Abstract: A thick tube welder for welder together a tubular end fitting and a tube. The end fitting and the tube are placed in axial alignment within a welding head housing with the end fitting being located in a mounting housing. The mounting housing is then fixedly secured to the welding head housing. An inner welding electrode is connected to the mounting housing and is located in alignment with the inner surface of the welding joint. An outer welding electrode is located in alignment with the exterior surface of the welding joint with this electrode being mounted on the welding head housing. Both electrodes are rotatably driven either simultaneously or in sequence in order to create the weld between the tube and the end fitting. Depending on the length of the end fitting, the inner welding electrode is to be adjustable longitudinally relative to the welding joint.

Abstract: A welding apparatus for pipes which provides for a guide means which is to be fixedly secured to the pipe adjacent the welding area, a first carriage and a second carriage is movably supported upon the guide means with each of the carriages supporting a pair of spaced apart welding heads. Attached to the guide means is a driving chain. Mounted on each of the carriages are motor means which, in turn, operate through the driving chain to move the carriages in a prescribed manner with respect to the guide means. The welding heads of each of the carriages move within the same plane but each are movable in a separate one hundred and eighty degree arc thereby forming a continuous circle. Associated with each welding head is a weld groove tracking system which automatically maintains each welding head correctly aligned within the welding groove. The entire apparatus of this invention, when combined with appropriate electronic computer equipment, automatically welds an adjoined pair of piping sections.