| 摘要 |
A method of manufacturing a double pipe includes a step of inserting a straight inner pipe into a straight outer pipe such that the inner pipe and the outer pipe are positioned at a predetermined relative position, a step of fixing a first end portion of the outer pipe to the inner pipe so as to form a first fixing portion, a step of bending the outer pipe and the inner pipe at the same time at a predetermined portion so as to form at least one bending portion after the fixing step of the first end portion, and a step of fixing a second end portion of the outer pipe to the inner pipe so as to form a second end portion after the bending.
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