This section is from the book "The Principles And Practice Of Modern House-Construction", by G. Lister Sutcliffe. Also available from Amazon: How Your House Works: A Visual Guide to Understanding & Maintaining Your Home.
Fig. 284. - View of Bramah's Water-c;loset.
Fig. 285 - Section of Pan- Closet.
The " D"-trap. referred to as usually forming a fourth part of the pan-apparatus is not an essential adjunct, but is almost invariably found in con-nection with it. It is, as the diagram (Fig. 286) shows, a receptacle or trap formed in had. and roughly in the shape of the letter D. A short piece of lead pipe, connected to the bottom of the container, passes through the top of the D-trap, and is continued down until the mouth of it is about an inch or so below the bottom of the outlet-pipe. Everything therefore which passes from the closet is discharged into the trap below the -landing-water line, and thus a water seal obtained. The form of this trap is peculiarly favourable to the deposit of frecal matter on all parts of its surface; more particularly on the edges of the dipping pipe and along the bottom. Several examples, showing more or less deposit, are to be seen at the Parkes .Museum of Hygiene, London. Another common arrangement, which added its quota to the insanitary conditions of this closet, was that the waste-pipe from the safe under the apparatus was commonly conducted into the back of the D-trap, sometimes below the water-line. Altogether the pan-closet and D-trap present a typical example of nearly every kind of fault which can be accumulated in one apparatus.
To return to the valve-closet. It must be conceded that there are circumstances which justify, if they do not compel, the use of a valve-apparatus. For the best water-closets in private houses of the better type, and generally for intended for ladies1 use, the valve-apparatus possesses advantages over the wash-out or wash-down closets, which will be deseribed later on. The large body of water contained in the basin is a distinct advantage, and the quiet working of the apparatus is also of great value. But if a valve-apparatus is to be filed, it should be the best obtainable. A cheap and flimsy valve-closet is only one degree better than the old pan-closet.
There are several forms of excellent valve-apparatus in the market, and it would take more space than is available to describe and illustrate them all. In order, therefore, to avoid advertising one make of closet at the expense of others equally good, it will be best to set forth briefly the conditions which should be fulfilled by a good and serviceable apparatus. In the first place, the water should be admitted to the basin all round the rim, and not by means of the old-fashioned fan-spreader. The overflow should have a wide, open mouth, in such a position that the whole of the arm can !»•• readily got at for cleaning. The overflow itself should not only be properly trapped, but should be thoroughly flushed out at every use of the basin. The working parts of the valve should be as simple and as strong as possible, and the interior of the valve-box should be porcelain-enamelled. The valve-box should be ventilated, and the overflow-aim should be connected into the ventilating pipe. so that the part just above the opening into the valve-box may be flashed regularly. Underneath the valve-box should be a lead trap, to cut off air-connection between the closet and the soil-pipe. The ventilation-pipe to the valve-box will prevent the trap from syphoning out when the contents of the basin are discharged. As an example of a valve-closet which fulfils all these conditions,we give an illustration of Hellyers "Optiimis" closet (Fig. 287).
Fig. 286- Section of "D",trap.
Fig. 287. - Section of Hellyers 'Optimus" Valve -closet and Slop closet: A. Section of Down-right Overflow.
The next type of apparatus to be considered is the plug or plunger closet. The plug-closet was first devised by the late Mr. Jennings, and was a praiseworthy effort to produce a closet in which the defects of the pan-closet should be avoided, while the mechanism of the working: parts should be simpler in construction than those of the valve-closet. It was also an attempt to reduce the amount of metal used, and to increase the amount of porcelain - a step in the direction of the more sanitary fittings of the present day. The apparatus consisted originally of a basin, at one side of which was a plug-chamber, or cylinder, in which was a plug with a hollow handle. Should the water in the basin rise above a certain point, it would flow down the hollow space in the ping-handle, which thus became an overflow. The plug, on being raised, allowed the water in the basin to flow out into the trap below. The objection to this apparatus was that the plug-chamber and the plug itself were liable to get fouled and become offensive. The overflow arrangement also was obviously open to the .same objection. In the improved form of this closet the plug-chamber is abolished, and an overflover -arm substituted for the hollow plug-handle. These are substantial improvements, but the objectionable plug still remains.
A modification of this apparatus is the trapless closet (Fig. 288), called by one maker the "twin-basin closet". This apparatus has all the objectionable features of the original plug-closet, combined with the added defect of there being no trap under the outgo. The closet is formed of two compartments, divided from each other by a septum or partition, which dips into the water, but allows a free passage between the two. The larger compartment forms the basin, while the smaller contains the plug and a ball-valve for regulating the admission of the water. The liability of the plug and the parts about it to become fouled is the same with this apparatus as with the plug-closet described above.It is evident also that, unless the plug is always forced well down into its place, the water in the basin will leak out; and the same thing would happen if paper got jammed between the plug and the side, and so prevented the plug from fitting tight In either case the basin would become drained of its water, and the overflow-opening, which is in the plug-chamber, would become a free passage for drain-air to pass into the house. What advantage is to be gained by the omission of a trap under the apparatus it is not easy to see. The trap is the only protection against the free admission of drain-air from the soil-pipe into the house;and if it if eliminated, the air from the drain will most certainly rush in every time the basin is emptied