Apollo Valves 1060805 Safety Relief ValveProtect against excessive water pressure due to failure of controls to regulate BTU input.High BTU capacity rating. Corrosion-resistant with silicone seat. Fabric reinforced, molded diaphragm isolates spring from water at all times. FNPT connections.Apollo Valves 1060805 Safety Relief Valve Features: Safety Relief Valve Inlet/Outlet 2 In FNPT Connection Material of Construction Bronze Preset Setting 30 PSI Pressure Range 15 To 160 PSI BtuH Rating 5193000 Temp Range 250 F Standards ASME Section IV CSA CRN