trap is elastic; the slightest force moves it, compresses it, ex- pands it; it rushes in when needed and re- cedes as rapidly when present in excess. I doubt, if ever any anti-siphon trap can be designed and built on otherwise scientific prin- ciples, which will have that capacity of quick adjustment to the unnatural conditions of at- mospheric positive or negative pressure, cre- ated within the drainage system of a building whenever plumbing fixtures are discharged. I say this advisedly, for I found in the 4-inch soil pipe stack at 366 West Broadway the simultaneous existence of a vacuum of 36 inches, another vacuum of 91% inches, and a positive pressure of 40 inches of water column during the same conditions of discharge and otherwise at different parts of the stack; and I found a variation of 13% inches of water col- 49 umn during the same discharge at the same location, namely, on the second floor. In a five-story building such as was used for our tests at 366 West Broadway, the atmos- pheric pressure within the soil stack, due to plumbing fixture discharges, varied from about 30 to 40 ounces positive to about an equal amount negative. This means that within the same stack of a five-story building there exist at the same time air pressures differing from each other as much as 5 pounds. It is a matter for conjecture how great this difference must be in a tall office building; and yet the “simplified plumbing” advocates would have us believe that there are traps in existence which, without special air relief or supply or vent pipes, will adapt their 4-inch to 6-inch water seals promptly, unfailingly and successfully to such tremendous air pressure variations which I doubt do not reach half an atmosphere at times, in our skyscrapers. Such statements seem to me, in the present state of the art at least, preposterous and wild. Three-Inch Waste Stack Some reasons existed why additional tests should be conducted besides thoge described. The 4-inch stack had fixture and branch con- nections on each floor below the fifth, which were thought to possibly have influenced to some extent the degree of vacuum. Also, since the first floor was occupied and was furnished with a vented toilet and vented YS trap wash basin, there were no means of ascertaining the intensity of the back pressure which we knew must exist in tne lower reaches of any soil pipe stack, the foot of which was not properly relieved by a vent line. Furthermore, it was desirable to ascertain if possible, how much of a variation of the rate or discharge through different size stacks would be required to produce complete de- struction of the seal of anti-siphon traps. For these reasons a 3-inch extra heavy cast iron waste stack was erected in the stairwell of the building at 366 West Broadway, New York City, up through the roof, and connected at its foot in the cellar by a 3-inch extra heavy cast iron line about 10 feet long, having Y-inch fall per foot and two 90-degree long sweep bends, into the 5x3-inch extra heavy Y branch of the 5-inch house drain. The de- 50 PLUMBING FIXTURE TRAPS A. Rate of Discharge=5 Gals. Per Second Name of Trap Diameter of Stack Opening After Ist Flush 4” 135/16" 1’ (GeCOR a etait ere ee ek Cece? 95.5% 97% 100% SS Te SAG eeane ok arg. oe ecraa valent vt eda a s 100% 100% 100% a Si ue iden he neuen ana webemneee es as 25% 69% Not plotted After 2nd Flush GeCO na Acar nish aire ta ahs eee re oe 100% 100% 100% WIPES ME Cee onn ont yeaa aca 100% 100% 100% DEO neat eta s each meee Aa eae 2570 88.57% Not plotted After 3rd Flush Ge6Os ae arctan BY eran age anes eee oe 100% 100% 100% WS GET Gavore tees meiapa Se ra teie aves hete eee tee mors 100% 100% 100% WIC S sou stusscsy si tala pos oie ncerenstaners aerate are 25% 91.5% Not plotted B. Rate of Discharge=2% Gals. Per Second After Ist Flush 4” 1 5/16” Is 9/16” GOCO% essed ion t ie cestou he Pea PepATA coe 35% 88% 91% 100% Wi SiH: (Gee bat ket been eck Mee. bee 93% 95.5% 100% 100% Op esc coats enone FRET ERTS a acta Sih T AT ee 11% 227% 27.5% 38.57% After 2nd Flush GeCo. ald nave t 70 : a 1 Discharge Perish jy Seconds Discharge Period in F2canas (10) Consecutive Tests of 5 Seconds’ Duration of 2-Inch Drum Trap with Various Rates of Discharge and Sizes of Opening at Top of Soil Stack ¥ Opening at Top of Soll Stack HE, (pening at Yon of Soil Stack! _ a. os pions aL > g 2 a x oes. 5 é 4 ® \ e 5 S ESS =| ae Won bicte k FP 2.5. 2 ih \Se ——— g : Nees gv V9 *y ‘ € \5 & \ g \i Bar \ he \ 0 s 10 we Fe lo es om Discharge Period 7 Secanas Discharge Period w7 Seconds. ‘Opening at top of Soil Stack ° z ‘Opening er Top of Sol) Stack. g ms a aoe. 5 i a histqeckiees = i S x. . t 5 ‘ 8 EyBEES t By i yy « i 8 2 i t } 8 i & i | | Ne PM ae a } g te. Ee oO eae 0 ve f Discharge Perrod ip Secands Lischarge Period in Seconds Ae (11) Consecutive Tests of 5 Seconds’ Duration of 1%-Inch Vented % S Trap with Various Rates of Discharge and Sizes of Opening at Top of Soil Stack PLUMBING FIXTURE TRAPS sayouyl %g=poag ‘dos § fjoy-aug ‘sayouy Wb =pag ‘dp1y 0999 “suompuoy poonuap] sapup) ‘sdo1y § f{wH-augQ youj-,[ pup 0994 youj-%J {oO poag fo sassoT asnjuaoiag fo uostupdwoy (ZL) { i | 4807) [22 fO yusDsay | 4807 709g \vo puaiay ait Te ac | oe ox Poteet, 2 | oy | a opr 26 Oe ow ( Amesnnel,/Sateteee, stiaener, aascrema. (Genarenaa {at | \ { | { pee ae v7 i : : frre } Pana ZS Ha j | | Geer EN Ay Se } 7 | aoe | tes Be. | ral SSR F | | | Fi ; 1. 8 & | He EE y : |p — 4 + t a i t - - _ sas oe | | | “A oe Nit +hyer pe sit | | } t La jae 2 E ¥ | t He [8 Wa O* & q a3 t She Ze eR Ne | ie fs | 13 wie aR i Hote Ha aes f | | | t | R Q srisites iE 1 | j| | Lo + | | 1 ! g ee = bea ; = be \z 2 BELAY ISIG JO Bi | | S26 Zi BOGS? 