Sealing device has body with dead cavity side end surfaces of which include placed symmetrically with respect to axis of the body supports and slide that consists of cover and fixation body that is arranged as plate one of surfaces of which at side of the openings has slots placed in parallel and symmetrically with respect to axis of fixation device. Axles of openings are normal to axis of the opposite slot. Side end surfaces of fixation body include springy teeth placed symmetrically with respect to axis of fixation body. Side end surfaces of dead cavity have additional supports and side end surface of fixation body has additional springy teeth.
