Griffco high flow diaphragm pressure relief valves are designed to protect chemical transfer systems from over pressure damage caused by defective equipment or a blockage in the chemical line. Large orifice sizes facilitate high flows and high viscosity. Wetted materials include PVC, CPVC, PP, PVDF, PTFE, 316SS, A20 and Hast. C. Available sizes: 1/2" , 3/4, and 1".