Watts 0138457 1/2" N36 Vacuum Relief Valve

Watts 0138457 1/2" N36 Vacuum Relief Valve. Vacuum Relief Valves function in water heater applications to automatically allow air to enter into the piping system to prevent vacuum conditions that could siphon the water from the system permanently damage or ruin your water heater. This Vacuum has a brass body, a single NPT male inlet connection, and a protective cap. The Vacuum Relief Valve can also be used with low pressure steam and water service tanks.