Special-shaped sleeve for local repair of plugging tee joint, mold and manufacturing and repairing method

Abstract

The invention provides a special-shaped sleeve for local repairing of a plugging tee joint, a mold and a manufacturing and repairing method. The manufacturing method of the special-shaped sleeve for local repairing of the blocking tee joint comprises the steps that S1, the blocking tee joint to be repaired is scanned, and the outer contour and contour parameters of the blocking tee joint to be repaired are obtained; s2, the outer contour of the to-be-repaired and blocked tee joint is amplified, and the gap between the amplified outer contour of the to-be-repaired and blocked tee joint and the outer contour of the to-be-repaired and blocked tee joint is made to be a preset value; s3, the amplified outer contour of the to-be-repaired blocking tee joint serves as the inner wall contour of a to-be-machined mold to manufacture the to-be-machined mold, and the to-be-machined mold is divided into a left mold body and a right mold body; and S4, the two steel plates are subjected to hot press molding through a left mold and a right mold correspondingly, and a left special-shaped sleeve and a right special-shaped sleeve matched with the plugging tee joint to be repaired are manufactured.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas pipeline repair, and in particular to a special-shaped sleeve for local repair of a plugged tee, a mold, and a manufacturing and repair method. Background Art

[0002] At present, among the more than 20 existing pipeline defect repair methods, pipe replacement and B-type sleeve repair are two permanent repair methods that are often used for pipeline defect repair. However, when pipe replacement is used, not only will the entire pipeline be shut down, causing natural gas supply interruption to downstream users, but the natural gas in the dozens of kilometers of pipelines between the two valve chambers where the defective pipeline is located must also be completely emptied, causing huge economic losses. When using the B-type sleeve repair, defects can be repaired without stopping the pipeline, which has the characteristics of low cost, good effect and high reliability. In addition, compared with composite materials, A-type sleeves, epoxy sleeves and other repair methods that can only withstand circumferential loads, the B-type sleeve repair method can not only withstand circumferential loads, but also axial and bending loads. At the same time, since the end of the B-type sleeve is connected to the repaired steel pipe through a circumferential fillet weld, it has good sealing performance and is also suitable for repairing leakage defects that occur during the service of the pipeline.

[0003] A large number of engineering practices have been carried out in the application of B-type sleeves, and certain successful experiences have been accumulated. However, in the early days, B-type sleeves were mainly used for the repair of low-grade steel and small and medium-sized oil pipelines. Limited by the construction period of X70 / X80 pipelines, the supporting repair technology update and upgrade were not considered. Therefore, when high-grade steel gas pipelines use B-type sleeves to repair girth welds, low-grade Q345R sleeves are habitually used for pipeline repair. Due to the large diameter and high pressure of high-grade steel pipelines, once unacceptable defects appear at the girth weld, the calculated wall thickness of the reinforced Q345R sleeve is far greater than the pipe wall thickness. The general wall thickness requirement is about 40mm, and the maximum wall thickness reaches 70mm, which increases the difficulty of welding and leads to new problems. In the process of repairing pipeline girth weld defects on site, many corner weld cracks of B-type sleeves have occurred, and the safety of its repair has attracted more attention.

[0004] The plugging tee leaked frequently at the project site. There was a plugging tee leak in a certain project. The outer diameter of the pipeline was φ559mm, the design pressure was 6.4Mpa, and the inner diameter of the plugging tee was φ559mm. The plugging tee played a great role in repairing pipeline corrosion defects and leaks, but there was a plugging tee leak at the site. A special-shaped sleeve was used for repair on site. The tee and the corresponding pipeline were completely covered and welded, but the designed full-coverage sleeve repair method did not achieve the expected effect. In addition, the pipeline counterweight was large, and the design needed to be improved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a special-shaped sleeve, a mould, a manufacturing method and a repair method for the local repair of a plugged tee in view of the deficiencies of the prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a method for manufacturing a special-shaped sleeve for local repair of a plugging tee, comprising: S1, scanning the plugging tee to be repaired to obtain the external contour and contour parameters of the plugging tee to be repaired; S2, enlarging the external contour of the plugging tee to be repaired, so that the gap between the external contour of the enlarged plugging tee to be repaired and the external contour of the plugging tee to be repaired is a preset value; S3, using the enlarged external contour of the plugging tee to be repaired as the inner wall contour of the mold to be processed to manufacture the mold to be processed, wherein the mold to be processed is divided into a left mold and a right mold; S4, hot-pressing two steel plates through the left mold and the right mold respectively to manufacture a left special-shaped sleeve and a right special-shaped sleeve that are compatible with the plugging tee to be repaired.

