Hoffman 401413

4A, ½” x ¾” Straight Steam Main Air Valve

Air Valve (non-vacuum)

• Float-type thermostatic vent
• For residential or small one-pipe or two-pipe systems
• Single non-adjustable port
• 1⁄2” NPT female and 3⁄4” NPT male straight shank
• Install 6-10” (150-250mm) above horizontal return and 18” (450mm) above the boiler water line
• Maximum operating pressure 2 psig (0.13 bar)(Drop away pressure - maximum pressure against which the vent can open).
• Maximum pressure 10 psig (0.7 bar)