RU2240468C1 - Coupling for pipeline repairing and mounting method therefore - Google Patents

Abstract

FIELD: transport pipeline, particularly for repairing oil and gas pipelines.

SUBSTANCE: method involves cleaning pipeline surface in defective area; determining local curvature in circumference direction and comparing thereof with nominal curvature; placing flexible band with connector on pipeline covered with elastic padding. Connector is formed as loop gripping means with embedded member and is provided with tightening mechanism. Loop gripping means are formed on both connector ends pulled together by screw connecting means of "nut-pin-nut" type. Nuts are arranged in depressions formed in embedded members and are restricted against rotation around their axes. Nuts cooperate with pins along right and left threads of each screw connection. Flexible band is made of oriented fiberglass plastic with cavities formed in loop gripping means areas and filled with foamed material. Tightening force of flexible band is selected on a base of a given mathematical dependence.

EFFECT: extended technical capabilities.

8 cl, 6 dwg

Description

The invention relates to pipeline transport and can be used in the repair of oil and gas pipelines with surface non-through defects of a steel wall, mainly of a corrosive and stress-corrosion type.

A known clamp for sealing cracks in pipelines, containing a steel strip, an inside equipped with a rubber seal interacting with a wedge-shaped element located in the location of the fasteners / 1 /. The fasteners are a bolted connection of the bent ends of the steel strip. The disadvantage of the device / 1 / is the increased deformability of the ends of the tape, which does not allow it to create significant effort.

A device for eliminating a leak in the pipeline / 2 / is known, which we have chosen as a prototype. The device consists of a flexible tape equipped with an elastic gasket and a tension mechanism made in the form of a roller with one of the ends of the flexible tape and the U-shaped body fixed to it with a clamping eccentric connected to the other end of the flexible tape, while the ends of the roller and the body are equipped with hubs on which pivot hinges are installed, connected by hinged bolts. The disadvantages of the device / 2 / are as follows:

- the tension mechanism does not allow creating significant tensile stresses in the flexible tape, which sharply reduces the coupling effect on large diameter pipelines (D _H = 1020 ÷ 1420 mm);

- the design of the flexible tape does not provide reliable sealing of defects along the longitudinal welds of pipelines, where the concentration of defects is massive.

A known method of repair / 3 / pipeline, including:

- opening the pipeline and removing the insulation coating at the defect site around the pipeline;

- mechanical cleaning of the pipe surface around the defective place;

- degreasing of the cleaned surface;

- application of sealing mastic in the defect cavity to restore wall thickness;

- installation of the composite tape in a defective place with the filling of the gaps between the turns of the adhesive composition;

- the tension of the tape using the device.

The disadvantages of the method / 3 /, adopted as a prototype, are as follows:

- the complexity of the work in highway conditions;

- increased consumption of adhesive composition;

- insufficient tension of the tape, not allowing to provide the necessary contact pressure on the pipeline around the circumference;

- sealing of defects concentrated in the zone of longitudinal welds of the pipeline is not ensured.

The objective of the invention in the device of the coupling for repair of the pipeline is to increase the efficiency of the tension of the flexible tape and expand the scope of application on the pipeline with longitudinal welds.

The task is in the device of the coupling for repairing the pipeline, including a flexible tape with a connector made in the form of a loop grip with a built-in element and equipped with a tension mechanism installed on the pipeline with a defect overlapped by an elastic gasket, loop grips with embedded elements are made at both ends of the connector, tightened screw connections of the type “nut - stud - nut", and the nuts are placed in the recesses of the embedded elements without the possibility of rotation around its axis and interacting with the spire s on the left and right of each thread screw connection, a flexible tape made of fiberglass oriented cavities in the vicinity of loop gripper filled with foam.

The task in the device of the coupling for repairing a pipe installed on a pipe with longitudinal welds is also solved by the fact that the flexible tape in diametrically opposite sections, shifted relative to the plane of the connectors by a quarter of the circumference, is provided with internal longitudinal grooves without reducing the cross-sectional area of the flexible tape in the grooves designed to accommodate longitudinal welds of the pipeline.

The task in the coupling device for repairing the pipeline is also solved by the fact that between the flexible tape and the defect there is a plate with a smooth decrease in thickness from the middle section to the edges in the circumferential direction.

The task in the device of the coupling for repair of the pipeline is also solved by the fact that in the coupling mounted on the pipeline with longitudinal welds, the plate in the middle section of the longitudinal direction has an internal groove facing the surface of the pipeline and accommodates its longitudinal weld.

