A special connector for insulated flexible composite pipes

Abstract

This application relates to a special connector for insulated flexible composite pipes, belonging to the field of composite pipe technology. To solve the problem of slippage in traditional connectors, it includes an intermediate connector for connecting the inner layers of two pipe bodies. Each end of the pipe body is provided with a sealing plate. An outer sleeve is commonly fitted over the outer layers of both pipe bodies. The sealing plates and the intermediate connector are both arranged within the internal cavity of the outer sleeve. A sealant-filled cavity is formed between the inner wall of the outer sleeve and the outer wall of the intermediate connector. Both ends of the outer sleeve are provided with crimping portions for radially crimping the outer layers of the pipe bodies. This application achieves both double sealing and reliable connection in the insulated flexible composite pipe connector.

Description

Technical Field

[0001] This application relates to the field of composite pipe technology, and in particular to a special connector for insulating flexible composite pipes. Background Technology

[0002] Insulated flexible composite pipes, as core equipment for transporting fluids such as oil and natural gas, have irreplaceable advantages in deep-sea oil and gas development, energy transportation in high-altitude and cold regions, and long-distance cross-sea pipeline projects. Typically, pipeline insulation is achieved by covering the surface with foamed material to a certain thickness, thereby increasing thermal resistance. However, due to their foamed structure, insulation materials usually have low strength and poor resistance to radial compression. Furthermore, once water enters the insulation material, the internal air pores are filled with water, which greatly reduces the insulation effect. Therefore, special design considerations are required during the installation of joints, especially when used underwater.

[0003] In existing technologies, flexible composite pipes generally use metal joints to connect pipe sections, and the locking force is usually transmitted through flange compression or end face clamping. However, the locking force acts directly on the insulation layer, and the strength of the foamed structure of the insulation material is low and cannot withstand the stress generated when the joint is locked, which leads to the insulation layer crushing and the joint slipping under pressure, causing water ingress problems and seriously affecting the sealing and insulation performance of the pipeline system. Therefore, it needs to be improved. Utility Model Content

[0004] To address the problem of slippage in traditional joints, this application provides a special joint for insulated flexible composite pipes.

[0005] The technical solution provided in this application for a special connector for insulated flexible composite pipes is as follows:

[0006] A special connector for insulated flexible composite pipe includes an intermediate connector for connecting the inner layers of two pipes. Each end of the pipe is provided with a sealing plate. The outer layers of the two pipes are jointly fitted with an outer sleeve. The sealing plate and the intermediate connector are both arranged in the internal cavity of the outer sleeve. An adhesive sealing cavity is formed between the inner wall of the outer sleeve and the outer wall of the intermediate connector. Both ends of the outer sleeve are provided with crimping parts for radially crimping the outer layers of the pipes.

[0007] Because the locking force acts directly on the insulation layer, and the strength of the foamed structure of the insulation material is too low to withstand the stress generated when the joint is locked, the insulation layer collapses and the joint slips under pressure, causing water ingress and seriously affecting the sealing and insulation performance of the pipeline system. By adopting the above technical solution, including an intermediate joint that connects the inner layers of the two pipes, a sealing plate is installed at the end of the pipe, and an outer sleeve is fitted on the outside of the two pipes. The outer sleeve is connected to the outer layer of the tank through a clamping part, and glue is injected into the glue-sealing cavity between the outer sleeve and the intermediate joint.

[0008] When sealing the composite pipe, the end of the flexible composite pipe is cut into a double-step structure, with the inner pipe protruding beyond the outer insulation material. The length meets the requirements for intermediate joint connection. The outer insulation material and sheath form a stepped transition with the inner step. The intermediate joint is inserted into the inner pipe, ensuring that its connection part is aligned with the inner pipe. The inner pipe is axially stretched by the inner expansion mold, while the outer clamping mold axially compresses the connection part of the intermediate joint, forming a mechanical interlock to achieve fluid sealing. Then, the outer clamping sleeve is inserted into the outer pipe. The outer clamping sleeve is then moved to the outer pipe, and a pipe shrinking machine is used to radially compress the clamping parts at both ends of the outer clamping sleeve, making it tightly fit with the outer surface of the outer pipe, forming a mechanical lock. Sealant is injected through the outer clamping sleeve. After the sealant has fully cured, the sealing cap is screwed into the injection hole to complete the final seal.