[0007] The beneficial effects of the technical solution of the present invention are: it can not only prevent leakage at the sealing point of the three-way plugging, but also ensure that the pipeline counterweight is small and the operation is simple. The sleeve blank is produced by compression molding, and then the sleeve is finely processed according to the actual situation to ensure the overall repair effect of the on-site plugging tee. The manufactured mold only has half of the structure, saving mold costs. It can solve problems such as difficulty in directly repairing and reinforcing the seal. The manufactured sleeve is used to be installed on the outside of the plugging three-way branch pipe, which can meet the requirements of the in-service repair and reinforcement of the sealing defects between the main pipe and the branch pipe of the plugging tee of different shapes without stopping the oil and gas transmission medium in the pipeline.

[0008] Furthermore, in step S1, the tee to be repaired and blocked is 3D scanned by a 3D scanner, and the external contour of the tee to be repaired and blocked includes: the external contour of the tee shoulder, the external contour of the tee branch and the external contour of the seal.

[0009] The beneficial effects of adopting the above further technical solution are: it is convenient to quickly scan the external contour and contour parameters of the plugging tee to be repaired, and it is convenient to make a mold according to the scanned data in the later stage. It is suitable for different plugging tees and various application scenarios.

[0010] Furthermore, in step S2, the preset value is the sum of the wall thickness of the steel plate used to process the sleeve and the gap between the inner wall of the sleeve and the outer contour of the butt steel pipe or the tee main pipe.

[0011] The beneficial effect of adopting the above further technical solution is that it is easy to accurately produce a mold and a sleeve that are compatible with the tee to be repaired and blocked, thereby improving precision.

[0012] Further, step S4 includes: S41, making a pressing tool that is compatible with the mold to be processed; S42, heating a steel plate to above the austenite temperature; S44, placing the steel plate on the left mold; S45, using the pressing tool to press the steel plate into the left mold to obtain a left sleeve; S42, heating another steel plate to above the austenite temperature; S44, placing a steel plate on the right mold; S45, using the pressing tool to press the other steel plate into the right mold to obtain a right sleeve.

[0013] The beneficial effects of adopting the above further technical solution are: implementing heat treatment after preheating to solve the problem of cracking of fillet welds, facilitating the production of sleeves, and improving the load strength of sleeves.

[0014] Further, after step S45, it includes: S46, machining the left sleeve and the right sleeve by a cutting method; S47, performing tempering heat treatment on the left sleeve and the right sleeve to obtain the left special-shaped sleeve and the right special-shaped sleeve adapted to the tee to be repaired and blocked.

[0015] The beneficial effects of adopting the above further technical solution are: implementing heat treatment after preheating to solve the problem of cracking of fillet welds. Firstly, the sleeve blank is produced by the die-forming method, and then the sleeve is finely processed by the cutting method to ensure the overall repair effect of the on-site plugging tee.

[0016] Furthermore, in step S3, a curve is set on the mold to be processed for smooth transition; and two parallel cavities are set at the center of the mold to be processed.

[0017] The beneficial effect of adopting the above further technical solution is: setting the curve for smooth transition, which is convenient for metal rheology during hot working. Two parallel cavities are respectively set in the center of the mold, with a certain length, for controlling the outer diameter size of the flange of the three-way branch pipe and having a certain processing margin.

[0018] Furthermore, in step S4, a machining margin is reserved on the left special-shaped sleeve and the right special-shaped sleeve during pressing, and the left special-shaped sleeve and the right special-shaped sleeve are necked.

[0019] The beneficial effect of adopting the above further technical solution is: the three-way main pipe is closed to achieve a light and practical repair effect. The main pipe end is necked to control the geometric size.

