Tube removal method

摘要

A method and apparatus for removing a hollow tube from a tube sheet in which the tube is held by expansive forces in the tube. A GTA arc is established between an electrode and the interior tube wall. The arc parameters are such that it melts partially through the tube wall and the arc is then translated in a desired pattern of movement along the length of the tube contained in the tube sheet. Upon re-solidfication of the melted part of the tube the compressive forces of solidification shrinkage and thermal contraction result in a reduction of the tube diameter. Apparatus is disclosed for carrying out the method which, through a dual drive arrangement, is capable of producing a variety of weld head translation paths.