CHAPTER VIII THE Burtpinc—Its SAnrrary FITTINGS AND (Part 5)

similarity of its shape to these letters when its outlet is vertical, sloping or horizontal respectively and shown in Figs. 272, 278 and 274. It is of circular section throughout, simple and self-cleansing, with a good seal while holding a comparatively small body of water. In the smaller sizes, 2-inch diameter and less, it is provided with a screw-cleaning eye at the lowest point, as shown in Fig. 278, which is a section of an S trap. A form which is mid- way between the S and the }-S, shown in Fig. 274, is known as a _Q or 3-S trap. With the smaller sizes of all these traps a screw- cleaning eye is provided. The question as to which of these traps is used for any particular case is largely dependent on the available room. One other form, also quite a sanitary trap, is that known as a “running” trap (Fig. 275). Materials for Traps. The best materials for traps are drawn lead, copper and copper alloy. They are easily connected to fittings and pipes, and are incorrodible. If iron is used, the trap should be glass-enamelled inside. B.S. 504 specifies the com- position and weight of drawn lead traps and their dimensions and 276 THE BUILDING—ITS SANITARY FITTINGS, ETC. water seal, while other non-ferrous traps are dealt with in B.S. 1184. W.C. Joints. The joints around the various fittings next call for attention. In the case of a W.C. there is the joint between the flushing pipe and the apparatus; also that between the trap and the soil pipe. The flushing pipe is joined to the cistern by means of a screw-union as in Fig. 241. The tail-piece of the union is soldered on to the flush pipe (if of lead) by a plumber’s wiped joint. The lower end is usually attached to the socket of the flushing rim by a rubber or plastic cone, shown in Fig. 242. The cone is first pushed up the pipe out of the way and the end of the flush pipe is placed into the socket of the flushing arm and a joint is made with putty of red and white lead, the cone being then pulled down from its temporary resting place on the lead flush pipe until the expanded end fits tightly over the fireclay socket and the smaller end over the lead flush pipe so as to completely cover the joint. Some joints are made with rubber rings compressed by screw collars, so as tightly to pack the space between the lead and earthenware. Another method is to use special collars of lead, hinged together in two pieces and secured by a small bolt. The collar connects the pipe to the flushing arm and is packed inside with red and white lead. One sometimes finds the rubber cone joint just mentioned bound with two or three strands of copper wire around the flushing rim socket and the base of the flush pipe, but this is not necessary if the rubber cone is a proper fit, and the securing twist of wire and the interstices of the coils provide lodgment for dirt and germs. In low-cost housing schemes, the flush pipe is often of telescopic pattern, in two or three sections, so as to be adjustable for different cistern positions. The material is then thin galvanised or vitreous enamelled steel and the sections are slightly varied so that the upper length can make a close fit inside the middle length and the middle length inside the bottom section. The sections are coated with a thick paste of red and white lead putty before being fitted into one another and adjusted, any surplus paste being cleaned off after the fixing is complete. The top section is provided with a flange with the shoulder-nut of the serew-union engaged, so that no separate flanged tailpiece is needed. The bottom section can then be fitted to the flushing rim socket in the same way as the lead flush pipe, with red and white lead putty and a rubber cone joint. The joint between the trapped pan and soil pipe depends on the material of the latter. If it is of iron a cement or bitumen joint is all that is needed, but a branch socket with a wide faucet for THE BUILDING—ITS SANITARY FITTINGS, ETC. 277 278 THE BUILDING—ITS SANITARY FITTINGS, ETC. cement should be specified if cement is to be used, as the normal socket for a caulked lead joint is too narrow for a first-class Port- land Cement joint. If the soil pipe is of lead, or if a lead branch soil-pipe is to be used, a variety of means may be adopted. One sometimes sees the lead dressed out to form a shallow socket which fits over the pan outlet, the space being filled in with red and white lead putty, but this is a poor method and should be condemned. A better plan is to use a copper, brass or gunmetal ferrule, as shown in Fig. 276, soldered to a lead pipe with a sloping shoulder wiped joint, or bronze welded to a copper pipe and connected to the pan with a cement or bitumen joint. As this joint and the one between the W.W.P. cistern and the flushing rim of the pan are exposed in the apartment to spillage of urine or slops, every care should be taken to obtain an easily cleansed, stream-lined joint, for which reason Fig. 276 should be preferred to Fig. 277. This joint (i.e. No. 277) is a quick and strong joint for the same conditions and materials as Fig. 276. It is shown half in section and half in elevation. It is made up as follows. Between the lead pipe (tafted out with the hardwood cone and tafting tool to the shape shown) is a flat rubber ring, and outside the lead a flat brass ring. Screw clamps, as shown, are used to bind the whole together. Still another method of getting over the difficulty of ensuring a strong watertight joint between the pan and the lead soil-pipe branch is found in the Metallo-Ceramie joint. The outgo of the pan is