High density polyethylene seamless electrofusion sleeve

Abstract

The utility model provides high density polyethylene seamless electric heat melting sleeve relates to electric heat melting sleeve technical field, including the outer protective tube, both ends of outer protective tube all are set up with first embedded groove and second embedded groove, first embedded groove is located the outside of second embedded groove, and the inside of first embedded groove is embedded with second nickel chromium alloy electric heat melting net, the inside of second embedded groove is embedded with first nickel chromium alloy electric heat melting net, the outside of outer protective tube is equipped with the reinforcing structure for improving the physical mechanics performance and the anti -underground complex environment damage ability of outer protective tube, compared with prior art, the utility model is equipped with reinforcing structure, can play the structure closed loop formation systematic protection to outer protective tube outside layer protection, middle layer support, interlayer buffer, effectively improved single high density polyethylene outer protective tube anti -aging and the weak defect of corrosion resistance ability, delays the outer protective tube performance recession from the source, prolongs overall structure use time.

Description

Technical Field

[0001] This utility model relates to the field of electrothermal welding sleeve technology, and in particular to high-density polyethylene seamless electrothermal welding sleeve. Background Technology

[0002] In the field of pipeline engineering, especially in scenarios such as underground pipe networks and oil and gas transmission pipelines, the sealing performance and thermal insulation effect of pipeline interfaces directly determine the long-term operational stability of the system. High-density polyethylene electrofusion sleeves, as key components for pipeline interface connection and protection, have always been a key focus of industry research and development.

[0003] Application No. 202123011015.2 discloses a high-density polyethylene seamless electrofusion sleeve. This sleeve, by incorporating dual-circuit nickel-chromium alloy electrofusion wires at both ends of the outer protective tube, further enhances the connection reliability and sealing performance of the field interface, effectively achieving the technical objectives of preventing groundwater infiltration and protecting the insulation layer. However, the outer protective tube is made solely of high-density polyethylene. While this material possesses certain corrosion resistance and insulation properties, its long-term anti-aging and impact resistance are relatively weak. In underground environments, it is susceptible to erosion from temperature cycles (such as alternating high temperatures in summer and low temperatures in winter) and corrosive substances produced by soil microbial metabolism. The outer protective pipe is prone to gradual aging and degradation, resulting in surface cracking and reduced structural strength, which in turn leads to the loss of its protective function for pipe joints and insulation layers. At the same time, the fused mesh embedded inside the outer protective pipe is a key connection and reinforcement component. When underground soil subsides, it is prone to breakage due to local stress concentration caused by soil displacement. Once the fused mesh breaks, not only will the electrothermal fused sleeve connection function fail, but subsequent secondary maintenance of the pipe joints will also lose its operational basis. The protective performance cannot be restored through conventional repair methods, which may ultimately lead to serious engineering problems such as pipe joint leakage and insulation layer damage, thus restricting the long-term stable application of this product in complex underground environments. Utility Model Content

[0004] To address the shortcomings of the existing technology, this utility model proposes a high-density polyethylene seamless electrothermal fusion sleeve.

[0005] The technical solution of this utility model is implemented as follows:

[0006] A high-density polyethylene seamless electrofusion sleeve includes an outer protective tube. Both ends of the outer protective tube are provided with a first groove and a second groove. The first groove is located outside the second groove, and a second nickel-chromium alloy electrofusion mesh is embedded inside the first groove. A first nickel-chromium alloy electrofusion mesh is embedded inside the second groove. The outer side of the outer protective tube is provided with a reinforcing structure to improve the physical and mechanical properties of the outer protective tube and its resistance to damage from complex underground environments. The inner side of the outer protective tube is provided with a self-healing anti-corrosion component to achieve active repair and double sealing protection for minor damage to the outer protective tube.

[0007] Preferably, the reinforcing structure includes a buffer composite transition layer sleeved on the outer wall of the outer protective tube, a glass fiber reinforced load-bearing layer on the outside of the buffer composite transition layer, and an anti-corrosion and wear-resistant composite layer on the outside of the glass fiber reinforced load-bearing layer.

[0008] Preferably, the outer outer wall of the outer protective tube has a placement groove, and two conductive copper wires are symmetrically connected inside the placement groove, with an insulating pad connecting the two conductive copper wires.

[0009] Preferably, both of the conductive copper wires are covered with protective sleeves, and the opening of the placement groove is covered with a protective cover.

[0010] Preferably, the outer wall of the reinforced structure has a groove, which is located on the outside of the protective cover.

