Series C500, C500N, C500Z Reduced Pressure Detector Assembly Backflow Preventers are designed to prevent the reverse flow of fire protection system substances from being pumped or siphoned into the potable water supply. The C500 incorporates a meter to detect ground leaks and unauthorized illegal taps, greatly reducing annual water expenses. It consists of a compact, stainless steel body with stainless steel internal parts, two check valves, a pressure-differential relief valve, shutoff valves, torsion spring checks and relief valve, and bronze, nickel-plated test cocks. Series C500, C500N, C500Z is 70% lighter than traditional designs and is ideal for health hazard cross-connections, such as on fire sprinkler systems. Check with local water authorities for installation requirements. Maximum Working Pressure: 175psi (12.06 bar).