[0020] In addition, the present invention also provides a special-shaped sleeve for local repair of a plugging tee manufactured by the manufacturing method of a special-shaped sleeve for local repair of a plugging tee described in any one of the above-mentioned items, comprising a special-shaped sleeve body formed by connecting a left special-shaped sleeve and a right special-shaped sleeve, the interior of the special-shaped sleeve body being, from top to bottom, a round head section cavity, a straight pipe section cavity and an elliptical section cavity respectively, a neck being provided at the bottom of the special-shaped sleeve body, a circular arc being adapted to the plugging tee to be repaired, and the special-shaped sleeve body being connected to the plugging tee to be repaired by means of a circumferential lap fillet weld.

[0021] The beneficial effects of the technical solution of the present invention are: the three-way main pipeline is closed to achieve a light and practical repair effect. It can not only seal the three-way seal to prevent leakage, but also ensure that the pipeline counterweight is small and the operation is simple. The end of the main pipe is controlled by the necking method for geometric dimensions. When installing and welding, the end of the sleeve main pipe is welded by a circumferential lap fillet weld. The sleeve cavity is large and can cover different special-shaped workpieces, which is convenient for actual assembly and application. The two ends of the sleeve have a certain roundness in the fitting area with the main pipe, and the inner and outer diameters can be cut according to the actual size of the main pipe to be repaired, which is convenient for actual assembly and application. The improved large round head plus straight pipe section plus elliptical section comprehensive structure method not only overcomes the problem of not being able to directly perform welding repair, but also uses this structure to achieve the reinforcement of the weak area of ​​the three-way branch pipe structure, which can realize the non-stop welding repair of the circumferential weld defects and sealing defects between the branch pipe and the connector in the in-service tee.

[0022] In addition, the present invention also provides a method for local repair of a blocked tee. Based on the above-mentioned special-shaped sleeve for local repair of a blocked tee, the method for local repair of a blocked tee includes: docking and covering the left special-shaped sleeve and the right special-shaped sleeve on the branch pipe of the blocked tee to be repaired, and welding the longitudinal weld and the circumferential weld.

[0023] The beneficial effect of the technical solution of the present invention is that during installation and welding, a circumferential lap fillet weld is used at the end of the sleeve main pipe to repair the local defects of the tee.

[0024] Again, the present invention also provides a mold made by the method for making a special-shaped sleeve for local repair of a plugged tee as described in any of the above-mentioned items, including a mold body formed by connecting a left mold and a right mold, the left mold and the right mold have the same structure, the molded section of the mold body is provided with a curved transition structure, and the interior of the mold body comprises, from top to bottom, a round head section mold cavity, a straight pipe section mold cavity and an elliptical section mold cavity.

[0025] The beneficial effects of the technical solution of the present invention are: the designed mold only has half of the structure, saving mold costs; setting curves for smooth transitions to facilitate metal rheology during hot working. Two parallel cavities are set in the center of the mold, each with a certain length, which is used to control the outer diameter of the flange of the plugged tee branch pipe and have a certain processing margin. The improved large round head plus straight pipe section plus elliptical section comprehensive structure not only overcomes the problem of not being able to directly perform welding repairs, but also uses this structure to achieve reinforcement of the weak areas of the plugged tee branch pipe structure, and can achieve non-stop welding repairs of circumferential weld defects and sealing defects between the branch pipe and the connector in the in-service tee.

[0026] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic flowchart of a method for manufacturing a special-shaped sleeve for local repair of a plugged tee provided in an embodiment of the present invention.

[0028] Figure 2 A schematic diagram of the sleeve repair effect provided in an embodiment of the present invention.

[0029] Figure 3 A schematic diagram of sleeve installation welding provided in an embodiment of the present invention.

[0030] Figure 4 This is one of the structural schematic diagrams of the sleeve provided in an embodiment of the present invention.

[0031] Figure 5 The second structural schematic diagram of the sleeve provided in the embodiment of the present invention.

[0032] Figure 6 The third structural schematic diagram of the sleeve provided in the embodiment of the present invention.

[0033] Figure 7 This is one of the structural schematic diagrams of the mold provided in an embodiment of the present invention.

[0034] Figure 8 The second structural schematic diagram of the mold provided in the embodiment of the present invention.

[0035] Fig. 9 A schematic diagram of the structure of a pressing tool provided in an embodiment of the present invention.

