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

• A. To vent air from the discharge line.
• B. To measure pump RPM.
• C. To prevent excessive discharge pressure by bypassing water back to the intake when set pressure is reached.
• D. To filter debris from water.

Answer: (C)

The main idea is protecting the pump system from overpressure by providing a controlled bypass when the discharge pressure reaches a set value. A relief valve opens at its preset pressure and allows water to flow from the discharge back to the pump intake (or to the tank). This creates a relief path that stops pressure from climbing higher, protecting hoses, fittings, gauges, and the pump itself, and helping maintain a stable flow when demand changes. Vents for air, RPM measurement, and debris filtering are accomplished by other components, not this valve.