An embodiment providing a seal assembly for turbomachinery for controlling flow of a fluid medium in a fluid path comprises a casing having an internal pressure load path and a seal carrier chamber. A movable seal carrier is disposed within the seal carrier chamber and interposed between the pressure load path and an external flow path. In addition, a pressure selecting apparatus is coupled to the pressure load path to control flow therethrough. Moreover, the position of the movable seal carrier moves in response to a pressure differential determined by the pressure selecting apparatus between the pressure load path and the external flow path.