Expansion tube and expansion tube set

Abstract

The utility model discloses an expansion pipe and expansion pipe group, the expansion pipe of disclosure includes pipe body, first sealing ring, second sealing ring and third sealing ring, the pipe body is integral type structure and includes first connecting end, second connecting end and the pipe main body between first connecting end with second connecting end, first connecting end is equipped with outer thread, and second connecting end is equipped with internal thread, at least one of the outer wall of first connecting end and the inner wall of second connecting end is equipped with first sealing ring, the part of pipe main body adjacent first connecting end is equipped with second sealing ring, or the part of pipe main body adjacent second connecting end or second connecting end is equipped with third sealing ring, the above -mentioned scheme can solve the docking of expansion pipe in background art and easily exist the problem of poor sealing performance after expansion.

Description

Technical Field

[0001] This utility model relates to the field of expansion tube design technology, and in particular to an expansion tube and an expansion tube assembly. Background Technology

[0002] Expansion tubing is a type of metal pipe commonly used in oil and gas wells, geothermal wells, and other mining operations. Due to its excellent expansion performance and the retention of its metallic properties after expansion, expansion tubing is widely used in scenarios such as casing patching, casing suspension, and open-hole plugging in mining. Taking casing patching as an example, during the installation process, an expansion tubing is lowered into the damaged area of ​​the casing. High-pressure fluid (such as high-pressure drilling fluid) is introduced into the patching tool, pushing the expansion cone upwards and inflating the tubing to fit tightly against the damaged area, ultimately repairing the damage. In open-hole plugging, an expansion tubing is lowered into the open hole. High-pressure fluid pushes the expansion cone upwards, inflating the tubing against the wellbore wall, ultimately achieving cementing and effectively sealing and isolating complex formations.

[0003] Due to limitations in technological and transportation conditions, the expansion tubes involved in related technologies are generally not very long; for example, most commercially available expansion tubes are between 9 and 12 meters in length. However, in practical applications, longer expansion structures may be required, and there are often scenarios where the length of a single expansion tube cannot meet the expansion length requirements. Taking casing patching as an example, in some scenarios, the damaged length of the casing is longer than the length of a single expansion tube, requiring multiple expansion tubes connected together to increase the expansion length and thus achieve patching at longer damaged sections of the casing. Another example is open-hole well plugging construction, where the formation to be plugged typically ranges from tens to hundreds of meters in length, also requiring multiple expansion tubes connected together to meet the construction requirements.

[0004] In related technologies, expansion tubes are connected by threaded joints, requiring the ends of the expansion tubes to have internal or external threads. These threaded structures result in relatively weak ends to the expansion tubes, yet good sealing performance is still required at the joint after expansion. However, the threaded structure makes the ends of the expansion tubes relatively weak, which easily leads to poor sealing performance at the joint after expansion. This is especially true in mines with high pressure resistance (such as shale gas, shale oil, and coalbed methane mines that require fracturing), where sealing problems are more likely to occur at the joint of the expansion tubes after expansion.

[0005] How to solve the problem of poor sealing performance at the expansion joint after expansion is a technical problem that technicians in related fields urgently need to solve. Utility Model Content

[0006] This utility model discloses an expansion tube and an expansion tube assembly to solve the problem in the background art where the joint of the expansion tube is prone to poor sealing performance after expansion.

[0007] To solve the above-mentioned technical problems, this application provides the following technical solution:

[0008] In a first aspect, this utility model embodiment discloses an expansion tube, which includes a tube body, a first sealing ring, a second sealing ring, and a third sealing ring.

[0009] The tube body is an integral structure and includes a first connecting end, a second connecting end, and a tube body located between the first connecting end and the second connecting end. The first connecting end is provided with an external thread, and the second connecting end is provided with an internal thread. At least one of the outer wall of the first connecting end and the inner wall of the second connecting end is provided with the first sealing ring. The second sealing ring is sleeved on the part of the tube body adjacent to the first connecting end, and the third sealing ring is sleeved on the part of the tube body adjacent to the second connecting end or on the second connecting end.

