Series L7 In-Line Testable/Serviceable Dual Check Valves prevent the reverse flow of polluted water from entering into the drinking water supply at the service entrance or at individual outlets. It consists of a bronze body construction, with two plastic check valves with top-mounted covers, silicone discs, stainless steel springs, and three test ports for easy in-line service. Series L7 is designed for non-health hazard residential water system containment, continuous pressure applications and is installed immediately downstream of the residential water meter. Check with local inspection authorities for installation requirements. Minimum Working Pressure: 10psi (69 kPa) Maximum Working Pressure: 175psi (12.06 bar).