Multiple welding head system for fabricating pipe

摘要

A pipe is fabricated from rolls of flat metal plate by continuously moving the plate into a pipe-forming station which shapes the flat plate into a pipe having a longitudinal seam therealong. A plate arc welding machine welds consecutive plates to each other thereby maintaining continuity of plate movement. Equal sections of the longitudinal seam are consecutively welded in a leapfrogging manner using two welding units movably positioned on the opposite sides of the moving pipe. The welding units alternatingly weld alternate and overlapping sections of the longitudinal seam. The welding operations are carried out without interference with the continuous movement of the pipe.