[0010] Optionally, in the above-mentioned expansion tube, the first connecting end of the expansion tube is used to be fixedly connected to the second connecting end of another expansion tube that is mated with it through the threaded engagement between the external thread and the internal thread. The first sealing ring is used to seal between the outer wall of the connected first connecting end and the inner wall of the second connecting end. The second sealing ring and the third sealing ring, which are respectively corresponding to the connected first connecting end and the second connecting end, are used to seal with the structure in contact with it in the mine after the expansion tube is expanded, so as to seal the mating seam between the connected first connecting end and the second connecting end.

[0011] Optionally, in the expansion tube described above, one of the second sealing ring and the third sealing ring is a cylindrical rubber structure, and the other is a cylindrical metal structure.

[0012] Optionally, in the above-mentioned expansion tube, the cylindrical rubber structure is fixed to the tube body or the second connecting end by a vulcanization process; the cylindrical metal structure is fixed to the tube body by a welding process.

[0013] Optionally, in the above-mentioned expansion tube, both the external thread and the internal thread are negative angle threads.

[0014] Optionally, in the above-mentioned expansion tube, the outer wall of the first connecting end has a first threaded section with the external thread and a first mounting section between the first threaded section and the tube body. The first mounting section is fitted with the first sealing ring. The inner wall of the second connecting end has a first sealing mating section. The first sealing ring installed on the first connecting end of the expansion tube is used to seal and fit with the first sealing mating section on the second connecting end of the other expansion tube that is mated with it.

[0015] Optionally, in the expansion tube described above, the number of the first sealing rings provided in the first mounting section is at least two, and they are distributed at intervals along the axial direction of the first mounting section.

[0016] Optionally, in the above-mentioned expansion tube, the inner wall of the second connecting end has a second threaded section with the internal thread, a second mounting section between the second threaded section and the tube body, and a first sealing mating section on the second threaded section facing away from the second mounting section; the second mounting section is lined with the first sealing ring, and the outer wall of the first connecting end has a second sealing mating section, which is located on the side of the first threaded section facing away from the first mounting section; the first sealing ring installed on the second connecting end of the expansion tube is used to seal and fit with the second sealing mating section opposite to the first connecting end of the other expansion tube.

[0017] Optionally, in the expansion tube described above, the number of the first sealing rings provided in the second mounting section is at least two, and they are distributed at intervals along the axial direction of the second mounting section.

[0018] Secondly, this utility model discloses an expansion tube assembly, which includes a plurality of expansion tubes as described in the first aspect. The first connecting end of one of two adjacent expansion tubes and the second connecting end of the other are fixedly connected by the threaded engagement between the external thread and the internal thread.

[0019] The expansion tube disclosed in this embodiment of the utility model is designed such that at least one of the outer wall of the first connecting end and the inner wall of the second connecting end of the tube body is provided with a first sealing ring, a second sealing ring is fitted on the part of the tube body adjacent to the first connecting end, and a third sealing ring is fitted on the part of the tube body adjacent to the second connecting end or the second connecting end. After multiple expansion tubes are joined together, the outer wall of the first connecting end and the inner wall of the second connecting end of two adjacent expansion tubes are sealed by the first sealing ring. After the multiple expansion tubes are expanded in the mine, the second sealing ring and the third sealing ring respectively seal with the structure in contact with them in the mine, thereby further sealing the joint between the first connecting end and the second connecting end. Ultimately, the joint of the expansion tube can still have good sealing performance after expansion, thus solving the problem of poor sealing performance at the joint of the expansion tube after expansion as described in the background art. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the expansion tube assembly when it is not expanded, as disclosed in this embodiment of the utility model;

[0021] Figure 2 This is a schematic diagram of the expansion tube assembly after expansion in a mine, as disclosed in this embodiment of the utility model.

[0022] Explanation of reference numerals in the attached figures:

[0023] 10-Pipe body, 11-First connecting end, 12-Second connecting end, 13-Pipe body, 14-Butt joint,

[0024] 20-First sealing ring,

[0025] 30 - Second sealing ring

[0026] 40 - Third sealing ring

[0027] 01-Expansion tube, 02-Casing,

[0028] 101-First threaded section, 102-First mounting section, 103-Second sealing section, 201-Second threaded section, 202-Second mounting section, 203-First sealing section. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0030] The technical solutions disclosed in the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0031] Please refer to Figure 1 and Figure 2 This utility model discloses an expansion tube 01. The disclosed expansion tube 01 may include a tube body 10, a first sealing ring 20, a second sealing ring 30, and a third sealing ring 40.

