CHAPTER VIII THE Burtpinc—Its SAnrrary FITTINGS AND (Part 2)

being of insufficient depth to cover deposits, resulting in smell. If the water be made deeper, the force of the flush from the cistern is insufficient to wash out the solids and change the contents of the basin. Further, the washing out of the basin throws solid matters against the side at A, leaving them to decompose until possibly washed out by the next flush, while the water merely falls into the trap without force. This type of pan should be condemned wherever found. The Valve Closet. Fig. 224 shows a type of pan which has been much discredited, known as the valve closet. It is rather com- plicated, and in the old forms had many objectionable features, In the most modern forms, however, it can be classed as a sanitary fitting. The chief advantages claimed for it are (1) that it is almost noiseless in action, (2) the discharges fall into a fairly deep body of water, and (3) if the house is unoccupied for a long time there is great protection given by the depth of water against evaporation. 252 THE BUILDING—ITS SANITARY FITTINGS, ETC. Even if the water above the valve is evaporated there is still some protection left by the valve fitting up tightly against the outlet and, further, there is still the trap with its water seal below the oint A. 4 In London the valve closet is doomed by the regulations of the Metropolitan Water Board, which provide that all valve closets shall be flushed by water waste-preventing cisterns, which will negative the noiseless action. The valve, V, is held up by leverage, and opens downwards on pulling up the handle in the seat. It allows the contents to pass through the valve box, V.B., into the trap below. It is possible that the valve may by accident become set fast, and an overflow pipe has therefore to be provided. The overflow openings are shown at O, and it will be seen that they communicate with the overflow pipe, O.P., which is open at the top for convenience of access. The overflow pipe is isolated from the valve box by a trap, and the valve box is provided with a ventilating pipe, V-P., carried to the outside of the building. The pan is of glazed earthenware, and the valve box and overflow pipe should be of cast iron, glass enamelled inside. Valve closets are usually cased in with a wooden seat and “riser” right across the apartment. In some of the later forms of valve closet, there is a vitreous-enamelled valve box, an accessible overflow pipe and the working parts are made so com- pact that the whole can be enclosed in a glazed earthenware casing or “pedestal”, but the fitting still has too many working parts and is too complicated to be considered a good type. The “Wash-down.” One of the best forms of closet at the present time is that known as the “wash-down”, one type of which is shown in Fig. 225. It will be seen that it is based on the hopper type, but that the outlet of the pan is sealed by water having a reasonable surface area. The back is made nearly vertical, and in some varieties of this type, quite vertical, to guard against fouling. There is a good seal to the trap, and a proper flushing rim is provided around the top of the pan. This is the type recommended in B.S. 1218 and students desiring more de- tailed dimensions, as recommended in the B.S.S., should obtain it from H.M.S.O. or borrow it from a library. In some types of wash-down pan the trap is separate, and in such case the joint between it and the pan should be below water level, so as readily to indicate any defect in the joint, though this type carries with it the disadvantages of a slight roughness at the joint in the entrance to the trap, while the trap itself is often of a different material, rather spoiling the clean, uniform THE BUILDING—ITS SANITARY FITTINGS, ETC. 258 appearance of the interior of the closet pan. The great advantage of the separate trap is that outlets can swivel in any direction in a half-cirele for use in W.C. apartments in awkward positions or at odd angles to the outside soil pipe. A recently introduced wash-down W.C. pan, known as the “pivot” closet, is designed with three-quarters of the trap made in one piece with the pan, but finishes with the spigot of the outlet vertically upwards just below the water level on the outlet side. The remainder of the outlet arm to complete trap can be sup- plied to form either a “P” or “S” type of trap and to swivel in any direction through approximately 180° as in the older forms of loose trap closet without any of its disadvantages. A wash-down closet should have a good seal, not less than 2 inches, as it is rather liable to become unsealed if a bucket of slops be thrown into the pan. Fig. 226 shows a second variety of this type of closet, a “‘ wash- down” with large water area. With this type fouling of the pan is much less likely. The larger area of water is obtained partly by making the front more concave, and partly by increasing the depth of the seal. In Fig. 227 a third variety of wash-down apparatus is illustrated, differing from the two previous examples in the addition of an after-flush chamber, A.F.C., between the top of the trap and the underside of the flushing arm of the pan. When the pan is flushed, water enters this chamber and fills it, while the bulk of the water from the cistern passes on to flush the pan. The outlet of the after-flush chamber is small, and