Reinforcing and maintaining device and method for non-stop conveying metal pipeline

Abstract

The invention discloses a device and a method for reinforcing and maintaining a non-stop metal pipeline, which are used for maintaining a damaged running pipeline and are particularly suitable for reinforcing and maintaining a long-distance pipeline. The device comprises a sleeve surrounding the periphery of a running pipeline, the two ends of the sleeve are connected with concentric and different-diameter plugging rings respectively, the large-diameter ends of the plugging rings are connected with the sleeve, the small-diameter ends of the plugging rings are connected with the running pipeline, and the sleeve is formed by welding two half sleeves with the same radius in pairs. And the plugging ring is formed by welding two same plugging semi-rings in pairs. A sleeve form is adopted for reinforcement and maintenance, an isolation space is formed at a damaged part of an operation pipeline, the damaged part of the metal pipeline is prevented from being continuously damaged or corroded due to external influence, and a welding sequence and a welding direction of a radial welding seam and a longitudinal welding seam of a semi-prefabricated sleeve and a circumferential welding seam of a plugging semi-ring and the operation pipeline are set; welding stress and welding deformation are effectively controlled, and safe operation of the pipeline is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of metal pipeline operation and maintenance engineering, and specifically to a device and method for reinforcing and repairing an operating metal pipeline when a large area of ​​the pipeline suffers from wall thickness thinning or long-length damage during operation. The device and method are particularly suitable for long-distance pipeline reinforcement and maintenance engineering. Background Art

[0002] As metal pipelines are used for a long time, a large area of ​​thinning wall thickness or long-length damage occurs. However, if the pipeline cannot be stopped in the short term, it must be repaired to ensure the safe operation of the pipeline. The existing domestic pressure plugging technology and steel plate welding method cannot meet the repair requirements of these situations. The current pressure plugging technology only plugs the leakage point or a small area of ​​damage, and the mechanical processing is complex and time-consuming. The commonly used steel plate covering welding method requires the curvature of the steel plate to be processed and the gap between its curvature and the metal pipeline to be controlled. If the gap is too large, the welding current will be large, and welding undercut defects are prone to occur. In severe cases, burn-through may cause accidents.

[0003] CN117847338A discloses a pipeline pressure-online non-stop rapid repair and plugging device, comprising a sleeve clamp for plugging the outer wall of the pipeline; the sleeve clamp comprises an upper shell and a lower shell; the upper shell and the lower shell are detachably spliced ​​to form a sealing shell for plugging the pipeline leakage; the upper shell and the lower shell are respectively provided with injection holes connected to the sealing shell. However, this patent relies on filling sealant to bond with the pipeline to achieve a reinforcement, and the bond between the sealant and the metal pipeline will age and debond with time and temperature changes, and gaps will soon appear, resulting in air leakage. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a reinforcement and maintenance device and method for non-stop metal pipelines. The on-site operation is safe and reliable, and the maintenance time is short. It can not only meet the pressure-bearing strength of the conveying pipeline but also effectively control the welding stress and pipeline deformation, thereby ensuring the safe operation of the conveying pipeline and avoiding leakage and continued corrosion of the conveying pipeline. The present invention changes the previous repair structure and welding method, reduces welding stress, and is suitable for repairing non-stop pipelines with long-length damage or large-area wall thinning of metal pipelines.

[0005] According to one embodiment of the present invention, there is provided a reinforcement and repair device for non-stop metal pipelines, which includes a casing surrounding the periphery of the running pipeline, and concentric and different-diameter sealing rings (i.e., truncated cone cylinders) are respectively connected at both ends of the casing, the large-diameter end of the sealing ring is connected to the casing, and the small-diameter end of the sealing ring is connected to the running pipeline, the casing is formed by welding two half-casing groups with the same radius, and the sealing ring is formed by welding two identical sealing half-ring groups, and the two sealing rings are respectively arranged on both sides of the damaged position of the running pipeline.

[0006] Furthermore, the casing is welded to the plugging ring, which is welded to the outer surface of the running pipeline. The wall thickness of the casing is consistent with the wall thickness of the running pipeline. The casing is graded according to the pipeline model. The diameter of the casing is two or three levels larger than the diameter of the running pipeline (for example, for a DN100 pipeline, the two largest levels are DN150, and the three largest levels are DN175). The materials of the casing and the plugging ring are the same as those of the running pipeline. The length of the casing is greater than the damaged length of the running pipeline, for example, 400-1000mm, preferably 300-500mm.

[0007] Furthermore, the inner diameter of the small diameter end of the blocking ring is slightly larger than the outer diameter of the running pipe, for example, 1.6-6mm larger, preferably about 3m or 4mm, the difference between the inner diameter of the small diameter end of the blocking ring and the outer diameter of the running pipe is twice the weld gap, and the wall thickness of the blocking ring is 1-5mm larger than the wall thickness of the running pipe, preferably about 2-4mm, for example about 3mm.

