Patent ID: 6966332

Claim:
An air valve assembly for use with a fire hydrant, said assembly having a housing with an air valve located therein, said fire hydrant having a barrel with a main valve located at a lower end of said barrel, said barrel being connected to a water supply, said main valve being operable to control flow of water under pressure to substantially fill and replenish said barrel when said main valve is on and to cut off said flow of water under pressure when said valve is off, said barrel having drainage valves located at or near said main valve, said drainage valves being pressure operated to open and close when said main valve closes and opens respectively, said barrel having a bonnet at a top thereof, said air valve assembly being mounted between said bonnet and said barrel to connect an interior of said barrel with ambient air when said air valve is open and to cut off said barrel from ambient air when said air valve is closed, said air valve being operable between an open position and a closed position in response to pressure within said barrel, said air valve closing when said main valve is on and opening as pressure within said barrel decreases when said main valve is off.