the water comes from it more slowly, in consequence, to ensure there being sufficient water left in the trap at the end of the flush. The dimensions of wash-down pans are specified in B.S.S. 1218, which specifies (among other requirements) that the water surface shall be not less than 6 inches from back to front and 44 inches from side to side and that the back plate shall have an angle of from 90° to 1074° to the horizontal. Siphonic W.C. Pans. We come next to closets of what are known as the “‘siphonie type, of which there are two principal varieties, (1) those with two traps, and (2) those with one only, A good example of the former is shown in Fig. 228. When the chain is pulled most of the water flows around the flushing rim and so into the pan, but a small amount passes through the small aper- ture at A, in the form of a jet; as the pipe between A and C is enclosed, the air previously in it is compressed, forcing down the level of B and C and raising the level of water in the pan at D, which is further raised by the water from the flushing rim, As 954 THE BUILDING—ITS SANITARY FITTINGS, ETC. CHAIN CONTROL HIGH LEVEL SUPPLY TO INJECTOR LEVER CONTROL “4 “ _- "FLUSH PIPE mc LOW LEVEL CISTERN 1% ” OR 1 a _- FLUSH PIPE nF ou INJECTOR pac Se te AFTER FLUSH JET INJECTOR TYPE SIN SYPHONIC W.C. Sere Ti it WITH 2 TRAPS ny 23) 232 THE BUILDING-——ITS SANITARY FITTINGS, ETC. 255 soon as the water level in the trap at C is depressed to the level of the bend at E, the compressed air escapes and the pressure in the pipe AC becomes normal. The heaped-up water in the pan now rapidly overflows into the outlet pipe and fills it completely, with the result that solids are removed from the pan by suction. This apparatus is simple in character and quite efficient in action. The only objections to it are that the trap and its outlet rather pre- vent thorough cleaning of the floor behind the apparatus, and that part of the water—that used to start the siphonic action—plays no direct part in the flushing of the pan. Another form of two- trap siphonic pan is shown in Fig. 231—this time with an injector tube from the top of the flush pipe to provide the starting jet. Single-trap Siphonic W.C. Pans. A good example of the siphonic closet with a single trap is shown in Fig. 229. It will be seen that it has an exceptionally deep seal and large water area. The siphonic action is set up by rapidly raising the water level in the basin, and so overbalancing the other column of water, which fills the arm A.B., full bore. This arm has an enlargement of its section just below B, to which the ventilating pipe is fixed, obviat- ing a check to the siphonic action at B, owing to the sudden compression of the air in that arm of the siphon. It will be seen that the soil pipe is still trapped if the basin is removed. An- other example with low level tank is shown in Fig. 282. a) Trough Closets and Latrines. Before leaving the description of the various types of water-closet, reference must be made to trough closets and latrines, such as are used in factories and some types of school. The oldest form is merely a semicircular trough, covered by a continuous seat with a series of holes in it, trapped at one end, and flushed out at intervals by means of an automatic flushing tank. Such a fitting is very liable to fouling, difficult to keep clean, and is quite lacking in privacy. Another type is in the form of an oval pipe running from end to end, with short oval branches passing up under the holes in the seat. This is better but still not good. ‘} Even in the roughest of communities all closets should be separate to ensure reasonable privacy. Fig. 230 shows, diagram- matically, a good arrangement for such cases, in the form of a siphonic latrine. There are separate pans divided by divisions or partitions, D, and communicating with a longitudinal pipe, the end of which is raised to provide a body of water in each pan. A siphon, §, is fitted at the end of the range of pans, with an access ITS SANITARY FITTINGS, ETC. 256 THE BUILDING (COVERS ARE OMITTED FOR SIMPLICITY) = S ne = & So) ~~ s <) S 2 i Ww 2 .S) se = = wy 9S % w ry = ~ x w THE BUILDING—ITS SANITARY FITTINGS, ETC. 257 cover, C, at the top of the bend. Each pan has a flushing rim, and the flushing pipe has a branch to each. An automatic flushing tank, F.T., provides the flush at frequent intervals and, after flushing, the siphonage is checked by a small pipe, P, which lets air into the siphon as soon as the water level in the flushing tank drops below the end of the pipe, shown by dotted lines inside the tank. The flushing tank would, of course, be higher than shown in the sketch, which is broken to save space. The best arrangement, of course, is to have a separate pan, trap and flushing cistern to each compartment, but naturally extra expense is involved. The Ministry of Education insists on this in new schools. W.C. Cisterns. We may next consider the means of flushing closets. The usual method is by means of a cistern, at a height of a few feet above the apparatus, with a capacity of two gallons. In some places a larger volume is permitted by the water authori- ties, but in very few. For a siphonic closet a three-gallon flush should be used wherever possible. Cisterns have ball-valve inlets similar to those in storage cisterns. Flushing cisterns have in some respects been standardised by B.S.S. 1125. They