Air Purger

Air Purger

Series FV-4M1 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.


• Body and cover are brass construction
• Air vent with silicone rubber seal
• Impurities do not usually affect function as maximum float line of water is always lower than the valve seal
• Float is high temperature resistant polyethylene
• Suitable for use with glycol systems
• Can be disassembled for inspection and cleaning

Pressure – Temperature

Minimum working pressure: 1.45psi (10 kPa)
Maximum working pressure: 150psi (10 bars)
Temperature Range: 33°F – 240°F (5°C – 116°C)


Air vent shall have brass body & cover and silicone rubber seal. Float shall be constructed of high temperature resistant polyethylene and shall be for use with glycol systems. Air vent shall be Watts Regulator Company Series FV-4M1.