[0008] Further, the half sleeve includes a semi-annular transverse surface located at both ends and a longitudinal surface connecting the two transverse surfaces, the transverse surface forms a first two-sided groove with a fifth blunt edge, and the longitudinal surface forms a first outer groove with a first blunt edge. When the longitudinal surfaces of the two half sleeves are butt welded, the two opposite first outer grooves form a first V-shaped groove. The angle of the first outer groove can be, for example, 30°±5°, preferably 30°, the angle of the first two-sided groove can be, for example, 30°±5°, preferably about 30°, the angle range of the first V-shaped groove is 50°-70°, preferably about 60°, and the width of the first blunt edge and the fifth blunt edge can be, for example, 1-4mm, preferably 2-3mm.

[0009] Further, the blocking half ring includes a small ring end face arranged at the small diameter end, a large ring end face arranged at the large diameter end, and a radial face connecting the small ring end face and the large ring end face, the small ring end face forms a second outer groove with a second blunt edge, the large ring end face forms a second two-sided groove with a third blunt edge, and the radial face forms a third outer groove with a fourth blunt edge. The widths of the second blunt edge, the third blunt edge, and the fourth blunt edge can be, for example, 1-4 mm, preferably 2-3 mm, respectively. The angle of the second outer groove can be, for example, 60°±5°, preferably about 60°, the angle of the second two-sided groove can be, for example, 30°±5°, preferably about 30°, and the angle of the third outer groove can be, for example, 30°±5°, preferably about 30°. When the radial faces of the two blocking half rings are butt welded, the two opposite third outer grooves form a second V-shaped groove, and the second two-sided groove of the blocking half ring is welded to the first two-sided groove of the half casing to form an X-shaped groove.

[0010] According to another embodiment of the present invention, there is provided a method for reinforcing and repairing a non-stop metal pipeline, which comprises the following steps: (1) Calculate the cutting dimensions of casing and plugging ring and prepare half casing and half plugging ring; (2) Processing the weld grooves of the half casing and the plugging half ring; (3) The half casing and the plugging half ring are welded to form a semi-prefabricated casing; (4) The two semi-prefabricated casings are welded to the outside of the damaged operating pipeline.

[0011] Furthermore, in step (1), material selection is performed before preparing the half casing: a metal pipe of the same type as the running metal pipe is selected as the casing, the diameter of the casing is two or three levels larger than the diameter of the running pipe, and its thickness is the same as the wall thickness of the running pipe.

[0012] Material selection before preparation of the plugging half ring: Use a concentric reducer of the same type as the operating pipeline as the plugging ring, and its thickness should be 1-5mm greater than the wall thickness of the operating pipeline, preferably 3-4mm.

[0013] In step (1), the half casing is cut into two pieces: the casing length is 400-1000 mm longer than the damaged length of the running pipeline, preferably 300-500 mm, and then the casing is divided into two halves along the longitudinal symmetrical line, and the casing is cut into two identical half casing pieces.

[0014] In step (1), the sealing half ring is cut into the following steps: the difference between the inner diameter of the small diameter end of the sealing ring and the outer diameter of the running pipe is twice the weld gap, wherein the weld gap is preferably 0.8-3 mm, usually 2 mm, the inner diameter of the large diameter end of the sealing ring is the same as the inner diameter of the casing, the wall thickness of the sealing ring is 1-5 mm greater than the wall thickness of the running pipe, preferably 3-4 mm, and then the sealing ring is cut into two sealing half rings of the same radius.

[0015] Furthermore, in step (2), the longitudinal surfaces of the two half-sleeves are processed into a single-sided first outer bevel, the angle of the first outer bevel is 30°±5°, preferably about 30°, and the first blunt edge is 2-3 mm; the transverse surfaces of the two half-sleeves are processed into a first two-sided bevel, the angle of the first two-sided bevel is 30°±5°, preferably about 30°, and the width of the fifth blunt edge is 2-3 mm.

[0016] The large ring end face of the sealing semi-ring is cut and polished to form a second two-sided groove with a third blunt edge. The angle of the second two-sided groove can be, for example, 30°±5°, preferably about 30°, and the third blunt edge is 1-4mm, preferably 2-3mm, which is convenient for double-sided welding root penetration and easy root cleaning; the small ring end face of the sealing semi-ring is processed into a single-sided second outer groove with a second blunt edge. The angle of the second outer groove can be, for example, 60°±5°, preferably about 60°, and the second blunt edge is 1-4mm, preferably 2-3mm; the radial surfaces of the two sealing semi-rings are processed into a single-sided third outer groove with a fourth blunt edge. The angle of the third outer groove can be, for example, 30°±5°, preferably about 30°, and the width of the fourth blunt edge is 1-4mm, preferably 2-3mm.

[0017] Furthermore, in step (3), the two ends of the half casing are respectively connected to the butt joints of the plugging half ring group to form a semi-prefabricated casing, the plugging half ring and the half casing are kept coaxial, the large diameter end of the plugging half ring is opposite to the end of the half casing, argon arc welding is used for base treatment, manual arc welding is used for filling and covering, and non-destructive inspection is performed on the welds between the plugging half ring and the half casing, and the semi-prefabricated casing is completed.