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Is : RQ q z Bet fi i R- | are. t 8 er Bi ae | i { Lie | } ort 4 { Is + | a Is - | Ce ' eapate ! } bie os ji | a > 1 | eer f ie { Petr STS GS TRDYING JO DP | i | SIC LF SIA PG JP ay | { i | { : sayouy Tg=ppag ‘dviy § f{ypH-2ug ‘sayouyl S;p=ppas ‘dpi onupg ‘suoiipuoy pnoiuspy sopuyy ‘sdoiy § {JOH-auQ your-Hl puv onupg youy-s{T fo jag fo sassoT aspjuadiag [0 uosiuvdwoy) (€[) uw wD (NOG fO {URIBE as at PLUMBING FIXTURE TRAPS PLUMBING FIXTURE TRAPS 56 sayouy W,g=pnas ‘doiy S fyppy-aug fsayouy %Z=]VIS ‘dpi, spnupg = ‘suompuoy pooruapl sapuyy ‘sdviy S$ [py-aug Yyouy-%{l puv sonupsg youl-%J {0 Joag fo sassoT aSpjuazsag fo uosispdwoy (Hp) 57 PLUMBING FIXTURE TRAPS Sayouyl YZ—poas ‘dosy § fyoH-aug ‘sayouy ‘diy OupAH “suomnpuog Joouuep] sopup) ‘sdoay § fpE-2uQ Youl-%] pup oupayy youy- WE = [09S HAI fo wag fo sassoy asnjuadsag {o uosiipdwoy (cy) PLUMBING FIXTURE TRAPS 9u219a]0 ff ; Steed Us=P2G “dos § {PH-2aug ‘sayouy OT /ET P=[Pag “dvsy suouipuoy poryuapy sapuf) ‘sdv1y § f{MY-2uQ youy-A] pup autsaajog youj-%y fo yoag fo sassoy aFvquads1ag {o uosiundwo0y) (9) 4807 | [Pas soyouy Wig—=poag ‘dosy § {yH-2ugQ fseyouy Yg=]r2g ‘dp1y youpuopy ‘suolipuoy Jooyuapy sapuyy ‘sdory ¢ {]MPY-aug youy-SAl pup yospuopy youy-TAT {0 wag {0 sassoT aspquaosag fo uostupdwoy) (11) aD wn PLUMBING FIXTURE TRAPS PLUMBING FIXTURE TRAPS ‘dos 12png p sayoul Hg=pasg ‘doy S fmy-2aug ‘fsayouy %~=]ve¢g suompuory poyuapy sapuy) ‘sdviy § fJMH-2ugQ youy-S,[ pun papny youp-HyJ fo poag fo sassoy aspjuaoiag {0 uosupdwoy (87) sayouy Wg=pnag ‘dosy S fwH-9ugQ fsayouy Wjpo=ypoos ‘dvi, Ooway ‘“SuorzIpuoy poijuapy sopuyQ ‘sdviy S f{joH-auQ Yyoul-Y{] pun ooway youy-%y fo pag fo sassoT aspzuaosag {0 uosiindwoy (61) et oO PLUMBING FIXTURE TRAPS PLUMBING FIXTURE TRAPS 62 : sayoul Wg=poas ‘dpiy § f{fH-aug ‘sayoul-%E= : é eee ; f fsayouy-8,¢—poasg ‘dps “d107y Suisnoy] “Ss * WIpUuoy jooyuapy] sapup) ‘sdv41y § {PH-?4O Yyoul-S4[ pun ‘dion Sursnoyy sf youl-%{I fo jas fo ee fo uostpdwoy (07) € | PSO [PRS JO ZUB1%/ eo ag oF tf i | Swe Hy Bloysog go Bay 63 PLUMBING FIXTURE TRAPS sayouy W,~—=ypoag ‘dose § f{mpyaug fsayouy OF /ET Twas “dosy wniq “suompuoy Jooyuapy sapuyy ‘sdp.ye § {mH-aug yous-I pur dpiy wnig youp-GJ {0 Joag fo sassoy aspjusoiag fo uostupdwoy) (TZ) Ort 2 YDS SWO/LDINNOD YVITZO W7 ONMONS NIVAE FSNOH NOILVAT 77 Y20/x ID//2> = rama ag oT cK Pi es ory eisppok* os F ee J004 YENOIYL VIPS /10G f~ L Q YY NOLS wag asnoy io ep Ores MH PRLS® £ SH, 40077, itt ap ob LUA LF, S007TF 15/ WO NOILIFINNO? CL TLL. YY 10/p gSuip wo AvT POM Yb 2 BM REE L/ WoRS 452 O D2] LIS LY Gupuez 1000 yy 5 SIA weuydis - yur Yay weypoouves AOA 20D PF Sday voyds- yup f Of voyeuUa? Yfood YEPory ys AY ORS vogrouvo> 2Osf =f seas GSAVKYL NOHANSS-HNE BP OF POY 1 SOO, WO TIRWLSINNOD YO TILIA ood ySno-yy Pons TAS O77 7 susay 40f AJ1Q YyIOX MaXl ul Surpping ur pazjpjisuy quawdinby BNIQNY7 HOOT! .-/ NVTS MW ON FHI sdp1f, § {JMH 2uQ pajuay, pun uoydrg-iqup ALID AW LS FOLIIT S == 615) & LSID SFINTNY AT CLINGS & OT WVIGE NY Taf SOOX NISNYH FT & AMID MOK MIN CALEMOLUSET LSIM FOL LE SOL SZ OIFINTA ONE NOHG/S-1INE OFLNIANA pares ‘ ONILSIL AOS LNIWA// aking 4422S («) 6 yen Ons ~o ces — IL WPT PF OF Ser w/ 8S 86/9" 87k ; ] | . K 2 |[% .! s Yi ZL Vy > G fo“? st ml 2” y 5 Poot Y ’ . . 2" vent pe Yi extended above 5 Yt roof same ot neigh? gS ky J Waste NY 4 r 9 * Ba lZ |\Peee| Wo Sa or MTs \ 2 Contavows Vay Waste gp Kear % See Dera / LU Pre ‘g 2 Gere J % * ‘7, e at 8 F°4 Koor cS g q Yj Y) Y * sl ; x NN ° n ‘\ wr” font: 7 ul Y | Z Li; 8 £ il PZAveor uy . Ly ‘ we Vth fh, Ah, Y 7 : Yo | er U} ‘| | | oF 4 = | PAP Fionn 8 HY Z | Ee = Law ys Drevmpge 7-1 ~ See Deters 8 4 Ly | Tt eo) ; 7 2 Sapte —> ” LM e/.0r Y 8 g WA Y WY wy Z 8 Uy ‘ ty e a Section Through Stair Well of Building at 366 W. Broadway, New York City, Showing —————————————_ 3-Inch Waste Stack and 2-Inch Vent Line 66 111 gallons per minute. The same result was obtained when the 2-inch Geco trap waste pipe was extended 7 feet from the stack with two 45-degree and two 90-degree elbows be- tween traps and 3-inch stack. The bathtub was then filled with water, the 2-inch gate on the barrel waste closed, and the bathtub discharged. A complete siphon- age of the trap seal took place as before. By repeated experiments it was found that the discharge of 35 gallons of water from the bathtub was sufficient to break the Geco seal. This discharge was at the average rate of 75 gallons per minute; also that it was broken by 5-second flushes from the bathtub, with 5- second intervals, these discharges being at the average rate of 110 gallons per minute. I am satisfied that any trap connected to a 3-inch waste stack in a five-story building, with the top of its waste line wide open, which, when brand new and clean, had its trap seal not merely decreased but entirely wiped out by the discharge of 35 gallons of water from a bathtub on a floor above con- nected to the 3-inch stack by means of a 2- inch waste pipe with a 2-inch standard %2S trap and a standard 2-inch waste connection such as is used in connection with high class bathtub work, is unsafe and unfit for use. One of the particularly interesting devel- opments of the 3-inch testing stack was its perfect demonstration of back pressure. A Geco trap with 5-inch tail piece in its inlet end was connected to the 3-inch by 2-inch Y branch on the first floor, 13 feet 9 inches above the foot of the stack. The bathtub on the roof was then discharged. The back pres- sure within the stack was so great at the first floor trap that the trap water spouted out in gushes, some of the highest drops reaching the ceiling over 6 feet above. These gushes would break up like fountains into bubbles and drops, covering an area about 4 feet in diameter. A moderately successful photo- graph of this back pressure is shown in photo designated as No. 13. This outpouring of the trap contents into the room, or rather stairwell in this instance, was unaffected by the simultaneous siphonage of the fifth floor traps. Indeed any one had by one discharge of the bathtub the opportunity of seeing both the complete siphonage of the upper floor trap and the complete breaking of the seal of the lower floor trap by back pressure. I regret PLUMBING FIXTURE TRAPS that the actual amount of this pressure was not measured. The amount of vacuum on the top floor was in excess of the capacity of the water column U tube gauge used, which was capable of registering 2% pounds. To compare the behavior of the vented 4% S trap under identically the same