Griffco high flow diaphragm back pressure valves are designed to enhance the performance of higher flow, continuos feed pumps that require a constant head pressure, while also acting as an anti-syphon valve. Larger orifice sizes make the valve ideal for use with higher viscosity fluids. Wetted materials include: PVC, CPVC, PP, PVDF, PTFE, 316 SS, A 20 and Hast. C. Available in ½", ¾" and 1" sizes..