This 1?” Sch 80 PVC True Union Ball Check Valve, VITON, (FNPT x FNPT) prevents flow from going in one direction using a ball inside the valve that seals with back pressure. a male adaptor, threaded pipe or pipe nipple connects to this part. Sch 80 PVC is robust and durable, perfect for commercial and industrial applications. VITON seals provide increased temperature resistance than EPDM seals and recommended for exposure to oils, gasoline and aggressive chemicals. Why pay more at your local store? Shop Petram PVC Supply for your best price.