Hoffman, #H40, 1/8" Male Pipe Angle Steam Radiator Air Valve Connector, Float-type vent, For ordinary one-pipe system that doesn¦t require proportional venting, Single non-adjustable port, 1/8" NPT angle connection, Maximum operating pressure 6 psig (0.4 bar)(Drop away pressure - maximum pressure against which the vent can open), Maximum pressure 10 psig (0.7 bar).