conditions, the Geco traps were removed from the 3-inch stack and the 3x2 branches plugged. A %2S trap was then connected to the 2-inch by 1%- inch TY on the 2-inch vent stack on the first floor (as is usual in New York City practice), and another % S trap connected to the 2-inch by 1%-inch TY in the 2-inch continuous waste and vent connection on the fifth floor. The gate valves at the foot of the 2-inch vent stack on the first floor and in the 2-inch continuous waste and vent connection on the fifth floor were then opened and the bathtub on the roof discharged. The fifth floor trap seal was lowered by only 3/16-inch, leaving 2-1/16-inch; the first floor trap was hardly disturbed, although a slight wave action was noticeable which removed about ¥%-inch of its seal. No tests were made at any time with the top opening of the 3-inch waste stack reduced in diameter. SUMMARY In summarizing I will adhere to the develop- ment of my subject, starting with the intro- duction of plumbing traps, reviewing the his- tory and present stage of trap development, referring to opinions of competent men about the Geco trap, and completing with the latest phases of the anti-syphon traps and % S vented trap tests in New York City. (A.) INTRODUCTION AND HISTORICAL DEVELOPMENT OF PLUMBING TRAPS The earliest records seem to indicate the use of the “Bell” or “Stench” trap as early as 1856 in this country, “improved” by a flap or check in 1862. The bent tube traps, D traps, Anti-D traps and similar forms appeared in about 1872 to 1875. Back-venting of traps seems to have been first agitated in 1875 to 1876 by the Brooklyn Board of Health and was recommended by Col. Waring in 1878. In 1879 unsuccessful attempts were made by a journeyman plumber to maintain patent claims on the back-venting system, The anti-siphon forms of traps with en- PLUMBING FIXTURE TRAPS larged body similar to that used by the U. S. Housing Corporation was patented in 1873. The Geco trap was patented in 1910. The first serious attempt to supplant back- venting by anti-siphon traps began by Col. George E. Waring in 1880, two years after he had patented his anti-siphon tiap. Since then there has been much confusion about the sub- ject and many attempts have been made to be- cloud the issue by those interested, and to clarify it by independent engineers who were not patentees of traps. An investigation was made by Col. Waring on the subject for the National Board of Health. It appears to have contradicted the colonel’s earlier statements about the necessity of back-venting, and the report was never pub- lished by the National Board of Health. In 1882, Messrs. Bowditch and Philbrick ex- perimented for the National Board of Health in an extensive and searching manner. These gentlemen recommended the use of back- venting. In 1882, S. S. Hellyer, of London, England, conducted a series of experiments. Although Mr. Hellyer was the patentee of the Anti-D trap, he advised the use of venting. In 1884, J. Pickering Putnam, of Boston, the patentee of the Sanitas trap, claims to have investigated the subject by experiments for the Boston City Board of Health. This board seems to have repudiated Mr. Putnam’s report because of self interest and because of the re- fusal of Messrs. Bowditch and Philbrick to co- operate with him. Mr. Putnam’s report was very strongly in favor of anti-siphon traps and the omission of back-venting. In 1885 the Master Plumbers’ Association of Boston conducted experiments of their own in Worcester, Mass., under the supervision of its chairman, J. O. Sisson. Its findings favored the use of venting. About 1884, Dr. Chas. F. Chandler, then president of the New York City Board of Health, and later Professor of Industrial Chem- istry at Columbia University, conducted ex- periments in New York City, and on their strength enforced the plumbing regulations making the individual venting of fixture traps obligatory. Dr. Chandler stated publicly that the forced introduction of an unvented pat- ented anti-siphon trap would be a crime. In 1886, J. Pickering Putnam installed an experimental testing apparatus at the Massa- chusetts Institute of Technology. The appa- 67 ratus, as illustrated in his book, shows that the trap vent connections were made on the house side of the trap under test and other irregularities which condemn the test and its results as being either incompetent or unfair. In 1886, Glen Brown, of Washington, was asked to investigate and report on the use of anti-siphon traps versus %S vented traps to the U. S. Navy Department. Mr. Brown strongly favored venting. In 1906 tests of anti-siphon traps were made urder the supervision of the Chicago Board of Health, resulting in the compulsory venting of traps. Tests were made in Washington, D. C., by the office of the Engineering Commission of the District of Columbia, on the basis of which venting was made compulsory in that district. Additional tests were made by the Depart- ments of Building in Davenport, Iowa; Elmira, N. Y., and Wilkes-Barre, Pa., resulting un- favorably to the use of unvented anti-siphon traps. The cities of Richmond, Va.; Rochester, N. Y., and Holyoke and Springfield, Mass., reported that tests were made and that the use of unvented anti-siphon traps has been permitted in these cities since that time. It is reported that experiments were also made by H. J. Luff, the patentee of an anti- siphon trap, at the Case School of Applied Science at Cleveland, Ohio; that these tests were not, however, carried on under ordinary operating conditions; they are therefore in- competent. T. N. Thomson, instructor of plumbing at the International Correspondence School, Scranton, Pa., reported on observations of actual conditions where traps were forced by back pressure because of the absence of venting. In 1919 tests were made in Bridgeport, Conn., at the direction of the U. S. Housing Corporation by a committee of five, consisting of three engineers, a plumbing contractor and a sanitary inspector. These tests were un- fortunately left incomplete. A survey of these investigations and tests shows that those made by