Where is a pressure relief valve typically mounted in an irrigation system?

• A. On the discharge line downstream of a valve to regulate flow.
• B. In the tank to maintain pressure.
• C. Mounted off a tee near the pump to vent excess pressure.
• D. In the suction line to prevent air intake.

Answer: (C)

Pressure relief valves are placed where they can quickly protect the pump and piping from overpressure. In irrigation systems, the valve is typically mounted on the discharge side of the pump, off a small branch near the pump. If flow is blocked or a zone valve shuts, pressure can spike; the relief valve opens at its set point and vents water to a safe drain or atmosphere, preventing damage to the pump, fittings, and piping. A valve on the suction side would risk drawing in air and harming the pump, while a valve inside a storage tank or downstream of another valve wouldn’t reliably protect the system. So mounting it near the pump on the discharge line is the standard, correct placement.