GIRTH AND SEAL WELDING APPARATUS

摘要

A welding apparatus is disclosed for seal welding closed the bore of a sealing plug which is positioned adjacent the end of a hollow tube and where the bore defines an axis in communication with the tube. The apparatus includes a head with an end stop member rotatably mounted thereto. The end stop member is movable between an extended position where the front sealing plug engaging end is extended for engaging and supporting a sealing plug during girth welding, and a retracted position where the end stop member is retracted. A seal welding electrode is supported in an axial passage of the end stop member and is movable therein between a retracted non-welding position and an extended seal welding position where the electrode tip extends outward beyond the front opening of the end stop member for permitting the seal welding closure of the sealing plug axial bore. Drive means is interconnected to the seal welding electrode and end stop member for 1) moving the end stop member to a retracted position while moving the seal welding electrode to an extended welding position and for 2) moving the end stop member to an extended position while moving the seal welding electrode to a retracted non-welding position.