Welding electron beam exit seal - with vacuum chamber of several collapsible segments

摘要

A beam exit seal for charge carrier (electron) beam welding, e.g. for the butt welding of tubes, consists of an annular chamber of U-section which is applied vacuum-tight against the inner wall of the joint and can be evacuated. The chamber is assembled from at least two(six) segments which form a tight joint at their ends and can be retracted radially inward before withdrawal. The sealing device can thus be inserted and withdrawn even when the access opening are much smaller than the inside dia. of the weld.