[0018] Furthermore, in step (4), two semi-prefabricated casing groups are used to enclose the running pipeline, the opposite semi-casings form a casing surrounding the running pipeline, and the opposite blocking semi-rings form a blocking ring surrounding the running pipeline. Before welding the semi-prefabricated casing and the running pipeline group, the damaged running pipeline is processed, the radial straight weld between the radial surfaces of the two blocking semi-rings is spot-fixed, and then the two longitudinal welds between the longitudinal surfaces of the semi-casings are spot-fixed, and finally the small diameter end of the blocking semi-ring and the circumferential weld of the running pipeline are welded.

[0019] By adopting the reinforcement and repair process of the present invention, a closed space is formed between the casing and the damaged position of the running pipeline, external erosion is isolated to prevent the pipeline from further corrosion, and the casing structure meets the pressure-bearing strength of the pipeline operation; the reinforcement process of the present invention clarifies the construction sequence and step methods, effectively controls welding stress and deformation, and ensures the safe operation of the transmission pipeline.

[0020] The above device and method have the following beneficial effects: 1. The reinforcement and maintenance device of the present invention solves the problem of large-area wall thickness thinning or long-length damage of metal pipelines in the state of non-stop operation, and can ensure the safe operation of the pipeline after maintenance without stopping the pipeline; 2. Use casing to reinforce and repair, and form an isolation space at the damaged part of the running pipeline to prevent the damaged metal pipeline from being further damaged or corroded by external influences; 3. The reinforcement and repair device of the present invention is welded to the running pipeline by the plugging rings arranged at both ends of the casing. The connection position between the reinforcement and repair device and the running pipeline is only the plugging rings at both ends, which solves the problem of large-area welding with the running pipeline in the past. The metal properties of the running pipeline are maintained, the welding amount with the metal pipeline is reduced, and the danger of pressure welding of the non-stop pipeline is reduced; 4. By setting the welding sequence and welding direction of the radial welds and longitudinal welds of the semi-prefabricated casing and the welding of the plugging half ring and the operating pipeline ring, the welding stress and welding deformation are effectively controlled, and the safe operation of the pipeline is guaranteed; 5. A semi-prefabricated casing is obtained by connecting the semi-casing with the plugging semi-ring. The two semi-prefabricated casings are enclosed and then connected to the running pipeline. The whole process is simple and easy to operate, which simplifies the welding process, reduces the difficulty of work, reduces the workload of welders, and improves work efficiency; 6. A complete set of metal pipeline non-stop reinforcement construction technology has been formed and applied in the natural gas long-distance pipeline operation inspection project, providing reference and guidance for the maintenance of metal pipelines with large-area wall thinning or long length damage without stopping the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a structural schematic diagram of a reinforcement and maintenance device for non-stop metal pipelines.

[0022] Figure 2 It is the front view of half casing.

[0023] Figure 3 A side view of a half casing.

[0024] Figure 4 A three-dimensional diagram of a half casing.

[0025] Figure 5 for Figure 4 A sectional stereoscopic view taken along the AA direction.

[0026] Figure 6 This is a front view of the blocking half ring.

[0027] Figure 7 for Figure 6 Schematic diagram of the slope at point I in the middle.

[0028] Figure 8 for Figure 6 Schematic diagram of the slope at II in the middle.

[0029] Fig. 9 for Figure 6 Schematic diagram of the slope at point III in the middle.

[0030] Fig.10 A three-dimensional diagram of a blocked half ring.

[0031] Fig.11 for Fig.10 A sectional stereogram in the BB direction.

[0032] Fig.12 This is a schematic diagram of the radial straight weld of the sealing ring.

[0033] Fig.13 Schematic diagram of casing longitudinal weld.

[0034] Reference numerals: 1- Run the pipeline, 2-sleeve, 20-half-sleeve, 201-longitudinal surface, 2011-first blunt edge, 2012-first outer groove, 202-transverse surface, 2021-fifth blunt edge, 2022-first two-side groove, 3-sealing ring, 30-sealing half ring, 301-large diameter end, 302-small diameter end, 303-small ring end face, 3031-second blunt edge, 3032-second outer bevel, 304-large ring end face, 3041-third blunt edge, 3042-second two-sided bevel, 305-radial face, 3051-fourth blunt edge, 3052-third outer bevel. DETAILED DESCRIPTION

[0035] The present invention is further described below with reference to the accompanying drawings and embodiments.

[0036] like Figure 1-11 As shown, the present invention provides a reinforcement and maintenance device for non-stop metal pipelines, which includes a casing 2 surrounding the periphery of the running pipeline 1, and the two ends of the casing 2 are respectively connected with concentric and different diameter plugging rings 3, the large diameter end 301 of the plugging ring 3 is connected to the casing 2, and the small diameter end 302 of the plugging ring 3 is connected to the running pipeline 1. The casing 2 is formed by welding two half casings 20 with the same radius, and the plugging ring 3 is formed by welding two identical plugging half rings 30. The two plugging rings 3 are respectively arranged on both sides of the damaged position of the running pipeline 1. In a specific application, since the casing 2 surrounds the periphery of the running pipeline 1, the plugging ring 3 is connected to both sides of the damaged position of the running pipeline 1, and the casing 2 forms an isolation space for the damaged position to prevent the damaged position of the running pipeline 1 from being further damaged.

