Hoffman 401434 # 75 1/2" Female X 3/4" Male Connection Steam Vent Model 75 Part No. 401434 Air Valve (non-vacuum) Specifications: Float-type thermostatic vent For medium and large systems Single non-adjustable port 1/2 NPT female and 3/4 NPT male straight shank Maximum operating pressure Model 75 3 psig (0.2 bar) Maximum pressure 15 psig (1.0 bar)