Analysis of fiber reinforced thermoplastic pipe perforation and bulging failure in gas field

A polyester fiber-reinforced thermoplastic composite pipe (FRTP) utilized for high-pressure water transportation experienced perforation leakage and bulging rupture of the outer protective layer after 6 months of service. The study was conducted by physical and chemical properties test, thermal analysis, mechanical analysis, pressure performance analysis, and morphology analysis. The failure primarily due to a crack defect on the inner surface of the cross-linked polyethylene (PEX) of this pipe, which allowed it to pass the pressure test but led to failure after a period of operation. Under the continuous action of high pressure, the crack expands and the lining layer is perforated, forming a leakage point through which high-pressure fluid entered the interlayer and accumulated in the outer protective layer of the pipe body. This outer protective layer gradually thinned and the high-pressure fluid at the leakage point pierced through the pipe, forming a perforation failure on the pipe body.