A method for plugging a flanged pipe

Abstract

The present application relates to the technical fields of oil and gas pipeline maintenance, in particular to a flange pipeline plugging method, comprising the following steps: S1: clamping and setting the clamping device of covering type at the pipeline leakage point, a gap space is formed between the inner wall of the clamping device of covering type and the outer wall of the pipeline; S2: filling the sealing filler in the gap space along the longitudinal direction of the pipeline; S3: setting the gland at both ends of the clamping device of covering type respectively, one end of each of the glands is inserted into the gap space and pushes against the sealing filler, and the other end is provided with a flange plate connected with the clamping device of covering type through an adjusting screw; S4: the sealing filler is sealed in the gap space by the glands pushing and extruding. The sealing filler is extruded and compacted between the sealing filler and the pipeline, the close contact is tight, the pressure bearing capacity is high, the secondary leakage is not easy to occur, the plugging effect is good, at the same time, the single side pushing and extruding or the double side synchronous pushing and extruding can be adopted according to the leakage amount of the leakage point, and the amount of gas retained between the two sealing fillers is minimized.

Description

Technical Field

[0001] This invention relates to the field of oil and gas pipeline maintenance technology, and in particular to a method for sealing leaks in flanged pipelines. Background Technology

[0002] Existing oil and gas extraction and transportation rely heavily on pipelines. Common oil and gas pipelines are typically composed of multiple pipe sections joined by flanges. These pipelines are exposed to outdoor environments for extended periods, suffering from corrosion from rainwater and dust, and are also affected by impurities and acidic substances in the oil and gas. This makes them prone to leaks at the flange joints, requiring maintenance. Due to the unique operational characteristics of oil and gas pipelines, shutting them down for maintenance and sealing would significantly disrupt normal oil and gas transport. Furthermore, the retention of oil and gas within the pipeline can easily lead to leaks when the flange joints are opened, resulting in resource waste and significant safety hazards. Therefore, how to maintain and seal leaks during normal pipeline operation has become a key research focus.

[0003] Existing methods for online leak sealing of oil and gas pipelines generally involve completely covering the leak point with sealant or filler. However, in practice, it has been found that the flanges are large, and the sealant or filler is applied manually to the leak point, resulting in poor contact between the sealant and the pipeline leak. Furthermore, leakage continues during the sealing process, with a large amount of leaked gas remaining between the sealant and the pipeline, leading to poor sealing effect and a short service life after sealing.

[0004] Therefore, there is an urgent need for a technical solution to address the problem of poor maintenance and sealing of leaks during the operation of existing oil and gas pipelines. Summary of the Invention

[0005] The purpose of this invention is to provide a flange pipeline leak sealing method to address the technical problem of poor maintenance and sealing effect of existing oil and gas pipelines during operation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for sealing leaks in flanged pipes, employing a covering clamp, includes the following steps: S1: The covering clamp is clamped at the leak point in the pipe, with the pipe flange at the leak point located within the sealing chamber of the covering clamp, forming a gap space between the inner wall of the covering clamp and the outer wall of the pipe; S2: Along the longitudinal direction of the pipe, sealing filler is filled into the gap space on both sides of the sealing chamber; S3: Pressure caps are respectively installed at both ends of the covering clamp, with one end of each pressure cap extending into the gap space and pressing against the sealing filler, and the other end being a flange connected to the covering clamp via an adjusting screw; S4: The adjusting screws at both ends of the covering clamp are adjusted respectively, and the pressure caps press against and squeeze the sealing filler to seal the gap space.

[0008] This invention discloses a flange pipe sealing method that uses a clamping and encasing fixture with a pressure cap to push and compress the sealing packing material filled in the gap space. Compared with manually applying the sealing packing material, this method ensures that the sealing packing material and the pipe are compressed and tightly fitted, resulting in high pressure resistance, reduced likelihood of secondary leakage, and good sealing effect. At the same time, the sealing packing material is pushed and compressed separately from both sides of the leak point, allowing for single-sided or double-sided simultaneous pushing and compression depending on the leakage amount, minimizing the amount of gas trapped between the two sections of sealing packing material.

