Hoffman 401461, Model 45 Convector Steam Vent, 1/2" F NPT x 3/4" M NPT Air Valve (non-vacuum). Single non-adjustable port. For small steam systems. Telescopic siphon tube with angle cut assures drainage. 1⁄2" NPT female and 3⁄4" NPT male straight shank Maximum operating pressure 6 psig (0.4 bar). Maximum pressure 10 psig (0.7 bar).Replaces Vend-Rite # 35 & Dole 1933 SS 3/4"