In the United States the water closets in general use in resi dences are flushed by "low-drain" tanks usually of vitreous china. The flush connection is generally about 2 in. diameter and short. The tank is supplied with water through a ball cash and a z in. supply pipe. The flushing appliance generally is either in the form of a syphon within the tank or a hollow flush valve usually of rubber. Each tank is provided with an overflow to the closet bowl, and a re-fill tube, which re-establishes the seal in the closet-trap after the flush has stopped and while the tank is being re-filled by the ball cock. Tank closets are generally installed in residences and other buildings where the water supply pipes are comparatively small in diameter.
having no moving parts. They may either stand on the floor or be supported by brackets.
The "valve" closet is the most modern adaptation of the now obsolete "pan" closet. It has the disadvantage of possessing many moving parts, and requires careful setting and use. It can, how ever, be quite a successful and hygienic apparatus but is usually expensive.
All closet basins are now made of the plainest and simplest design possible and are usually of white glazed stoneware. All sharp bends or angles are carefully avoided, and no part of the apparatus is allowed to be concealed by woodwork or ornamental finish. The flushing is arranged to not only throw a strong rush of water into the trap, but a portion of the flush is passed round the hollow rim to cleanse the sides of the basin.
In Great Britain these are always speci fied to be of the "waste-water-prevention" type as the Water Direct Flush Valves.—In large buildings such as hotels, office buildings, etc., where the water supply pipes are compara tively large, the water closets are flushed directly from the water supply pipes through slow-closing, flush valves. These may be regulated to any length of flush desired. When the closet is prop erly flushed the valve shuts automatically. It is a mistake to install these valves when the supply pipes are too small or the pressure too low. The pipes should be larger than one inch and the pressure greater than 20 lb. per square inch behind the valve.
In Great Britain baths are now usually made of enamelled cast iron or glazed stoneware, but copper and zinc have occasionally been used. The two latter, however, require the sup port of framing, which is usually of wood, a material which is un suitable for the hot, moist atmosphere of a bathroom. Cast iron baths may be provided with feet, but the stoneware type generally rest direct on the floor. The end at which the taps and outlet are fixed should be as close to the outer wall of the room as possible, so as to shorten the branch waste-pipe, and an overflow must be provided, which should not discharge into the trap as is sometimes permitted, but into the open air. The bath should be not less than
six feet in length and should hold about 3o gallons of water when filled up to the overflow level.
In the United States baths are generally made of cast iron enamelled, both inside and out. Those standing on feet and de tached from the wall are now seldom installed, except in cheap buildings. The most popular forms of baths are of the "built-in" type. Their sides are extended down to the floor and their rims are let into the wall, the floors and walls being tiled around the bath and made watertight.
As a sanitary precaution to prevent the bath contents from be coming syphoned back into the water supply pipes, when the wa ter is shut off, and thereby contaminating them, it is advisable to have the bath supply-nozzle above the bath overflow level. Sub merged supply-nozzles should not be installed.
The shower is the most hygienic form of bath, as one bathes in running water. It is very popular in residences, hotels, schools, factories, gymnasiums, etc. Special care should be taken in designing shower supply piping that the temperature of the shower will not change suddenly while a bather is under it. Otherwise the bather may become scalded. Prevention lies in a proper piping arrangement, or a hot water supply temperature 120 degrees or lower, or by the installation of appliances to control automatically the shower temperature. A shower may be arranged over a bath, or over a floor receptor furnished with a floor drain. The control valves should be located so that they may be reached from outside the shower. Shower bathing has become so popular in America that many of the leading hotels are now equipped with one shower in each room, in addition to the regular plunge baths.
In Great Britain these fittings are not usually pro vided in private houses but are necessary in such places as hotels and clubs. They should be simple in design and provided with an automatic flushing cistern. They are usually about 4 feet high, are made of glazed porcelain and in as few parts as possible, and flushed by pipes or sprays at the back. The old types with straight sides and back and made of slate or cast iron cannot be kept clean and are to be considered obsolete. The liquids are removed by an open channel to a trapped gulley close to the outside wall. The liquid is then removed by a pipe similar to a soil pipe which is not trapped at ground level.