Maid O Mist 75 psi Auto-Vent Automatic Air ValveThe model No. 72 Auto Vent is a fast venting valve of the expansion type, up to 75 lb. pressure. For vertical or horizontal mounting on convectors, baseboard, and freestanding radiators. 1 8" I. P. Male connection, 1 1 4" x 1 2". All expansion and contraction of the single nonporous, composition disk is confined to 4 vent ports. Manual venting and tight shutoff are controlled by a valve cap with screwdriver slot adjustment. %search_data%72