[0036] Explanation of the accompanying figures: 1. Left special-shaped sleeve; 2. Right special-shaped sleeve; 3. Neck reduction; 4. Tee to be repaired and blocked; 5. Arc; 6. Longitudinal weld; 7. Circumferential weld; 8. Mould; 9. Press. DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0038] like Figure 1 As shown, an embodiment of the present invention provides a method for manufacturing a special-shaped sleeve for local repair of a plugging tee, comprising: S1, scanning the plugging tee to be repaired to obtain the outer contour and contour parameters of the plugging tee to be repaired; S2, enlarging the outer contour of the plugging tee to be repaired, so that the gap between the outer contour of the enlarged plugging tee to be repaired and the outer contour of the plugging tee to be repaired is a preset value; S3, using the enlarged outer contour of the plugging tee to be repaired as the inner wall contour of the mold to be processed to manufacture the mold to be processed, wherein the mold to be processed is divided into a left mold and a right mold; S4, hot-pressing two steel plates through the left mold and the right mold respectively to manufacture a left special-shaped sleeve and a right special-shaped sleeve that are compatible with the plugging tee to be repaired.

[0039] The beneficial effects of the technical solution of the present invention are: it can not only prevent leakage at the sealing point of the three-way plugging, but also ensure that the pipeline counterweight is small and the operation is simple. The sleeve blank is produced by compression molding, and then the sleeve is finely processed according to the actual situation to ensure the overall repair effect of the on-site plugging tee. The manufactured mold only has half of the structure, saving mold costs. It can solve problems such as difficulty in directly repairing and reinforcing the seal. The manufactured sleeve is used to be installed on the outside of the plugging three-way branch pipe, which can meet the requirements of the in-service repair and reinforcement of the sealing defects between the main pipe and the branch pipe of the plugging tee of different shapes without stopping the oil and gas transmission medium in the pipeline.

[0040] Furthermore, in step S1, the tee to be repaired and blocked is 3D scanned by a 3D scanner, and the external contour of the tee to be repaired and blocked includes: the external contour of the tee shoulder, the external contour of the tee branch and the external contour of the seal.

[0041] The beneficial effects of adopting the above further technical solution are: it is convenient to quickly scan the external contour and contour parameters of the plugging tee to be repaired, and it is convenient to make a mold according to the scanned data in the later stage. It is suitable for different plugging tees and various application scenarios.

[0042] Furthermore, in step S2, the preset value is the sum of the wall thickness of the steel plate used to process the sleeve and the gap between the inner wall of the sleeve and the outer contour of the butt steel pipe or the tee main pipe.

[0043] The beneficial effect of adopting the above further technical solution is that it is easy to accurately produce a mold and a sleeve that are compatible with the tee to be repaired and blocked, thereby improving precision.

[0044] Further, step S4 includes: S41, making a pressing tool that is compatible with the mold to be processed; S42, heating a steel plate to above the austenite temperature; S44, placing the steel plate on the left mold; S45, using the pressing tool to press the steel plate into the left mold to obtain a left sleeve; S42, heating another steel plate to above the austenite temperature; S44, placing a steel plate on the right mold; S45, using the pressing tool to press the other steel plate into the right mold to obtain a right sleeve.

[0045] The beneficial effects of adopting the above further technical solution are: implementing heat treatment after preheating to solve the problem of cracking of fillet welds, facilitating the production of sleeves, and improving the load strength of sleeves.

[0046] Further, after step S45, it includes: S46, machining the left sleeve and the right sleeve by a cutting method; S47, performing tempering heat treatment on the left sleeve and the right sleeve to obtain the left special-shaped sleeve and the right special-shaped sleeve adapted to the tee to be repaired and blocked.

[0047] The beneficial effects of adopting the above further technical solution are: implementing heat treatment after preheating to solve the problem of cracking of fillet welds. Firstly, the sleeve blank is produced by the die-forming method, and then the sleeve is finely processed by the cutting method to ensure the overall repair effect of the on-site plugging tee.

[0048] Furthermore, in step S3, a curve is set on the mold to be processed for smooth transition; and two parallel cavities are set at the center of the mold to be processed.

[0049] The beneficial effect of adopting the above further technical solution is: setting the curve for smooth transition, which is convenient for metal rheology during hot working. Two parallel cavities are respectively set in the center of the mold, with a certain length, for controlling the outer diameter size of the flange of the three-way branch pipe and having a certain processing margin.

[0050] Furthermore, in step S4, a machining margin is reserved on the left special-shaped sleeve and the right special-shaped sleeve during pressing, and the left special-shaped sleeve and the right special-shaped sleeve are necked.

