| Suitable for residential commercial industrial irrigation marine and fire protection applications | Prevents the reverse flow of water gases or other substances into the distribution system of the potable water supply | Pressure differential relief valve between two independent spring-loaded "Y" type center guided check valves complete with two full port ball valves and four ball valve test cocks | Noryl replaceable seats and silicone rubber check discs | Entire unit serviceable in-line | Temperature range 33°F to 180°F | Maximum pressure 175 psi | Listed ASSE 1013" AWWA |Compliant for Lead Free legislation