Abstract: Production situation of steel-plastics composite pipes was summarized and the emphasis was focused on the end sealing technology. Discussed in this paper included the first-generation injection sealing, the second-generation butt welding sealing, and the third-generation self-melting sealing technology. Steel-plastics composite pipes can be sealed using the plastics itself by third-generation self-melting sealing technology. The third generation self-melting sealing technology can effectively overcome the disadvantages of conventional sealing technology which included big equipment investment, high energy consumption, and poor sealing quality. The third-generation self-melting sealing technology constituted also the important development trend of end sealing technology of steel-plastics composite pipes.

Key words: steel-plastic composite pipe, self-melting sealing, butt welding sealing, injection sealing