METHOD OF MANUFACTURING MULTILAYER TUBES FROM STEEL STRIP Russian patent published in 1994 - IPC

FIELD: production of tubes. SUBSTANCE: method involves unwinding strips from rolls; forming tubular profiles and exposing them to thermal treatment; winding them onto rolls with subsequent unwinding from rolls, with tubes being arranged one within the other in the process of unwinding. The following operations are performed: forming of tubular profiles having different diameters; arranging small-diameter tubular profile within large-diameter tubular profile in the process of unwinding tubular profile from rolls; glueing adjoining surfaces of tubular profiles with glue being preliminarily applied to initial portion, where profile is formed into tube, followed by reduction of initial portion of formed tube; cutting tube into required lengths of tube after glueing. EFFECT: increased efficiency and high quality of tubes. 5 dwg