The Principle Operation of a Pressure Vacuum Breaker Backflow Prevention Device Assembly – Flow Capacity
When the PVB is fully pressurized and there is a demand downstream, (dynamic state) the check valve is open and the air inlet valve is closed. The grater the rate of flow (gpm) through the PVB, the grater the check valve will open. As the rate of flow in gallons per minute through the PVB increases, the pressure loss in pounds per square inch increases. Consult manufactures’ literature or capacity rate for specific PVB.
