RU2525103C1 - Pipeline repair procedure and device to this end - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: device consists of flexible sheet material with two layers of hybrid textile impregnated with composite, of carbonate and Kevlar threads. Polyethylene ply is sprayed on hydride textile. Epoxy resin-based compound ply is arranged opposite polyethylene layer. One end of flexible sheet is composed of loops on both sides. Lengthwise metal plates are arranged inside every loop and on both there thereof and secured thereto. Besides that loops are equipped with tightener with through bore for bolts. Said tightener is composed of metal structure with U-like cross-section wit lengthwise slot accommodating loops with metal plates. Device with applied compound layer are cured in open air for tine required for impregnation of hybrid layers and partial solidification of the compound. Then, device is gripped by tightener and placed on pipeline section to be repaired and fitted to pipe by the side with compound. Then, it is locked by bolt joint and tightened. Tightening force is larger at central part that at ends.

EFFECT: expanded hardware means.

5 cl, 9 dwg

Description

Technical field

The invention relates to methods for repairing pipelines with and without stopping the pumping of the product. Most effectively, the present invention can be used for pipelines transporting gas, oil and / or oil products.

State of the art

The known solution "Method of pipe repair and repaired pipe" according to the patent of the Russian Federation No. 2380606.

According to the patent, the method consists in the following: for repairing a pipe, a fiber structure, for example carbon fiber, is placed on the pipe section to be strengthened or repaired, then it is fixed with special devices, after which mechanical seals are installed at the borders, for example rubber gaskets, metal elements, etc., then install the outer shell, such as a sleeve, casing, housing, container, etc. The additional shell together with the seals forms a sealed structure with an internal cavity. After that, the cavity is filled with a polymer material, which impregnates the fiber, after which the polymer material is cured. The outer shells are provided with openings for introducing a polymer material. The polymer is impregnated after placing the shell on the pipe.

The polymer material saturates the reinforcing material, namely the fiber structure, after which it is cured to obtain a hardened polymer composite.

A repaired pipe or pipe repair device or sheath of the invention comprises one or more layers of fiber covering the pipe and a cured polymer material placed inside the sheath component, while the cured polymer material impregnated with the fiber reaches the outer surface of the pipe.

The disadvantage of this design is the following:

- repair is possible only for a section of small length, if necessary, repair of extended sections of the pipeline, the process becomes very time-consuming due to the use of a large number of additional equipment;

- when using this device, it is possible that the polymer-impregnated fiber may not adhere sufficiently, which leads to the formation of voids on the surface of the pipeline in which corrosion processes will develop;

- after the completion of the polymerization process, additional stress concentrators appear at the edges of the repaired section due to the use of the forming element (couplings, casing), which may ultimately lead to the destruction of the pipeline;

- it is impossible to obtain a structure that is qualitatively impregnated with a polymeric material due to the fact that the polymeric material passes through the structure from the fiber to the surface of the object under the action of gravity, or capillary forces, or their combined effect, and the impregnation of the fibers under the influence of gravity and / or due to capillary action is possible only in the upper part of the pipe. In its lower part, gravity will act in the opposite direction and the creation of additional pressure during resin supply will also not be able to solve the problem of high-quality impregnation without creating special systems for removing air from under the fibrous structure, which is not provided for by this patent.

There is also known a method of repairing a pipe pipe and a device for its implementation, patent for the invention of the Russian Federation No. 2438065. This solution is chosen by the authors for the prototype.

In the inventive method, the fibrous structure is superimposed on the pipe section to be hardened; pumping the resin through the fibrous structure to a portion of the pipe to substantially impregnate the fibrous structure with the resin; provide the ability to cure the resin under environmental conditions. The method of curing the resin includes curing the resin under ambient conditions without using an external heat source. In this method, when injecting the resin, a flexible forming element is installed around the fibrous structure; establish a reinforcing holding element around a flexible forming element; the resin is poured through the reinforcing holding element and into the forming element over the fibrous structure, and the flexible forming element is compressed to pump the resin through the fibrous structure to the pipe. At the same time, the reinforcing holding element forms an annular space together with the pipe, it facilitates the regulation of the thickness of the resin around the pipe. The reinforcing holding member is radially flexible and provides rigidity in the axial direction. According to the method, the imposition of a fibrous structure is carried out on the surface of the object (pipe); the resin is applied to the fibrous structure located on the surface of the object to substantially impregnate the fibrous structure and form a layer of resin on the fibrous structure and allow the resin to cure to form a composite material from a dry fibrous structure and resin on the surface of the object.

