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.
[Illustration: View of Marsh Steam Pump, Showing Water Valves, Steam
Valves, Suction Chamber and Piston.]