[0009] By incorporating intermediate joints, sealing plates, external sleeves, and adhesive-filled sealing cavities, a dual-sealing and reliable connection for insulated flexible composite pipe joints is achieved. The intermediate joint directly connects to the inner layer of the pipe, forming a mechanical interlock through an internal expansion and external snap-fit ​​process to ensure fluid sealing. The external sleeve independently snaps onto the outer sheath of the insulation material, combined with the chemical curing seal of the adhesive-filled sealing cavity. This not only prevents the insulation layer from collapsing due to direct force but also blocks the path of water infiltration, reducing the possibility of joint slippage. It effectively solves the problems of insulation layer failure caused by the locking force of traditional joints and the decline in insulation performance caused by water seepage, improving the sealing reliability and insulation durability of the pipeline system underwater and under complex working conditions.

[0010] Optionally, the outer sleeve has at least one injection hole on its cylindrical wall, which is used to inject sealant into the sealant injection cavity. The outer sleeve also has an injection vent hole on its cylindrical wall.

[0011] By adopting the above technical solution, the injection hole and the vent hole are opened on the outer sleeve. The setting of the injection hole and the vent hole enables efficient injection of sealant and venting of the cavity. The injection hole positions the injection path to ensure that the sealant evenly fills the injection sealing cavity between the outer sleeve and the intermediate joint. The vent hole simultaneously vents the air in the cavity to avoid air bubbles. Combined with the negative pressure vacuum introduction method, the sealant, such as epoxy resin, can fully penetrate all gaps. After curing, it forms a defect-free continuous sealing layer, which improves the sealing performance of the joint, blocks the path of moisture penetration, and extends the service life of the insulation layer.

[0012] Optionally, the injection hole is a threaded hole, and a sealing cap is provided at the opening of the injection hole. The sealing cap is used to seal the injection hole after the injection is completed.

[0013] By adopting the above technical solution, the injection hole is a threaded hole, and the threaded cap is installed at the opening of the injection hole. The threaded cap further improves the sealing performance of the joint. The threaded hole structure ensures that the sealing cap and the injection hole are firmly connected, effectively preventing sealant leakage or intrusion of external impurities after injection. At the same time, the sealing cap is installed by screwing in the thread, which is simple to operate and can quickly seal the injection hole after injection, ensuring the long-term curing effect of the sealant.

[0014] Optionally, the inner sides of the crimping portions at both ends of the outer sleeve are coated with thread sealant.

[0015] By adopting the above technical solution, thread sealant is applied to the crimping parts at both ends of the outer sleeve. The thread sealant further improves the sealing performance of the joint. The thread sealant is uniformly filled with the tiny gap between the crimping part and the outer layer of the tube as the crimping part is radially compressed, forming a chemical sealing layer. This layer works in synergy with the mechanical crimping structure to effectively block the path of moisture or medium seeping in along the thread gap, reducing the risk of seal failure.

[0016] Optionally, the outer sleeve is made of a soft metal material.

[0017] By adopting the above technical solution, the outer sleeve is made of soft metal material; by selecting the material of the outer frame sleeve, soft metal has good ductility and plasticity, and can be uniformly deformed by radial compression during the crimping process, closely fitting the surface contour of the outer layer of the tube to form a mechanical locking structure.

[0018] Optionally, the clamping portions at both ends of the outer sleeve are radially compressed and deformed to form an integral sealing structure with the outer layer of the tube.

[0019] By adopting the above technical solution, the crimping parts at both ends of the outer sleeve form an integrated sealing structure with the outer layer of the tube through radial compression deformation; through the crimping method of the crimping parts, the integrated sealing structure forms a gapless mechanical lock with the outer surface of the tube through the plastic deformation of the metal material. Combined with the ductility of soft metal, it can adaptively compensate for tube processing errors or surface unevenness, ensuring that the sealing surface is continuous and defect-free, and blocking the path of water seepage along the contact surface.

[0020] Optionally, the intermediate connector includes a central connecting body and two connecting parts, with the two connecting parts symmetrically arranged on both sides of the central connecting body. The connecting parts are used to connect and press with the inner layer of the pipe body.

[0021] By adopting the above technical solution, the intermediate joint includes a central connecting body and two connecting parts; through the setting of the intermediate joint, the central connecting body serves as the centering support of the two pipes, ensuring uniform contact between the connecting parts and the inner layer of the pipe, concentrating the sealing function in the inner layer of the pipe, while the insulation layer is independently protected by the outer sleeve, realizing division of labor and cooperation, and ensuring sealing performance.

