| 摘要 |
PURPOSE:To prevent the oxidation of the inner periphery of the joining part by forming a partitioning space with sandwiching the joining part of the pipe to be welded by an inserting tool into the pipe, by filling up an inert gas in this space and by performing a welding with this condition. CONSTITUTION:The bevel of the tip of pipes 5, 5' to be joined is held with abutting each other and an inserting tool 6 is inserted from one part of the pipe 5, 5' so that the joined part 7 thereof is made about the center of the rubber sheet 2, 2' of the inserting tool 6 into the pipe. An inert gas 8 of Ar, etc. is passed to the joined part 7 from a gas 8 releasing hole 4 which is made between the rubber sheet 2, 2' through a pipe 1. Accordingly the air is discharged from the contact part of the pipes 5, 5' and the gas 8 only is filled up and with this condition the pipe 5, 5' are joined with welding by arc welding, etc. along the bevel which is provided on the outer periphery of the joined part 7. With such method as like this the oxidation of the inner periphery of the joined part 7 due to the heating at welding time and the deterioration in the quality, performance, etc. can be prevented. |
