Which option is NOT a stated purpose of the discharge-side relief valve?

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

Answer: (D)

The discharge-side relief valve is used to protect the system from pressure issues and help regulate flow, not to start or prime the pump. It opens when discharge pressure gets too high to absorb surge energy and keep the system within safe limits, and it can help modulate flow to maintain a steady pressure in the network. Priming the pump, by contrast, is a suction-side process aimed at filling the pump with water and removing air to enable starting; a relief valve on the discharge side does not perform priming. So the statement that is not a stated purpose is priming the pump.