[0011] Preferably, the self-healing corrosion protection component includes multiple capsule slots formed on the inner surface of the outer protective tube, with microcapsules embedded inside the multiple capsule slots, and the microcapsules being encapsulated with epoxy resin adhesive.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. In use, this utility model, by setting a reinforcing structure on the outside of the outer protective pipe, forms a closed-loop structure that provides outer protection, middle support, and interlayer buffering, effectively improving the weak aging and corrosion resistance of a single high-density polyethylene outer protective pipe. This delays the performance degradation of the outer protective pipe from the source, extending the overall structural lifespan. Simultaneously, it significantly improves the outer protective pipe's resistance to soil static pressure and construction machinery impact, preventing pipe deformation and cracking after burial. It indirectly provides stable support for the internal fused mesh, reducing the risk of mesh breakage, and also mitigates interlayer modulus differences, absorbing... The interface stress is reduced to prevent interlayer delamination and ensure structural integrity. At the same time, the synergistic effect of the three factors significantly enhances the physical and mechanical properties and resistance to environmental damage of the outer protective pipe, making up for the performance shortcomings of traditional outer protective pipes in complex underground environments, ensuring the long-term stability of the overall structure, providing a stable embedding carrier for the inner thermal fusion components, ensuring heating uniformity and sealing reliability during pipe connection, reducing the risk of groundwater infiltration and insulation layer damage, and ultimately expanding the application scenarios of the electrothermal fusion sleeve from ordinary soil to complex environments such as saline-alkali land and gravel layers, greatly extending service life and reducing later maintenance costs and safety hazards.

[0014] 2. In use, this utility model, by setting a self-healing anti-corrosion component in the inner layer of the outer protective pipe, can achieve active repair and dual-sealing synergistic protection of the outer protective pipe, effectively addressing the shortcomings of traditional outer protective pipes, which are weak in long-term anti-aging and impact resistance due to their single material, are prone to cracking, and offer passive protection. It can autonomously repair minor cracks in the outer protective pipe that appear during buried service without human intervention, quickly filling the cracks to prevent damage from spreading and avoiding a decrease in the structural strength of the outer protective pipe, while maintaining the integrity of the outer protective pipe to protect the inner insulation layer. Furthermore, it can utilize the physical sealing of the water-swellable material on the outer layer of the microcapsule and the chemical reinforcement of the internal epoxy resin adhesive after curing to form a dual protection system, effectively preventing groundwater infiltration. This design breaks through the limitations of traditional passive protection of outer protective pipes, significantly reducing the risks of water ingress into the insulation layer and accelerated pipe corrosion, reducing the frequency and cost of subsequent manual maintenance, extending the service life of the outer protective pipe and the entire electrothermal fusion sleeve, and further improving its applicability and reliability in complex underground environments. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is an enlarged schematic diagram of the reinforcing structure of this utility model;

[0018] Figure 3 This is a cross-sectional view of the outer protective tube of this utility model;

[0019] Figure 4 This is an enlarged schematic diagram showing the connection between the protective cover and the placement groove of this utility model;

[0020] Figure 5 This is an enlarged schematic diagram of the self-healing corrosion-resistant component of this utility model.

[0021] In the diagram: 1. Outer protective tube; 2. First groove; 3. Second groove; 4. First nickel-chromium alloy electrofusion mesh; 5. Second nickel-chromium alloy electrofusion mesh; 6. Reinforced structure; 61. Buffer composite transition layer; 62. Glass fiber reinforced load-bearing layer; 63. Corrosion-resistant and wear-resistant composite layer; 7. Groove; 8. Self-healing anti-corrosion component; 81. Capsule groove; 82. Microcapsule; 83. Epoxy resin adhesive; 9. Placement groove; 10. Conductive copper wire; 11. Insulating gasket; 12. Protective sleeve; 13. Protective cover. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] like Figures 1-4As shown, the high-density polyethylene seamless electrofusion sleeve includes an outer protective tube 1. This outer protective tube 1 is a closed-loop seamless structure manufactured using a continuous extrusion process, fundamentally avoiding the transverse lap weld defects caused by traditional coil production, providing a stable foundation for pipe joint protection. Both ends of the outer protective tube 1 are correspondingly provided with a first groove 2 and a second groove 3 for embedding the electrofusion assembly. The first groove 2 is located outside the second groove 3, and a second nickel-chromium alloy electrofusion mesh 5 is embedded inside the first groove 2. The second groove 3 is embedded inside the second groove 3 with a first nickel-chromium alloy electrofusion mesh 4. The double-layered mesh, through a reasonable spacing arrangement, can achieve uniform heat transfer during electrofusion, enhancing the weld seal of the pipe joint and preventing localized melting. To address leakage issues caused by insufficient connection, the outer protective tube 1 has a groove 9 on its outer wall for accommodating electrical connection components. The position of the groove 9 corresponds to the conductive ends of the fused mesh embedded in the grooves at both ends. Two conductive copper wires 10 are symmetrically connected inside the groove. One end of each conductive copper wire 10 is reliably connected to the conductive ends of the first nickel-chromium alloy electrothermal fused mesh 4 and the second nickel-chromium alloy electrothermal fused mesh 5, respectively, while the other end is reserved as an external power interface. At the same time, an insulating gasket 11 is fixedly connected between the two conductive copper wires 10. The insulating gasket 11 is made of high-temperature resistant insulating material, which can effectively separate the two conductive copper wires 10, prevent short circuits caused by contact of copper wires during power-on, and ensure the safe operation of the electrothermal fused sleeve electrical system.

