=An Independent Steam Pump= is virtually an engine with two cylinders,
one for the steam piston, the other for the water piston or plunger,
and is used in connection with a steam boiler for supplying it with
water. The discharge pipe of a pump is generally connected with a feed
water heater of some sort, which heats the water to a high temperature
before entering the boiler, though there is a late pattern of steam
pump which delivers the feed water to the boiler at about the same
temperature as the injector. The cylinder of steam pump should always
be well oiled before starting in the morning and stopping at night. The
stuffing boxes on piston and valve rod should in all cases be kept well
filled with soft and moist packing. If the packing is allowed to become
dry and hard, it will cut the rod, inducing leakage and necessitating
repairs. When a steam pump is not in use in cold weather all the drain,
drip and pet cocks should be left open, to allow the water to run out.
While most farm engines are furnished with an independent steam pump,
some are equipped with what is called a cross-head pump.
[Illustration: J. I. Case Steam Pump.]
=A Cross-Head Pump= is operated by a plunger attached to the cross-head
of engine and has two valves, a supply and a discharge valve, also is
supplied with an air chamber. This style of pump is available only when
engine is running. Engines with a cross-head pump should always be
supplied with an injector to be used in case of failure of pump to work
and while engine is shut down. The cross-head pump is connected to the
heater in the same manner as an independent pump.
Q. How high will the steam pump lift water?
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.