Bramah's valve-closet was followed by many others on similar lines. The improvements which were gradually made included the better flushing of the basin, the improvement of the valve so as to fit closely against the seating, the reduction of the size of the valve-box and the improvement of its shape, the introduction of a self-cleansing trap under the valve-box, the trapping of the overflow, and the ventilation of the valve-box. Fig. 87 shows such a closet, with the trap and part of the mechanism omitted. A is the basin of white-ware with flushing-rim, B the valve, C the lead valve-box with brass cover, D the ventilating socket of the valve-box, E the overflow from the basin trapped before its connection with the valve-box, and so designed that it receives a certain amount of water every time the closet is flushed, and thus the trap is kept charged; F is the supply-pipe, and G the supply-valve with regulating thumb-screw. The overflow-arm shown in this illus-tion is not of the best design, as it cannot possibly be cleaned. The valve-box is sometimes made of cast-iron enamelled inside, and occasionally of pottery.

The ventilation of the valve-box is an important point, as it prevents the siphonage of the overflow-trap and affords an escape for the foul gases generated in the closet-trap and valve-box. The ventilation-pipe may be carried through the external wall, and finished with crossed wires. In some closets the trap of the overflow discharges into the ventilation-pipe, and not directly into the valve-box. The object is to prevent the lower portion of the overflow-pipe or trap being blocked with paper or soil. More commonly, however, the valve is placed so as to cover the end of the overflow when the valve is open; this is the arrangement shown in fig. 87.

Fig. 87. Valve Closet with Regulating Supply Valve.

Fig. 87. Valve-Closet with Regulating Supply Valve.

It will be observed that the basin retains a large quantity of water, and an arrangement must be adopted whereby this quantity will be supplied automatically after the handle of the flushing apparatus has been released. One of the best-known devises for this purpose is the bellows-regulator in fig. 88. When the handle A of the flushing apparatus is raised it lifts the lever B, which actuates the valve of the closet, and also raises the lever C, which is pivoted at D and attached to the supply-valve at E. The lever C raises the spindle of the supply valve and admits water to the basin, and at the same time raises the spindle and valve of the regulator F, and forces air out of the bellows into the outer compartment, from which the air can only escape through the small cock. When the handle of the closet is released the valve-lever B at once drops back into position and closes the closet-valve. The lever C, however, can only descend as the air is expelled through the cock of the regulator; consequently the supply-valve E does not close for some seconds after the handle has been released. The quantity of the after-flush can be regulated by adjusting the air-cock on the bellows-regulator. The device shown at G in fig. 87 is another arrangement for regulating the after-flush.

Fig. 88. Valve Closet with Bellows Regulator.

Fig. 88. Valve-Closet with Bellows Regulator.

The supply-pipe and valve are usually only 1 in. in diameter, but this is often too small to give an adequate flush and after-flush. Where the cistern is less than 10 ft. above the closet the valve should be 1 1/4 in.; where it is less than 6 ft. the valve should be 1 1/2 in. In London the smallest diameter allowed for flush-pipes is 1 1/4 in.

Some plumbers do not connect the overflow-arm and the valve-box, but permit the overflow to discharge on to a lead safe under the closet, from which it escapes by a pipe to the open air. This is a very faulty arrangement and often causes great annoyance, particularly if (as is often the case) the closet is used to receive slops. Unless the handle of the closet is held up during the whole time occupied in emptying the slops, these, mixed with the water contained in the basin, will overflow and foul the safe and give rise to unwholesome emanations. Even when the overflow and valve-box are connected, the pouring of slops into the basin will foul the overflow-arm and trap, and as these are generally inadequately flushed, the surfaces will in time become very nasty.

Fig. 89. Valve Closet with Stoneware Trap above Floor.

Fig. 89. Valve-Closet with Stoneware Trap above Floor.

The ordinary valve-closet has its trap below the level of the floor. This position is very unsatisfactory, as it renders inspection and repair of the trap more difficult. It is a better plan to raise the whole closet on a step, so that the trap is above the main floor. Some sanitary authorities lOI wisely insist on the joints at the outlets of closets being above the floor level, and the ordinary valve-closet is rejected as it does not comply with this regulation. Special valve-closets are made to meet the difficulty, an example being given in fig. 89. In this the valve-box, closet-trap, and overflow-trap are formed in one piece of stoneware. An inspection-opening, fitted with a ground cap, is formed in the top of the trap at A, and a ventilating socket is formed on one side of the valve-box. The closet cannot be recommended; the trap is of such a shape that deposits are almost certain to occur in it, and there are other defects which need not be particularised.