A relief valve that is activated will dump the excess pressure to the:

• A. Intake side of the pump
• B. Discharge side of the pump
• C. Tank
• D. Atmosphere

Answer: (A)

A relief valve on a fire pump is there to protect the pump and piping by bypassing excess pressure back to the low-pressure side. When the valve opens, it sends the surplus flow from the discharge side back into the pump’s intake (suction side). This creates a recirculation path that keeps discharge pressure from rising above the set point, preventing damage and cavitation.

Venting to the discharge side would not relieve pressure where it’s where the pressure is already high, and dumping to a tank or to the atmosphere bypasses the intended low-pressure return path, which can cause imbalanced flow, backflow issues, or safety hazards. So the correct behavior is to dump the excess back to the intake side.