[0037] The casing 2 is welded to the plugging ring 3, and the plugging ring 3 is welded to the outer surface of the running pipeline 1. The wall thickness of the casing 2 is consistent with the wall thickness of the running pipeline 1, and is graded according to the pipeline model. The diameter of the casing 2 is two or three levels larger than the diameter of the running pipeline 1. The materials of the casing 2 and the plugging ring 3 are the same as the material of the running pipeline 1. The length of the casing 2 is greater than the damaged length of the running pipeline 1, for example, 400-1000mm greater, preferably 300-500mm greater.

[0038] The inner diameter of the small diameter end 302 of the plugging ring 3 is slightly larger than the outer diameter of the running pipeline 1, for example, 1.6-6mm, further 2.0-4.0mm, preferably about 4mm, the difference between the inner diameter of the small diameter end 302 of the plugging ring 3 and the outer diameter of the running pipeline 1 is twice the weld gap, and the wall thickness of the plugging ring 3 is 1-5mm, preferably 3-4mm, larger than the wall thickness of the running pipeline 1. In specific applications, the inner diameter of the small diameter end 302 of the plugging ring 3 is larger than the outer diameter of the running pipeline 1 to retain the weld gap between the small diameter end 302 of the plugging ring 3 and the running pipeline 1 to ensure welding quality.

[0039] The half sleeve 20 includes a semi-annular transverse surface 202 located at both ends and a longitudinal surface 201 connecting the two transverse surfaces 202, the transverse surface 202 forms a first two-sided groove 2022 with a fifth blunt edge 2021, and the longitudinal surface 201 forms a first outer groove 2012 with a first blunt edge 2011. When the longitudinal surfaces 201 of the two half sleeves 20 are butt-welded, the two opposite first outer grooves 2012 form a first V-shaped groove. The angle of the first outer groove 2012 can be, for example, 30°±5°, preferably about 30°, the angle of the first two-sided groove 2022 can be, for example, 30°±5°, preferably about 30°, the angle range of the first V-shaped groove is 50°-70°, preferably about 60°, the width of the first blunt edge 2011 and the fifth blunt edge 2021 can be, for example, 1-4mm, preferably 2-3mm, for example 2±0.5mm. In a specific application, the longitudinal surface 201 forms a first outer groove 2012 with a first blunt edge 2011. The width of the first blunt edge 2011 can be, for example, 1-4 mm, preferably 2-3 mm. When the longitudinal surfaces 201 of the two half sleeves 20 are butt-welded, the two opposite first outer grooves 2012 form a first V-shaped groove. The angle range of the first V-shaped groove is 50°-70°, preferably about 60°, to improve the filling and formability of the weld.

[0040] The blocking half ring 30 includes a small ring end face 303 disposed at the small diameter end 302, a large ring end face 304 disposed at the large diameter end 301, and a radial surface 305 connecting the small ring end face 303 and the large ring end face 304. The small ring end face 303 forms a second outer groove 3032 with a second blunt edge 3031, the large ring end face 304 forms a second two-sided groove 3042 with a third blunt edge 3041, and the radial surface 305 forms a third outer groove 3052 with a fourth blunt edge 3051. The widths of the second blunt edge 3031, the third blunt edge 3041, and the fourth blunt edge 3051 can be, for example, 1-4 mm, preferably 2-3 mm, respectively. The widths of the fifth blunt edge 2021 and the third blunt edge 3041 are preferably equal. The angle of the second outer groove 3032 can be, for example, 60°±5°, preferably about 60°, the angle of the second two-sided groove 3042 can be, for example, 30°±5°, preferably about 30°, the angle of the third outer groove 3052 can be, for example, 30°±5°, preferably about 30°, when the radial surfaces 305 of the two blocking half rings 30 are butt-welded, the two relative third outer grooves 3052 form a second V-shaped groove, and the angle range of the second V-shaped groove is 50°-70°, preferably about 60°, and the second two-sided groove 3042 of the blocking half ring 30 is welded to the first two-sided groove 2022 of the half casing 20 to form an X-shaped groove, and the angle range of the X-shaped groove is 50°-70°, preferably about 60°. In specific applications, the widths of the second blunt edge 3031, the third blunt edge 3041, and the fourth blunt edge 3051 can be, for example, 1-4 mm, preferably 2-3 mm, respectively, to reduce stress concentration during welding and reduce the risk of cracks in the weld. The angle of the second outer groove 3032 can be, for example, 60°±5°, preferably about 60°, the angle of the second two-sided groove 3042 can be, for example, 30°±5°, preferably about 30°, and the angle of the third outer groove 3052 can be, for example, 30°±5°, preferably about 30°. The angle settings of the first two-sided groove 2022, the first outer groove 2012, the second outer groove 3032, the second two-sided groove 3042, and the third outer groove 3052 make it easy for the welder to control the welding current and avoid incomplete penetration and porosity. On the other hand, the metal filling amount is reduced, the welding line energy is reduced, and large welding stress or deformation is avoided.

