The Principle Operation of a Dual Check Valve Backflow Prevention Device – General Specifications

The Dual Check Valve (DuCV) is a backflow prevention device designed to prevent the non-potable from enter the potable water system during a backflow event in the plumbing system. The DuCV is designed for non-health hazard residential water system containment and continuous pressure applications, such as the drinking water supply service entrance or individual outlets. The DuCV is equipped with two independent operating spring-loaded check valves. Each check valve is designed to hold at least 1 psi in the direction of flow. The check valves are force loaded to a normally closed position. The DuCV is capable of being used under constant pressure and can be used where backpressure or backsiphonage is present. The DuCV is suitable for hot or cold water service installations with an inlet temperature range of 33 to 180 degrees F. Hot water use may be limited by the manufacture specification. The maximum working pressure is 175 psi. The minimum required inlet pressure is 10 psi. The DuCV sizes range from ½ inch and 1 inch sizes. Temperature and working pressure can be size dependent, refer to manufacture specifications. The DuCV is not equipped with test cocks or upstream and downstream shut-off valve therefor; the DuCV is not listed as an “assembly.” The DuCV is classified as a backflow prevention “device” that can be installed vertically or horizontally. The DuCV shall only be used for low hazardous situations where there are no chemical hazardous being used downstream. The DuCV shall comply with ASSE Standard 1024.