Series M200, M200N Double Check Valve Assemblies are specifically designed for high flow fire systems to prevent the backflow of pollutants that are objectionable but not toxic, from entering into the potable water supply. Its compact housing consists of two independently operating tri-link check valves, two shutoff valves, and four test cocks. It features a stainless steel housing and sleeve and is 70% lighter than traditional designs. The Series M200, M200N features the certified lowest pressure loss and is designed for non-health hazard applications. It may be installed under continuous pressure service to protect against both backpressure and backsiphonage. Maximum Working Pressure: 175psi (12.06 bar).