coated before firing, with a liquid composition containing a solder adhesive metal in solution. On removing from the kiln a thin film of metal is left on the outgo, which will hold the solder. A short length of lead pipe is then soldered on at the factory, and to this the plumber on the job makes his conventional wiped joint. Plumbing for Basins and Baths. The joint between lavatory basins, baths and sinks and their respective traps, if of lead, are made by means of screw-unions and wiped joints, both before described, Anti-Siphonage Arrangements. In almost all cases a trap below a fitting is liable to lose its seal. It may do so in either of three ways: (1) By evaporation, (2) by siphonage, and (3) by momentum, To guard against evaporation, a deep seal should be provided, To guard against the second and third eases, the trap should be ventilated. The reasons for this will be seen from Fig. 278, For example, if the fitting charged the trap full bore when emptying, the volume of water acting on C would overbalance the atmospheric THE BUILDING—ITS SANITARY FITTINGS, ETC. 279 resistance at D, and the water would either all pass through CDE, emptying the trap, or would cause a partial vacuum at D. It is, however, well known that nature does not allow a vacuum, there- fore the trap would be emptied. This may be obviated by putting a ventilating pipe, V.P., near the outgo of the trap, in order to supply air and preserve the seal. Again, if there were two or three fittings, one over the other, discharging into the same waste pipe, the lower traps would be liable to siphonage from another cause. A discharge down the pipe AB tends momentarily to compress the air in front of it and the effect of this would be to cause a slight excess of pressure at D, momentarily overcoming the normal atmospheric pressure at C and raising the level of the water at that point. Almost im- mediately after, however, the discharge has passed the end E ot the pipe DE, suction is caused behind the falling liquid, tending momentarily to lessen the pressure on the surface of the water at D, allowing the atmospheric pressure on C to raise the water level at D and lower it at C. This is called siphonage by momen- tum, and if the discharge is fairly vigorous and fills the pipe, the contents of the trap are almost certain to be forced out. This increasing and decreasing of the pressure on the surfaces of the water forming the seal is very similar to the bouncing of an elastic material. The ventilating pipe near the outgo of the trap provides an escape for the increased pressure in the first instance and supplies the air to meet the diminished pressure in the second case. A ventilating pipe to a trap is generally known as an anti- siphonage pipe. The form of the connection of the vent pipe should be particu- larly noted from Fig. 281. It will be seen that the pipe is joined by a bend, pointing in the direction of the flow through the trap, which is the only satisfactory method, as it obviates the fouling of the entrance to the pipe. If it is connected vertically, or in any other way than that shown, the entrance is very liable to become stopped up. Though not generally provided for in the provinces, the by-laws of the London County Council prohibit any other method in the Metropolis than that shown in the illustration. Should a fitting be quite separate from any others, its trap may be ventilated, except in the case of a closet or housemaid’s sink, by carrying the vent pipe through the nearest external wall, enlarging its outer end, and fitting it with a circular grating flush with the wall, well away from windows, being then described as a “‘puff pipe”. Each trap should be separately ventilated, but where the fittings 280 THE BUILDING—ITS SANITARY FITTINGS, ETC. . are arranged in tiers, or in ranges, the anti-siphonage pipes of the traps may be branched into a main anti-siphonage pipe. This method is shown diagrammatically in Fig. 280, which shows a method of dealing with the wastes of a range of three lavatory basins. Each basin is shown separately trapped, and discharging into a main waste pipe, W.P., and each trap is ventilated into a main anti-siphonage pipe, A-S.P. At the end of the waste pipe a screw-cleaning eye would be provided, S.C.E., and a similar clean- ing eye would be put at the bottom of each trap. Sometimes ranges of lavatory basins are dealt with differently, the separate waste pipes not being trapped but discharging over and into an open channel trapped at the end, the lower ends of the waste pipes being furnished with a bend pointing along the channel. Anti-siphonage Pipes for Water Closets. Fig. 281 shows the arrangement of a tier of closets with each trap ventilated into a main anti-siphonage pipe, which is finally turned into the soil-pipe at least 3 feet above the highest fitting. An alternative is to carry the main anti-siphonage pipe well above the roof instead of con- necting it to the soil-pipe. In the sketch, the anti-siphonage and soil-pipes are shown one behind the other for the sake of clearness, but the two pipes would be parallel on the outside face of the wall. Anti-siphonage pipes can be of either lead, copper or iron. It should be noted, in passing, that it is not necessary for the anti- siphonage pipe to flow in the same direction as the waste or soil pipes as in Figs. 280 and 281. If it suits the lay-out better, or a neater appearance is obtained thereby, the anti-siphonage pipe can discharge to the left with the waste or soil-pipe delivering to the right (or vice versa) so that the anti-siphonage pipe reaches the eaves by an independent route. For