disinterested and competent men invariably resulted in reports favoring the use of venting and the elimina- tion of unvented anti-siphon traps, except in the case of Rochester, Holyoke, Springfield and Richmond, Va. In these instances the apparatus uged for testing was not an actual 68 plumbing installation, but differed therefrom so completely that it became merely a labora- tery apparatus which undoubtedly was capa- ble of determining the relative siphonage re- sisting qualities of anti-siphon traps as com- pared with each other, but which was not fit to determine the advisability of the use of anti- siphon traps in place of vented % S traps. The reports on tests which favored the use of anti-siphon traps were made by Col. War- ing, J. Pickering Putnam and H. J. Luff. A‘ three of these men were patentees of anti- siphon traps. Tests which formed the basis of reports favoring venting systems were made by Bow- ditch and Philbrick, sanitary engineers of Bos- ton, Mass.; S. S. Hellyer, sanitary engineer, London, England; Glen Brown, architect, Washington, D. C.; Dr. Chas. F. Chandler, president, New York City Board of Health and professor of Columbia University; and the Building or Health Departments or similar official bodies of the following cities: Chicago, Ill.; Davenport, Iowa; Washington, D. C.; Elmira, N. Y., and Wilkes-Barre, Pa. In ad- dition thereto the Master Plumbers’ Associa- tion of Boston reported favorably on indi- vidual venting. (B.) PRESENT STAGE OF TRAP DEVELOPMENT By means of a questionnaire sent to the chief plumbing inspectors of 185 cities in this coun- try outside of New York City, which were re- corded in the “Standard Diary” as having in 1916 an estimated population of over 35,000 inhabitants, information was elicited about the present trap situation in cities, in number 107, having a total population of about 23,000,000. The total population of the cities to which the . questionnaire was sent was about 30,000,000, so that the replies to the questionnaire cover 58 per cent. of the number of the cities and 77 per cent. of their population. Analyses of the returns show the following facts: 1. In 81 per cent. of the number, and in 84 per cent. of the population of the cities, unvented anti-siphon traps are not permitted for general use in new buildings. 2. In about 40 per cent. of this number and about 24 per cent. of this population, anti- siphon traps are not allowed, whether vented or unvented, for general use in new buildings. 3. In about 4 per cent. of the number, and PLUMBING FIXTURE TRAPS ir. about 4 per cent. of the population of the cities from which information is available, are unvented siphon traps permitted for general use, but with decided limitations. 4. In about 17 per cent. of the number, and in about 11 per cent. of the population‘ of the cities, is general use of the unvented anti- siphon traps permitted. 5. In these cities, in which unvented anti- siphon traps are permitted, the maximum al- lowable distances from the traps to the soil or waste stacks vary from 18 inches to 25 feet; in the case of Macon, Ga., there is no extreme limit. 6. In not a single city, except New York, is only one anti-siphon trap reported approved to the exclusion of all others. 7. In not a single city is the 144-inch or 2- inch Geco trap approved by the Board of Standards and Appeals of New York City, reported as approved or in use. (C.) OPINIONS OF THE GECO TRAP An actual size blueprint of the cross section of the Geco trap was sent by me to a number of the chief plumbing inspectors of various leading cities, together with a letter request- ing them to express their opinions on this trap and asking their permission to publish their opinions, which permission was given in all cases except that request was made by a few to withhold their names. Twenty-six such replies show that the offi- cials of only three cities, with a total popula- tion of only 280,000, are apparently not op- posed to the Geco trap without venting; in only two cities, with a total population of 430,- 000, apparently not opposed to the Geco trap for emergency use without venting; of six cities, with a total population of 930,000, not opposed to the general use of the Geco trap with vent- ing; but of twelve cities, with a total popula- tion of over 8,500,000, opposed to the use of the Geco trap whether vented or unvented. It is of especial interest to note that among the latter are Washington, Chicago, St. Louis, Philadelphia and Cleveland, and that more- over Rochester and Schenectady, both of which do permit certain forms of anti-siphon traps, are opposed to the Geco trap with or without venting; so is also Cincinnati, which permits a limited use of anti-siphon traps. Springfield, Massachusetts, which has tested and approved numerous anti-siphon traps without vents, PLUMBING FIXTURE TRAPS No. 10.—The Geco Trap Ready for Testing in Building at 366 W. Broadway, New York City is also opposed to the Geco trap without venting. In addition to these opinions T. N. Thom- son, of Scranton, Pa., finds several flaws in the trap; Professor Chandler opposes its in- troduction. My own opinion of the trap per se, without any reference to the question of whether it should be vented or unvented, is that, while it has a pleasing exterior and prob- ably not an excessive depth of seal, it violates provisions 90, 100 and 112 of the New York City Plumbing Rules and Regulations as adopted by the superintendents of buildings, effective April 23, 1912, and as amended by the Board of Standards and Appeals, July 5, 1917, and December 27, 1918, effective January 27, 1919, in that it has a lower partition upon which the trap depends for its seal under cer- tain conditions, and in that it has three re- strictions in its diameter or cross-section areas, namely at the top of the inlet tube, at the bot- tom of the inlet tube and at the outlet tube. I consider that the trap offers greater resist- ance to the flow of liquids and thereby greater opportunity for fouling than a 1¥%-inch S trap. I consider that its rough interior surfaces will stimulate fouling, and that under high rates of 69 flow there will be circular eddies within the trap tending to wrap hair, lint and other fibrous materials into balls and to reject them together with other suspended substances into the contracted inlet. I estimate from the ratio of the wetted areas to the trap contents that during the same rest periods and with water containing the same percentage of grease, the thickness of grease congealed on the walls of the 144-inch Geco trap will be twice as thick as that deposited on the walls of the 1%-inch P trap. Since the velocity of flow through the P trap is about eight times as great as it is through the enlarged body of the Geco trap, there exists a considerably greater tendency for the passing water to tear away any grease collected on the No. 11—The One Half S Back Vented Trap Ready for Testing in Building at 366 West Broadway, New York City PLUMBING FIXTURE TRAPS No. 12.