Kingston Model 305B Balanced Normally Closed, Quick Opening Valve has a stem design that permits pressure equalization across stem seat allowing ease of operation at high pressures. This valve has a body of heavy cast brass with internal components of machined brass. Springs are stainless steel. The standard valve disc and O-ring are Buna-N. Teflon and Viton seals are available on most sizes. Maximum working pressure, 400 psi, @ 60°F. Maximum working temperature, 200°F. Kingston Model 305B Balanced Normally Closed, Quick Opening Valve is widely used for agricultural spraying, carwash systems, high pressure washers, liquid transfer, air and liquid control applications. This valve has been in service for years on both compressed air and liquid.This valve is not recommended for steam service. Applications requiring manual operation at pressures below 150 psi, please refer to Kingston Model 305A Flow Control Valves.