An apparatus for connecting a respiratory device with a patient is provided, including a breathing tube for insertion into a patients trachea, an inflatable cuff positioned around the breathing tube, a connection tube connected to the cuff for providing inflating air flow thereto, a pressurized air reservoir, and a valve connected to the pressurized air reservoir and to the proximal end of the connection line. The valve includes an entry port associated with an entry differential force chamber, a first exit port associated with a first differential force chamber and coupled with the connection line, a second exit port associated with a second differential force chamber and coupled with the pressurized air reservoir, and a flexible membrane selectively sealingly separating the differential force chambers. The flexible membrane is configured to selectively connect the first and second differential force chambers to maintain a substantially constant air pressure in the cuff.
