An air valve for the demand or second stage of a scuba regulator disposed between the intermediate pressure region and the low or breathing pressure region which includes, a stationary valve seat and a tubular, movable valve element whose sealing edge is sealingly biased against the valve seat. The interior of the tubular element is in communication with the low pressure chamber and the forward portion of the exterior of the tubular element is in communication with the intermediate pressure chamber. And a flexible sealing means forming a wall between the low and the intermediate pressure regions and supporting the valve element for limited movement between a closed and an open position.