The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Hot Water Suply
Each closet tank is arranged to be shut off separately, because the ball-cocks or the tank valves in them generally require repairs more frequently than other parts of the system. This illustration does not indicate any return circulation of hot water between the fixtures and the tank; therefore a considerable quantity of cold water must be drawn from some of the fixtures before the hot water flows. Air chambers h and i are attached to the piping and fixtures respectively, to prevent water hammer. The scaled size of the piping as drawn in Fig. 20 is exaggerated, and hence appears out of proportion with the fixtures. This was done to show the pipe connections more clearly.
50.21 illuTank-Pressure Hot-Water Supply System.—Fig. strates the same building and fixtures that are shown in Fig. 20, but in this case the water pressure in the street mains is assumed to be insufficient to force the water past the line AB and to the upper floor. This floor is therefore supplied from a house tank a, the water being pumped to the tank by an electric pump b. The main supply pipe is valved near the pump at c, and a branch is taken from this line and valved at d. When the pump is in operation and water is used from the tank, the valve d is closed and the valve c opened. Should the pump and tank be out of commission, the valve c is closed and the valve d opened, and in this way the fixtures on the first three stories may be supplied with water until repairs can be made. The piping could be arranged so that only the fixtures on the upper stories would take water from the tank and the lower stories would be supplied direct from the street main. This method, however, would necessitate the use of a double boiler and a multiplicity of pipes, consequently the system shown is considered better. It is frequently used in installations where the pressure in the street main is sufficient to raise the water to the tank and the use of a force pump is not necessary. The advantage of using a house tank is that all the fixtures have a low, even water pressure.
The suction pipe e, Fig. 21, for the pump is taken from the street mains and is valved as shown. The delivery pipe f leads over and into the tank a. An automatic switch g that operates the motor b is placed near the tank, and this is operated by the rising and falling of the float h in the tank. When the water falls below a certain point in the tank the current will be turned on, and when enough water has been pumped to refill the tank the float automatically operates the switch and cuts off the current. The switch shown near the motor in the basement is used to turn off the current by hand when repairs are necessary.
