END FITTING OF FLEXIBLE PIPELINE Russian patent published in 2011 - IPC F16L33/00 

FIELD: machine building.

SUBSTANCE: invention refers to machine building, particularly to end fitting of flexible pipeline and can be implemented in oil and gas wells for well tubing. The end fitting of the flexible pipeline consists of a nipple matching and installed into internal diameter of the flexible pipeline; the nipple has conic notches on an external side and internal thread for connection with pipe accessories. On the external side of the nipple there is made external thread; a capture nut and a stop sleeve with external thread on an upper cone are arranged on external thread of the nipple, below of which there is made a lug in form of big bases of a cone facing one another. A lower end of the nipple under the lug has conic notches; on external surface of the stop sleeve there is made external thread; a case with internal thread on ends is screwed on this thread; inside the case there is successively arranged a collet with flexible elements; on internal surface of the elements there are made conic notches facing external surface of the flexible pipeline; also, the latter consists of an expanding sleeve and a bottom box. The expanding sleeve from external side envelops the flexible elements and at the end contacts with the bottom box, while the case with internal thread on ends envelops the flexible element and the expandable sleeve clasping the collet. The end fitting of the flexible pipeline corresponds to an internal pipe out of polyethylene reinforcing load bearing layer of filaments; coils of spiral winding enveloped with a polyethylene external coating are wound around the bearing layer at a specified lead.

EFFECT: increased bearing capacity of end fitting of flexible pipeline; uniform distribution of axial stretching load on all elements of pipeline structure; sealing circular gap at installation of elements of end fitting on flexible pipeline sustaining internal and external pressure of reservoir fluid.

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