METHOD FOR LINING OF PIPES HAVING A MALE THREAD WITH THERMOPLASTIC SHELL Russian patent published in 2000 - IPC

FIELD: pipe lining. SUBSTANCE: thermoplastic shell is introduced inside the pipe, leaving the thermoplastic shell ends projecting from the pipe ends. The projecting ends of the thermoplastic shell are heated to the softening temperature, and flanges are formed from them. Thread is produced on the projecting ends of thermoplastic shell, on its inner surface, and bushes with an external flange, whose diameter does not exceed the inside diameter of the pipe thread, are driven on the thread up to the stop against the end faces of the thermoplastic shell. After heating of the projecting ends of the thermoplastic shell the bushes with a flange are driven right home. Flanges are formed with an outside diameter not exceeding the inside diameter of the pipe thread. The ends of the thermoplastic shell are fixed against longitudinal movement by rings of corrosion- resisting metal located beyond the limits of the pipe thread taper. Bushes with an external flange are made of corrosion-resisting material, for example, corrosion-resisting metal, thermosetting plastics, cermet material and other composite materials. EFFECT: simplified process of manufacture of lined pipes, having a male thread, enhanced protection of pipelines against corrosion. 3 cl, 2 dwg