| 摘要 |
<p>PURPOSE: A process for manufacturing a double pipe with naturally friendship feature is provided by using noticeably great variation between contraction and expansion of synthetic resin pipe and less variation between contraction and expansion of metallic pipe. CONSTITUTION: The process comprises a cooling step of the metallic and synthetic resin pipes(1,2) to reduce diameter of both pipes; a coupling step of both pipes with reduced diameters by means of an insertion device; and an connection step of both pipes by leaving the metallic pipe into which the synthetic resin pipe is inserted at room temperature to allow outer side of the resin pipe to be closely connected to inner side of the metallic pipe. The process may further have a step of applying adhesive(3) to the inner side of the metallic pipe before the coupling step and anther step of applying paint to the outer side of the metallic pipe before the cooling step in order to resist corrosion of the metallic pipe caused by moisture generated during the cooling step.</p> |