The task in the device of the coupling for repairing the pipeline is also solved by the fact that the elastic gasket is made of an adhesive layer with a filler, for example, epoxy adhesive with asbestos fibers, and polyurethane foam is used as the foam.

The objective of the invention in the method of installation of the coupling is to increase the tension force of the flexible tape and ensure the reliability of hardening of defective sections on the pipeline, including along longitudinal welds.

The problem in the installation method of the coupling, including opening the defective section of the pipeline, removing the insulation coating and cleaning the surface on the defective section, applying an adhesive layer to it, installing a flexible tape on the adhesive layer and tensioning the flexible tape, is solved by the fact that after cleaning the surface of the pipeline on the defective plot determine the local curvature in the circumferential direction, compare it with the nominal curvature according to the dependencies

where R ₀ is the nominal value of the radius of the pipeline on the outer surface, m;

R is the actual value of the radius on the defective area, m,

moreover, when dependence (1) is realized, after applying the adhesive layer, the sleeve is installed by blocking the defective area with the plate, installing a flexible tape around the defective area with the plate, tensioning the flexible tape by tightening the screw joints, and the tension of the flexible tape is selected from the greatest of the conditions

where P _in - internal (working) pressure of the pumped medium, MPa;

In - the width of the flexible tape, m;

R ₀ is the nominal radius of the cross section of the pipeline, m;

N is the tension force of the flexible tape, MN;

R _PL is the radius of the outer surface of the plate, m;

To _ol - the coefficient of decrease in the strength of the wall of the pipeline in the defective area, dimensionless value,

and when dependency (2) is realized, after applying the adhesive layer, a sleeve is installed by blocking the defective area with flexible tape, tensioning the flexible tape by tightening the screw joints, and the tension force of the flexible tape is selected from condition (3).

The problem is also solved by the fact that for a pipeline having longitudinal welds, a flexible tape with diametrically opposed grooves is installed by combining the grooves with the sections of the longitudinal welds, and the tension force is selected from condition (3).

The problem is also solved by the fact that for a pipeline with a defective section located along the longitudinal welds, a plate with a groove is installed on the defective section by combining the groove with the longitudinal weld, and the tension force is selected according to conditions (3), (4).

The salient features of the claimed invention in a coupling device for repairing a pipeline are:

- performing loop captures with embedded elements at both ends of the connector;

- making screw connections in the form of "nut-stud-nut";

- placement of screw connection nuts in the recesses of the embedded elements without the possibility of turning the nuts around its axis and their interaction with the studs on the right and left threads in each screw connection;

- a flexible coupling tape is made of oriented fiberglass and has cavities in the area of loop grips filled with foam;

- a flexible tape in diametrically opposite sections, shifted relative to the plane of the connectors by a quarter of a circle, is provided with internal longitudinal grooves without reducing the cross-sectional area of the flexible tape in the grooves;

- between the flexible tape and the defect on the surface of the pipeline there is a plate with a smooth decrease in thickness from the middle section to the edges in the circumferential direction, and the plate mounted on the pipeline with a longitudinal weld is provided with an internal groove facing the surface of the pipeline and accommodates a longitudinal weld.

Salient features of the method of installation of the coupling are:

- determination of the local curvature of the surface of the pipeline in the defective area in the circumferential direction;

- overlapping the defective area with a plate, installing a flexible tape and its tension by tightening the screw joints with a certain force;

- a flexible tape with diametrically opposite grooves is installed by combining the grooves with the sections of the longitudinal welds;

- when repairing a pipeline with a defective section located along the longitudinal weld, use a plate with a groove, installing it on the defective section by combining the groove with the longitudinal weld of the pipeline.

The above significant distinguishing features of the claimed invention were not known to us from the patent and scientific and technical information and, together with the known features, allow us to solve the problems posed to the invention, so the invention is “new”.

The invention meets the criterion of "Industrial applicability", because It can easily be used in the repair of existing trunk pipelines.

The design of the coupling for repairing the pipeline is shown in FIGS. 1 to 6. FIG. 1 is a cross-sectional view of the pipeline with the coupling installed; figure 2 is a side view of the coupling; figure 3 is a section of a screw connection; figure 4 is a fragment of the coupling with a groove in the region of the longitudinal weld of the pipeline; figure 5 is a fragment of the coupling with the plate on the longitudinal weld with a defect in the wall of the pipeline; figure 6 - plate with a longitudinal groove.

