The Principle Operation of a Spill-Resistant Pressure Vacuum Breaker – Backflow Prevention Device Assembly

The Spill-Resistant Pressure Vacuum Breaker Backflow Prevention Device Assembly (SRPVB) is a mechanical backflow prevention method used to prevent backsiphonage of non-potable water into the potable water system. The SRBVB is a similar to the pressure vacuum breaker and essentially has the same applications and specifications as the PVB. It consists of a spring-loaded independent check valve, a spring-loaded independent air inlet valve, and two resilient seated shut-off valves upstream and downstream of the SRPVB. Unlike the PVB, which has two test cocks, the SRPVB has only one test cock and a bleed screw or vent valve. The SRPVB can be used within a building contrasting the PVB which cannot be used internally within a building where water spillage could cause damage. The SRPVB is designed to prevent spillage upon start-up by closing the air inlet valve before the check valve opens. Like the PVB, the SRPVB is used for indirect cross-connections and can be installed to control high and low hazardous backsiphonage cross-connection situations. The SRPVB is NOT designed to control backflow backpressure and should not be used where there is a possibility that backpressure would develop. However, the SRPVB can operate under continuous or intermittent pressure conditions meaning that the SRPVB can retain pressure when in a static state condition. Therefore, downstream shut-off valves can be utilized without compromising the integrity of the backflow prevention device assembly. Maximum working water pressure is 150 psig and the operating temperature is in the range of 33 degrees F to 180 degrees F. The SRPVB comes in sizes ranging from 3/8 inch to 1 inches. The SRPVB shall comply with the American Society Sanitary Engineering 1056 Standard.