[0032] The tube body 10 is the main body of the expansion tube 01. The tube body 10 includes a first connecting end 11, a second connecting end 12, and a tube body 13. The first connecting end 11 and the second connecting end 12 are the connecting portions of the tube body 10, and the tube body 13 is the main body of the tube body 10, located between the first connecting end 11 and the second connecting end 12. In this embodiment of the invention, the tube body 10 is a one-piece structure, meaning that the first connecting end 11, the second connecting end 12, and the tube body 13 are manufactured using an integral forming process (e.g., cold rolling, cutting, etc.).

[0033] The first connecting end 11 is provided with an external thread, and the second connecting end 12 is provided with an internal thread. The connection between two adjacent expansion tubes 01 is achieved by the threaded engagement of the first connecting end 11 of one of the two adjacent expansion tubes 01 and the second connecting end 12 of the other through the external and internal threads.

[0034] The first sealing ring 20, the second sealing ring 30, and the third sealing ring 40 are all sealing structural components. The first sealing ring 20 directly seals the outer wall of the first connecting end 11 and the inner wall of the second connecting end 12 of two adjacent expansion tubes 01 after they are joined. The second sealing ring 30 and the third sealing ring 40, after the two adjacent expansion tubes 01 have expanded in the mine, achieve a sealing fit with structures in contact with them in the mine (such as the wall of an open-hole mine or the inner wall of a casing 02), thereby indirectly sealing the connection between the first connecting end 11 and the second connecting end 12. Please refer again. Figure 1 and Figure 2 For a more intuitive understanding, in this embodiment of the invention, the diameter of the expanded tube 01 after expansion is D2, and the diameter of the expanded tube 01 before expansion is D1, where D2 is greater than D1. This embodiment of the invention does not limit the specific values ​​of D1 and D2; it merely indicates that the inner diameter of the expanded tube 01 after expansion is greater than the inner diameter of the expanded tube 01 before expansion.

[0035] In this embodiment of the invention, at least one of the outer wall of the first connecting end 11 and the inner wall of the second connecting end 12 may be provided with a first sealing ring 20. In one embodiment, the outer wall of the first connecting end 11 is provided with a first sealing ring 20, while the inner wall of the second connecting end 12 is not provided with a first sealing ring 20. In another embodiment, the outer wall of the first connecting end 11 is not provided with a first sealing ring 20, while the inner wall of the second connecting end 12 is provided with a first sealing ring 20. In yet another embodiment, the outer wall of the first connecting end 11 is provided with a first sealing ring 20, and the inner wall of the second connecting end 12 is also provided with a second sealing ring 30.

[0036] During the docking of two adjacent expansion tubes 01, the first connecting end 11 of the expansion tube 01 is fixedly connected to the second connecting end 12 of the other expansion tube 01 through a threaded engagement between the external and internal threads. The first sealing ring 20 is used to seal between the connected first connecting end 11 and the second connecting end 12, that is, the first sealing ring 20 seals between the outer wall of the first connecting end 11 and the inner wall of the second connecting end 12.

[0037] In this embodiment of the invention, a second sealing ring 30 is fitted onto the portion of the pipe body 13 adjacent to the first connecting end 11, and a third sealing ring 40 is fitted onto the portion of the pipe body 13 adjacent to the second connecting end 12 or onto the second connecting end 12. The second sealing ring 30 and the third sealing ring 40, respectively corresponding to the first connecting end 11 and the second connecting end 12, are used to seal the contact points in the mine after the expansion pipe 01 is expanded, thereby sealing the butt joint 14 between the connected first connecting end 11 and the second connecting end 12. Specifically, the second sealing ring 30 and the third sealing ring 40 achieve the sealing of the butt joint 14 on the outside of the expansion pipe 01.

[0038] In one embodiment, after the expansion tube 01 is expanded in the mine, both the second sealing ring 30 and the third sealing ring 40 are sealed to the structure in contact with them in the mine (e.g., the inner wall of the casing 02). The butt joint 14 is located between the second sealing ring 30 and the third sealing ring 40. The butt joint 14 may not contact the second sealing ring 30 or the third sealing ring 40. In this case, the butt joint 14 is sealed by the sealing structure formed by the second sealing ring 30, the third sealing ring 40, and the structure in contact with them in the mine, thereby further achieving a seal between the first connecting end 11 and the second connecting end 12.

