Plastics lined pipes prodn - by introduction of compressed lining and allowing the lining to expand to grip the pipe wall

摘要

Thermoplastic resin lining is introduced into a pipe with a lengthwise passage whose dia. is smaller than that of the lining, by compressing the lining in a radially inwards direction in order to decrease its dia., placing the lining in the pipe, and allowing the dia. of the lining to increase so that it is firmly gripped against the inside face of the pipe. The lined pipes can be produced rapidly e.g. steel pipes lined with polypropylene.