FIELD: oil and gas industry.
SUBSTANCE: device includes a coupling which can expand in radial direction under influence of fluid medium. Coupling is fixed on end members and includes a pair of cylindrical membranes 20, 21 with flexible and elastic wall coaxially inserted one into the other. Fluid medium pressure influences inner membrane 20. Outer membrane 21 is intended to be pressed to the wall of well or pipeline. Between membranes 20, 21 there is at least one annular and fibre construction 5 of increased density, which is formed by many thin and long fibres with high mechanical strength with diametre of 5 mcm to 100 mcm. Fibres attach end members to each other and are wound in a spiral manner around inner membrane 20. Fibre winding angle in relation to longitudinal symmetry axis X-X' is 45° to 60° in end sections and 15° to 30° in central part of that coupling. Fibre winding density decreases in direction from each end to central section of the coupling wall.
EFFECT: decreasing non-uniform distribution of stresses in fibre construction, and preventing extrusion.
13 cl, 23 dwg