The device is a pipe with a fibrous structure superimposed on it, while the fibrous structure includes winding around the outer surface of the pipe. The fibrous structure is not wetted with resin before application or during application to the surface of the object. A fabric forming element is applied around the fibrous structure; thereafter, the drum is installed in a predetermined position around the fabric forming element and the polymer material is placed inside the fabric forming element, after which the polymer material is injected into the fibrous structure to impregnate the fibrous structure. The curing of the polymer material to form the composite material from the fibrous structure and the polymer material occurs on the surface of the object (pipe).

A pipe repair system comprising a reinforcing material configured to be wound around a pipe, allowing it to receive resin after placing the reinforcing material around the pipe; malleable forming element made with the possibility of placing it around the reinforcing material wound around the pipe, while the malleable forming element is made with the possibility of receiving and holding resin around the reinforcing material; a support structure configured to form a sheath around at least a portion of the ductile forming element and provide support for at least a portion of the ductile forming element located on the pipe; and a resin with a chemical composition that allows it to be poured into the ductile forming element to impregnate the fiber and to form a composite material together with a reinforcing material on the pipe.

The disadvantage of this design is the following:

- repair is possible only for a section of small length, if necessary, repair of extended sections of the pipeline, the process becomes very time-consuming due to the use of a large number of additional equipment;

- when using this device, it is possible that the polymer-impregnated fiber may not adhere sufficiently, which leads to the formation of voids on the surface of the pipeline in which corrosion processes will develop;

- after the completion of the polymerization process, additional stress concentrators appear at the edges of the repaired section due to the use of the forming element, which may ultimately lead to the destruction of the pipeline;

- it is impossible to obtain a structure that is qualitatively impregnated with a polymeric material due to the fact that the polymeric material passes through the structure from the fiber to the surface of the object under the action of gravity, or capillary forces, or their combined effect, and the impregnation of the fibers under the influence of gravity and / or due to capillary action is possible only in the upper part of the pipe. In its lower part, gravity will act in the opposite direction and the creation of additional pressure during resin supply will also not be able to solve the problem of high-quality impregnation without creating special systems for removing air from under the fibrous structure, which is not provided for by this patent.

Great complexity in the implementation of the method. The inability to repair a pipeline of long length due to the fact that the method and device has not resolved the issue of implementing hardening of joints at a sequential overlay of the claimed device.

Disclosure of invention

The objective of the invention is to provide a device that provides a reliable fit of the coating of the reinforcing sheet to the surface of the pipe pipe, ensuring the absence of stress concentrators on the edges of the repaired section, and also makes it possible to repair extended sections of the pipeline with a small laborious process.

This problem is solved due to the fact that the device for repairing the pipeline consists of a flexible sheet material containing layers of fabric and a composite, which is impregnated with the fabric, while the flexible sheet material contains at least two layers of a hybrid fabric, consisting, for example, of carbon fibers and threads Kevlar, and each subsequent layer of fabric is attached to the previous one, for example, with glue, and the third layer is a layer of polymer, for example polyethylene, deposited on a hybrid fabric, for example, by deposition, the fourth layer represents a compound based on, for example, epoxy resin, with the fourth layer located on the device from the side opposite to the polymer layer, in addition, one end of the flexible sheet material is made in the form of loops on one and the other side, and inside each loop, and also on both outer sides of the hinges there are longitudinal metal plates fixed to the hinges, in addition, hinges with metal plates are equipped with tensioners. In this case, the tensioners are a U-shaped metal structure with a longitudinal groove in which a loop with metal plates is placed, and the tensioners also have a through hole parallel to the base to secure the tensioners located opposite each other when using the device and the tensioners are mounted on opposite loops against each other along the device at predetermined distances. In the device, the end of the loop on one side of the device is protruding beyond the tensioners to a predetermined length, that is, free, while on the other hand, the end of the loop does not extend beyond the base of the tensioners, while the tensioners are pre-fixed on loops with metal plates, for example, rivets.

A method of repairing a pipeline is to use the inventive device, and it includes the following sequences: an assembled device with a previously applied layer of a compound, for example, epoxy resin with a hardener, is kept outdoors for a predetermined time required for impregnation of layers of hybrid fabric and partial curing of the compound , that is, until the specified viscosity of the compound is obtained, after that the device is taken by the tensioners, either manually or using mechanisms and overlay The device is placed on the pipe section to be repaired, then it is pressed tightly to the pipe with flexible sheet material from the side on which the compound is applied, that is, from the side opposite to the side with the polymer coating layer, then it is fixed using a bolted connection and tension is applied, and tension in the central part of the device produce more than at the ends of it.

