METHOD OF MANUFACTURE OF REINFORCED PIPES FROM THERMOPLASTIC MATERIAL AND DEVICE FOR ITS ACCOMPLISHMENT Russian patent published in 1994 - IPC

FIELD: processing of plastic materials. SUBSTANCE: reinforcement is effected by application of a load-carrying member from steel or synthetic materials on each of the two diametrically opposite sections of the thermoplastic material shell. Longitudinal members from porous material impregnated by an inhibited compound are positioned on both sides of the load-carrying member. Then a helical metal cage is wound. The thermoplastic material shell is subjected to the influence of intrinsic pressure after the application of the protective coating by continuous pumping of liquid working medium of a definite pressure and temperature. To this end, the device has drain and feeding lines, a pump and a delivery valve placed in the feeder line. Besides, a regulated throttle valve is installed in the drain line, the delivery valve and throttle valve drain lines communicate with the vessel for the working liquid medium. When pressure is applied, the shell gets deformed, squeezes out the lubricant from the porous members. It decreases the pipe stiffness, decreases friction between the cage layers, prevents corrosion. EFFECT: facilitated procedure. 3 cl, 3 dwg