Fig. 105.—Siphon-jet closet with the high flush tank.
Fig. 106.—Form of closet not now used in good practice.
Flush Tanks.
—The water closet depends for its action on one of two general types of flush tanks, the high and the low forms. The tank is automatically filled with water and when wanted, a large volume of water is suddenly discharged into the sewer, carrying with it the contents of the seat. The tank again fills and is ready for use when required.
As illustrations of high flush tanks, those shown in Figs. 105 and 106 furnish examples of a simple and efficient form. The details of the mechanism of this type of tank are shown in Fig. 107. The pipe from the water supply is attached at G to the automatic valve F, which keeps the tank filled with water. The piece F of the valve is held against the opening by the pressure exerted through the float E. The float is a hollow copper ball. As the ball is lifted it exerts a pressure in proportion to the amount it is submerged. When the water reaches the level A-A, the valve is tightly closed. As the water is discharged from the tank the ball follows the level of the water and opens the valve, allowing the water to enter and again fill the tank.
Fig. 107.—Details of construction of a simple type of siphon flush tank.
The siphon is made of cast iron, and in the figure is shown cut through the center. The lower end fits loosely in the piece K, and makes a water-tight joint around its outer edge, by resting on a rubber ring C-C. The right-hand side of the siphon is open at H, and when the tank is full, the level of the water is at A-A, which is almost at the top of the division plate. To discharge the tank, the chain L, attached to the lever B, is pulled down; this action raises the siphon from its seat. As soon as the siphon is lifted, the water rushes through the opening around C-C, into the pipe K; this causes a partial vacuum to form in D, and the water is lifted over the division plate K, and flows out at D, forming the siphon. As soon as the siphonic action begins the siphon may be dropped back on the seat and the water will continue to discharge until the tank is empty.