[0051] The beneficial effect of adopting the above further technical solution is: the three-way main pipe is closed to achieve a light and practical repair effect. The main pipe end is necked to control the geometric size.

[0052] The present invention aims to improve the shortcomings of large size and bulkiness after repair, and adopts means such as closing the three-way main pipeline to achieve the effect of light and practical repair.

[0053] According to the different leakage positions of the plugging tee, the sleeve structure design for different application scenarios is carried out. On the basis of meeting the repair needs, the focus is on optimizing the sleeve structure to reduce the sleeve's own weight and reduce the workload of on-site installation and welding. Through customized molds, sleeves are manufactured by molding, cutting and other processing methods, forming supporting welding processes and non-destructive testing methods, and repairing the plugging tee with leakage.

[0054] The present invention provides a partially covered sleeve structure for a plugging tee (a special-shaped sleeve for partially repairing a plugging tee), and provides a hot pressing molding die and a manufacturing method for the sleeve, which can repair the plugging tee, prevent leakage at the sealing part of the plugging tee, and ensure that the pipeline counterweight is small and the operation is simple.

[0055] In order to solve the safety problem of B-type sleeve repair (cracking of fillet weld), basic research and product development work on low-grade B-type sleeves (Q345R material) and high-grade B-type sleeves (X65, X70 and X80 materials) were systematically carried out for the repair of girth weld defects of pipelines with steel grades of X70 and above. A lot of research has been done on the analysis of the stress conditions of B-type sleeves, sleeve processing and forming inspection, welding process, non-destructive testing, etc. Through preliminary research, the theoretical basis for the development of B-type sleeves has been systematically mastered, including the selection and forming theory of sleeve materials, sleeve structure optimization design technology, and the relationship between the residual stress of fillet welds and the heat treatment temperature and time. For the first time, the structural design theory of B-type sleeves was proposed, and the structural size optimization design method of B-type sleeves was established. The structural design method of B-type sleeves was proposed. The bending resistance of the sleeve is not lower than the bending resistance of the steel pipe required by the standard, and the internal pressure bearing capacity of the sleeve is not lower than the safety level of the girth weld to be repaired. The sleeve structure size is optimized, solving the problem of lack of theoretical basis for sleeve design and inconsistent sleeve size requirements in existing standards. For Q345R steel grade B-type sleeves, the appropriate welding process regulations were finally determined through welding process optimization research, and heat treatment after preheating was implemented to solve the problem of corner weld cracking; new thin-walled X65 and X70 steel grade B-type sleeves were developed, and the optimized high-grade B-type sleeves were 19% to 30% thinner than the traditional Q345R sleeves through the optimization design of the B-type sleeve structure dimensions. The material selection scheme and heat processing technology of X65 and X70 steel grade B-type sleeves were systematically standardized, and the production and Relevant technical requirements were inspected, industry standards were issued, and large-scale physical tests were conducted to verify the quality of the products, providing new products for the repair of defects in high-grade steel girth welds in service; the non-destructive testing technology of B-type sleeve fillet welds was studied, and the non-destructive testing process of B-type sleeve fillet welds was improved, the interlayer magnetic particle testing was cancelled, and the magnetic particle testing and ultrasonic phased array testing 24 hours and 48 hours after welding were added, forming a new non-destructive testing method for fillet welds; at the same time, a sleeve repair product technology evaluation index system and inspection method were established to guide on-site construction. The above research results have basically solved the problem of fillet weld cracking, and industrial trials have been carried out on site, achieving very good results.

[0056] 1. In view of the defects in the sealing of the plugged tee branch and the flange, in order to better ensure the overall repair effect of the plugged tee on site, the sleeve blank is first produced by the compression molding method, and then the sleeve is finely processed by the cutting method; for the end of the main pipe, the necking method is used for geometric dimension control, and during installation and welding, the circumferential lap fillet weld is used at the end of the sleeve main pipe.

[0057] 2. Installation diagram of partial covering sleeve for blocking tee as shown below: Figure 2 and Figure 3 As shown, the sleeve product is shown as Figures 4 to 6As shown in the figure, the sleeve blank is produced by the compression molding method, and then the sleeve is finely processed by the cutting method.

