What does it indicate if water is coming out of the atmospheric port of a reduced pressure zone (RP)?

When water is observed coming out of the atmospheric port of a reduced pressure zone (RP) valve, it indicates that there is likely debris in the check valve or an issue such as high demand downstream.

The RP valve is designed to maintain a lower pressure on the discharge side than on the supply side, preventing backflow and potential contamination of potable water. If there is debris stuck in the check valve, it could prevent the valve from closing properly or cause fluctuations in the pressure that could lead to discharge at the atmospheric vent. Additionally, high demand downstream could lead to temporary drops in pressure that might force water out of the atmospheric vent.

Recognizing this condition is crucial for maintaining system integrity and ensuring safety standards in plumbing systems. Addressing debris within the check valve or assessing downstream demand is essential for correcting the issue and restoring normal operation. Understanding the mechanics of the RP valve and the implications of water discharge from its atmospheric port helps in diagnosing and resolving plumbing problems effectively.