Abstract: A joint between adjacent ends of two pipes arranged to convey liquid under pressure, and which permits relative movement of the pipes, has a first sealing surface of annular form associated with one of the pipe ends and a sealing member supported by the other pipe and movable axially relatively thereto, and having a second sealing surface of annular form which co-operates with the first sealing surface, the sealing member being urgeable away from the first sealing surface by the pressure of liquid within the pipes against a restraining force to provide a clearance between the sealing surfaces which is adequate to permit relative transverse movement of the sealing surfaces to take place without sliding contact, but at the same time provides a high resistance to the flow of fluid between them.