In addition, in the method, when repairing large linear sections of the pipeline before applying each subsequent device to the pipe, a cover plate is preliminarily installed by any method, for example by winding polymer material, and after installing the cover plate, the second device is overlapped so that the flexible sheet material of the second device contacts the tension-free flexible sheet material of the first device, and all subsequent overlays are carried out similarly to the previous one.

Pipelines located in the ground are destroyed by soil corrosion, which in turn is divided into chemical and electrochemical, as well as electrical corrosion, external influences and pipe defects, welds and installation.

Accident statistics show that the above factors can cause corrosion ulcers and cracks in the pipe. Therefore, for axially extended structures characterized by the presence of an internal force directed radially outward, more precisely for pipelines through which gas, oil or oil products move under pressure, it is especially important to create a structure aimed at hardening a corroded or otherwise damaged section of the pipeline as if it were stopped and without stopping the transport of the product.

The inventive device and method of repairing the pipeline are intended for reinsulation and selective repair of linear sections of trunk pipelines with the ability to repair for critical defects (including through) for a short period to organize the subsequent overhaul.

Brief Description of the Figures

In Fig.1 shows a coating device reinforcing sheet in cross section.

Figure 2 shows the tensioners in cross section:

a) - the left tensioner, b) - the right tensioner.

Figure 3 shows a view A of the left tensioner.

Figure 4 shows a coating device for reinforcing sheet in cross section with tensioners.

Figure 5 shows a bolt for connecting tensioners.

Figure 6 shows a view In the bolt of figure 5.

Fig. 7 shows a perspective view of a pipeline pipe with a coating fixed to it by a reinforcing sheet in cross section.

On Fig depicts a pipeline pipe with a coating fixed to it by a reinforcing sheet in longitudinal section.

In Fig.9 shows a section along aa in Fig.8.

The images in the figures are not made in accordance with the scale of each figure in relation to the other, which is done to maximize understanding of the claimed method and device design.

Examples of specific performance

The claimed device is a reinforcing sheet coating, which consists of a flexible sheet material 1 of a given design size in length and width. The basis of the sheet material 1 is a hybrid fabric 2, consisting, for example, of carbon fibers and Kevlar threads, while carbon fibers have a high tensile strength, and Kevlar threads additionally allow to absorb loads in the radial direction.

Strengthening sheet coating contains at least two layers of hybrid fabric 2. Each subsequent layer of fabric 2 is attached to the previous one, for example, with special glue. The third layer is a layer of polymer 3, for example polyethylene, which is applied to a hybrid fabric, for example, by deposition. The fourth layer 4 is an epoxy resin compound, the fourth layer 4 being applied to the device from the side opposite to the polymer layer 3 before using the device. One end of the flexible sheet material 1 is made in the form of a loop 5 on one side and a loop 6 on the other side. Inside each loop 5 and loop 6, as well as on both outer sides of the loop 5 and loop 6, there are longitudinal metal plates 7 attached to the loop 5 and loop 6 by, for example, riveting 8 made over a given distance, while for a more reliable connection loops 5 with plates 7 and loops 6 with plates 7 the sheet material is lubricated with compound 4 before forming loops 6 and 7. Loop 5 with metal plates 7 is equipped with tensioners 9. Loop 6 with metal plates 7 is equipped with tensioners 10. Tensioners 9 represent fight metal structure U-shaped in cross section with a longitudinal groove 11 and the chamfer 12 from the base 13 (see FIG. 2, b). At a given distance from the base 13, a through hole 14 is made parallel to the base 13. The tensioners 10 are a U-shaped metal structure in cross section with a longitudinal groove 15 and a bevel 16 from the side of the base 17 (see Fig. 2, a). At a given distance from the base 17, a through hole 18 is made parallel to the base 17. Tensioners 9 and 10 are mounted on loops 5 and 6, respectively, along the device at predetermined distances.

Chamfer 12 of tensioner 9 and bevel 16 of tensioner 10 (see Fig. 2, a and b) are made to ensure a tight fit of the claimed device on the pipe 19 of the pipeline.

The through hole 14 is made round in cross section and has a thread, and the through hole 18 is made larger in height than the through hole 14, and has the shape of an oval to secure the bolt 20, which has, in addition to the thread, an additional longitudinal notch 21 in the end part, providing reliable fixing the bolt in the tensioners 9 and 10 when assembling the device on the pipe 19 of the pipeline. The central axis of the through hole 14 and the skovoz holes 18 are offset by the value of "N".