[0009] In a preferred embodiment of the present invention, in step S1, a support strip is provided on the pipe or at the edge of the sealing chamber corresponding to the encapsulated clamp, and then the encapsulated clamp is clamped onto the pipe. This allows the support strip to support the encapsulated clamp and form a gap space between them. Depending on the actual situation, an annular support strip can be used to prevent the encapsulated clamp from adhering to the pipe due to gravity, thus avoiding affecting the uniformity of the circumferential width of the gap space and ensuring a consistent circumferential sealing effect on the flanged pipe after sealing. Simultaneously, depending on the actual situation, a segmented support strip can be used to increase the width of the gap space along the pipe axis corresponding to the leak point, resulting in a thicker sealing filler in the area corresponding to the leak point, capable of withstanding greater gas pressure, and achieving targeted sealing filler thickness settings.

[0010] In a preferred embodiment of the present invention, the encapsulated clamp is provided with a first filling chamber, a first connecting channel, a sealing chamber, a second connecting channel, and a second filling chamber arranged sequentially along the axial direction. The inner diameter of the sealing chamber is larger than the outer diameter of the pipe flange where the leak point is located. Stepped structures are formed between the first filling chamber and the first connecting channel, and between the second connecting channel and the second filling chamber. In S1, a portion of the sealing filler is filled into the stepped structure before the encapsulated clamp is clamped onto the pipe. The structure of the encapsulated clamp is adapted to the flange pipe, and the internal stepped design facilitates the filling of sealing filler, reduces the amount of sealing filler to be filled after the encapsulated clamp is clamped onto the pipe, and shortens the leak sealing process time.

[0011] As a preferred embodiment of the present invention, the encapsulating clamp includes a first stuffing box and a second stuffing box that are fastened together. The outer walls of the first stuffing box and the second stuffing box are respectively provided with connecting flanges adapted to the gland. In S3, the connecting flanges and the gland are connected by the adjusting screw. The flange connection between the connecting flange and the gland is adapted to the flange pipeline structure, so that the overall structure of the flange pipeline after the leak point is sealed is not obtrusive. It is suitable for online installation on existing gas production and transmission pipelines, and the adjusting screw can be adjusted later to facilitate the smooth disassembly of the encapsulating clamp and the secondary adjustment of the pushing and squeezing pressure, which is convenient for maintenance.

[0012] In a preferred embodiment of the present invention, in step S3, the gland includes several pressure blocks, each of which is connected to an adjusting screw. The gland composed of multiple pressure blocks can provide multi-regional, small-area compression of the sealing packing, resulting in higher compactness compared to the overall annular space compression, thus improving the overall density of the sealing packing, achieving better sealing performance, and extending its sealing life.

[0013] In a preferred embodiment of the present invention, during step S4, all the pressure blocks are adjusted one by one by clockwise or counterclockwise using the adjusting screw. This causes the gas trapped in the sealing packing to move from the packing area corresponding to the pressure block being adjusted to the packing area corresponding to the pressure block not being adjusted, so as to facilitate centralized output from the area corresponding to the pressure block with lower pushing pressure, reduce the gas trapped in the sealing packing, and improve the sealing effect and extend the sealing life.

[0014] In a preferred embodiment of the present invention, a sealing groove is provided on the mating surface of the first stuffing box and / or the second stuffing box, the sealing groove connecting the first stuffing chamber and the second stuffing chamber, and a sealing strip is embedded in the sealing groove. In S1, the covering clamp is clamped onto the pipeline after the sealing strip is embedded in the sealing groove. The sealing strip is used to seal the mating surface of the first stuffing box and the second stuffing box.