[0058] 3. In order to solve the problem of sealing leakage of three-way branch pipes, the present invention provides a special-shaped sleeve structure (special-shaped sleeve for local repair of plugging three-way pipes), and provides a hot pressing molding mold and manufacturing method of the sleeve (manufacturing method of special-shaped sleeve for local repair of plugging three-way pipes), which can meet the needs of repairing sealing defects of three-way branch pipes with large wall thickness.

[0059] The present invention adopts the following steps to produce the sleeve:

[0060] (1) Step 1: Use a 3D scanner to perform a 3D scan on the tee shoulder, tee branch pipe and seal to be repaired and blocked, so as to obtain the external contour image and contour parameters of the tee shoulder, tee branch pipe and seal.

[0061] (2) Step 2: Enlarge the outer contours of the tee branch pipe and the seal obtained in step 1 so that the outer contour gap before and after enlargement is T+g, where T is the wall thickness of the steel plate used to process the sleeve, and g is the gap between the inner wall of the sleeve and the outer contour of the butt steel pipe or the tee main pipe.

[0062] (3) Step 3: The enlarged outer contour obtained in step 2 is used as the inner wall contour of the mold to be processed, and the two steel plates are hot-pressed through the left and right molds respectively.

[0063] 4. Sleeve manufacturing method (manufacturing method of special-shaped sleeve for local repair of plugging tee)

[0064] The initial design of the mold for production is one-piece molding, but considering the impossibility of actual production, the improved design adopts two steel plates to be extruded in sequence by the pressing tool 9 and the mold hot pressing molding process (see Figures 7 to 9 ), heat the steel plate to above the austenite temperature, place it on the mold, press the steel plate into the mold with the press 9, control the amount of pressing, press out the left part of the special-shaped sleeve (i.e. half of the sleeve), use the same method to press out the right part of the special-shaped sleeve (i.e. the other half of the sleeve), reserve a machining margin when pressing, and set a curve for smooth transition (curve transition structure) to facilitate metal rheology during hot working; after hot pressing into two blanks, use cutting method to machine the blanks, pay attention to the feed amount during R4 machining, and finally perform tempering heat treatment to process the special-shaped sleeve. Among them, Figure 7 In the figure, R1 can be a round head segment mold cavity, R2 can be a straight tube segment mold cavity, R3 can be an elliptical segment mold cavity, and R4, R1 and R2, R2 and R3, and R4 and R3 can all be curved transition structures.

[0065] 5. Sleeve repair method (local repair method for blocking tee)

[0066] Figure 2 and Figure 3 The schematic diagram of sleeve repair is as follows: the special-shaped sleeve is covered on the three-way branch pipe to be repaired, and the longitudinal weld and the circumferential weld are welded respectively, so that the defects on the three-way branch pipe can be repaired. Among them, the sleeve cavity is large and can cover different special-shaped workpieces.

[0067] The present invention provides a B-type sleeve structure for repairing large shape difference sealing defects, and its mold and manufacturing method (special-shaped sleeve, mold, manufacturing and repair method for local repair of blocked tees) to solve the problems of difficulty in directly repairing and reinforcing the seal in the prior art.

[0068] Regardless of the internal pressure or axial tensile stress, the actual stress acting on the sleeve is very small, so the sleeve only needs to basically meet the sealing and pressure-bearing effects. Therefore, by analyzing and considering the difficulty of molding during the molding process, a B-type sleeve structure solution for repairing sealing defects in pipelines with large shape differences (special-shaped sleeve for local repair of plugging tees) is designed. It has the following advantages:

[0069] (1) The designed mold only needs half of the structure, saving mold costs; the molding section is set with a curve for smooth transition to facilitate metal rheology during hot working; two parallel cavities (straight pipe section cavities) are set in the center of the mold, with a certain length, which is used to control the outer diameter of the flange of the three-way branch pipe and have a certain processing margin.