The design of the coupling for repairing the pipeline installed on the pipeline 1 contains a flexible tape 2 made of oriented fiberglass, two (or one) connectors with loop captures 3, in which the flexible tape 2 is filled with polyurethane foam 5, cavities 4, embedded elements 6 with square recesses and placed in them, nuts 7, worn on studs 8, each with a right and left thread, adhesive layer 9, plates 10 with a longitudinal groove 11. Flexible tape 2 can be made with an internal groove 12 equally spaced from the plane of the connectors. The studs 8 are equipped in the middle with a turnkey hex head 13.

The claimed method is implemented as follows. Open the defective section of the pipeline 1 with defect 14, free it from the soil, remove the anticorrosive insulation coating around the defect 14, clean the surface of the pipe to a metallic luster, determine the local curvature of the outer surface of the pipe in the circumferential direction next to defect 14, compare it with the nominal curvature according to dependences (1), (2). If dependence (1) is fulfilled, an adhesive layer 9 with a filler is applied around the pipeline at the width of the coupling, then the inner surface of the flexible tape 2 is greased with glue, a plate 10 is glued to it in the middle, a flexible tape 2 with embedded elements 6 is installed on the pipe 1, blocking the defect 14 plate 10, mount the tension mechanism in the form of a screw connection “nut 7 - stud 8 - nut 7”, tighten the stud 8 with a design torque using a torque wrench installed around the head 13. The tension force of the flexible tape is selected It is taken from conditions (3), (4). The position of the coupling for repairing a pipeline with two connectors after installation is shown in FIG. 1, while the pipeline 1 either does not have longitudinal welds (seamless pipe), or the protruding weld beads are removed by grinding, or the weld beads are placed in the couplings of the coupling (FIG. 1) . If the protruding weld beads are located in a plane close to vertical, then use flexible tape 2 with longitudinal grooves 12. The plane of the tape connectors is installed in a plane close to horizontal, which greatly simplifies the process of tightening screw connections when repairing an underground gas pipeline into a trench.

In the case when the pipe surface curvature in the circumferential direction at the defect location 14 corresponds to dependence (2), after applying the adhesive layer 9 with a filler, the flexible tape is installed without plates 10 and tightened with force under condition 3. If defects of the 15 type of cracks are concentrated in the longitudinal region weld 16, where the curvature of the pipe surface corresponds to dependence (1), then plate 10 with a longitudinal groove accommodating the longitudinal weld is installed on the defects (Figs. 5, 6). In this case, the radius of the surface of the plate R _{PL is} selected from condition (4), and the tension force of the tape is the largest of conditions (3), (4).

The method of installation of the coupling using the plates 10 is used mainly for crack-like defects such as stress-corrosion cracks.

Example 1

It is necessary to determine the design parameters of the coupling for repairing a pipeline with a defect in the form of a longitudinal crack on the outer surface of the pipe at the junction of the longitudinal weld bead with the wall in order to ensure the strength of the defective spot equal to the strength of the undamaged wall. Initial data: diameter of the pipeline D _n = 1220 mm; pipe wall thickness δ = 12 mm; height of the longitudinal seam roller - 6 mm, width - 30 mm; defect length L = 220 mm, depth h = 4 mm; the radius of the local curvature of the pipe surface at the crack in the circumferential direction R = 640 mm; the internal pressure of the pumped product P _in = 5,4 MPa, the yield strength of the metal pipe σ = 360 MPa.

Destructive pressure for a defective area with a crack is determined by the formula (see Kupershlyak-Yuzefovich G.M., Razumov Yu.G. Calculation of destructive pressure in gas pipelines damaged by stress corrosion cracking - КРН / Pipeline construction. - 1996. - №6, p. 17-18)

- давление текучести металла, МПа;Where

- metal flow pressure, MPa;

- относительная глубина трещины;

- relative depth of the crack;

коэффициент Фолиаса.

folias coefficient.

At L = 0, the destructive pressure for a defect-free wall is obtained by formula (5).

