A foot valve is a purpose specific check valve. Designed for immersion in a well, tank, or other liquid containing vessel, it serves as a one-way inlet valve to the piping leading to the suction side of a pump. Foot valves and their connected piping will extend downward from the pump suction elevation. The purpose of the valve is to maintain prime on the pump by preventing the water column in the suction line from collapsing, due to gravity, and draining all the liquid from the suction side of the pump system.