A feature of the loop 5 located in the longitudinal groove 11 of the tensioner 9 is that the end of the loop is made flush with the plate 7. A feature of the loop 6 located in the longitudinal groove 15 of the tensioner 10 is that the end of the loop extends beyond the plate 7 for a given length, that is, free. To ensure the convenience of the work carried out when fixing the coating of the reinforcing sheet on the pipeline, the tensioners 9 and 10 are pre-fixed on the loop 5 with the plates 7 and the loop 6 with the plates 7 rivets 22. The tensioners 9 and 10, located on the device against each other, are installed on the loop 5 and 6 in length so that the left tensioner is installed at the same level with the edge of the flexible sheet material, and the latter at a distance from the other edge of the flexible sheet material, providing the possibility of connecting each last the guide cover of the reinforcing sheet overlap in the repair of large linear pipeline segments. The device, ready to use, is a hardening sheet coating, namely flexible sheet material 1, before installing it on the pipe 19 of the repaired pipeline is covered with a layer of compound 4 from the side opposite to the polymer layer 3. For fixing on the pipe 19 of the repaired pipeline, the tensioners 9 and 10 are pulled together using bolt connection 20. Tensioners 9 and 10 are designed for loads up to 25 MPa. When repairing large linear sections of the pipeline, one end of the flexible sheet material 1 is superimposed on the other, while a patch 23 is placed on the surface of the pipe 19 at the joints of the flexible sheet materials 1, for example, made of a polymer material for more reliable fixation of the flexible sheet materials with each other.

The device operates as follows.

The reinforcing sheet coating is intended for re-insulation and selective repair of linear sections of trunk pipelines with the ability to repair for critical defects, including through ones, for a short period for organizing subsequent overhauls.

The previously cleaned surface of the part of the pipe 19, which will be subject to repair, is treated with an inhibitor to eliminate the existing foci of corrosion and cover the surface of the part of the pipe 19 with a protective film. The inhibitor is selected so that the composite 4 layer can be applied well to the surface treated and, after the polymerization process is completed, high adhesion of the flexible sheet material 1 to the pipe 19 is ensured. A layer of composite 4 is applied to the flexible sheet material 1 and after the composite 4 is impregnated for a certain time of the layers of fabric 2 and dissolution in the composite layer of glue used to fix one layer of fabric 2 in relation to another, which depends on the composition of composite 4 and its flow properties. In this case, partial curing of composite 4 occurs, and, consequently, an increase in its viscous flow properties. After that, the reinforcing sheet coating is installed on the pipe section 19 of the pipeline pretreated by the inhibitor and the tensioners 9 and 10 are placed against each other by bolting 20. Moreover, when installing the reinforcing sheet coating on the pipe 19, the protruding end of the sheet material 1 of the loop 6 is brought under the tensioner base 17 10. It is this that ensures the tightness of the structure installed on the pipe 19 after tightening with bolt connections 20 of the tensioners 9 and 10 in pairs. Pulling is performed with a pre-calculated force, and it is different in size in the central part along the length of the coating of the reinforcing sheet and at its ends. This is done in order to relieve additional stress concentrators arising at the edges of the repaired section of the pipe 19 of the pipeline after the completion of the polymerization process, due to which the pipeline can be destroyed. After the polymerization process of composite 4 is completed, a monolithic reinforcing structure is obtained on the surface of the pipeline with a reinforcing layer of hybrid fabric 2. Composite 4 is selected so that it completely impregnates the fibers of hybrid fabric 2 and, when cured, allows the structure to compensate for stresses arising in the pipeline. As the composite, an epoxy resin with a hardener can be used, selected in such a way as to achieve its viscosity necessary and sufficient to impregnate the hybrid fabric and ensure reliable adhesion to the pipe 19 with an inhibitor layer.

Due to the fact that the claimed device — a reinforcing sheet coating — is installed on the pipeline with a hybrid cloth 2 to the pipe 19, the surface of the pipe 19 is externally covered with a layer of polyethylene 3, which excludes subsequent application of insulation materials from the pipeline repair technology.

To carry out major and other types of pipeline repairs, the repair structure must take the load and unload the defective area both in the radial and axial directions, thereby preventing the existing defect from developing further. The proposed design solves this problem due to two layers of high-strength hybrid fabric 2, with the help of which the existing pipeline is pulled together with the possibility of regulating the degree of tension during repairs under pressure. Also, after repairing the pipeline by the method of re-isolation (with relieved pressure inside the pipeline), it will perceive the arising loads after raising the pressure in the pipeline and starting to transport the product.