may be of 3% inch cast iron, } inch glazed ware, pressed steel of 16 B.G., ? inch wood lined with 4 lb. lead or 24 5.W.G. copper, or 4 inch asbestos-filled or fibre-filled bituminous composition. ° The old type of cistern was operated by means of valves, the pulling of the handle raising the valve and letting the water out. To empty the cistern, it was necessary to hold the handle till the water had all gone. Some types had one valve, others two, but cisterns of this kind have now been superseded by others of siphonic action, of the “‘ pull and let go” type, termed siphonie water-waste preventers (or ““W.W.Ps” for short). They are so called because they limit the amount of water which can be used at each flush, There are very many forms of such cistern, but a few examples will indicate the principles underlying the construction of practic- ally all of them. They differ only in the method of setting up the siphoniec action. In the following sketches, which are diagram- matic, the ball valves and overflow pipes are omitted for the sake of clearness. It should be mentioned, in this connection, that the overflow (or “warning” pipe which is a better name for it) should be a size bigger than the inlet, since the water coming in is under pressure, whilst the overflow has none and would certainly not be able to deal with the surplus water in the event of a defective ball valve, unless of larger size. The water-supply pipe is usually 9—D.S. 258 THE BUILDING—ITS SANITARY FITTINGS, ETC. } inch, while the overflow is made 3 inch. The example shown in Fig. 283, though siphonic in action, has a valve, and in conse- quence is objected to by most water undertakings. On pulling the handle the valve, V, is raised and allows water to rush through the branch, B. The effect of this is to lessen the pressure of the atmosphere on the small surface of water, A, with the result that the water rises over the bend and sets the siphon in action, the water continuing to flow until it falls below the level of the open inlet of the pipe. In Fig. 284 the pulling of the handle lifts a body of water into the bend and so starts the siphon. The end of the pipe in the cistern terminates in a cylinder, C, closed at the top and open at the bottom so that water can rise into it when the cistern fills. Through this cylinder passes a vertical spindle which lifts a circular disc, D.D., on the handle being pulled. It is by this dise that the water is lifted, the disc fitting quite loosely in the cylinder. An- other variety of this type is shown in Fig. 235, in which the cylinder or dome is movable. It is raised by pulling the handle, and lifts a body of water on a loose disc, D.D., as before, into the mouth of the vertical pipe. This removes the atmospheric pressure in the dome and starts the siphonage. Another way in which the same principle is applied is shown in Fig. 240. In this case the pulling of the handle pushes a loosely fitting piston, P, along the -open end of the pipe and forces a body of water over the bend. The examples in Figs. 234 and 285 show that siphonage can be started by lifting a body of water vertically, that in Fig. 240 by a horizontal force, and that in the next illustration, Fig. 287, by a vertical downward force, Fig. 288 being an outline oo of the | cistern. Around the dome, which in this ease is fixed, is an iron dise or washer, I.W., which on being forced down forees the water . up under the dome and into the mouth of the flushing pipe. There are three levers all joined together in one casting and pivoted on the line P.P. At the end of lever L is the handle, and at the ends of the levers L, and Lg are vertical rods, R.R., connected to the iron washer. As the handle is pulled down, the rods go down too, forcing down the washer; the equilibrium of the apparatus is restored by a balance weight, B.W. In cisterns of the type shown in Fig. 236 the lever is forked so | as to grip the two opposite sides of the heavy cast-iron dome, or bell, the short connecting piece, shown in dotted lines, ensuring the vertical rise of the latter. On releasing the handle, the weight of the dome forces the water up and over into the flushing pipe, thus setting up siphonage. THE BUILDING—ITS SANITARY FITTINGS, ETC. 259 +4 RUBBER CONE HALF ‘Y (70 CONNECT FLUSH SECTION ¥- FLEVATION PIPE 70 PAN) WIPEO JOINT 242 260 THE BUILDING—ITS SANITARY FITTINGS, ETC. Pneumatically Operated W.C. Tank. Fig. 289 shows a cistern operated pneumatically instead of by a handle. A loosely hinged valve, V, enables the water to rise into the open end of the flush pipe, F.P., and into the chamber, C. The small pipe A.P. is an air pipe passing down to a point about 2 feet above the seat, where it terminates in a small circular leather bellows actuated by a push button like that of an electric bell. On pushing the button, sufficient force of air is exerted at A to drive the water out of the chamber and over the bend of the flushing pipe. Low-level Cisterns. Figs. 239 and 240 show mechanisms suit- able for use in “low-level” cisterns for placing at the back of the pan and just above seat level. In Fig. 240, a piston, P, actuated by a pivoted handle, H, and a piston rod, R, works in a cylinder, C; the cylinder communicates with the siphon, S, which is fixed at a slight cant so that its long outlet leg may be clear of the cylinder. In the cylinder are some holes at X, by which water