MANUFACTURE OF PIPE FOR HEAT EXCHANGER

摘要

PROBLEM TO BE SOLVED: To realize outstanding weeping characteristics and an improved resistance to sulfuric acid by coating the outer circumference of a draw-molded pipe with a heat-resistant film and winding a reinforcing fiber impregnated with a heat-curable resin around the surface of the heat-resistant film to perform the heat curing of the reinforcing fiber. SOLUTION: A carbon fiber 1a is adopted as a reinforcing fiber 2 and a phenol resin is used as a heat curable resin 1b. First the carbon fiber 1a is impregnated with the heat curable resin 1b such as the phenol resin or an epoxy resin and the impregnated fiber 1a is introduced through a mold 3 into a draw- molded pipe 1 by draw molding. After that, the surface of the pipe 1 is impregnated with the phenol resin and then a heat-resistant film 4 is wound around the pipe 1. Further the less twisted carbon fiber 1a impregnated with the phenol resin is wound on the film 4 to be thermally cured by a heating part 8. In this case, a tapelike fluororesin film or the like is used as the film 4 and is wound in such a manner that some part equivalent to about one third of the film 4 is overlapped. Thus it is possible to realize the outstanding weeping characteristics and the improved resistance to sulfuric acid.