What is the minimum reading required on the air inlet of a Pressure Vacuum Breaker (PVB)?

The minimum reading required on the air inlet of a Pressure Vacuum Breaker (PVB) is 1.0 psi. This reading is critical as it indicates that the PVB is functioning correctly to prevent backflow in a plumbing system. The PVB is designed to maintain a specific air gap to separate the drinking water supply from water of questionable quality, and a minimum pressure reading ensures that the atmospheric pressure necessary to prevent siphoning is present.

When the pressure is at or above this threshold, it guarantees that the device can effectively keep contaminants from entering the potable water supply during instances such as changes in water pressure. This is particularly important in irrigation systems and other applications where the potential for contamination is a concern. Proper maintenance and testing of the PVB, including checking that it registers at least 1.0 psi at the air inlet, is essential for compliance with health and safety standards in plumbing systems.