This valve, of course, should be closed when once pump is under way, to prevent waste of water.
46. Priming.
a. Each pump must be fitted with a set of brass priming pipes and valves, according to either one or the other of the following methods:
b. For 1,000 and 1,500 gallon pumps, the priming pipes must be 11⁄4 inches. For the 500 and 750 gallon pumps, the pipes must be 1 inch. Pump-makers are to furnish these pipes and the fittings called for below, and are to connect them up providing a 2-inch outlet, looking upwards, ready for the supply from the priming tank.
The pipe from the priming tank to this outlet should be at least 2-inch, and may be of iron, and is to be furnished by the purchaser. All parts furnished by the pump-maker are to be of brass, and are to be included in the price of the pump.
Controllable Valve Arrangement.
c. Four 2-seat controllable valves, one for each pulsation chamber, and of the general type illustrated in [Fig. 14], must be provided. In these the inlet of water and outlet of air are simultaneously opened and closed by the pump operator.
Fig. 14.