—Showing the Apparatus Installed on the Roof of the Building at 366 W. Broadway, New York City, Utilized for Trap Testing Purposes walls of the P trap, while it remains attached to the walls of the Geco trap. (D.) TESTS OF VENTED % S AND ANTI- SIPHON TRAPS IN NEW YORK CITY 1, Board of Standards and Appeals Tests of Geco Traps at 30 City Hall Place These tests were made informally in the afternoon of August 13, 1918, and were wit- nessed by me. They were similar to those performed at Rochester, N. Y.; Springfield and Holyoke, Mass., and like these, were en- tirely devoid of any semblance to conditions prevailing in actual plumbing. As laboratory tests they would answer per- haps to compare the siphonage resisting power of anti-siphon traps; but as a means of deter- mining their reliability in actual plumbing practice, these tests were a farce as I saw them; no attempt was made to gauge the rate of flow; the flushing periods were not even timed by a watch. . The use of a 1%-inch waste pipe is against the rules of the plumbing code, which pre- scribes not less than a 2-inch pipe. The pipe was closed at the top and open at the bottom without connection to the sewer, and thereby created conditions essentially different from those encountered in a plumbing system. It is inconceivable to the trained engineer that the greatest city in the world should have attempted to determine the reliability of an apparatus which is intended to protect man- kind against foul air produced from the decom- position of its own waste products by means of a testing apparatus erected on a fire escape entirely disconnected from a plumbing system, completely different from actual plumbing practice, not even complying with the plumb- ing code, and operated in a manner similar to that used by children playing with toys. 2. Board of Standards and Appeals in the Hallenbeck Building This test was made on May 1, 1919. It was not witnessed by me. A description of it was PLUMBING FIXTURE TRAPS No. 13.—Photo Showing Results of Back Pressure in Geco Trap Test in West Broadway Building, New York City given in the June 4, 1919, issue of the American Architect by Edward F. Hammel, formerly engineer of the board. I inspected the plumbing in the building on the following day and had photographs made of certain por- tions of it. These tests were incompetent in the following respects: a. The only Geco trap under test for siphon- age by water flushing through its waste stack was placed on the first floor, where practically no siphonic action occurs, but where the at- mospheric pressure within the stack is almost always positive, resulting in blowing the trap rather than siphoning it. b. The Geco traps claimed to have been placed on the waste pipes from flush tanks on the upper floors could not have been siphoned, because they would refill from the trickle when the flush tank was practically empty. c. The plumbing system was fitted in nu- s with unvented 4% S basin traps merous plac ; be immediately siphoned by which 71 flushes into the stack and would then act as vents, promptly relieving any vacuum which might have existed in the upper reaches of the stack. d. The connections from the flush tanks to the lead bends were made by putty joints, which are subject to air leakages. My opinion is, therefore, that these tests made by the Board of Standards and Appeals at the Hallenbeck Building showed a com- plete lack of appreciation on the part of those responsible for them of the fundamental es- sentials necessary for such tests. 3. Tests at 366 West Broadway a. 4-Inch Stack These tests were comparative tests between 10 different types of unvented anti-siphon traps and the vented 14 S trap. The anti- siphon traps held from about 4 to 6 times as much water as the % S trap and their cross sectional area is about 2 to 5 times as great. Both of these qualities increase the tendency of fouling materially. The traps were tested by flushing from a roof tank into the 4-inch stack, at the rates of 50, 100, 150 and 300 gallons per minute. They were also tested under varying conditions of soil stack openings above the roof, that is, 4 inch, 1-5/16-inch, l-inch and 9/16-inch. Dur- ing these tests the Geco trap seal was broken completely 6 times; the U. S. Housing Cor- poration trap seal 9 times; the 42S vented trap seal only once, and ‘that under the most severe conditions purposely imposed to de- termine the limit of resistance of the vented 1% § trap. The Geco trap seal was destroyed with 150 gallons per minute flushing rate and a soil pipe opening of 1-5/16-inch, while the U. S. Housing Corporation trap seal yielded com- pletely under the still less severe condition of a 4-inch stack opening and 100 gallons per minute flushing rate. Under these same con- ditions the vented %4 S trap retained 1%4-inch seal, Other anti-siphon traps behaved similarly to the Geco and U. S. Housing Corporation trap. The flushing rate, 150 gallons per minute, rep- resents the simultaneous discharge rate of only 2 siphon-jet or siphon-action water closets, supplied with the usual type of flush valves. The decrease in diameter of a 4-inch soil pipe to an opening 1-5/16-inch above the roof may reasonably be expected after extended