| 摘要 |
<p>PURPOSE:To prevent a removal owing to a thermal contraction by covering the inner wall surface of a metal pipe with a synthetic resin, making desired parts of the inner surface contract its diameter to the inner side in the radius direction of the pipe, forming the diameter-contraction parts continuously in the axial direction drawing spirals, and forming an air core at the center of the pipe constantly. CONSTITUTION:A lining pipe 1 furnishes a metal pipe 2 and a synthetic resin inner tube 3 to form a lining layer, and the metal pipe 2 and the inner tube 3 are connected unitary through an adhesive layer 4. Furthermore, while the desired parts of the tube wall are contracted in the diameter to the inner side of the tube, the diameter-contracting parts are formed continuously drawing spirals in the tube axial direction. As a result, no pressure change occurs in the tube, and it is unnecessary to prepare a vent pipe and the like.</p> |