[0041] The present invention further provides a method for reinforcing and repairing a non-stop metal pipeline, which comprises the following steps: (1) Calculate the cutting dimensions of casing and plugging ring and prepare half casing and half plugging ring; (2) Processing the weld grooves of the half casing and the plugging half ring; (3) The half casing and the plugging half ring are welded to form a semi-prefabricated casing; (4) The two semi-prefabricated casings are welded to the outside of the damaged operating pipeline.

[0042] In step (1), material selection is performed before preparing the half casing: metal pipes of the same type as the running metal pipes are selected as casings. The diameter of the casing is two or three levels larger than the diameter of the running pipe, and its thickness is the same as the wall thickness of the running pipe.

[0043] Material selection before preparation of the plugging half ring: Use a concentric reducer of the same type as the operating pipeline as the plugging ring, and its thickness should be 1-5mm greater than the wall thickness of the operating pipeline, preferably 3-4mm.

[0044] In step (1), the half casing is cut into pieces: the casing is cut to a length that is 400-1000 mm, preferably 300-500 mm, greater than the damaged length of the running pipeline. The casing is then divided into two halves along a longitudinal symmetrical line and cut into two identical half casing pieces. Different casing materials require different cutting methods and tools, such as gas cutting for carbon steel and plasma cutting for stainless steel.

[0045] In step (1), the plugging half ring is cut into two plugging half rings of the same radius. Different metal pipe materials require different cutting methods and tools, such as gas cutting for carbon steel and plasma cutting for stainless steel.

[0046] In step (2), the longitudinal surfaces of the two half-sleeves are processed into a single-sided first outer bevel, the angle of the first outer bevel is 30°±5°, preferably about 30°, and the first blunt edge is 2-3 mm; the transverse surfaces of the two half-sleeves are processed into a first two-sided bevel, the angle of the first two-sided bevel is 30°±5°, preferably about 30°, and the width of the fifth blunt edge is 2-3 mm.

[0047] The large ring end face of the sealing semi-ring is cut and polished to form a second two-sided groove with a third blunt edge. The angle of the second two-sided groove can be, for example, 30°±5°, preferably about 30°, and the third blunt edge is 1-4mm, preferably 2-3mm, which is convenient for double-sided welding root penetration and easy root cleaning; the small ring end face of the sealing semi-ring is processed into a single-sided second outer groove with a second blunt edge. The angle of the second outer groove can be, for example, 60°±5°, preferably about 60°, and the second blunt edge is 1-4mm, preferably 2-3mm; the radial surfaces of the two sealing semi-rings are processed into a single-sided third outer groove with a fourth blunt edge. The angle of the third outer groove can be, for example, 30°±5°, preferably about 30°, and the width of the fourth blunt edge is 1-4mm, preferably 2-3mm, in order to ensure single-sided welding and double-sided forming.

[0048] In step (3), the two ends of the half casing are respectively connected to the plugging half ring group at the docking point to form a semi-prefabricated casing, the plugging half ring and the half casing are kept coaxial, the large diameter end of the plugging half ring is opposite to the end of the half casing, the second two-sided groove of the plugging half ring and the first two-sided groove of the half casing form an X-shaped groove, and both sides of the weld are cleaned; the welding is carried out in layers, and argon arc welding is used for base welding (that is, argon arc welding is the first layer of welding, and argon arc welding base welding ensures the quality of the root weld, and the weld is uniform and gas-free Hole), manual arc welding filling and covering (manual arc welding is the second and subsequent welding layers to ensure uniform weld height and improve the mechanical properties of the welded joint). The specific operation is: first weld the inner weld of the sealing half ring and the half casing once, then weld the outer weld once, and weld alternately in sequence to reach the weld height. After the weld cools naturally, the size of the semi-prefabricated casing is inspected and measured, and the welds of the sealing half ring and the half casing are non-destructively tested. If they meet the specifications, they are qualified and the semi-prefabricated casing is completed.

[0049] In step (4), two semi-prefabricated casing groups are used to enclose the running pipeline, the opposite semi-casings form a casing surrounding the running pipeline, and the opposite plugging semi-rings form a plugging ring surrounding the running pipeline. Before welding the semi-prefabricated casing and the running pipeline group, the damaged running pipeline is treated: the anti-corrosion layer at both ends of the damaged position of the running pipeline is treated according to the length of the semi-prefabricated casing, the welding position of the small diameter end of the plugging semi-ring and the running pipeline is measured and marked, and the metal luster is polished to ensure that the weld position is clean.