[0015] As a preferred embodiment of the present invention, the sealing groove includes a connecting section that is conformally arranged along the first connecting channel, the sealing chamber, and the second connecting channel, and a return bend section disposed at both ends of the connecting section. One end of the return bend section is connected to the connecting section, and the other end is radially connected to the first packing chamber or the second packing chamber. A variable diameter section is disposed at one end of the return bend section that passes through the covering clamp.

[0016] In a preferred embodiment of the present invention, the encapsulating clamp is provided with a grease injection hole on the sealing chamber. During S4, the grease injection hole remains open. After S4, S5 is performed: sealing grease is injected into the sealing chamber through the grease injection hole, and the grease injection hole is then sealed. This ensures that during the compression and sealing process of the sealing packing, continuously leaking gas is output from the grease injection hole, preventing excessive gas retention from affecting the overall leak-sealing effect.

[0017] As a preferred embodiment of the present invention, during step S5, a drainage tube is inserted through the grease injection hole. After the volume of sealant filled exceeds three-quarters of the designed volume of the sealing chamber, the drainage tube is removed, and then pressurized grease injection is performed. This reduces the amount of gas trapped in the sealing chamber and further improves the overall leak-sealing effect.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0019] 1. By using a clamping and covering fixture and setting a pressure cap to push and squeeze the sealing filler filled in the gap space, compared with manually applying the sealing filler, the sealing filler and the pipeline are squeezed tightly and fit tightly, with high pressure resistance, less prone to secondary leakage, and good sealing effect.

[0020] 2. The sealing packing is pushed and squeezed separately from both sides of the leak point, so that the single-sided pushing and squeezing or double-sided simultaneous pushing and squeezing can be adopted according to the leakage amount of the leak point, so as to minimize the amount of gas trapped between the two sections of sealing packing. Attached Figure Description

[0021] Figure 1 This is a schematic flowchart of a flange pipe sealing method according to the present invention;

[0022] Figure 2 This is a schematic diagram of the usage state of the encapsulated clamp described in this invention;

[0023] Figure 3 This is a schematic diagram of the structure of the encasing fixture described in the embodiment;

[0024] Figure 4 This is a schematic diagram of the structure of the first stuffing box in the embodiment;

[0025] Figure 5 This is an isometric view of the first stuffing box in the embodiment;

[0026] Figure 6 This is a schematic diagram of the structure of the second stuffing box in the embodiment;

[0027] Figure 7 This is a schematic diagram of the structure of the pressure block described in the embodiment.

[0028] icon:

[0029] 1-Pipe, 2-Gap space, 3-Sealing packing, 41-First packing box, 42-Second packing box, 43-Connecting flange, 5-Gland, 51-Pressure block, 52-Adjusting screw, 6-Supporting rubber strip, 71-First packing chamber, 72-First connecting channel, 73-Sealing chamber, 74-Second connecting channel, 75-Second packing chamber, 8-Sealing groove, 81-Connecting section, 82-Bend section, 83-Reducing diameter section, 9-Grease injection hole. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings.

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] Example 1

[0033] like Figure 1 As shown, a method for sealing leaks in flanged pipes employs the following techniques: Figures 2-7 The encasing clamp shown includes a first stuffing box 41 and a second stuffing box 42 that are fastened together. The outer walls of the first stuffing box 41 and the second stuffing box 42 are respectively provided with connecting flanges 43 that are adapted to the gland 5. After the first stuffing box 41 and the second stuffing box 42 are fastened together, the encasing clamp forms a first stuffing chamber 71, a first connecting channel 72, a sealing chamber 73, a second connecting channel 74 and a second stuffing chamber 75 that are connected sequentially along the axial direction. The inner diameter of the sealing chamber 73 is larger than the outer diameter of the flange of the pipe 1 where the leakage point is located. Step structures are formed between the first stuffing chamber 71 and the first connecting channel 72, and between the second connecting channel 74 and the second stuffing chamber 75. A sealing groove 8 is provided on the fastening surface of the first stuffing box 41. The sealing groove 8 connects the first stuffing chamber 71 and the second stuffing chamber 75. A sealing strip is embedded in the sealing groove 8.

