A coupler adaptor is provided for use in operative association with a container and a valve. The container houses relatively high pressurized carbon dioxide gas for use in carbonating a beverage. The valve is actuated in order to release the gas to an interface passage formed in the coupler adaptor. The coupler adaptor also has a pair of grooves formed on opposite sides of the interface passage for receiving O-rings. The coupler adaptor is also in operative association with a pressure regulator. The pressurized gas enters the pressure regulator from the coupler adaptor interface passage. In one embodiment, the coupler adaptor remains operatively joined to the pressure regulator without retaining structure due to the balanced gas pressure which results because of the O-rings positioned adjacent the coupler adaptor interface passage.