This 4″ Sch 80 CPVC True Union Diaphragm Valve, VITON, (FNPT x FNPT) is a true union diaphragm valve restrics flow through it as the handel is turned. The clear section on top allows you to see the valve position. 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. Have a question? Check our technical resources section or give us a call and take advantage of our years of experience.