If a pump has to work on a suction lift, what is typically installed on the suction line?

When a pump operates with a suction lift, it is important to ensure that the pump can maintain its prime and continue drawing liquid effectively. To achieve this, a foot valve is typically installed on the suction line.

A foot valve is a type of check valve that is placed at the bottom of the suction line, submerged in the liquid being pumped. Its primary function is to prevent the backflow of liquid when the pump is turned off, which would otherwise cause the pump to lose its prime and require re-priming to operate again. By keeping the liquid in the suction line, the foot valve ensures that there is a constant column of liquid ready for the pump, which is essential for effective operation in a suction lift scenario.

While a flow strainer, check valve, and pressure relief valve all serve important functions in fluid systems, they do not have the specific role of maintaining the water column in the suction line like the foot valve does. A flow strainer filters out debris, a check valve prevents backflow but does not necessarily keep the suction line full, and a pressure relief valve protects the system from overpressure, which doesn't relate directly to suction lift conditions. Thus, the foot valve is specifically critical in maintaining prime during suction lift applications.