[0039] It should be noted that both the second sealing ring 30 and the third sealing ring 40 will deform after the expansion tube 01 expands in the mine. The deformation of the second sealing ring 30 and the third sealing ring 40 is multi-directional. At least one of the second sealing ring 30 and the third sealing ring 40, after being deformed in the axial direction of the expansion tube 01, will have part of its structure inserted into the joint 14, thereby achieving filling in the joint 14. This embodiment of the present invention does not limit the thickness, material, or distance from the joint 14 of the second sealing ring 30 and the third sealing ring 40 when not expanded. Those skilled in the art can make adaptive adjustments according to the size of the expansion tube 01 and the specific internal environment of the mine to ensure that at least one of the second sealing ring 30 and the third sealing ring 40 can be squeezed and deformed after the expansion tube 01 expands, and that part of the deformed structure can extend to the joint 14 and be inserted into the joint 14.

[0040] In another embodiment, after the expansion tube 01 expands in the mine, both the second sealing ring 30 and the third sealing ring 40 seal against the structure in contact with it in the mine. Simultaneously, one of the second sealing ring 30 and the third sealing ring 40 is deformed during the expansion of the expansion tube 01 and fills the joint 14 between the first connecting end 11 and the second connecting end 12 through deformation. In this case, the joint 14 is not only sealed by the second sealing ring 30, the third sealing ring 40, and the structure in contact with it in the mine, but one of the second sealing ring 30 and the third sealing ring 40 further penetrates into the joint 14, thereby achieving a better seal.

[0041] The expansion tube 01 disclosed in this embodiment of the utility model is designed such that at least one of the outer wall of the first connecting end 11 and the inner wall of the second connecting end 12 of the tube body 10 is provided with a first sealing ring 20, a second sealing ring 30 is fitted on the part of the tube body 13 adjacent to the first connecting end 11, and a third sealing ring 40 is fitted on the part of the tube body 13 adjacent to the second connecting end 12 or on the second connecting end 12. After multiple expansion tubes 01 are connected, the outer wall of the first connecting end 11 and the inner wall of the second connecting end 12 of two adjacent expansion tubes 01 are sealed by the first sealing ring 20. After the multiple expansion tubes 01 are expanded in the mine, the second sealing ring 30 and the third sealing ring 40 respectively seal with the structure in contact with the mine, thereby further sealing the joint 14 between the connected first connecting end 11 and the second connecting end 12. Ultimately, the joint of the expansion tube 01 can still have good sealing performance after expansion, thus solving the problem of poor sealing performance at the joint of the expansion tube after expansion as described in the background art.

[0042] This embodiment of the invention does not limit the specific shapes of the first sealing ring 20, the second sealing ring 30, and the third sealing ring 40. For example, the cross-sections of the first sealing ring 20, the second sealing ring 30, and the third sealing ring 40 can be O-shaped, rectangular, trapezoidal, etc. Similarly, this embodiment of the invention does not limit the specific materials of the first sealing ring 20, the second sealing ring 30, and the third sealing ring 40. The materials of the first sealing ring 20, the second sealing ring 30, and the third sealing ring 40 can be rubber, metal, or other types of polymer materials.

[0043] In one embodiment, one of the second sealing ring 30 and the third sealing ring 40 may be a cylindrical rubber structure, and the other may be a cylindrical metal structure. In another embodiment, both the second sealing ring 30 and the third sealing ring 40 may be cylindrical rubber structures. In yet another embodiment, both the second sealing ring 30 and the third sealing ring 40 may be cylindrical metal structures.

[0044] In this embodiment of the utility model, the second sealing ring 30 and the third sealing ring 40 adopt a cylindrical structure. The cylindrical structure has a certain length in its axial direction. After the expansion tube 01 is expanded in the mine, the cylindrical structure can easily generate sufficient deformation, which is conducive to forming a longer sealing surface and also conducive to filling the butt joint 14 after deformation.

