A. A steam pump will lift or draw water about 33 feet, as with one inch area, 33 feet of water will weigh 14.7 lbs., but the pump must be in very good order to lift 20 feet and all pipes must be absolutely air tight. A pump will give better satisfaction lifting from 10 to 15 feet. No pump however good will lift hot water, for the reason that as soon as air is expelled from the barrel of the pump the vapor occupies the space, thereby destroys the vacuum and interferes with the supply of water. When necessary to pump hot water, place the pump below the supply, so that the water will flow into the valve chamber. Always have a strainer at lower end of suction or supply pipe. A pump should be set up so that it is accessible for inspection, cleaning and repairs, and so that the shortest and straightest suction and delivery pipes can be used.
MARSH STEAM PUMP.
The Marsh Steam Pump is so constructed that the exhaust steam may be turned into the suction, thereby condensing its exhaust steam and returning it with its heat to the boiler, thus heating the feed water to a high degree.
The pump is automatically regulated and can never run too fast to take suction, or should the water supply give out when the throttle valve is wide open no injury can occur to the moving parts.
The steam valve, though nicely fitted, moves freely in the central bore of the steam chest, and has no mechanical connection with other moving parts of the pump, but is actuated to admit, cut off and release the steam by live steam currents which alternate with the reciprocation of the piston.
Each end of the valve is made to fit the enlarged bore of the steam chest, and it is due to these large valve heads, which present differential areas to the action of steam and the perfect freedom of the valve to move without hindrance from other mechanical arrangements or parts, that the flow of steam into the pump is automatically regulated.
MARSH PUMP.
Capacity 10 to 35 Horse-Power.
The steam valve does not require setting, as it has no dead center and will always start when steam is admitted.
The steam piston is double and each head is provided with a metal packing ring. The piston rod is made of Tobin bronze, the stuffing boxes and water piston are made of brass, and the water cylinder is brass lined. The water valves may be removed for inspection by simply taking off the air chamber.