Abstract: In order to permanently ensure the confinement of two closed volumes with respect to the outside atmosphere, while permitting the linking of said volumes, use is made of two gaskets, each having in section an approximately circular and generally hollow part, as well as a part forming a member. One of the gaskets is mounted by its member in a groove formed in a door received in a flange of the volume, whereas the member of the other gasket is fixed in a groove formed in a flange in which is received a door of the other volume. During engagement, the circular parts of the gaskets are in tight contact with one another and on V-shaped inclined surfaces formed within the flange and on the periphery of the door.