[0070] (2) The designed sleeve cavity is large and can cover the requirements of workpieces of different shapes. The fitting area between the two ends of the sleeve and the main pipe has a certain roundness (arc). The inner and outer diameters can be cut according to the actual size of the main pipe to be repaired, which is convenient for actual assembly application.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] The present invention provides a B-type sleeve structure for repairing sealing defects of a large-shape-difference plugging tee branch pipe and a manufacturing method thereof (a special-shaped sleeve for local repair of a plugging tee, a mold, a manufacturing method and a repair method). The sleeve is used to be sleeved on the outside of the plugging tee branch pipe, and can complete the in-service repair and reinforcement of sealing defects between the main pipe and branch pipes of plugging tees of different shapes without stopping the oil and gas conveying medium in the pipeline. The improved large round head (round head section cavity) plus straight pipe section (straight pipe section cavity) plus elliptical section (elliptical section cavity) comprehensive structure is utilized to overcome the difficulty of not being able to directly perform welding repair, and the weak area of ​​the plugging tee branch pipe structure is reinforced with the help of the structure, so that the non-stop welding repair of the circumferential weld defects and the sealing defects between the branch pipe and the connecting piece in the in-service tee can be realized.

[0073] like Figures 4 to 6As shown, in addition, the present invention also provides a special-shaped sleeve for local repair of a plugging tee manufactured by the manufacturing method of a special-shaped sleeve for local repair of a plugging tee described in any one of the above items, comprising a special-shaped sleeve body formed by docking a left special-shaped sleeve 1 and a right special-shaped sleeve 2, the interior of the special-shaped sleeve body being respectively a round head section cavity, a straight pipe section cavity and an elliptical section cavity from top to bottom, a necking 3 being provided at the bottom of the special-shaped sleeve body, a circular arc 5 being adapted to the plugging tee 4 to be repaired, and the special-shaped sleeve body being connected to the plugging tee 4 to be repaired by means of annular lap fillet welds.

[0074] The beneficial effects of the technical solution of the present invention are: the three-way main pipeline is closed to achieve a light and practical repair effect. It can not only seal the three-way seal to prevent leakage, but also ensure that the pipeline counterweight is small and the operation is simple. The end of the main pipe is controlled by the necking method for geometric dimensions. When installing and welding, the end of the sleeve main pipe is welded by a circumferential lap fillet weld. The sleeve cavity is large and can cover different special-shaped workpieces, which is convenient for actual assembly and application. The two ends of the sleeve have a certain roundness in the fitting area with the main pipe, and the inner and outer diameters can be cut according to the actual size of the main pipe to be repaired, which is convenient for actual assembly and application. The improved large round head plus straight pipe section plus elliptical section comprehensive structure method not only overcomes the problem of not being able to directly perform welding repair, but also uses this structure to achieve the reinforcement of the weak area of ​​the three-way branch pipe structure, which can realize the non-stop welding repair of the circumferential weld defects and sealing defects between the branch pipe and the connector in the in-service tee.

[0075] like Figures 2 to 3 As shown, in addition, the present invention also provides a method for local repair of a blocked tee. Based on the above-mentioned special-shaped sleeve for local repair of a blocked tee, the method for local repair of a blocked tee includes: docking the left special-shaped sleeve 1 and the right special-shaped sleeve 2 and covering them on the branch pipe of the blocked tee 4 to be repaired, and welding the longitudinal weld 6 and the circumferential weld 7.

[0076] The beneficial effect of the technical solution of the present invention is that during installation and welding, a circumferential lap fillet weld is used at the end of the sleeve main pipe to repair the local defects of the tee.

[0077] like Figures 7 to 9 As shown, again, the present invention also provides a mold 8 made by the method for making a special-shaped sleeve for local repair of a plugged tee as described in any one of the above items, including a mold body formed by connecting a left mold and a right mold, the left mold and the right mold have the same structure, the molded section of the mold body is provided with a curved transition structure, and the interior of the mold body is respectively a round head section mold cavity, a straight pipe section mold cavity and an elliptical section mold cavity from top to bottom.

[0078] The beneficial effects of the technical solution of the present invention are: the designed mold only has half of the structure, saving mold costs; setting curves for smooth transitions to facilitate metal rheology during hot working. Two parallel cavities are set in the center of the mold, each with a certain length, which is used to control the outer diameter of the flange of the plugged tee branch pipe and have a certain processing margin. The improved large round head plus straight pipe section plus elliptical section comprehensive structure not only overcomes the problem of not being able to directly perform welding repairs, but also uses this structure to achieve reinforcement of the weak areas of the plugged tee branch pipe structure, and can achieve non-stop welding repairs of circumferential weld defects and sealing defects between the branch pipe and the connector in the in-service tee.