[0034] And includes the following steps:

[0035] S1: The encapsulating clamp is clamped at the leak point of pipe 1. The flange of pipe 1 where the leak point is located is located inside the sealing chamber 73, and a gap space 2 is formed between the inner wall of the encapsulating clamp and the outer wall of pipe 1; S2: Along the longitudinal direction of pipe 1, the gap space 2 on both sides of the sealing chamber 73 is filled with sealing filler 3; S3: Pressure caps 5 are respectively set at both ends of the encapsulating clamp. One end of each pressure cap 5 extends into the gap space 2 and pushes against the sealing filler 3, and the other end is set with a flange connected to the encapsulating clamp through adjusting screws 52; S4: Adjust the adjusting screws 52 at both ends of the encapsulating clamp respectively, and the pressure caps 5 push and squeeze the sealing filler 3 to seal the gap space 2.

[0036] Specifically, in this embodiment, the encapsulated clamp is configured with a symmetrical structure. The distance between the first connecting channel 71 and the second connecting channel 74 and the outer wall of the pipe 1 is 2-15mm. The inner diameter of the first filling chamber 71 and the second filling chamber 75 is greater than the inner diameter of the first connecting channel 72 and the second connecting channel 74. The length of the first connecting channel 72 and the second connecting channel 74 is greater than their inner diameter. This extends the distance between the filling chamber and the sealing chamber 73, making the flow distance of the leaked gas in the encapsulated clamp longer and less prone to secondary leakage. In specific operation, some sealing filler 3 is filled on the stepped structure, and after the sealing strip is embedded in the sealing groove 8, the encapsulated clamp is clamped and installed on the pipe 1.

[0037] Preferably, an annular support strip 6 is provided on the edge of the sealing chamber 73 along the axial direction on the pipeline 1, that is, at the position of the first connecting channel 72 and the second connecting channel 74 near the sealing chamber 73. The support strip 6 is a hard rubber structural component with slits. The support strip 6 supports the covering clamp from the annular direction of the pipeline 1, so that after the covering clamp is clamped onto the pipeline 1, an annular gap space 2 with similar circumferential volume is formed. This ensures that the sealing effect of the leakage point is consistent on both sides along the axial direction of the pipeline 1, avoids uneven thickness of the sealing filler 3, ensures the uniformity of the thickness of the sealing filler 3 around the pipeline 1, and facilitates the insertion of the gland 5. At the same time, the support strip 6 divides the gap space into multiple segments to achieve isolation between adjacent gap spaces. During the filling process of the sealing filler 3, the support strip 6 prevents gas from the leakage point from entering the sealing filler 3 area, and prevents the leaked gas from affecting the compactness of the sealing filler 3.

[0038] Preferably, in this embodiment, the pressure cap 5 can be a ring-shaped structure formed by two parts fastening together, or it can be a ring-shaped structure composed of multiple pressure blocks 51, such as... Figure 1 , Figure 7 As shown, this embodiment takes the pressure cover 5 formed by the fastening of two pressure blocks 51 as an example. Each pressure block 51 is provided with a local flange structure and an adjusting bolt 52 is inserted to connect with the connecting flange 43 on the covering fixture. When the sealing packing 3 is pushed and squeezed, the two pressure blocks 51 can be adjusted at the same time or adjusted one by one multiple times to make the sealing packing 3 squeezed and compact, reducing the influence of leaked gas on the compression and compaction of the sealing packing 3.

[0039] Specifically, depending on the actual situation, the number of pressure blocks 51 constituting the pressure cap 5 can be increased. A spring and a pressure plate are connected to the side of each pressure block 51 near the sealing packing 3, so that each pressure block 51 can be adjusted one by one towards the sealing packing 3 by adjusting the bolts 52. This causes the pressure plate to squeeze the sealing packing 3. The sealing packing 3 has better compactness through the combined compression of multiple local areas. In addition, the spring is compressed during the adjustment of the pressure block 51. During use, the elastic force of the spring provides continuous pushing pressure to the sealing packing 3, which further improves the sealing effect of the sealing packing 3 and extends its sealing life.

