This 3″ Sch 80 CPVC Pneumatic Butterfly Valve, VITON, Single Acting, (FLANGE x FLANGE) is a butterfly valve with a pneumatic actuator on top for automatic control when compressed air is applied. the penumatic actuator opens when compressed air is applied to it but closes due to internal springs. Butterfly valves are installed between a pair of flanges with falnge bolts. No gaskets are required, they are built into the valve face. 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. Our prices are a fraction of what you pay at your local plumbing store, order from Petram PVC Supply for quick shipping.