Watts Series FV-4M1-3/4 Automatic Air Vent Valves provide automatic air venting for hot or cold water distribution systems. These vents purge air that may be in the water system. The vent valve utilizes 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. The float vent can also operate as an anti-vacuum device since it will permit air to enter the system when it must be drained. It can also be installed to permit the separation and dispersal of air while fluid is actually circulating in the system. 

Brass body and cover

Air vent with silicone rubber seal

Float is high temperature resistant polyethylene

Suitable for use with glycol systems

Can be disassembled for cleaning and inspection

Working Pressure Range: 1.45 - 150 psi

Temperature Range: 33° - 240° F