[0045] To prevent the second sealing ring 30 and the third sealing ring 40 from failing to fill the joint 14 through deformation during the expansion of the expansion tube 01, one of the second sealing ring 30 and the third sealing ring 40 can be made of rubber, and the other can be made of metal. This method avoids the homogenization of the second sealing ring 30 and the third sealing ring 40. The second sealing ring 30 and the third sealing ring 40, which are made of different materials, are more likely to undergo greater deformation under pressure, thus making it easier to fill the joint 14.

[0046] To improve the sealing performance of the connection and thus enhance the subsequent sealing effect, in one embodiment, the cylindrical rubber structure can be fixed to the tube body 13 or the second connecting end 12 by a vulcanization process. The cylindrical metal structure can be fixed to the tube body 13 by welding. In other embodiments, the second sealing ring 30 can be simply fitted onto the tube body 13 near the first connecting end 11, and the third sealing ring 40 can be simply fitted onto the tube body 13 near the second connecting end 12 or onto the second connecting end 12. During the expansion of the expansion tube 01, the second sealing ring 30 and the third sealing ring 40 are compressed to achieve a seal.

[0047] To further improve the sealing performance at the joint, both the external and internal threads can be negative angle threads. This structure allows for a better sealing engagement after thread mating. In other embodiments, the external and internal threads can also be ordinary threads.

[0048] In this embodiment of the invention, the outer wall of the first connecting end 11 may have a first threaded section 101 with external threads and a first mounting section 102 disposed between the first threaded section 101 and the pipe body 13. A first sealing ring 20 may be fitted onto the first mounting section 102. The inner wall of the second connecting end 12 may have a first sealing mating section 203. The first sealing ring 20 installed on the first connecting end 11 of the expansion tube 01 is used to seal and fit with the corresponding first sealing mating section 203 on the second connecting end 12 of the other expansion tube 01. The first mounting section 102 may have a mounting groove, and the first sealing ring 20 may be installed in the mounting groove.

[0049] In one embodiment, the number of first sealing rings 20 provided on the first mounting section 102 may be one. In other embodiments, the number of first sealing rings 20 provided on the first mounting section 102 may be at least two, and they are distributed at intervals along the axial direction of the first mounting section 102. It should be explained that the axial direction of the first mounting section 102 is also the axial direction of the expansion tube 01. In this case, having at least two first sealing rings 20 installed on the first mounting section 102 can further improve the sealing effect.

[0050] In this embodiment of the invention, the inner wall of the second connecting end 12 may have a second threaded section 201 with internal threads, a second mounting section 202 located between the second threaded section 201 and the pipe body 13, and a first sealing mating section 203 located on the second threaded section 201 facing away from the second mounting section 202. A first sealing ring 20 is lined inside the second mounting section 202, and the outer wall of the first connecting end 11 has a second sealing mating section 103 located on the side of the first threaded section 101 facing away from the first mounting section 102. The first sealing ring 20 installed on the second connecting end 12 of the expansion tube 01 is used to seal and fit with the corresponding second sealing mating section 103 on the first connecting end 11 of the other expansion tube 01. This structure allows the first threaded section 101 with external threads and the second threaded section 201 with internal threads to be threadedly mated, with both sides of the threaded mating area sealed by corresponding first sealing rings 20, which further improves the sealing performance.

[0051] In one embodiment, the number of first sealing rings 20 provided in the second mounting section 202 can be one. In another embodiment, the number of first sealing rings 20 provided in the second mounting section 202 can be at least two, and they are distributed at intervals along the axial direction of the second mounting section 202. It should be explained that the axial direction of the second mounting section 202 is also the axial direction of the expansion tube 01. In this case, having at least two first sealing rings 20 installed in the second mounting section 202 can further improve the sealing effect.

[0052] Based on the expansion tube 01 disclosed in this utility model embodiment, this utility model embodiment discloses an expansion tube assembly. The disclosed expansion tube assembly includes multiple expansion tubes 01 as described in the above embodiments. The first connecting end 11 of one of two adjacent expansion tubes 01 and the second connecting end 12 of the other are fixedly connected by the threaded engagement between the external thread and the internal thread.