ordinary closet work, branch vent pipes of 2 inches in diameter are sufficient, discharging into a main anti-siphonage pipe a size larger. Special Anti-siphonage Fitments. In order to reduce the num- ber of joints to be made at each floor when a tier of soil fittings has to be connected to iron, soil and anti-siphonage pipes respect- ively, special castings are sometimes used, incorporating the anti- siphonage branch, and providing one socket only to take the closet outlet, two sockets upwards (to take the spigots of the main vent and soil-pipes from upper floors) and two spigots down- wards, ready to be jointed to two similar plain lengths of main vent and soil-pipe passing down to the lower floors and to the drains. The “Spruce-Thrower”’ Soil Unit. In one fitment of this type, THE BUILDING—ITS SANITARY FITTINGS, ETC. 281 shown in Fig. 286, (the ‘“Spruce-Thrower Soil Unit’’) the anti- siphonage branch is taken from the soil branch of the unit straight towards the main soil-pipe without staggering right or left, and by-passes it in the form of a circular ring-duct immediately below the socket, this ring-duct for air, opening out into the main anti- siphonage pipe which is bolted on as a prefabricated unit alongside. In this fitment, bosses are cast on in suitable places and drilled and tapped, so that, in areas where “‘one-pipe” plumbing is per- missible, bath, basin and sink wastes can be connected directly to the “general-purpose” soil-pipe. The anti-siphonage branch for lavatory basins, baths and sink traps can be a size smaller than the diameter of the trap concerned, the main anti-siphonage pipe, if for waste pipes only, being of the same diameter as the trap. For the range of basins in Fig. 280 fair sizes would be as follows: traps and branch wastes 14 inches, waste pipe 2 inches, branch vent pipes 1} inch, and anti-siphonage pipe 14 inch. If the main vent pipe is very long, its diameter should be slightly increased. Traps and Fittings not needing Anti-siphonage Pipes. The trap of a single closet on a ground floor, with none above it, is not usually ventilated, but it becomes necessary if another is at any time allowed to discharge into the same soil pipe at a higher level. A scullery sink on a ground floor need not have its trap ventil- ated, for the reason that a flat-bottomed vessel does not charge its trap full bore all the time it is emptying, and also, that in the case of such a fitting on a ground floor, the waste pipe would be of short length, and disconnected, so that the air in it could never exert any appreciable excess over the normal pressure of the atmosphere. Anti-siphonic Traps. An alternative to the use of anti-siphonage pipes for waste fittings is to use anti-siphonic traps or “ re-sealing”’ traps. Fig. 282 illustrates one, known as the “Sure-seal”’. It is an improved form of bottle-trap, with complete accessibility by means of a screw-cap base. Normally water stands in it at level A. When water is discharged from the basin and flows through the outlet full-bore, causing suction, siphoning will begin, When, however, water falls to level B air will pass from the room to the outlet and bring its pressure up to the normal. Meanwhile the water in the “reservoir” R has been unable to escape through the very small holes H at its top, and, as soon as equilibrium of pressure is restored, this water will fall and the water in all the trap will reach a common level C, the outlet being sealed once more. 282 THE BUILDING—ITS SANITARY FITTINGS, ETC. Waste Pipes. We may next consider the kinds of waste pipe, the materials used for them, their joints, fixing and the methods of dealing with their top and bottom ends. They should normally be outside the building; but where it is permissible to use the “ one- pipe” system of drainage, to be described later, it is advantageous to put the vertical soil and ventilation pipes in a vertical shaft constructed as part of the building, with suitable means of access. The waste pipes comprise rainwater pipes, carrying the rain water from the roofs, soil-pipes, taking wastes from closets and house- maids’ sinks, and pipes taking the wastes from baths, lavatories and sinks. Material for R.W. and Waste Pipes. Rainwater pipes are usually of east iron, while waste and soil-pipes may be of lead, copper or cast iron. The branch wastes from baths, basins and sinks are generally of lead, though drawn copper is a most satisfactory alternative, being very durable. Copper pipes may be chromium or nickel plated, if desired, and are especially suitable for the waste pipes from basins in bedrooms. A cheap, but not very sightly, alterna- tive material for waste pipes is galvanised wrought iron. Pipes are also made of asbestos cement, with bends, branches, shoes and swan-necks of the same material. They form a cheap and fairly satisfactory rainwater pipe, but they are rather brittle and may be broken by a knock, as, for example, by a ladder. If used as soil, waste, or ventilating pipes they are coated with bitu- minous composition. They are specified in British Standard Specifications 569 and 582. “Drawn Lead” Pipes. Lead pipes should be of what is known as drawn lead, that is to say, seamless, and they may usefully be specified as to be to the Standard of B.S. 602. Before the introdue- tion of drawn-lead pipes, the pipes were made up of sheet-lead with soldered seams, and such pipes are often found in old build- ings; they are very apt to be found defective. Lead and copper have the advantage over iron in that they are incorrodible, obtain- able in longer lengths (necessitating fewer joints), will give slightly,