METHOD OF PIPE MANUFACTURING FROM COMPOSITE MATERIALS AND PIPE WITH BEND OF COMPOSITE MATERIALS (VERSIONS) Russian patent published in 2010 - IPC B29C53/82 B29C53/56 

FIELD: technological processes.

SUBSTANCE: group of inventions relates to method for manufacturing of pipe of composite materials and pipe with bend of composite materials manufactured by specified method. Method includes laying of sealing layer into composite mandrel, winding of power shell helical layers and thermal treatment. Part of mandrel is arranged with axis bend without distortion of radius R of cross section, and helical turns are fixed along edge of mandrel bend zone. Then part of mandrel is bent with layers of composite materials along radius of its medium axis r₀, deforming sealing layer, and bend is fixed prior to thermal treatment. Besides helical turns are fixed along line built with contact of edge circumference in zone of bend, which represents a sine-shaped wave on involute of this circle with maximum deviation, which does not exceed 0.04 H, where H - length of bend zone cylinder generatrix. Helical turns are laid with angle of winding where β₃ - permanent angle of helical turns winding on cylindrical stock pipe; k_fr - coefficient of friction for turn thread impregnated with binder - for wet method of winding, friction coefficient is in the range of 0.1-0.2; t - parametre of pipe curve, bend; where r₀ - average radius of pipe axis bend; R - radius of cross section of mandrel bend part.

EFFECT: increased reliability of composite high-pressure pipelines operation with curvilinear bends due to increased uniformity of stressed condition of reinforcement fibres on curvilinear sections.

7 cl, 9 dwg