[0040] Specifically, the spring can also be replaced with a rubber block according to the actual situation. The rubber block after compression deformation not only provides continuous pushing pressure on the sealing filler 3, but also has a certain sealing effect, which can further prevent gas from escaping and improve the sealing effect.

[0041] This embodiment of a flange pipe sealing method uses a clamping and encasing fixture, and a pressure cap 5 to push and compress the sealing packing 3 filled in the gap space 2. Compared with manually applying the sealing packing 3, this method compresses the sealing packing 3 and the pipe 1 to make them dense and tightly fitted, with high pressure resistance, less prone to secondary leakage, and good sealing effect. At the same time, the sealing packing 3 is pushed and compressed separately from both sides of the leakage point, so that single-sided pushing and compression or double-sided simultaneous pushing and compression can be used according to the leakage amount. When the leakage amount is small and does not affect the sealing, double-sided simultaneous pushing and compression is used. When the leakage amount is large, single-sided sealing is performed and the other side of the sealing packing 3 is compressed, minimizing the amount of gas trapped between the two sections of sealing packing 3.

[0042] Preferred, such as Figure 2 , Figure 3 As shown, the sealing groove 8 includes a connecting section 81 that conforms to the shape of the first connecting channel 72, the sealing chamber 73, and the second connecting channel 74, and a bend section 82 located at both ends of the connecting section 81. One end of the bend section 82 is connected to the connecting section 81, and the other end is radially connected to the first packing chamber 71 or the second packing chamber 75. A variable diameter section 83 is provided at one end of the bend section 82 that passes through the covering clamp. The conformally shaped connecting section 81 can provide a better sealing effect on the mating surface. The bend section 82 disperses the extrusion pressure from different directions during the compaction of the sealing packing 3, making it less likely for the sealing strip to deform and affect the sealing effect. At the same time, the variable diameter section 83 causes the sealing packing 3 to be squeezed into the sealing groove 8 radially along the pipe 1 and squeezed along the extension direction of the sealing strip, thus compensating for the sealing gap between the sealing strip and the sealing groove 8. The combination of multi-position structure and pressure makes the sealing device itself have a better sealing effect.

[0043] Example 2

[0044] This embodiment of the flange pipe sealing method is the same as that in embodiment 1, except that: the covering clamp is provided with a grease injection hole 9 on the sealing chamber 73. When S4 is performed, the grease injection hole 9 is kept open. After S4 is completed, S5 is performed: sealing grease is filled into the sealing chamber 73 through the grease injection hole 9 and the grease injection hole 9 is sealed. When S5 is performed, a drainage tube is inserted through the grease injection hole 9. After the volume of sealing grease filling exceeds three-quarters of the designed volume of the sealing chamber 73, the drainage tube is removed and grease is injected under pressure.

