METHOD AND EQUIPMENT FOR MANUFACTURING INTERNAL AND EXTERNAL LINING PIPES

摘要

PROBLEM TO BE SOLVED: To provide a method and equipment for manufacturing internal and external lining pipes which can facilitate manufacture of a combined article of internal and external synthetic resin pipes and a metal pipe and enable reduction of the cost and improvement of productivity. SOLUTION: An internal covering pipe 12 covering the inner surface of the metal pipe 11 is inserted through an external covering pipe 13 covering the outer surface of the metal pipe 11 and the two covering pipes are disposed concentrically. In this state, the metal pipe 11 is inserted between the two covering pipes 12 and 13 and then heat treatment is executed.