Intro4u2u

A double check valve or double check assembly (DCA) is a backflow prevention device designed to protect water supplies from contamination. It consists of two check valves assembled in series usually with a ball valve or gate valve installed at each end for isolation and testing. Often, test cocks (very small ball valves) are in place to attach test equipment for evaluating whether the double check assembly is still functional.

The double check valve assembly is suitable for prevention of back pressure and back siphonage, but is not suitable for high hazard applications. It is commonly used on lawn irrigation, fire sprinkler and combi-boiler systems.

Double Check Valve Assemblies are designed to prevent the reverse flow of polluted water from entering into the potable water system. Check with local jurisdictional authority as to installation requirements. The check valves utilize a single torsion spring design to minimize pressure drop through the assembly. The check valves shall be modular and shall seal to the main valve body by the use of an O-ring. The main assembly consists of two independently operating torsion spring check assemblies, two resilient seated isolation valves, and four ball valve type test cocks