HAV Series automatic vent valves are used in commercial, residential, and industrial hydronic heating applications to provide automatic or manual air venting in baseboards, connectors, radiators, and high points in piping systems. It consists of a 2-piece, chromed brass body construction, stainless steel check valve, brass disc bearing cover, copper thermostat assembly, neoprene O-ring, cellulose fiber disc, replaceable cartridge, and ABS heat resistant handwheel. Cartridge can be easily maintained or replaced without system shutdown. It is ideal for use with hot water and low pressure steam systems. Maximum pressure: 125 P.S.I. (8.6 bars). Size 1/8".