[0045] This embodiment of a flange pipe sealing method involves filling and sealing the sealing chamber 73 through the grease injection hole 9 on the sealing chamber 73. During the compression and sealing process of the sealing filler 3, the continuously leaking gas can be output from the grease injection hole 9, avoiding excessive gas retention that would affect the overall sealing effect. During operation, a rigid gas guide tube is inserted through the grease injection hole 9 to connect the space near the leak point with the external space of the covering clamp. After the sealing grease is partially filled, it is pulled out to minimize the gas retained in the sealing grease and extend the overall sealing effect and sealing life.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for sealing leaks in flanged pipes, characterized in that, A wrap-around clamp is used, comprising a first stuffing box (41) and a second stuffing box (42) that are fastened together. After the first stuffing box (41) and the second stuffing box (42) are fastened together, the wrap-around clamp forms a first stuffing chamber (71), a first connecting channel (72), a sealing chamber (73), a second connecting channel (74), and a second stuffing chamber (75) connected sequentially along the axial direction. The inner diameter of the sealing chamber (73) is larger than the outer diameter of the flange of the pipe (1) where the leak point is located. The inner diameters of the first stuffing chamber (71) and the second stuffing chamber (75) are larger than the inner diameters of the first connecting channel (72) and the second connecting channel (74). The first stuffing chamber (71) and the first connecting channel (72), and the second connecting channel (74) and the first connecting channel (72) are connected together. The second packing chambers (75) are respectively formed with stepped structures. A sealing groove (8) is provided on the fastening surface of the first packing box (41) and / or the second packing box (42). The sealing groove (8) connects the first packing chamber (71) and the second packing chamber (75). A sealing strip is embedded in the sealing groove (8). The sealing groove (8) includes a connecting section (81) that is arranged in a shape along the first connecting channel (72), the sealing chamber (73), and the second connecting channel (74), and a bend section (82) provided at both ends of the connecting section (81). One end of the bend section (82) is connected to the connecting section (81), and the other end is provided with a variable diameter section (83) that is radially connected to the first packing chamber (71) or the second packing chamber (75). And includes the following steps: S1: A covering clamp is clamped at the leak point of the pipeline (1). The flange of the pipeline (1) where the leak point is located is located in the sealing chamber (73) set in the middle area of ​​the covering clamp. A gap space (2) is formed between the inner wall of the covering clamp and the outer wall of the pipeline (1). A support rubber strip (6) is set on the pipeline (1) or at the edge position of the sealing chamber (73) in the axial direction. The covering clamp is then clamped on the pipeline (1). The support rubber strip is a hard rubber material structure with a cut opening. The support rubber strip includes annular support rubber strip or segmented support rubber strip. S2: Along the longitudinal direction of the pipe (1), fill the gap space (2) on both sides of the sealing chamber (73) with sealing filler (3); S3: Pressure caps (5) are provided at both ends of the covering clamp. One end of each pressure cap (5) extends into the gap space (2) and pushes against the sealing packing (3). The other end is provided with a flange and connected to the covering clamp through an adjusting screw (52). The pressure cap (5) includes several pressure blocks (51). Each pressure block (51) is connected to the adjusting screw (52). S4: Adjust the adjusting screws (52) at both ends of the covering clamp respectively, and press the sealing packing (3) with the pressure cap (5) to seal the gap space (2). According to the leakage amount of the leakage point, single-sided pressing or double-sided synchronous pressing is adopted. All the pressure blocks (51) are pressed and adjusted one by one in clockwise or counterclockwise order through the adjusting screws (52), so that the gas trapped in the sealing packing moves from the packing area corresponding to the pressure block during the pressing and adjustment process to the packing area corresponding to the pressure block that has not been pressed and adjusted.

2. The flange pipe sealing method as described in claim 1, characterized in that, In S1, after filling part of the sealing filler (3) on the stepped structure, the covering clamp is then clamped onto the pipe (1).

3. A method for sealing flanged pipes as described in any one of claims 1-2, characterized in that, The outer walls of the first stuffing box (41) and the second stuffing box (42) are respectively provided with connecting flanges (43) that are adapted to the gland (5). In S3, the connecting flanges (43) and the gland (5) are connected by the adjusting screw (52).

4. The flange pipe sealing method as described in claim 1, characterized in that, In S1, the sealing strip is embedded in the sealing groove (8) and then the covering clamp is clamped onto the pipe (1).

5. A flange pipe sealing method as described in claim 1, characterized in that, The encapsulated clamp is provided with a grease injection hole (9) on the sealing chamber (73). During S4, the grease injection hole (9) is kept open. After S4 is completed, S5 is performed: sealing grease is injected into the sealing chamber (73) through the grease injection hole (9) and the grease injection hole (9) is sealed.

6. A flange pipe sealing method as described in claim 5, characterized in that, During S5, a drainage tube is inserted through the grease injection hole (9). After the volume of the sealant filling exceeds three-quarters of the designed volume of the sealing chamber (73), the drainage tube is removed, and then the grease is injected under pressure.

Images