[0050] In step (4), the gap between the small diameter end of the plugging half ring and the running pipeline is maintained at 0.8-3mm, preferably 2mm, the third outer groove of the radial surface of the two opposite plugging half rings forms a second V-shaped groove, the longitudinal weld between the two half casings is placed in the horizontal direction, and the first outer groove of the longitudinal surface of the two half casings forms a first V-shaped groove, and the gap is maintained at 2-3mm. After the measurement is qualified, the radial straight weld between the radial surfaces of the two plugging half rings is first spot-fixed, and then the two longitudinal welds between the longitudinal surfaces of the half casings are spot-fixed. The fillet weld between the plugging ring and the running pipeline is not spot-fixed for the time being.

[0051] In step (4), all welding methods are argon arc welding for base welding and manual arc welding for filling and covering. Fig.12 As shown, specifically: first, weld the two radial straight welds of the plugging half ring, and two welders weld from the inside to the outside at the same time to ensure that the plugging ring is not deformed and the welding stress is small; after the radial straight welds of the plugging half ring are inspected and qualified, Fig.13 As shown, the longitudinal welds of the half casing are welded, and the two longitudinal welds are welded in reverse at the same time. Each layer of weld is welded in sections to reduce welding stress, and the number of welding layers is preferably sufficient to meet the weld height. The straight welds of the sealing ring and the longitudinal welds of the casing are subjected to non-destructive testing, and those that meet the requirements of the specifications are qualified.

[0052] In step (4), the small diameter end of the semi-ring is finally welded to the girth weld (i.e., fillet weld) of the running pipeline, and argon arc welding is used for base welding, and manual arc welding is used for filling and covering. Specifically, two welders weld symmetrically at the same time, and multi-layer reverse welding is adopted, that is, the base welding direction is from bottom to top, and the filling and covering direction is from top to bottom, so as to reduce welding stress and deformation. After the weld is cooled (usually 24 hours), non-destructive testing is carried out, and defects are repaired, and the same position cannot be welded more than twice. Example 1

[0053] A high-pressure natural gas long-distance pipeline has a design pressure of 1.6MPa and an operating pressure of 1.2MPa. The steel pipe material of the operating pipeline is L245, with a specification of D406.4×8mm (the outer diameter of the pipeline is 406.4mm and the wall thickness is 8mm). The owner found during the inspection that the 3PE anti-corrosion layer of a section of pipeline about 5 meters long in a ditch was seriously damaged and the metal surface had been corroded. The thickness gauge was used to detect that the wall thickness of the pipeline section had been thinned to varying degrees, and it was necessary to carry out reinforcement maintenance without stopping the pipeline.

[0054] (1) Calculate the cutting size of casing and plugging ring, and prepare half casing and half plugging ring for plugging the running pipeline: Material selection for half casing and plugging half ring: Select L245, which is the same material as the running pipeline, and the casing pipe specification D508×8mm as the cutting material for half casing; select concentric reducer specification DN500×DN400×9mm as the cutting material for plugging half ring.

[0055] Cutting of half casing and plugging half ring: The casing length should be 500mm greater than the damaged length of the running metal pipe, and then the metal casing is divided into two halves along the longitudinal symmetrical line and cut into two identical half casings.

[0056] According to the difference between the inner diameter of the small diameter end of the plugging ring and the outer diameter of the running pipe, which is twice the weld gap and 2mm, the inner diameter of the small diameter end of the plugging ring is D410.4mm, and the outer diameter of the large diameter end of the plugging ring is D508mm, and then it is cut into two identical plugging half rings.

[0057] (2) Processing the weld groove of the half casing and the plugging half ring like Figure 2-11 As shown, the longitudinal surfaces of the two half sleeves are processed into a single-sided first outer bevel, the first outer bevel angle is 30°, the first blunt edge is 2mm, and the transverse surfaces of the two half sleeves are processed into a first two-sided bevel, the first two-sided bevel angle is 30°, and the width of the fifth blunt edge is 2mm.

[0058] The large ring end face of the sealing half ring is cut and polished to form a second two-sided groove with a third blunt edge. The angle of the second two-sided groove is 30°, and the third blunt edge is 2mm, which is convenient for double-sided welding to penetrate the root and easy to clean the root; the small ring end face of the sealing half ring is processed into a single-sided second outer groove with a second blunt edge. The angle of the second outer groove is 60°, and the second blunt edge is 2mm; the radial surfaces of the two sealing half rings are processed into a single-sided third outer groove with a fourth blunt edge. The angle of the third outer groove is 30°, and the width of the fourth blunt edge is 2mm, in order to ensure single-sided welding and double-sided forming.

[0059] (3) The half casing and the plugging half ring are welded to form a semi-prefabricated casing; The two ends of the half casing are respectively connected to the butt joints of the blocking half ring group to form a semi-prefabricated casing. The blocking half ring and the half casing are coaxial, the large diameter end of the blocking half ring is opposite to the end of the half casing, the second two-sided grooves of the blocking half ring and the first two-sided grooves of the half casing form an X-shaped groove, and both sides of the weld are cleaned; argon arc welding is used for primer, manual arc welding is used for filling and covering, and the specific operation is: first weld the inner weld of the blocking half ring and the half casing once, and then weld the outer weld once, and weld alternately in sequence to reach the weld height. After the weld is naturally cooled, the semi-prefabricated casing is inspected and measured for size, and the weld of the blocking half ring and the half casing is non-destructively inspected. If it meets the specifications, it is qualified and the semi-prefabricated casing is completed.

