Series 909 Reduced Pressure Zone Assemblies prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage and or backpressure. It consists of a bronze body construction, bronze ball valve shutoffs, and bronze test cocks. Series 909 features a patented "air-in/water-out" design principle for protection during emergency combined backsiphonage and backpressure conditions. It is ideal for health hazard cross-connections or for containment at the service line entrance. Check with local water authorities for installation requirements. Maximum Working Pressure: 175psi (12.06 bar).