Abstract: This invention relates to apparatus for sealing a clearance between two components in relative movement one with respect to the other. A sealing strip between the two components is arranged in a direction transverse to the direction of movement to bear against a sealing face of the first component to seal the clearance. The sealing strip is allowed to float in a groove in the second component on a fluid flowing all around between the groove and sealing strip. This invention finds preferred use on rectangular-section exhaust gas nozzles of turbojet engines, where the components represent the lateral wall or nozzle flaps and the fluid is air tapped at the compressor, which simultaneously serves to cool the nozzle flaps and the sealing strip. The contact pressure of the sealing strip against the sealing face can therefore be made a function of engine load.