What testing procedure verifies the performance of a PRV after installation?

• A. After installation, the PRV is judged by the color of the device and brand label.
• B. Observe that downstream pressure stabilizes at the setpoint under varying flow, and check for leaks; adjust using gauges as needed.
• C. Only verify that the PRV is physically present and not leaking.
• D. Checking upstream pressure alone is sufficient.

Answer: (B)

Verifying a PRV’s performance means confirming it actually maintains the downstream pressure at the intended setpoint as flow changes, and that there are no leaks in the system. The right approach is to monitor downstream pressure while varying flow to simulate different demands. If the downstream pressure stabilizes at the setpoint across a range of flows and there are no leaks, the valve is regulating correctly. If the pressure drifts away from the setpoint or leaks are detected, adjust the PRV using the appropriate adjustment method and gauges, then re-test until the pressure remains steady. Relying on the device’s color or label doesn’t test performance, and simply confirming the PRV is present or checking upstream pressure alone doesn’t verify proper downstream regulation.