cold weather periods. It must be borne in mind also that the traps tested were thoroughly clean and would probably have been siphoned much more easily had they been fouled by usage. All plumbing work including fixture traps should possess, similar to all engineering con- struction, a factor of safety. There is no fac- tor of safety in the Geco trap. Since the standard fixture trap the country over has been the %-S vented trap no other trap can be offered in substitution successfully which does not have at least as strong siphonage resist- ing power as the standard which it is intended to replace. The seal of the Geco trap exceeds that of the %4S trap tested by. about 90 per cent. For a comparative test a 4S trap of equal seal to the Geco trap should have been used. No reason exists why the % S trap should not have a 4%4-inch seal instead of a 2%4-inch seal. Under such conditions its strength of with- standing siphonage would have been greatly increased. Calculations and graphic determinations were made to determine the percentage of seal loss from each trap in order to compare the siphonage resisting qualities of the various traps including the % S trap inch for inch of water seal. These graphic illustrations are striking and convincing proof of the inherent weakness of anti-siphon traps as compared to the inherent strength of vented 1% S traps. Tests of the atmospheric pressures within the 4-inch soil pipe stack due to the plumbing fixture discharges indicated variations of from 30 to 40 ounces positive to about an equal amount negative, that is, total variations of from 4 to 5 pounds at different points of the stack. It seems impossible that any anti- siphon trap no matter how well designed could possibly adapt itself with its small water col- umn to any conditions within such wide limits, without the use of special and effective means for furnishing or removing air as required by the variations of the atmospheric pressures within the plumbing system. There is no doubt but that traps can be con- structed of sufficient size to accomplish this result, but they would have to be so out of proportion that they would be smal! cesspools. b. 3-Inch Stack The traps connected to this stack were PLUMBING FIXTURE TRAPS tested to determine the minimum rate of flush required to siphon them without any decrease in the size of the stack opening. It was found that the Geco trap seal was completely broken by a flushing rate of 76 gallons per minute, with a total discharge of 53 gallons from a barrel; or it could be broken completely by three 5-second flushes with an average flush- ing rate of 111 gallons per minute. The Geco trap seal was also destroyed en- tirely by discharging 35 gallons of water from Showing the Apparatus Installed for the New York City Board of Standards and Ap- peals on the Fire Escape of 30 City Hall Place Building, For Its Test August 13, 1918 PLUMBING FIXTURE TRAPS the bathtub on the floor above through a 2- inch trapped waste pipe into the 3-inch stack. This discharge was at the rate (average) of 75 gallons per minute. The vented % S trap was tested under the identical conditions as the Geco trap and other anti-siphon traps, but its seal remained at 2-1/l6-inch and could not be lowered be- lew this point in any of the tests. The 3-inch stack was also used to determine the effect of back pressure, if any, on an anti- siphon trap located on the first floor when the bathtub was discharged on the sixth floor. The back pressure was developed to such an extent that it erupted the water from the first floor trap to the ceiling, 6 feet above, covering an area of about 4 feet in diameter on the floor and leaving the trap seal destroyed. The discharge of sewage atomized in this manner by compressed air into a room is an extremely dangerous occurrence, in my .opin- ion more so than the siphonage of a trap. I do not believe that any anti-siphon trap can be made without mechanical features or with- out disproportionate size which will effectively withstand such back pressures. The vented %S trap exposed to the same 73 conditions of back pressure indicated merely a slight wave action of its seal, losing only about Y%-inch in depth of seal. In conclusion, I wish to say that any trap tests made on clean traps must always lay due stress on that fact. Nothing has been done so far as I know by other investigators to deter- mine the ratio between the siphonage resist- ing power of clean anti-siphon traps and of those fouled to such a degree that they are filled with sediment or grease with the excep- tion of a slight passageway. When these are made, a great deal more light will be shed on this subject, but I am satisfied that the tests directed by me with clean anti-siphon traps gave conclusive evi- dence of their insufficiency and inherent weak- ness and lack of resiliency to condemn them for general use in high grade plumbing work. It would be negligent of me were I to fail in expressing my gratitude to those officials of other cities and to those brother engineers, who gave expression to their views, and who so kindly furnished me with replies to my questionnaire, with copies of their cities’ plumbing codes and descriptions of their tests. STOOL. Was7nxz —] Wasy | 7va x | wae STACK STACK a ee 2” 2 “FL 00R. IVENT ees) 2 UM IS SOUL Wa LE Y FLOOR. Plumbing diagram of typica .three- story apartment house. Heavy solid lines show the soil, waste, and vent pipes required by the New York City Plumbing Code, if anti-siphon traps are installed for all of the fixtures (exclusive of water closets). The dotted lines show additional vent pipes required if 14-S vented traps are used. IFA INLET CLLLAF PLUMBING FIXTURE TRAPS 75 THE ECONOMIC SIDE OF THE PROBLEM T was intended to make this book cover only the technical or engineering proper- ties of traps, but so much stress has been laid recently on the economic side of the anti- siphon traps, and so many statements have been made and are now being made in regard to the reduction of the cost of plumbing in- stallations by the use of unvented anti-siphon traps, that it is of general interest to