An access chamber assembly for use in a pneumatic transport system with a sealing arrangement that provides an intended bearing clearance relative to an access door device which is rotated between an open, access state and a closed state. The bearing clearance allows for radial adjustment of the door while being rotated between states of being fully closed and fully open to avoid binding and seal friction noise. When a seal status is desired, as when the access door is closed and the access chamber is in a pressurized state (such as when a carrier is being braked to a stop state in the access chamber), the seal arrangement provides for a tight seal as the access door device is radially adjusted by the pressure to take up the clearance, at a diametrically opposed side, which movement also increases a seal enhancement effect provided by the seal components surface interrelationship as with door bar seals having a slight taper that provides an increased seal wedge effect as the access door is radially pushed out by the pressure against a second seal component such as a fixed lip seal of a carrier support pocket.