[0053] This embodiment of the invention does not limit the specific number of expansion tubes 01 included in the expansion tube assembly, nor does it limit the length of a single expansion tube 01. Those skilled in the art can flexibly adjust the specific number of expansion tubes 01 included in the expansion tube assembly and the length of each expansion tube 01 according to specific application scenarios. In one embodiment, the lengths of the multiple expansion tubes 01 included in the expansion tube assembly may all be equal. In another embodiment, the lengths of the multiple expansion tubes 01 included in the expansion tube assembly may not all be equal. In yet another embodiment, the lengths of the multiple expansion tubes 01 included in the expansion tube assembly may all be unequal.

[0054] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An expansion tube, characterized in that, It includes a pipe body (10), a first sealing ring (20), a second sealing ring (30), and a third sealing ring (40); The tube body (10) is an integral structure and includes a first connecting end (11), a second connecting end (12), and a tube body (13) located between the first connecting end (11) and the second connecting end (12). The first connecting end (11) is provided with an external thread, and the second connecting end (12) is provided with an internal thread. At least one of the outer wall of the first connecting end (11) and the inner wall of the second connecting end (12) is provided with the first sealing ring (20). The portion of the tube body (13) adjacent to the first connecting end (11) is provided with the second sealing ring (30), and the portion of the tube body (13) adjacent to the second connecting end (12) or the second connecting end (12) is provided with the third sealing ring (40).

2. The expansion tube according to claim 1, characterized in that, The first connecting end (11) of the expansion tube (01) is used to be fixedly connected to the second connecting end (12) of another expansion tube (01) that is mated with it through the threaded engagement between the external thread and the internal thread. The first sealing ring (20) is used to seal between the outer wall of the connected first connecting end (11) and the inner wall of the second connecting end (12). The second sealing ring (30) and the third sealing ring (40) corresponding to the connected first connecting end (11) and the second connecting end (12) are used to seal with the structure in contact with it in the mine after the expansion tube (01) is expanded, so as to seal the butt joint (14) between the connected first connecting end (11) and the second connecting end (12).

3. The expansion tube according to claim 2, characterized in that, One of the second sealing ring (30) and the third sealing ring (40) is a cylindrical rubber structure, and the other is a cylindrical metal structure.

4. The expansion tube according to claim 3, characterized in that, The cylindrical rubber structure is fixed to the tube body (13) or the second connecting end (12) by a vulcanization process; the cylindrical metal structure is fixed to the tube body (13) by a welding process.

5. The expansion tube according to claim 1, characterized in that, Both the external thread and the internal thread are negative angle threads.

6. The expansion tube according to claim 1, characterized in that, The outer wall of the first connecting end (11) has a first threaded section (101) with the external thread and a first mounting section (102) between the first threaded section (101) and the pipe body (13). The first mounting section (102) is fitted with the first sealing ring (20). The inner wall of the second connecting end (12) has a first sealing mating section (203). The first sealing ring (20) installed on the first connecting end (11) of the expansion tube (01) is used to seal and fit with the first sealing mating section (203) on the second connecting end (12) of the other expansion tube (01) that is connected to it.

7. The expansion tube according to claim 6, characterized in that, The number of the first sealing rings (20) in the first mounting section (102) is at least two, and they are distributed at intervals along the axial direction of the first mounting section (102).

8. The expansion tube according to claim 6, characterized in that, The inner wall of the second connecting end (12) has a second threaded section (201) with the internal thread, a second mounting section (202) between the second threaded section (201) and the pipe body (13), and a first sealing mating section (203) on the second threaded section (201) facing away from the second mounting section (202); the second mounting section (202) is lined with the first sealing ring (20), and the outer wall of the first connecting end (11) has a second sealing mating section (103), which is located on the side of the first threaded section (101) facing away from the first mounting section (102); the first sealing ring (20) installed on the second connecting end (12) of the expansion tube (01) is used to seal and fit with the second sealing mating section (103) on the first connecting end (11) of the other expansion tube (01) that is connected to it.

9. The expansion tube according to claim 8, characterized in that, The number of the first sealing rings (20) in the second mounting section (202) is at least two, and they are distributed at intervals along the axial direction of the second mounting section (202).

10. An expansion tube assembly, characterized in that, The expansion tube (01) includes any one of claims 1 to 9, wherein the first connecting end (11) of one of two adjacent expansion tubes (01) and the second connecting end (12) of the other are fixedly connected by the threaded engagement between the external thread and the internal thread.

Images