[0022] Optionally, the inner surface of the connecting part of the intermediate joint has a deep serrated structure to enhance the connection and sealing with the inner layer of the tube.

[0023] By adopting the above technical solution, the inner surface of the connecting part of the intermediate joint has a deep serrated structure. Through the setting of the inner surface of the connecting part, the sharp teeth of the deep serrated structure can form a mechanical interlocking effect, increase the contact area and frictional resistance, effectively prevent the pipe body from sliding relative to each other under fluid pressure or external vibration, and ensure the anti-slipping ability of the pipe body connection.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. By setting up intermediate joints, sealing plates, external sleeves, and glue-filled sealing cavities, the double sealing and reliable connection of the insulated flexible composite pipe joint are achieved. The intermediate joint directly connects to the inner layer of the pipe, and a mechanical interlock is formed through an internal expansion and external snapping process to ensure fluid sealing. The external sleeve is independently snapped onto the outer sheath of the insulation material. Combined with the chemical curing sealing of the glue-filled sealing cavity, it not only avoids the insulation layer from being crushed by direct force, but also blocks the path of water seepage. It effectively solves the problems of insulation layer failure caused by the locking force of traditional joints and the decline in insulation performance caused by water seepage. It improves the sealing reliability and insulation durability of the pipeline system in underwater and complex working conditions.

[0026] 2. By setting up injection holes and venting holes, efficient injection of sealant and venting of cavities are achieved. The injection holes position the injection path to ensure that the sealant is evenly filled into the injection sealing cavity between the outer sleeve and the intermediate joint. The venting holes simultaneously expel air from the cavity to avoid air bubbles. Combined with the negative pressure vacuum introduction method, the sealant, such as epoxy resin, can fully penetrate all gaps. After curing, it forms a defect-free continuous sealing layer, which improves the sealing performance of the joint, blocks the path of moisture infiltration, and extends the service life of the insulation layer.

[0027] 3. By setting the intermediate joint, the middle connector serves as the centering support for the two pipes, ensuring uniform contact between the connection and the inner layer of the pipe. The sealing function is concentrated in the inner layer of the pipe, while the insulation layer is independently protected by the outer sleeve. This division of labor and cooperation ensures the sealing performance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a special connector for insulating flexible composite pipe in an embodiment of this application.

[0029] Figure 2 This is a schematic diagram illustrating the structure of the sealing plate in the embodiments of this application.

[0030] Figure 3 This is a schematic diagram of the structure used for connecting the intermediate joint to the inner layer of the pipe in an embodiment of this application.

[0031] Figure 4 This is a structural schematic diagram illustrating the external sleeve structure in the embodiments of this application.

[0032] Explanation of reference numerals in the attached drawings: 1. Pipe body; 2. Intermediate joint; 21. Middle connecting body; 22. Connecting part; 3. Sealing plate; 4. Outer sleeve; 41. Crimping part; 5. Glue injection sealing cavity; 6. Glue injection hole; 7. Glue injection vent hole. Detailed Implementation

[0033] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0034] This application discloses a special connector for insulating flexible composite pipes. (Refer to...) Figure 1 The special connector for insulated flexible composite pipe includes an intermediate connector 2. In this embodiment, the intermediate connector 2 is used to connect the inner layers of two pipe bodies 1 that need to be connected. The end of the flexible composite pipe is cut into a double-step structure, which is divided into an inner layer and an outer layer. The inner layer pipe body 1 protrudes from the outer layer insulation material, and the length meets the connection requirements of the intermediate connector 2. The outer layer insulation material and sheath form a stepped transition with the inner layer step. Using hot melt glue or an extrusion hot melt glue gun, the end face of the insulation material is hot melt bonded to the plastic material of the outer sheath, ensuring that the plastic completely covers the end face of the insulation material. The bonded end face is sanded and smoothed, and heat shrink tape or heat shrink sleeve is wrapped to form a water-proof protective layer on the end face.

[0035] Reference Figure 1 and Figure 2 Each end of the pipe body 1 is equipped with a sealing plate 3. In this embodiment, the sealing plate 3 is an annular plate. The sealing plate 3 is sleeved on the inner layer of the pipe body 1 and located at the end of the outer layer of the pipe body 1.

