RU2396477C1 - Procedure for connecting pipeline out of polymer composite material with metal tip - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: procedure for connecting consists in arranging pipeline with fixing component on metal tip. The fixing component is made by winding tape out of polymer material soaked with epoxy adhesive and by forming an internal and external rings. The internal ring is wound with fifty percent, while the external one with one hundred percent overlapping; whereupon there is performed polymerisation.

EFFECT: reduced level of pipeline material deformation, its increased strength and pressure tightness.

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Description

The invention relates to the field of engineering and can find application in connecting preformed parts, in particular when connecting a pipeline of a polymer composite material with a metal ending.

From the patent literature there is known a pipe made with an inner shell made of composite material on which end endings are mounted, an airtight layer of molten polymer tape fixed on them, wound on the inner shell and part of the ending steps, and a layer of composite material covering it, bonded to the remaining steps endings (RF patent No. 2240463).

In the zone of maximum stresses at the boundary of the materials to be joined together, the end tip and the inner shell of the composite material, the joint is depressurized.

The closest analogue to the proposed technical solution can be considered a pipe containing a metal pipe with a fixing element, covering their thermoplastic shell and a reinforcing fiberglass layer (RF patent No. 2262027).

The disadvantage of this connection is its complexity, which leads to its insufficient operational reliability.

The problem to which the invention is directed, is to ensure reliable tightness of the connection of the metal ending and the pipeline of the polymer composite material.

The problem is solved in that in the proposed method for connecting a pipeline of a polymer composite material with a metal ending, including installation on the last pipeline with a fixing element, the latter is obtained by winding a tape of polymer material impregnated with epoxy adhesive with the formation of an inner and outer ring, while winding the inner ring is performed with a 50 percent, and the outer ring with a 100 percent overlap, and then polymerized.

Ensuring the strength and, accordingly, the tightness of the connection of the pipe from the polymer composite material with the metal ending, was decided by reducing the level of deformation of the pipe material in the joint zone, as a result of winding the layers of tape of the inner ring with a 50 percent overlap, and the outer one with 100 percent.

The drawing shows a cross section of the connection of the ending and the shell of the pipeline of a polymer composite material obtained by the implementation of the proposed method.

The connection comprises a stainless steel end 1, a pipe shell 2 of a polymer composite material based on a polymer film with a double-sided fluoroplastic coating, a fixing element consisting of an inner ring 3 and an outer ring 4.

The need for the selected percentage overlap of the turns of the inner and outer rings is confirmed by the following examples.

1. As a result of winding eight layers (4 passes) of the inner ring 3 of the tape LES, 0.2 × 20 GOST 5937-81, impregnated with glue EPK-1 according to OST 92-0949-74, with overlapping turns in the range of less than 50% and the tension force (2-3) kgf at the maximum working pressure of the liquid (12-13) kgf / cm ² , there is a decrease in tightness in the sealing area of the ends 1 and shell 2 of the pipeline more than 1.33 × 10 ^-17 W (1 × 10 ^-3 l μm Hg / s).

2. As a result of winding eight layers (4 passes) of the inner ring 3 of the LES tape, 0.2 × 20 GOST 5937-81, impregnated with EPK-1 adhesive according to OST 92-0949-74, with overlapping turns of the LES tape in the range of more than 50 % causes high local stresses in the sealing zone (σ _equiv.max = 20 kgf / mm ² ), which leads to an increase in the level of deformation of the material of the shell 2 of the pipeline and, accordingly, to the loss of tightness of the connection of the end 1 and the shell 2 of the pipeline.

3. As a result of winding eight layers (4 passes) of the outer ring 4 of tape KL-11-5,0 TU 5952-181-0578904-2004, impregnated with EPK-1 glue according to OST 92-0949-74, and the tension force (2 -3) kgf with overlapping layers of less than 100%, in the sealing zone of the tip 1 and shell 2 of the pipeline leads to a loss of its strength and an increase in the level of deformation of the material of the shell 2 of the pipeline and, accordingly, to a decrease in the operational reliability of the pipeline at maximum fluid pressures (12-13) kgf / cm ² in the inner cavity of the pipeline.

Using the proposed method for connecting a pipeline of a polymer composite material with a metal ending provides the following advantages compared to existing methods:

- reducing the level of deformation of the material of the pipeline improves its strength and tightness;

- significant simplification and reduction of labor costs due to the exclusion of additional elements;

- increase operational reliability due to the structural combination of the implementation of the inner and outer rings.

Claims (1)

A method of connecting a pipe made of a polymer composite material with a metal ending, including installing on the last pipe with a fixing element, characterized in that the fixing element is obtained by winding a tape of polymer material impregnated with epoxy adhesive to form an inner and outer ring, while the inner ring is wound with fifty percent, and the outside with a one hundred percent overlap, and then polymerization is carried out.

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