What is a Double Check Valve Assembly (DCVA) device?
A Double Check Valve Assembly (DCVA) is a mechanical backflow prevention device that consists of two internally loaded check valves. It includes two shut-off valves and four test cocks. With the two check valves in series, a DCVA prevents backflow even if one check valve fails to close tightly. It can be used to prevent backflow due to both Back-siphonage and Back-pressure where a minor or moderate hazard exists. Since no visible warning is given of a failure of check valves, a DCVA must be tested at least annually to ensure proper operation.
