Which component is specifically used to prevent the pump from losing prime when pumping from a well?

• A. Pressure regulating valve.
• B. Foot valve in the intake line.
• C. Strainer in discharge line.
• D. Air relief valve.

Answer: (B)

Maintaining prime on a well pump hinges on keeping the suction line full of water. The foot valve in the intake line is a one-way valve with a screen at the end of the suction pipe. It closes when the pump stops, holding water in the suction line and preventing backflow and air from entering. That way, when the pump starts again, it’s already primed and ready to move water. The screen also helps protect the pump from debris. The other devices serve different roles: a pressure regulating valve controls downstream pressure, a strainer in the discharge line protects against debris on the discharge side, and an air relief valve vents trapped air but doesn’t keep the suction line from losing prime.