Abstract: A free draining, corrosive resistent valve for regulating the flow of corrosive fluids therethrough includes a plastic valve housing. An inlet passage extends into the housing and upwardly therein terminating in a valve seat. An inclined panel surrounds the inlet passage below the valve seat. An outlet passage extends from the lower most portion of the inclined panel through the housing. A plastic valve poppet is located above the seat having a diaphragm therearound with an upwardly extending stem. A plastic retainer is located above the diaphragm into which the stem extends. The retainer is adapted for affixing the diaphragm is a sealing relationship to the valve housing.