отражает снижение прочности дефектного участка трубы. Подставляя

получим

т.е. прочность дефектной стенки составляет 84% от бездефектной. Полученный коэффициент относится к трубе, поперечное сечение которой представляет идеальную окружность. Фактически при воздействии давления радиус кривизны стенки трубы будет изменятся от R=640 мм к номинальному значению R₀=D_н/2=1220/2=610 мм, что вызовет изгиб поперечного сечения с растягивающими напряжениями σ _геом, которые будут складываться с кольцевыми безмоментными напряжениями от рабочего давления и дополнительно нагружать стенку трубы. Величина σ _геом без учета трещины определяется по формулеAttitude

reflects the decrease in strength of the defective pipe section. Substituting

we get

those. the strength of the defective wall is 84% of the defect-free. The resulting coefficient relates to a pipe whose cross section represents an ideal circle. In fact, under the influence of pressure, the radius of curvature of the pipe wall will change from R = 640 mm to the nominal value R ₀ = D _n / 2 = 1220/2 = 610 mm, which will cause cross-sectional bending with tensile stresses σ _geom that will add up to ring torqueless stresses from the working pressure and additionally load the pipe wall. The value of σ _geom excluding cracks is determined by the formula

where E is the modulus of elasticity of the steel pipe, MPa. Substituting the initial data in (7), we obtain

Ring momentless stresses in the pipe wall without taking into account cracks are determined by the formula

In order to neutralize the crack development during operation, it is necessary to create contact pressure on the pipe in the defect area by compensating for the wall weakening, expressed by the coefficient K _PR = 0.84 and bending stress σ _geom = 95 MPa by installing the sleeve and tightening it.

Compensation of bending stresses is achieved if a plate is installed between the flexible tape and the defect, while the contact pressure of the coupling is Р _М ≥ Р _В , where Р _М is connected with the radius R _{PL of the} curvature of the contact surface of the flexible tape with the plate according to the formula Р _М = N / (R _pl × B), from which the formula for the tension force is derived

To restore the strength of the pipeline in a momentless state, the contact pressure P _M must compensate for part of the working pressure P _In accordance with the coefficient K _PR

where P _M = N / (R ₀ × B), where does the dependence (3) obtained in the claims

By combining formulas (8) and (10), we obtain a relationship between the radii R _PL and R ₀ given in dependence (4) of the claims

The dimensions of the coupling are selected as follows. The length of the flexible web along the axis of the pipeline (size B) corresponds to the width of the coupling according to the prototype / 3 / and is equal to B = 0.32 m. The length of the plate along the axis of the pipeline is also equal to B = 0.32 m. The width of the plate in the circumferential direction, its thickness, the radii, as well as the height of the longitudinal weld bead, are related by the following relationships:

a) the plate is installed and fixed on the pipeline by tightening the flexible tape

b) the plate in the free state before installation

where Δ at _RPL is the bend arrow of the outer surface of the plate, i.e. the distance from the chord, tightening the arc of the outer surface to the center of the arc, mm;

Δ at _R - bending arrow of the inner surface of the plate, mm;

l is the length of the plate around the circumference of the pipeline, mm;

δ _PL - maximum plate thickness, mm;

N - height of the longitudinal weld bead, mm;

Δ N is the residual thickness of the plate above the bead of a longitudinal weld;

R _PL1 is the radius of the outer surface of the plate when its inner surface is flat, mm

It is convenient to carry out the calculation, knowing the values of H and Δ N and determining the radius R of the _submarine according to formula (8), and the force N is determined from the condition of the wall strength of the flexible coupling tape:

where [σ _m ] - calculated allowable stresses in the flexible tape, MPa;

· Δ _m - the thickness of the tape, m

According to the developed manufacturing technology of the coupling · δ _m = 0.0075 m (7.5 mm); [δ _m ] = 250 MPa. The value of H = 6 mm, the value of Δ N = 2 mm. Substituting the data in (18), we obtain N ≤ 250 0.32 0.0075 = 0.6 MH (61 tf), then, using formula (8), we obtain R _PL ≤ N / P _in · B = 0.6 / 5 , 4 0.32 = 0.347 m.

