What is the primary purpose of a discharge relief valve in a fire pump system?

• A. To prevent over-pressurization of the discharge side and protect hoses and equipment.
• B. To reduce pump efficiency.
• C. To heat the discharge water.
• D. To provide backward flow.

Answer: (A)

The main idea is to keep the discharge pressure from rising beyond what the piping and hoses can safely handle. A discharge relief valve is set to open at a specific pressure so that if the pump tries to push more water than the system can absorb—such as when a discharge valve is closed or a hose is capped—the excess water is released through the valve back into the suction side or to a drain. This prevents damage to hoses, fittings, and the pump, and it also helps reduce the risk of water hammer and unsafe pressure spikes. It isn’t intended to improve efficiency, heat the water, or create backward flow; its job is to relieve excess pressure on the discharge side.