| 摘要 |
FIELD: plastic metal working; applicable in manufacture of pipes with shape, which are used as blank patches in reconditioning of tightness of water, oil and gas wells. SUBSTANCE: shaped pipe, mainly, welded, is made with shaped section in form of symmetrical combination of three tear-shaped hollows formed from round billet, two of which touch each other by their external surfaces of expanded part with formation of the third hollow between them. In so doing, internal surfaces of two tear-shaped hollows are formed by internal surface of round billet, and their external surfaces are formed by external surface of round billet, and internal surface of the middle hollow is formed by external surface of round billet, and external surface of middle hollow is formed by internal surface of round billet. EFFECT: reduced value of residual deformation due to decreased curvature of profile and reduced longitudinal deformations of pipe. 1 cl, 2 dwg |
