| 摘要 |
PROBLEM TO BE SOLVED: To provide a positioning tool for double pipe capable of realizing its light weight and performing its easy attaching and removal at an optional location of a real pipe.SOLUTION: This invention relates to a double pipe having a real pipe 2 with round section and a protection pipe 3 with round section forming a space around the real pipe 2 to cover it in which a part of a ring having a certain width in a radial direction as seen in its top plan view has a substantial C-shape, a first arc 13 with a short radius of curvature is abutted against an outside part of a side circumferential surface of the real pipe 2, a second arc 14 with a long radius of curvature is abutted against an inside part of a side circumferential surface of the protection pipe 3, a central angle of the first arc 13 exceeds 180 degrees and a center of the round section of the real pipe 2 and a center of the round section of the protection pipe 3 can be coincided to each other. |
