| 摘要 |
PROBLEM TO BE SOLVED: To provide a double pipe structure that is double pipeline, and in which at least pipe end parts are made concentric, and a joint utilizing the double pipe structure.SOLUTION: In a double joint 1 in which the pipe ends of an outer pipe 2 and an inner pipe 4 are concentric with each other, the outer pipe and the inner pipe are welded at the pipe ends, and then subjected to bending. In the end part of the outer pipe, at its center, provided is a flange 6 to which the inner pipe is welded and fixed. At the center of the flange, a recess part having a diameter larger than an inner pipe contour is engraved on the opposite surface to the outer pipe. At the center of the recess part, the inner pipe end part is protrusively provided.SELECTED DRAWING: Figure 1 |