[0036] Reference Figure 1 and Figure 3 Meanwhile, the intermediate joint 2 includes a central connecting body 21 and two connecting parts 22. The two connecting parts 22 are symmetrically installed on both sides of the central connecting body 21. The connecting body can be fixed to the central connecting body by welding. The connecting parts 22 are used to connect and press with the inner layer of the pipe body 1 to ensure uniform contact between the connecting parts 22 and the inner layer of the pipe body 1.

[0037] Reference Figure 1 and Figure 3 In this embodiment, the inner surface of the connecting part 22 of the indirect connector 2 has a deep serrated structure; the sharp teeth of the deep serrated structure can form a mechanical interlocking effect, increase the contact area and frictional resistance, effectively prevent the tube body 1 from sliding relative to each other under fluid pressure or external vibration, and ensure the anti-slipping ability of the tube body 1 connection.

[0038] Reference Figure 1 and Figure 4Both pipe bodies 1 are fitted with an outer sleeve 4, which is made of soft metal material. The outer sleeve 4 can be made of low carbon steel or stainless steel, such as Q235 steel, 316L, 2205 duplex steel, etc. In this embodiment, the sealing plate 3 and the intermediate joint 2 are arranged in the internal cavity of the outer sleeve 4. The outer sleeve 4 has a crimping part 41 formed at both ends for radially crimping the outer layer of the pipe body 1. The crimping part 41 at both ends of the outer sleeve 4 forms an integral sealing structure with the outer layer of the pipe body 1 through radial compression deformation. The integral sealing structure forms a gapless mechanical lock with the outer surface of the pipe body 1 through the plastic deformation of the metal material. With the ductility of the soft metal, it can adaptively compensate for the processing error or surface unevenness of the pipe body 1, ensuring that the sealing surface is continuous and defect-free, and blocking the path of water seepage along the contact surface.

[0039] Reference Figure 1 and Figure 4 The inner sides of the crimping parts 41 at both ends of the outer sleeve 4 are coated with thread sealant; the thread sealant further improves the sealing performance of the joint. The thread sealant is evenly filled with the tiny gap between the crimping part 41 and the outer layer of the pipe body 1 as the crimping part 41 is radially compressed, forming a chemical sealing layer. It works in synergy with the mechanical crimping structure to effectively block the path of water or medium to seep in along the thread gap and reduce the risk of seal failure.

[0040] Reference Figure 1 A sealant injection cavity 5 is formed between the inner wall of the outer sleeve 4 and the outer wall of the intermediate joint 2. A sealant injection hole 6 is provided through the sleeve wall of the outer sleeve 4 for injecting sealant into the sealant injection cavity 5. A sealant venting hole 7 is also provided through the sleeve wall of the outer sleeve 4. Both the sealant venting hole 7 and the sealant injection hole 6 are connected to the sealant injection cavity 5. In this embodiment, there is at least one sealant injection hole 6 and one sealant venting hole 7, preferably two sealant injection holes 6 and two sealant venting holes 7. This achieves efficient sealant injection and cavity venting. The injection hole 6 positions the injection path, ensuring that the sealant evenly fills the injection sealing cavity 5 between the outer sleeve 4 and the intermediate joint 2. The injection vent hole 7 simultaneously vents air from the cavity to avoid air bubbles. Combined with the negative pressure vacuum introduction method, the sealant, such as epoxy resin, fully penetrates all gaps. In this embodiment, the viscosity of the epoxy resin is required to be between 100-1000 cp centipoise, and the curing exothermic peak of the epoxy resin should be below 120°C. After curing, a defect-free continuous sealing layer is formed, which improves the sealing performance of the joint, blocks the path of moisture penetration, and extends the service life of the insulation layer.

[0041] Reference Figure 1The injection hole 6 is a threaded hole, and a sealing cap is installed at the opening of the injection hole 6. The sealing cap is used to seal the injection hole 6 after the injection is completed. At the same time, in this embodiment, the injection vent hole 7 can also be sealed by the sealing cap. The threaded cap further improves the sealing performance of the joint. The threaded hole structure ensures that the sealing cap and the injection hole 6 are firmly connected, effectively preventing the sealant from leaking or external impurities from entering after the injection. At the same time, the sealing cap is installed by screwing in the thread, which is simple to operate and can quickly seal the injection hole 6 after the injection is completed, ensuring the long-term curing effect of the sealant.

