| 摘要 |
PURPOSE:To reduce the connecting cost of large and small cylindrical pipes by subjecting the mild metallic wire press-fitted into the space between the two pipes to inert gas tungesten welding then subjecting the weld zone to inert gas metal arc welding. CONSTITUTION:A mild metallic wire consisting of an annealed aluminum wire is wound by one turn in the space between the front end of a large-diameter cylindrical pipe 14 and a small-diameter cylindrical pipe 15 and the wire ends are lappsed adequately. Such mild matallic wire is press-fitted into the space between the pipes 14 and 15 by a caulking chisel to form a tentative sealing part 16. The part 16 is subjected to one layer of inert gas arc welding by an inert gas tungsten arc welding machine to form a weld zone 21 connecting the pipe 14 and the pipe 15. If a weld zone 23 is formed thereon by inert gas metal arc welding, intrusion of dust into the pipe is prevented by the part 16. The need for a packing and fastener, etc. is eliminated and the reduction in cost and operating time is made possible. |
