Marine Foot Valve
Marine foot valves are a special type of lift check valve that is installed at the suction end of the pump piping. Most pumps require water injection prior to startup to vent air in the pump casing and in the piping at the suction end, where a check valve is required to prevent loss of the injected liquid.
Overview
Design:
The pump casing and suction piping can be filled by manually dumping liquid to fill the pump, or by inducing liquid into the piping and casing by applying a vacuum into the pump casing. In both cases, a foot valve prevents the flushed liquid from flowing directly out or exhausting air from the pump casing. The suction system of the foot valve is a retardation that results in a loss of suction pressure to the pump, and this retardation must be taken into account in the design of the piping and in the selection of the valve.
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