This 2½” Sch 80 CPVC Swing Check Valve, VITON, (FNPT x FNPT) has a disk inside the swings open and closed to prevent flow in one direction using back pressure. a male adaptor, threaded pipe or pipe nipple connects to this part. CPVC is a higher temperature version of PVC and has better chemical resistances. VITON seals provide increased temperature resistance than EPDM seals and recommended for exposure to oils, gasoline and aggressive chemicals. Petram PVC supply has a huge inventory of Sch 80 PVC and CPVC parts.