Δ у_RПЛ-Δ у_R=17,1-90,1=8 мм, что соответствует заданной толщине стенки · δ _пл=8,0 мм.Now, setting various values of l in formulas (12) and (13), we achieve equality (14). We select l = 215 mm, then

Δ for _RPL -Δ for _R = 17.1-90.1 = 8 mm, which corresponds to a given wall thickness · δ _PL = 8.0 mm

При установке на дефект и затяжке гибкой ленты радиус R_пл1 переходит в радиус R_ПЛ=347 мм за счет изгиба пластины по наружной поверхности трубы. На плоской поверхности пластины по ее середине в направлении оси трубопровода выполнен паз шириной 30 мм, глубиной 6 мм для размещения в нем продольного сварного шва трубопровода. По величине усилия N проверяется прочность винтовых соединений. Шпильки выполнены из стали 30ХГСА с пределом текучести σ _т=1080 МПа, расчетным допускаемым напряжением на растяжение [σ ]р=390 МПа. Выбираем по n=4 шпильки в каждом разъеме муфты и проверяем их на прочность по формулеWe check condition (10) N≥ (1-0.84) · 5.4 · 0.32 · 0.61 = 0.17 MH (17.2 tf). Obtained by the formula (18) N = 0.6 MH satisfies condition (10). Plate radius

When installed on a defect and tightening a flexible tape, the radius R _PL1 passes into a radius R _PL = 347 mm due to the bending of the plate along the outer surface of the pipe. On the flat surface of the plate along its middle in the direction of the axis of the pipeline, a groove of 30 mm wide and 6 mm deep is made to accommodate a longitudinal weld of the pipeline in it. The strength N is checked for the strength of screw joints. The studs are made of 30KhGSA steel with a yield strength σ _t = 1080 MPa, a design allowable tensile stress [σ] p = 390 MPa. We select n = 4 studs in each connector of the coupling and check their strength by the formula

where d is the diameter of the stud, m, where

Substituting the initial data in (20), we obtain

choose the closest standard upward diameter of the stud d = 24 mm. Thus, the basic design parameters of the coupling are determined.

Note. When the dependence (2) of the claims is realized, a sufficient tightening force N, found by formula (10), is 0.17 MN (17.2 tf).

Example 2. Consider the main elements of the proposed method of installation of the coupling. The parameters of the pipeline, defect and coupling are shown in example 1. The pipe is a two-seam, longitudinal welds are oriented in a plane close to the vertical. The defect is located on the lower weld. The adhesion of the film insulation to the pipe is absent on an area of 1 m ² , in the center of which is a longitudinal crack-like defect.

The defective area is opened by excavating a pit, remove the insulation in the area of lack of adhesion, and strip the metal with a grinder. A curvature meter in the form of a rigid metal bar 200 mm long, equipped with reference points at the ends, and a clock-type indicator in the middle that records the change in the curvature of the pipe surface curvature determining the radius of curvature in the region of defect R ₁ at a gas operating pressure of 5.4 MPa, then compliance with regulatory requirements is reduced by 30% for repairs. Again, the radius of curvature is determined in the same place R ₂ and the radius R, which corresponds to the absence of pressure in the pipeline and is equal to R = 640 mm, is determined by the conversion method. A decision is made on the use of the coupling design according to claim 1, 2, 4, 5 of the claims with two connectors located in a horizontal plane.

After stripping the metal, its surface is degreased, anti-corrosion insulation is restored, then a layer of epoxy adhesive with asbestos fibers is applied to the area of the ring covered by the sleeve, then the lower half of the sleeve is taken, the flexible tape of which is made without a groove for the longitudinal seam and contains embedded elements in the loop captures, the inner surface of which is covered with an adhesive layer of identical composition, then a plate with a groove is laid in the middle of the flexible tape, covered with the same adhesive on both sides, after which UFTA with a plate is brought under the defective pipe so that the groove of the plate hits the longitudinal seam and is fixed on the lower half of the pipe using a flexible connection or a temporary support from below. Next, the upper coupling half is installed, the flexible tape of which is provided with a groove in the middle and covered with glue, and the loop clamps contain embedded elements with studs screwed in 1 ÷ 2 turns, after which the studs are installed in the nuts of the reciprocal loop clamps and wrapped for 1 ÷ 2 turns. The entire structure is aligned, the studs for the middle part, made in the form of a hex head, are wrapped with a torque wrench at the same time on both sides, starting from the middle of the coupling to its edges, turning the key within the free space, while alternating the studs after each rotation. Gradually reach the calculated moment of 450 ÷ 500 N · m.

The effectiveness of the use of the invention is as follows. After tightening the studs, the flexible tape tightly covers the pipeline, and in the zone of the crack-like defect, increased contact pressure is created, which unloads the pipe wall from bending, and ring stresses are reduced due to the uniform contact pressure, which compensates for part of the working pressure of the pumped product. At the same time, the strength of the defective pipe increases to the level of defect-free, thereby increasing the reliability of the operation of the pipeline without the use of cutting the defective section and the associated losses of the pumped product and environmental damage.