all con- cerned to clear up the economic question. Perhaps the most recent example of such statements in my experience occurred during May, 1921, where testimony was given by a builder before Mr. Samuel Untermyer, chief counsel for the Lockwood (New York State) Housing Investigating Committee, to the effect that the installation of approved anti-siphon “Geco” traps in a certain New York City build- ing would have reduced the cost of a plumbing installation about 50 per cent below that of a vented 14-S trap system. This assertion was widely published in the -daily press and at- tracted large attention, especially since the usual story of robbery by the “Plumbing Ring” was interwoven in the press reports. That the witness was thoroughly misin- formed on the subject of his testimony, will be clear to any one who reflects for a moment on the fact that the cost of the plumbing fixtures—that is, the water closets, urinals, slop sinks, wash basins, bathtubs, kitchen sinks, and wash tubs; of the hot and cold water supply pipes and fittings, and of the soil and waste pipe systems is entirely unaffected by the use or absence of anti-siphon traps, and remains the same, whether these or \4-S traps with vents are used. The total cost of these items is from 90 to 98 per cent. of the cost of the entire plumbing job. Furthermore, if the witness had been quali- fied to testify or had been properly informed, he would have appreciated that under the New York City Plumbing Code requirements, all water closets must be backvented, there being no approved deep-seal fixtures of this kind on the market. He would also have known that a separate vent stack would have to be installed, and that therefore the only actual saving by the use of anti-siphon traps would be the short vent branches from the fixtures (other than water closets) to the vent stack. In order to satisfy myself on the real econ- omy, if any, of anti-siphon traps as compared with 14-S vented traps, I prepared a plumbing diagram of a typical three-story apartment house, reproduced herewith, which shows in full lines the soil, waste, and vent pipes re- quired by the New York City Plumbing Code, if the approved “Geco” anti-siphon trap is installed for all of the fixtures (exclusive of the water closets), and in dotted lines the ad- ditional vent pipes required, if the 14-S vented traps are used. I submitted this diagram to three responsible New York master plumbers with the request that they estimate the costs of the 14-S traps and their vent branches as shown in dotted lines, and also of the “Geco” anti-siphon traps without vents, as permissible under the New York City Code. I asked them further to consult with each other, and to present to me, if possible, joint estimates which they would consider fair. These esti- mates were as follows: Unventep “Greco” Traps. 6—144"” Geco Traps @ $7.. $42.00 3—2” Geco Traps @ $11... 33.00 Total Cost..26.2 os .0:. $75.00 Plus 10% Profit..... 7.50 $82.50 VentTeD 14-S Traps. 24’—1¥4" Galv. Pipe @ $.18.. $4.32 9’—14” Galv. Pipe Mall. Fit- tings @ $.30.... 2.70 6—14" Brass 44-S Traps @ S130 ws sant en 7.80 3—2” Brass 4-S Traps @ G20! | ars orators 7.50 De Day Asabore. vse anedecaec 10.00 Total Gost asvescacs $32.32 Plus 10% Profit..... 3.23 $35.55 Excess Cost of Unvented “Geco” Traps Over Vented WoeS! PADS siiveuccs sc eeoess $46.95 The estimates, it will be observed, show that the actual cost to the owner, including a 10 per cent plumbers’ profit, which I asked to be included, of the vented 14-S traps, is about $50.00 cheaper than of the “Geco” unvented traps. I believe that the estimates are in- tended to be proper and are deserving of con- ~] D fidence. Assuming, however, that the labor item of the vented 14-S traps had been 200 per cent underestimated, there would still remain a balance of $25.00 in favor of the vented 14-S traps. An analysis of the estimates of cost made by the plumbing contractors, indicates that the materials required are correctly inventoried and priced, and that the labor to be performed consists of measuring and cutting 14 pieces of 144” galvanized iron pipe to lengths not exceeding 3 feet; of cutting 28 114” pipe threads, and of installing 14 pieces of 114” pipe and nine 114” fittings. The measuring and cutting should reasonably consume not over 14 hour each, or 3% hours total; the cutting of 28 threads not over 1/7 hour each or 4 hours total; the installation of 14 pieces and nine fittings not over 1/3 hour each or 8 hours total. My own estimate of the total labor required would, therefore, be 15% hours, or say 2 days, instead of 1 day, or $20.00 in- stead of $10.00; but even under this condi- tion the 144-S vented traps are about $36.00 cheaper than the unvented “Geco” anti-siphon traps. If the number of floors were increased, or the number of apartments per floor multi- plied, each requiring a similar typical plumb- ing installation, this difference would, of course, become correspondingly greater. It is evident that the greater cost of the un- vented “Geco” anti-siphon traps is largely due to the high cost of the traps themselves. PLUMBING FIXTURE TRAPS Seven dollars for a 144” and $11.00 for a 2” trap are big prices which seem unwarranted except on the ground of patent or other fees. From the representative example given, it is fair to conclude that the much-voiced opin- ion on the invariably lesser cost of unvented anti-siphon traps is not based on actual facts; there are, no doubt, certain individual cases, especially in alteration work or in small dwell- ings in which this opinion will be found to be true, but the evidence shows, particularly where the plumbing is condensed near the vertical stacks and where toilet or bathrooms are located repeatedly alike and directly over each other, as is usually the case in apart- ment buildings, hotels, and office buildings, that the 144-S vented traps are as cheap and per- haps cheaper than unvented expensive anti- siphon traps. It must be borne in mind in this connection also, that patented articles are unlimited in price and not subject to com- petition, especially where, as at present in New York City, only one such article is ap- proved for use. The chief item of-cost in a back-venting sys- tem is involved in the venting of water closets, which are not made with anti-siphon traps; these must be back vented in any event, according to most of the plumbing codes. The only additional vent pipes required, there- fore, for the other plumbing fixtures, consist of the short 1144” and 2” branches which con- nect the individual traps to the main vent stack or to the water-closet vent branch. INDEX ATR ‘Circulation’; ccc svee wanes coteecesecrs 2 Pressures: ssiitcavsecass se iveciewiaiees 5, 9, 49 Akron Ohi. is ssseanceaw ee anavataia ees 18 Albany; (NS OV oi susse ocsace cases a sieptoaleece 18 Allentowns Rae aikecccthi cov ccdwieecawe es 18 Altoona; Pas atccsieldsls ss esac eeeeteeer es 18 American Inst. of Arch’ts. ...........0.02 9 Amsterdam, Ny Yi. e.s.cce0:s cdnsasecietege. 