[0060] (4) Welding of semi-prefabricated casing to damaged operating pipeline.

[0061] Use two semi-prefabricated casing groups to enclose the running pipeline. The opposite half casings form a casing surrounding the running pipeline, and the opposite sealing half rings form a sealing ring surrounding the running pipeline. According to the length of the semi-prefabricated casing, the anti-corrosion layer at both ends of the damaged position of the running pipeline is treated, the welding position of the small diameter end of the sealing half ring and the running pipeline is measured and marked, and the metallic luster is polished to ensure that the weld position is clean, and the two semi-prefabricated casings are assembled with the running pipeline. The gap between the small diameter end of the sealing half ring and the running pipeline is maintained at 2mm, and the third outer groove of the radial surface of the two opposite sealing half rings forms a second V-shaped groove. The longitudinal weld between the two half casings is placed in the horizontal direction, and the first outer groove of the longitudinal surface of the two half casings forms a first V-shaped groove, and the gap is maintained at 2mm. After qualified measurement, the radial straight weld between the two sealing half rings and the two longitudinal welds between the half casings are spot-fixed.

[0062] All welds are welded by argon arc welding for base welding and manual arc welding for filling and covering. The specific operation process is as follows: first, weld the two radial straight welds between the sealing half rings (such as Fig.12 As shown in the figure), the welding direction is from inside to outside. The two straight welds of each plugging half ring are welded symmetrically by two welders at the same time. After the radial straight welds of the plugging half ring are inspected and qualified, the longitudinal welds on both sides of the half casing are welded. Fig.13The two longitudinal welds must be reverse welded at the same time, the longer welds must be welded in sections, the number of welding layers must meet the weld height, and the appearance inspection must be qualified.

[0063] Finally, weld the circumferential fillet weld between the inner ring of the small diameter end of the sealing half ring and the running pipeline. The same argon arc welding base and manual arc welding filling and covering method are used for welding. Each sealing half ring is welded symmetrically by two welders at the same time. The first welding (base welding) is from bottom to top, and the filling cover welding is from top to bottom to reduce welding stress and deformation. After the weld cools down (usually 24 hours), the straight welds are inspected by flaw detection, the fillet welds are inspected by coloring or ultrasonic inspection, and defects are repaired. The same position cannot be welded more than twice.

[0064] To summarize the above, the on-site construction process steps are: construction preparation → on-site investigation and measurement → material selection → calculation of cutting → cutting and slicing → making grooves → welding the half ring and half casing into a semi-prefabricated casing → spot welding to seal the radial straight edge weld of the half ring → symmetrical reverse welding of the butt welds on both sides of the half casing → non-destructive testing of welds → inspection and repair → symmetrical welding to seal the inner ring of the half ring and the ring weld of the running pipeline → ultrasonic testing of fillet welds → surface anti-corrosion after passing the test → overall acceptance.

[0065] The above describes the preferred embodiments of the present invention, but the above description is not intended to be limiting. A person skilled in the art may make targeted changes or modifications to the present invention without departing from the spirit and scope of the present invention, and the changes or modifications should be included in the scope of the appended claims.

Claims

1. A reinforcement and maintenance device for non-stop metal pipelines, characterized in that: It includes a casing surrounding the periphery of a running pipeline, with concentric and different-diameter sealing rings connected to both ends of the casing respectively, the large-diameter end of the sealing ring is connected to the casing, and the small-diameter end of the sealing ring is connected to the running pipeline. The casing is formed by welding two half-casing groups with the same radius, and the sealing ring is formed by welding two identical sealing half-ring groups. The two sealing rings are respectively arranged on both sides of the damaged position of the running pipeline.

2. The reinforcement and repair device according to claim 1, characterized in that: The casing is connected to the plugging ring by welding, and the plugging ring is connected to the outer surface of the running pipeline by welding. The wall thickness of the casing is consistent with the wall thickness of the running pipeline. The diameter of the casing is two or three levels larger than the diameter of the running pipeline. The materials of the casing and the plugging ring are the same as that of the running pipeline. The length of the casing is greater than the damaged length of the running pipeline.

3. The reinforcement and repair device according to claim 1 or 2, characterized in that: The inner diameter of the small diameter end of the plugging ring is larger than the outer diameter of the running pipe. The difference between the inner diameter of the small diameter end of the plugging ring and the outer diameter of the running pipe is twice the weld gap. The wall thickness of the plugging ring is 1-5mm larger than the wall thickness of the running pipe, preferably 3-4mm.

4. The reinforcement and repair device according to any one of claims 1 to 3, characterized in that: The half sleeve includes a semi-annular transverse surface located at both ends and a longitudinal surface connecting the two transverse surfaces. The transverse surface forms a first two-sided groove with a fifth blunt edge, and the longitudinal surface forms a first outer groove with a first blunt edge. When the longitudinal surfaces of the two half sleeves are butt-welded, the two opposite first outer grooves form a first V-shaped groove. The angles of the first outer groove and the first two-sided groove are 30°±5°, preferably 30°, respectively. The widths of the first blunt edge and the fifth blunt edge are 1-4mm, preferably 2-3mm.