Thus, the proposed sleeve for repair of the pipeline, its installation and method provide more reliable protection of the defective area from loads than the technical solutions of the prototypes, require less material consumption and labor costs during installation.

By the combination of positive properties, this technical solution can be successfully applied in the repair of the most dangerous defects - stress-corrosion cracks, which are the most common cause of accidental destruction of large gas pipelines of large diameters 1020 ÷ 1420 mm and thereby increase the economic efficiency and safety of operation of gas main pipelines.

Sources of information

1. USSR author's certificate No. 1810719, IPC F 16 L 55/17. Publ. 04/23/1993 g. (Analog).

2. USSR author's certificate No. 1068654, IPC F 16 L 55/17. Publ. 01/23/1994 (Prototype).

3. Instructions for the repair of defective pipes of gas pipelines with polymer composite materials. BCH 39-1.10-001-99. The publication is official. Moscow, 2000, pp. 6-8 (Prototype).

Claims (8)

1. A coupling for repairing a pipeline, including a flexible tape installed on a pipeline with a defect blocked by an elastic gasket, with a connector made in the form of a loop grip with a built-in element and equipped with a tension mechanism, characterized in that the loop grips with embedded elements are made at both ends of the connector tightened with screw connections of the type nut - stud - nut, and the nuts are placed in the recesses of the embedded elements without the possibility of rotation around its axis and interact with the studs on the right and the left thread of each screw connection, and the flexible tape is made of oriented fiberglass with cavities in the area of the loop grips filled with foam. 2. The coupling according to claim 1, mounted on a pipeline with longitudinal welds, characterized in that the flexible tape in diametrically opposite sections, shifted relative to the plane of the connectors by a quarter of the circumference, is provided with internal longitudinal grooves without reducing the cross-sectional area of the flexible tape in the grooves intended for placement of longitudinal welds of the pipeline. 3. The coupling according to claim 1 or 2, characterized in that between the flexible tape and the defect there is a plate with a smooth decrease in thickness from the middle section to the edges in the circumferential direction. 4. The coupling according to claim 1 or 2, mounted on a pipeline with longitudinal welds, characterized in that the plate in the middle section of the longitudinal direction has an internal groove facing the surface of the pipeline and accommodates its longitudinal weld. 5. The sleeve according to any one of claims 1 to 4, characterized in that the elastic gasket is made of an adhesive layer with a filler, for example epoxy adhesive with asbestos fibers, and polyurethane foam is used as the foam. 6. The method of installing the coupling on the defective section of the pipeline, including opening the defective pipeline, removing the insulation coating and cleaning the surface on the defective section, applying an adhesive layer thereon, installing a flexible tape on the adhesive layer and tensioning the flexible tape, characterized in that after cleaning the surface of the pipeline on the defective area, local curvature in the circumferential direction is determined, it is compared with the nominal curvature according to the dependencies

where R ₀ is the nominal value of the radius of the pipeline on the outer surface, m; R is the actual value of the radius on the defective area, m, moreover, when the dependence (1) is realized, after applying the adhesive layer, the coupling is installed according to claims 1, 3 and 5 by blocking the defective area with a plate, installing a flexible tape around the defective area with the plate, tensioning the flexible tape by tightening the screw joints, while the tensioning force is flexible tapes choose the most from conditions

where P _in - internal (working) pressure of the pumped medium, MPa; In - the width of the flexible tape, m; R ₀ is the nominal radius of the cross section of the pipeline, m; N is the tension force of the flexible tape, MN; To _PL is the radius of the outer surface of the plate, m; To _ol - the coefficient of decrease in the strength of the wall of the pipeline in the defective area, dimensionless value, and when dependency (2) is realized, after applying the adhesive layer, a sleeve is installed by blocking the defective area with flexible tape, tensioning the flexible tape by tightening the screw joints, and the tension force of the flexible tape is selected from condition (3). 7. A method of installing a coupling on a defective section of a pipeline having longitudinal welds according to claim 6, characterized in that a flexible tape with diametrically opposed grooves is installed by aligning the grooves with the sections of the longitudinal welds, and the tension force is selected from condition (3) . 8. The method of installing the coupling on a defective section of the pipeline located along the longitudinal welds according to claim 6, characterized in that the plate with the groove is installed on the defective section by combining the groove with the longitudinal weld, the tension force being selected according to the conditions (3) , (4).

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