What is the purpose of the relief valve setting on a portable pump?

• A. To prevent damage by opening at a preset pressure and bypassing water back to the intake or tank.
• B. To regulate the pump speed for smooth operation.
• C. To vent exhaust from the engine.
• D. To monitor water temperature.

Answer: (A)

The relief valve setting on a portable pump is to protect the pump and the system from overpressure. It opens at a preset relief pressure and sends water back to the pump intake or tank, creating a bypass. This keeps discharge pressure from climbing too high, preventing damage to the pump, hoses, seals, and fittings, and helps the engine operate within safe limits, especially when a nozzle is closed or flow is restricted. It’s not about controlling pump speed, venting engine exhaust, or monitoring water temperature.