[0079] The curvature transition (curve transition structure) of the mold can be set to an arc, a parabola or others.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a special-shaped sleeve for local repair of a plugged tee, characterized in that: include: S1. Scan the blocked tee to be repaired to obtain the external contour and contour parameters of the blocked tee to be repaired; S2, enlarging the outer contour of the blocked tee to be repaired, so that the gap between the enlarged outer contour of the blocked tee to be repaired and the outer contour of the blocked tee to be repaired is a preset value; S3, using the enlarged outer contour of the tee to be repaired and blocked as the inner wall contour of the mold to be processed to make the mold to be processed, wherein the mold to be processed is divided into a left mold and a right mold; S4. Hot-pressing the two steel plates through a left mold and a right mold respectively to produce a left special-shaped sleeve and a right special-shaped sleeve that are compatible with the tee to be repaired and blocked.

2. The method for manufacturing a special-shaped sleeve for partial repair of a plugged tee according to claim 1, characterized in that: In step S1, a 3D scanner is used to perform a 3D scan on the tee to be repaired and blocked. The external contour of the tee to be repaired and blocked includes: the external contour of the tee shoulder, the external contour of the tee branch pipe, and the external contour of the seal.

3. The method for manufacturing a special-shaped sleeve for partial repair of a plugged tee according to claim 1, characterized in that: In step S2, the preset value is the sum of the wall thickness of the steel plate used to process the sleeve and the gap between the inner wall of the sleeve and the outer contour of the butt steel pipe or the tee main pipe.

4. The method for manufacturing a special-shaped sleeve for partial repair of a plugged tee according to claim 1, characterized in that: Step S4 includes: S41, making a pressing tool adapted to the mold to be processed; S42, heating a steel plate to above the austenite temperature; S44, placing the steel plate on the left mold; S45, using a press to press the steel plate into the left mold to obtain a left sleeve; S42, heating another steel plate to above the austenite temperature; S44, placing a steel plate on the right mold; S45. Use a press to press another steel plate into the right mold to obtain a right sleeve.

5. The method for manufacturing a special-shaped sleeve for partial repair of a plugged tee according to claim 4, characterized in that: Step S45 and subsequent steps include: S46, machining the left sleeve and the right sleeve by a cutting method; S47, performing tempering heat treatment on the left sleeve and the right sleeve to obtain a left special-shaped sleeve and a right special-shaped sleeve that are compatible with the tee to be repaired and blocked.

6. The method for manufacturing a special-shaped sleeve for partial repair of a plugged tee according to claim 1, characterized in that: In step S3, a curve is set on the mold to be processed for smooth transition; and two parallel cavities are set at the center of the mold to be processed.

7. The method for manufacturing a special-shaped sleeve for partial repair of a plugged tee according to claim 1, characterized in that: In step S4, a machine margin is reserved on the left special-shaped sleeve and the right special-shaped sleeve during pressing, and the left special-shaped sleeve and the right special-shaped sleeve are necked.

8. The special-shaped sleeve for local repair of a plugged tee manufactured by the manufacturing method of the special-shaped sleeve for local repair of a plugged tee according to any one of claims 1 to 7, characterized in that: It includes a special-shaped sleeve body formed by connecting a left special-shaped sleeve and a right special-shaped sleeve, the interior of the special-shaped sleeve body comprises a round head section cavity, a straight pipe section cavity and an elliptical section cavity from top to bottom respectively, a neck is provided at the bottom of the special-shaped sleeve body, a circular arc adapted to the tee to be repaired and blocked is provided at the bottom of the neck, and the special-shaped sleeve body is connected to the tee to be repaired and blocked by adopting a circumferential lap fillet weld.

9. A method for local repair of a blocked tee, characterized in that: Based on the special-shaped sleeve for local repair of the plugged tee described in claim 8 above, the local repair method of the plugged tee includes: docking the left special-shaped sleeve and the right special-shaped sleeve and covering them on the branch pipe of the plugged tee to be repaired, and welding the longitudinal weld and the circumferential weld.

10. A mold made by the method for making a special-shaped sleeve for partial repair of a plugged tee according to any one of claims 1 to 7, characterized in that: It includes a mold body formed by connecting a left mold and a right mold. The left mold and the right mold have the same structure. The molding section of the mold body is provided with a curved transition structure. The inside of the mold body is composed of a round head section mold cavity, a straight tube section mold cavity and an elliptical section mold cavity from top to bottom.

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