Griffco diaphragm back pressure valves are designed to enhance the performance of chemical feed systems by applying a continuous back pressure to the chemical feed pump, while also acting as an anti-syphon valve. Robust construction ensures reliability in the rigorous service of municipal and industrial applications. Wetted materials include: PVC, CPVC, PP, PVDF, PTFE, 316 SS, A 20 and Hast. C. Available sizes: ¼" - ½".