Hybrid fabric 2 with composite 4 previously applied to the surface during compression is pressed into the pipe 19 of the pipeline, without leaving voids on the pipe surface, which in combination with the inhibitor film deposited on the surface of the pipeline protects the surface from further corrosion and the development of existing defects.

A method of repairing a pipeline, which consists in using the claimed device, includes the following sequences. The device is assembled with a pre-deposited layer of compound 4, for example an epoxy resin with a hardener, is kept outdoors for a predetermined time required for the impregnation of layers of hybrid fabric 2 and partial curing of compound 4, that is, until the desired viscosity of compound 4 is obtained. After that, the device take the tensioners 9 and 10, either manually or using mechanisms (depending on the diameter of the pipe 19 and, accordingly, the size of the device) and make the device overlay on the pipe section 19 to be repaired, after To do this, they are pressed tightly to the pipe with flexible sheet material 1 from the side on which the compound is applied, that is, from the side opposite to the side with the polymer coating layer 3, then they are fixed with bolt joint 20 and tension is applied, the degree of which is the calculated value, and the force the tension in the central part of the device is greater than at the ends of it. When carrying out repairs of large linear sections of the pipeline before applying each subsequent device to the pipe 19 in advance by any method, for example by winding polymer material, a patch 23 is installed with its center position between the edges of the devices, that is, so that after applying the second device to the first patch 23 provided tightness of the created design. After installing the lining 23, a second lap device is installed so that the flexible sheet material of the second device comes into contact with the flexible sheet material 1 of the first device free of tensioner 9 and 10. All subsequent overlays are carried out similarly to the previous one.

Industrial applicability

The claimed method and device for repairing a pipeline are industrially applicable, because The device is made from available materials. The method and device can find wide consumer demand due to ease of use and high technology for solving especially important problems in the repair of pipelines.

Thus, the technical problem, namely, the creation of a device that provides a reliable fit of the coating of the reinforcing sheet to the surface of the pipeline pipe, ensuring the absence of stress concentrators at the edges of the repaired section, as well as the possibility of repairing extended sections of the pipeline with a small laboriousness of the process, is solved in this technical solution.

Claims (5)

1. Device for repairing a pipeline, consisting of a flexible sheet material containing layers of fabric and composite, which is impregnated with fabric,
characterized in that
the flexible sheet material contains at least two layers of hybrid fabric, consisting, for example, of carbon fibers and Kevlar threads, and each subsequent layer of fabric is attached to the previous one, for example, by glue, the third layer being a layer of polymer, for example polyethylene, applied to the hybrid fabric , for example, by deposition, the fourth layer is a compound based on, for example, epoxy resin, while the fourth layer is located on the device from the side opposite to the polymer layer, in addition, one end of the flexible zealous material is in the form of loops with one on each side, and inside each loop, and on both outer sides of loops disposed longitudinal metal plates are fixed to the hinges, in addition, a loop with metal plates equipped with tensioners. 2. The device according to claim 1, characterized in that the tensioners are a U-shaped metal structure in cross section with a longitudinal groove, in which a loop with metal plates is placed, while the tensioners also have a through hole parallel to the base, for securing the tensioners, located opposite each other, with each other when using the device, and the tensioners are installed on opposite loops against each other along the device at predetermined distances. 3. The device according to claim 1, characterized in that the end of the loop on one side of the device is protruding beyond the tensioners to a predetermined length, that is, free, while on the other hand, the end of the loop does not protrude beyond the base of the tensioners, while the tensioners are pre-fixed on hinges with metal plates, for example, rivets. 4. The method of repairing the pipeline, which consists in using the device according to claim 1, wherein it includes the following sequences: the device assembly with a previously applied layer of a compound, for example, epoxy resin with a hardener, is kept in the open air for a predetermined time required for the impregnation of the layers hybrid fabric and partial curing of the compound, that is, until the specified viscosity of the compound is obtained, after that the device is taken by the tensioners, either manually or using mechanisms and apply e devices on the pipe section to be repaired are then pressed tightly to the pipe with flexible sheet material from the side on which the compound is applied, that is, from the side opposite to the side with the polymer coating layer, then fixed by means of a bolted connection and tension is applied, and the force tension in the central part of the device produce more than at the ends of it. 5. The method according to claim 4, characterized in that when repairing large linear sections of the pipeline before applying each subsequent device to the pipe beforehand by any means, for example by winding polymer material, a cover plate is installed, and after installing the cover plate, a second device is overlapped so that the flexible sheet material of the second device went into the tension-free flexible sheet material of the first device, and all subsequent overlays are carried out similarly to the previous him.

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