What is a residential dual check valve (rdc)?
An rdc is similar to a DC in that it is amechanical backflow preventer consisting of two independently acting, spring-loaded check valves. However, it usually does not include shutoff valves, mayor may not be equipped with test cocks or ports, and isgenerally less reliable than a DC. An rdc is effective against backpressure backflow and backsiphonage but should be used to isolate only non-health hazards and is intended for use only in water service connections to single-family homes. back to top Why do backflow preventers have to be testedperiodically? Mechanical backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested with properly calibratedgauge equipment.
A RDC is similar to a DC in that it is a mechanical backflow preventer consisting of two independently acting, spring-loaded check valves. However, it usually does not include shutoff valves, may or may not be equipped with test cocks or ports, and is generally less reliable than a DC. An rdc is effective against backpressure backflow and backsiphonage but should be used to isolate only nonhealth hazards and is intended for use only in water service connections to single-family homes.
