DCA – A double check valve or double check assembly (DCA) is a backflow prevention device designed to protect water supplies from contamination. … Secondly the closure of one valve reduces the pressure differential across the other, allowing a more reliable seal and avoiding even minor leakage.
RP – A Reduced Pressure Zone (RPZ) lets you know that the valve is working properly. RPZ backflow preventers consist of two independent check valves. They work like a double-check backflow preventer, but they also have an intermediate relief valve that opens to atmosphere if both check valves should fail.
HCVB – Hose Connection Vacuum Breaker
AVB – An Atmospheric Vacuum Breaker
DCDA – A Double Check Detector Assembly includes two check valves which ensures that one valve will close even if the other doesn’t.