Watts 150 psi Automatic Air Vent Valve FV-4M1-

Provides automatic air venting for hot or cold water distribution systems, this WATTS automatic air vent valve,uses a float to actuate the valve plug which is located at the top of the valve. Once the air is displaced and the system pressure is sustained, the valve plug seals and prevents any water from escaping from the system. This valve can also purge air that may be in the water system. Model can be disassembled for maintenance.