17 Anderson; Adolph’ sis ssc-easiees eecteoaes 20 Anti-Siphon Traps, Patents On aid sets ae eer raw aeces 1; 2 Adjustment to air pressure variations ....49 See Traps, Anti-siphon Atlantic: City; Nic Jy we:scsaiaiweraeeee hess 17 Atlanta Gao acc vase ecmosovscue tuyere to ude 18 Auburn iN Ve eiuecencaaeuseewac cans 18 Augusta; “Gar. gitiasia cx soeweneweee count 17 Avery, Fac Lim accastersterneies eu iaveaismlsce epee 15 BACK Venting, Patent Claims on ........2, 3 Balls: GhasiSo convertases gre lata asiettere satars cee 16 Baltimore, «Mid *s..ccrss sotudveiestarecereuvcnees 17 Barhydt;. D3 {Pe gored siaiisecaseueeccieseg 2 Bayonne, Ni Vec waves cs cancewncees elec sees 18 Bay: Citys "Mich, cssiacieaaniccoes vas 18, 19, - Bell Sh rap rccocsisctacna tacts secant ata mane Bennior, Joseph: ws sss2 evacuees ova news s 5 Berkeley; Gals. siseccwsuensariesavevnan ees 18 Binghamton, Ni Yi. <-cseccusdeeaueetwtncas ss 17 Birmingham, “Alay siicccdvecieieiesie oe ete es 18 Boston Board of Health ........... 6, 7, 8, 67 Boston: Massy ics iecs reeeeiieacaens secs 17 Boston Master Plumbers’ ASSOCIAtION <6 6c esceecsceseae ee. 8, 67, 68 Bowers;--Bi. Pe siatitcarcscuraliasiigite ewes 2 Bowditch, Ernest W. ............ 5, 10, 67, 68 Brandeis, Ludwig .............eeceeeeeee 2: Bridgeport, Conn. ..............0.- 16, 18, 67 Brockton; Mass: 11, 15, 16 Menton Nir Dis ca cess carcveiatevaesusin as ahapectenchesarees 18 TrOys Ne Va eB Micaicancre aaa a as da taehetatonaraes 18 Traps— Anti-siphon, Ades 2 oe Pataca ee teins 5 American Pin Co. ..........0- cece ee eee 18 American Sanitary Mfg. Co. ............ 18 ATIEIED se lcesscxe osc te ayoare sus ste ested sc 5, 66, 67 Anti-D, Narrow Band ...............05 5 Bell. or: Stench: 2.20 .eceeewocowsas auc 1, 66 Bennor otaasdekeer detec owhaecon smnsadaiales 8 BOOSEY sass testa ane te auossian tee eed eae 18 Bottle: eck eraeas ceaccmeen ey oes ae 6, 8 Bowers? site's ceasing 3, 5, 8, 12, 15, 18 Buckeye Seneca Sanitary Co. ........ 14,18 Centrifugal xs > 2 i2.54 dans ce nadedcect davon 15, 18 Traps (continued) Care ince ccasstare ois ioraneetawinie, Bneestatavartedts 18 Clean ISWeep ye aanashon sess eeu asee 15, 18 ClOWees + saseetinoatinces accor oaks 11, 18 Cody ioe sca aachcrdccumenen uns ucuwoen 14 Connolly: osewestieiecnrcaenciers 11, 15, 16 Cudell ..... 2, 5, 8, 14, 15, 18, 39, 47, 48, 60 Dome? ei weiner han oeisna aioe ee 11, 15, 16 Drum) cessyraesnece's 11, 15, 16, 18, 39, 53, 63 DuMond-Baker hrccvsclccisis ices ote4sareats 18 Eclipse: ws seeacnanikiceesie deo tasnsioie aes 5 Economic Side of Anti-Siphon Traps......75 Hlgin= Brass: Cocca ssieiaiceiste a rats’ ealateniees 18 EMCO is7.cs0:b bse ei 11, 15, 16, 39, 51, 61 Garland x'o.e'se25.srccipetertivies te ivena ate ates 3 GOC0: i esrecees wave 11, 12, 19, 22, 23, 24, 39, 67 Ha OCA a scare 323-405 sesernmlenecn 11, 14, 15, 16, 18 Helmetycu diss vivansiaiee sincebeeet ca canaues 5 Hi Ma erase ss cee aadesmeness res nex 14 Hy dries 3s ckasvrneiccieierm ens 39, 45, 57 Vde@aill: sisi elec redievs ciate aeteaue aiaa ateongeaevatue 18 IMC 9 science etessiccees 11, 15, 16, 18 Ran 2 havarou a kiwis cacaney nese ets 15 Marvel v22 nioseuasmnttesnieet tee eaves 18 McAuliffe scccewssaceneccees 11, 15, 16, 18 Mechanical ssid sitet oxtee stan aie 1-4, 9, 18 Monarch ...... 11, 14, 15, 16, 18, 39, 47, 59 Newton: wadersess ccna tees 11, 15, 16, 18 Nicholson Mercury Seal ............... 3 IN OVS), cciaiacavavert/oiwraneepayavare/are a sieves eacesuave 11, 18 Oldfield: o7.c02 saeeieneee eons cs eaaes 18 Paragon. cic yeeencnian 3, 4, 11, 14, 15, 16, 18 POSITIVE: oeeieciereeene abe Sree LE, 15,: 16,18 Ot Sos sce, ece avaens ofa sispncedaininis wose-ba es aarti 6 Public: Safety: i222 ce anes veaiees ¢ 14, 18 Radelitve: setae ce acct taco ute toreaee 11, 15, 16 Rochester Lead Works ................ 14 Round) 2yhxc2cueoscneee eee eae e ce aes 8 SA aCO wartaveretarnie wereve sarees 39, 41-43, 47-50, 52 Sanitas’ sac teases 8, 11, 15, 16, 18, 39, 44, 56 SANItO: eieseeie Acker arose eretemels 18, 39, 43, 55 SeneGa? 2 teice veteccie asta nesaiain ne weer ecs 18 Shiler.s5.f i weceaemeee se ccedoe nee 14, 18 SIMPLEX: JAaewnvek wantnnccmeenceee-eate ee 18 IPUINEL: ws saicisw ose wees ess Beet eee 14 Wae® OW. Sloe sates. eeu seeee ae 14, 18 Whiteford) o.cce2 osscex seers 11, 18 Wolff Mig: Gon save sseecamaeed 11, 14, 18 Wolverine ......... 11, 14, 16, 18, 39, 46, 58 Woodward, McAuliffe, Wanger ......... 18 Back-pressure on ...... 5, 9, 10, 26, 33, 34, 49, 66, 71, 72 Comparison of Siphonage resisting quali- ties of vented 1% S traps with un- vented Gudelltrap sc asesacnwtccescascrcons cui 60 PLUMBING FIXTURE TRAPS Traps (continued) Druin: trap. siiankel vole acsiedsecies 65 Geco trap .........--- 1-43, 47-52, 54, 71 Hemico trap 7.. waisiaciesscsits ial syarersiccerotsess 61 Hydric: trap: .v.ceeeciexe ccs sacvassen 57 Monarch’ trap sesendicpeetac ce sees sistercrsms 59 Saaco: trap: esaciecsacse 41-43, 48-50, 62, 71 Sanitag® trap: secreierrece tetera weave sovetecsce 56 Sanit: trap, aeraicesiee wena esse ue Ses 55 U. S. Housing Corp. trap ........... 41-43, 48-50, 62, 71 Wolverine v0.2 sieiccn carey cerca carats 17 MOR So Palio <. faacetsraceceesse jesaucsavshesecatscn Bees wine mies 17