| 摘要 |
PROBLEM TO BE SOLVED: To provide an expansion joint having a simple configuration and improved durability, and suitable for detecting the occurrence of a broken hole, and to provide a method for detecting a broken hole using the same.SOLUTION: The expansion joint 10 includes a first PTFE-made coating layer 15 to cover a surface of a cylindrical part 14 which is disposed at a connection part of a channel 11 and expandable in the axial direction, and a second coating layer 17 which covers a surface of the first coating layer 15 with a spacing 16 therebetween, and has higher durability against the cyclic bending than that of the first coating layer 15. The method for detecting a broken hole of the expansion joint detects a variation in pressure in the spacing 16. |
