RU2108912C1 - Method of manufacture of hose - Google Patents

Abstract

FIELD: mechanical engineering, pipe-line transport, for instance in oil industry. SUBSTANCE: an intermediate layer in the form of adhesive compound, reinforcing layers with application of polymeric adhesive compound between them are successively applied onto polymeric pipe, then adhesive polymeric compound, external sealing layer are applied onto the last reinforcing layer, and heat treatment is performed. During heat treatment of the hose the layers of adhesive polymeric compound are foamed. EFFECT: facilitated procedure. 1 tbl

Description

 The invention relates to mechanical engineering, namely, to high pressure hoses and can find application in pipeline transport, for example, in the oil industry.

 A known method of manufacturing a high pressure sleeve with metal braids, which consists in applying layers in the following sequence: a rubber chamber, a textile braid, one or more metal braids (with rubber interlayers between them — an intermediate layer), a rubber layer (over a metal braid), a textile braid (protective layer), rubber lining of the sleeve [1].

 However, this method does not provide for the protection of metal braids from corrosion and does not take into account the operation of the sleeve under dynamic loads, as a result of which friction between metal braids can occur.

 There is another method of manufacturing a sleeve, in which an intermediate layer in the form of an adhesive polymer composition is successively applied to the polymer pipe, reinforcing layers with the adhesive polymer composition applied, reinforcing layers with the adhesive polymer composition between them, and then an adhesive polymer composition is applied to the last reinforcing layer, outer sealing layer and heat treat [2].

 However, this method does not provide sufficient monolithicity of the sleeve between the reinforcing layers, and there is a need to apply an inhibitor to protect the reinforcing layers from corrosion, which complicates the process due to cooling of the sleeve to subzero temperatures, in addition, the intermediate layer does not have sufficient strength and elasticity, necessary to reduce friction under conditions of high hydrodynamic loads between the composite layers of the sleeve.

 The technical result of this method is to increase the elasticity of the intermediate layers and increase the solidity of the sleeve by increasing the adhesion between the component layers of the sleeve.

 To achieve a technical result in a method for manufacturing a sleeve in which an intermediate layer in the form of an adhesive polymer composition is successively applied to the polymer pipe, reinforcing layers are applied between them and then an adhesive polymer composition is applied to the last reinforcing layer, the outer sealing layer is heat treated, According to the invention, during the heat treatment of the sleeve, the layers of the adhesive polymer composition are foamed.

 A method of manufacturing a sleeve is as follows.

An extrusion method makes a polyethylene pipe. Into an adhesive mastic based on divinylstyrene thermoplastic elastomer DST-30 or DST-50, a pore-forming agent, ammonium bicarbonate NH ₄ CO _3, or another pore-forming agent of this type is introduced and thoroughly mixed. 2 lines of mastic with a layer thickness of 1.5-2 mm are applied to the polymer pipe.

A braiding machine is applied a braid layer of brass steel wire (reinforcing layer). A layer of mastic (2 strokes) is applied to the braid layer. If it is necessary to apply several layers of braid, a layer of mastic is applied between each layer. The resulting sleeve assembly is passed through the heating chamber at a speed of 1-3.5 m / min, with a temperature not lower than 80 ^o C. In this case, the solvent of the mastic evaporates, the pore former decomposes and the mastic layers are foamed. The drying process is accompanied by the release of vapors of ammonia, carbon dioxide, solvent, which evaporate at the drying temperature. Drying the layers of mastic is carried out until there is no stickiness to the touch. As a result, a porous closed-cell porous elastic layer forms, enveloping the braid layer both from below and from above; it protects the braid wire from friction at high hydrodynamic loads.

A mastic layer is applied to the upper layer of the braid without the addition of a blowing agent, then with a winding with an overlap of 10-15% of a material such as non-woven, a protective layer is applied that protects the braid from damage and improves adhesion between the outer sealing layer. After that, the sleeve is again passed through the heating chamber and dried at a temperature of 80 ^o C. A sealing layer of high pressure polyethylene is applied to the protective layer by extrusion.

As a result of the implementation of the proposed technical solution, a technical result is obtained that ensures the adhesive strength of the intermediate layers of the sleeve, equal to 6.58-8.2 kg / cm ^2, in contrast to the standard data, where it is taken 3 kg / cm ² for high-pressure hoses. An increase in the adhesive strength at the reinforcing - intermediate layer boundary occurs due to an increase in the contact surface by foaming the intermediate layer, which in turn creates an elastic cushion layer on the polymer pipe and between the reinforcing steel layers.

 As a result of the implementation of the proposed technical solution received an additional positive effect, which was not the purpose of this invention.

 The intermediate layer foamed during drying creates a durable film that protects the reinforcing layers (braids) from aggressive media (formation water). Thus, reinforcing layers (braids) with a corrosion-resistant coating are obtained.

 To assess the protection of the sleeves from corrosion, the polymer coating resistance index was used (the proposed method considers the resistance of a foamed intermediate layer of adhesive mastic based on DST-30 thermoplastic elastomer) in aggressive environments (for example, an artificial mixture identical to the composition of formation water to maintain reservoir pressure).

 Resistance tests of polymers are carried out according to the method of GOST 9.030-74.

 The test results are shown in the table.

,
где
m₁ - масса образца до испытания, (г);
m₂ - масса образца после испытания (г) за исследуемый период 1 год.Resistance was calculated by the formula%:

,
Where
m ₁ is the mass of the sample before the test, (g);
m ₂ - the mass of the sample after the test (g) for the study period of 1 year.

As can be seen from the table, the resistance of the foamed intermediate layer is from 0.1 ^o C0.0 wt.%, Which means that when tested up to one year, no changes in properties are observed. If we apply a point system to assess the resistance of polymers (Handbook "Anticorrosion Service of Enterprises", I. M. "Metallurgy", 1987, p. 39), this corresponds to a score of 5, which means that the test coating has a resistance of 10 years or more .

 As a result of the implementation of the proposed technical solution by applying an intermediate layer, foamed during drying, on the polymer pipe and between the reinforcing steel layers (braids), excellent adhesion of all composite layers of the sleeve is ensured, which makes it monolithic, eliminating large loads during hydrodynamic influences, due to the formation of elastic cushion layer, on the polymer pipe and between the braids, and also provides corrosion resistance of the sleeve in aggressive environments without additional processing of ingi a bitor.

Claims (1)

 A method of manufacturing a sleeve in which an intermediate layer in the form of an adhesive polymer composition is successively applied to the polymer pipe, reinforcing layers with the adhesive polymer composition applied between them and then an adhesive polymer composition is applied to the last reinforcing layer, the outer sealing layer is heat treated, characterized in that during the heat treatment of the sleeve, the layers of the adhesive polymer composition foam.

Images