What is the primary function of a foot valve in a pump system?

The primary function of a foot valve in a pump system is to prevent the pump from running backwards. A foot valve is a type of check valve that is installed at the bottom of a suction line in a pump system. Its main purpose is to maintain the prime of the pump by allowing liquid to flow into the pump while preventing it from flowing back out when the pump is not in operation.

When the pump is turned off, the foot valve ensures that the liquid remains in the suction line and pump casing, which helps to avoid any potential issues with cavitation or loss of prime upon re-starting the pump. This feature is essential, especially in applications where the pump is located above the fluid source, as it ensures the system remains operational without the need for constant manual priming. The emphasis on preventing reverse flow is what distinguishes the foot valve in its role within the pump system.