Abstract: The sealing device has a sealing element which can be moved axially relative to the column by means of a positioning ring. A threaded bushing and a threaded ring that is screwed into it enclose the positioning ring. By means of these, the sealing element on the one hand is held at the column and, on the other hand, can be moved by turning the positioning ring. Thus, the connection points of the finished column can be matched to an existing line system.