Tetningssystem

Seal assembly comprising a seal ring (3) sealing between an inner and outer tubular element. Inner or outer surface (7, 5) has an inclined element surface (9) against which the seal ring (3) moves, thereby altering its circumference (C). An activation arrangement (2) exerts actuation force onto the seal ring, forcing an inclined seal ring surface (11) of the seal ring (3) against the inclined element surface. The activation arrangement maintains said actuation force along a function path of the seal ring, as a result of radial expansion or reduction of the inner or outer surface. When radial distance between inner and outer surface increases, the activation arrangement moves the seal ring along the inclined element surface in one direction. When radial distance decreases, the activation arrangement is compressed, and the seal ring moves along the inclined element surface in a second opposite direction.