5. The reinforcement and repair device according to claim 4, characterized in that: The plugging semi-ring includes a small ring end face arranged at the small diameter end, a large ring end face arranged at the large diameter end and a radial face connecting the small ring end face and the large ring end face, the small ring end face forms a second outer groove with a second blunt edge, the large ring end face forms a second two-sided groove with a third blunt edge, and the radial face forms a third outer groove with a fourth blunt edge. The widths of the second blunt edge, the third blunt edge and the fourth blunt edge are 1-4mm, preferably 2-3mm, respectively. The angle of the second outer groove is 60°±5°, preferably 60°, the angle of the second two-sided groove is 30°±5°, preferably 30°, and the angle of the third outer groove is 30°±5°, preferably 30°. When the radial faces of the two plugging semi-rings are butt welded, the two opposite third outer grooves form a second V-shaped groove, and the second two-sided groove of the plugging semi-ring is welded to the first two-sided groove of the half casing to form an X-shaped groove.

6. A method for reinforcing and repairing a non-stop metal pipeline, comprising the following steps: (1) Calculate the cutting dimensions of casing and plugging ring and prepare half casing and half plugging ring; (2) Processing the weld grooves of the half casing and the plugging half ring; (3) The half casing and the plugging half ring are welded to form a semi-prefabricated casing; (4) The two semi-prefabricated casings are welded to the outside of the damaged operating pipeline.

7. The method according to claim 6, characterized in that In step (1), material selection before preparing the half casing: metal pipes of the same type as the running metal pipes are selected as casings, the diameter of the casings is two or three levels larger than the diameter of the running pipes, and the thickness is the same as the wall thickness of the running pipes; Material selection before preparation of plugging half ring: Use concentric reducer of the same type as the running pipeline as the plugging ring, and its thickness is 1-5mm greater than the wall thickness of the running pipeline, preferably 3-4mm; In step (1), the half casing is cut into two pieces: the casing length is 400-1000 mm longer than the damaged length of the running pipeline, preferably 300-500 mm, and then the casing is divided into two halves along the longitudinal symmetrical line, and the casing is cut into two identical half casings; In step (1), the sealing half ring is cut into the following steps: the difference between the inner diameter of the small diameter end of the sealing ring and the outer diameter of the running pipe is twice the weld gap, wherein the weld gap is preferably 0.8-3 mm, usually 2 mm, the inner diameter of the large diameter end of the sealing ring is the same as the inner diameter of the casing, the wall thickness of the sealing ring is 1-5 mm greater than the wall thickness of the running pipe, preferably 3-4 mm, and then the sealing ring is cut into two sealing half rings of the same radius.

8. The method according to claim 7, characterized in that In step (2), the longitudinal surfaces of the two half-tubes are processed into a single-sided first outer bevel, the first outer bevel angle is 30°±5°, preferably 30°, and the first blunt edge is 2-3 mm; the transverse surfaces of the two half-tubes are processed into a first two-sided bevel, the first two-sided bevel angle is 30°±5°, preferably 30°, and the width of the fifth blunt edge is 2-3 mm; The large ring end face of the sealing half ring is cut and polished to form a second two-sided bevel with a third blunt edge, the angle of the second two-sided bevel is 30°±5°, preferably 30°, and the third blunt edge is 1-4mm, preferably 2-3mm; the small ring end face of the sealing half ring is processed into a single-sided second outer bevel with a second blunt edge, the angle of the second outer bevel is 60°±5°, preferably 60°, and the second blunt edge is 1-4mm, preferably 2-3mm; the radial surfaces of the two sealing half rings are processed into a single-sided third outer bevel with a fourth blunt edge, the angle of the third outer bevel is 30°±5°, preferably 30°, and the width of the fourth blunt edge is 1-4mm, preferably 2-3mm.

9. The method according to claim 8, characterized in that In step (3), the two ends of the half casing are respectively connected to the plugging half ring group at the docking point to form a semi-prefabricated casing, the plugging half ring and the half casing are kept coaxial, the large diameter end of the plugging half ring is opposite to the end of the half casing, argon arc welding is used for primer, manual arc welding is used for filling and covering, and non-destructive inspection is performed on the weld between the plugging half ring and the half casing, and the semi-prefabricated casing is completed.

10. The method according to claim 9, characterized in that In step (4), two semi-prefabricated casing groups are used to enclose the running pipeline, the opposite semi-casings form a casing surrounding the running pipeline, and the opposite blocking semi-rings form a blocking ring surrounding the running pipeline. Before welding the semi-prefabricated casing and the running pipeline group, the damaged running pipeline is processed, the radial straight weld between the radial surfaces of the two blocking semi-rings is spot-fixed, and then the two longitudinal welds between the longitudinal surfaces of the semi-casings are spot-fixed, and finally the small diameter end of the blocking semi-ring and the circumferential weld of the running pipeline are welded.

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