The relief valve on the discharge side of a pump is for what purpose?

• A. protecting the pump from excessive surge pressure
• B. flow control
• C. pressure regulation
• D. priming the pump

Answer: (A)

Relief valves on the discharge side exist to protect the pump and piping from overpressure caused by surge. When a valve closes quickly or demand drops suddenly, the discharge pressure can spike (water hammer). The relief valve opens at its set pressure and returns excess fluid back to the source or a safe return path, preventing damage to the pump, seals, and piping. It’s a safety feature, not a device for normal flow control or steady pressure regulation, and it’s not used for priming the pump.