[0042] The implementation principle of a special connector for insulated flexible composite pipes in this application embodiment is as follows: When sealing the composite pipe, the intermediate connector 2 is inserted into the inner layer of the pipe body 1, ensuring that its connecting part 22 is aligned with the inner layer of the pipe body 1. The inner layer of the pipe body 1 is axially stretched by the inner expansion mold, while the connecting part 22 of the intermediate connector 2 is axially squeezed by the outer buckling mold, so that the deep serrated structure forms a mechanical engagement with the inner layer of the pipe body 1, achieving fluid sealing. Then, the soft metal outer buckling sleeve 4 is inserted into the outer layer of the pipe body 1 and pulled to one side to leave operating space. If the intermediate connector 2 includes a flange or an integrated connection mechanism, the outer buckling sleeve 4 needs to be inserted into the pipe body in advance. 1. Move the sleeve to a non-interference position and apply thread sealant evenly to the inner side of the crimping part 41 at both ends of the outer sleeve 4 to enhance the sealing of subsequent crimping. Then move the outer sleeve 4 to the outer layer of the tube body 1 and use a tube shrinking machine to radially compress the crimping part 41 at both ends of the outer sleeve 4 so that it fits tightly with the outer surface of the outer layer of the tube body 1 to form a mechanical lock. Inject two-component sealant through the injection hole 6 on the outer sleeve 4 and at the same time expel the air in the cavity through the vent hole. Use the negative pressure vacuum introduction method to ensure that the sealant is filled evenly. After the sealant has completely cured, screw the sealing cap into the injection hole 6 to complete the final seal.

[0043] By setting up intermediate joint 2, sealing plate 3, outer sleeve 4 and glue injection sealing cavity 5, the double sealing and reliable connection of the insulated flexible composite pipe joint are achieved. Among them, intermediate joint 2 is directly connected to the inner layer of pipe body 1, and mechanical interlocking is formed through internal expansion and external snapping process to ensure fluid sealing. The outer sleeve 4 is independently snapped onto the outer sheath of the insulation material. Combined with the chemical curing seal of glue injection sealing cavity 5, it not only avoids the insulation layer from being crushed by direct force, but also blocks the water seepage path. It effectively solves the problem of insulation layer failure caused by the locking force of traditional joints and the decline in insulation performance caused by water seepage. It improves the sealing reliability and insulation durability of the pipeline system in underwater and complex working conditions.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A special connector for insulated flexible composite pipes, comprising an intermediate connector for connecting the inner layers of two pipes, characterized in that: The ends of the tubes are provided with sealing plates, and the outer layers of the two tubes are jointly fitted with an outer buckling sleeve. The sealing plates and the intermediate joint are arranged in the inner cavity of the outer buckling sleeve. An injection sealing cavity is formed between the inner wall of the outer buckling sleeve and the outer wall of the intermediate joint. Both ends of the outer buckling sleeve are provided with buckling parts for radially buckling the outer layers of the tubes.

2. The special connector for insulated flexible composite pipe according to claim 1, characterized in that: The outer sleeve has at least one injection hole on its cylindrical wall, which is used to inject sealant into the sealant injection cavity. The outer sleeve also has an injection vent hole on its cylindrical wall.

3. The special connector for insulated flexible composite pipe according to claim 2, characterized in that: The injection hole is a threaded hole, and a sealing cap is provided at the opening of the injection hole. The sealing cap is used to seal the injection hole after the injection is completed.

4. The special connector for insulated flexible composite pipe according to claim 1, characterized in that: The inner sides of the snapping portions at both ends of the outer sleeve are coated with thread sealant.

5. A special connector for insulating flexible composite pipes according to claim 1, characterized in that: The outer sleeve is made of soft metal material.

6. A special connector for insulating flexible composite pipes according to claim 5, characterized in that: The clamping portions at both ends of the outer sleeve are radially compressed and deformed to form an integral sealing structure with the outer layer of the tube.

7. A special connector for insulating flexible composite pipes according to claim 1, characterized in that: The intermediate connector includes a central connecting body and two connecting parts. The two connecting parts are symmetrically arranged on both sides of the central connecting body. The connecting parts are used to connect and press with the inner layer of the pipe body.

8. A special connector for insulating flexible composite pipes according to claim 7, characterized in that: The inner surface of the connecting part of the intermediate joint has a deep serrated structure to enhance the sealing performance of the connection with the inner layer of the tube.

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