| 摘要 |
CONSTITUTION: A double pipe 10 is used for supplying hot water or cold water and comprises a synthetic resin inner pipe 12 and a cladding tube 14 covering an outer peripheral surface of the inner pipe. The cladding tube has a thickness of tube wall formed uniformly or in a substantial uniform manner. In addition, the cladding tube is formed with a plurality of crest segments 16 protruding toward its outer peripheral direction. The crests are arranged in a circumferential direction under a desired spacing and extend in an axial direction of the cladding tube. A part between the adjoining crests acts as a supporting part 18 for supporting the outer peripheral surface of the inner pipe, its inner peripheral surface abuts against the outer peripheral surface of the inner pipe. The inner pipe is abutted against and supported by this supporting part over a full length in an axial direction of the cladding tube, i.e. irrespective of its axial position.EFFECT: Impact noise generated through contact between an inner peripheral surface of a cladding tube and an outer peripheral surface of the inner pipe can be reduced even if the inner pipe shows a substantial vibration due to water hammer phenomenon.SELECTED DRAWING: Figure 2 |