[0024] Furthermore, protective sleeves 12 are fitted over the two conductive copper wires 10, and a protective cover 13 is provided over the opening of the placement groove 9.

[0025] In use, an insulating protective sleeve 12 made of polytetrafluoroethylene is fitted over the surface of the conductive copper wire 10, covering the non-connected areas of the conductive copper wire 10, leaving only the ends connected to the fusion mesh and externally exposed. This achieves full insulation protection for the non-connected sections of the conductive copper wire 10, preventing dust and moisture in the construction environment from contacting the copper wire and fundamentally avoiding the risk of electric shock from accidental contact with conductive parts by operators during construction. Simultaneously, a protective cover 13 made of high-temperature resistant silicone rubber is fitted over the placement groove 9 using a screw and snap-fit ​​structure. This cover 13 completely covers the conductive copper wire 10 and the connection points of all components within the placement groove 9, leaving only the necessary interfaces for power supply. This utilizes the excellent high-temperature resistance of silicone rubber. The protective sleeve 12 is designed to withstand the high temperatures generated during the hot-melt process to prevent deformation and failure of the protective structure. It also effectively isolates underground soil, moisture, impurities, and conductive areas from direct contact, thus preventing short circuits caused by external contaminants from the source. These two protective measures work synergistically. The protective sleeve 12 focuses on the basic insulation and protection against electric shock of the non-connecting section of the conductive copper wire 10, while the protective cover 13 enhances the high-temperature adaptability and contaminant isolation capability of the docking area. The two complement each other and provide layer-by-layer protection. This not only specifically solves the problems of single insulation protection and the risk of electric shock or short circuits caused by exposed conductive areas in traditional electrofusion sleeves, but also significantly improves the insulation reliability of electrofusion sleeves in complex underground construction environments, providing double safety guarantees for on-site energized hot-melt operations.

[0026] refer to Figure 1 and Figure 2 As shown, the outer side of the outer protective pipe 1 is provided with a reinforcing structure 6, which is used to improve the physical and mechanical properties of the outer protective pipe 1 and its ability to resist damage from complex underground environments.

[0027] The reinforced structure 6 includes a buffer composite transition layer 61 sleeved on the outer wall of the outer protective tube 1, a glass fiber reinforced bearing layer 62 on the outside of the buffer composite transition layer 61, and an anti-corrosion and wear-resistant composite layer 63 on the outside of the glass fiber reinforced bearing layer 62.

[0028] The outer wall of the reinforced structure 6 is provided with a groove 7. The groove 7 is located on the outside of the protective cover 13. The groove 7 can not only assist in positioning and operation during construction and reserve deformation space for the reinforced structure 6, but also guide the discharge of accumulated water and impurities to help improve the sealing effect of the protective cover 13 and ensure the overall stability and safety of the electrothermal fusion sleeve.

[0029] Through the above technical solution:

[0030] In use, a reinforced structure 6 is provided on the outside of the outer protective pipe 1, consisting of a buffer composite transition layer 61, a glass fiber reinforced load-bearing layer 62, and an anti-corrosion and wear-resistant composite layer 63. This structure forms a systematic protection through a closed-loop structure of outer protection, middle support, and interlayer buffer. The outermost anti-corrosion and wear-resistant composite layer 63 can resist sand and gravel friction and corrosive media erosion, preventing wear and aging of the outer protective pipe 1 and improving the defects of weak anti-aging and anti-corrosion of single materials. The middle glass fiber reinforced load-bearing layer 62 relies on its high strength characteristics to improve the outer protective pipe 1's resistance to soil pressure and impact, prevent pipe deformation and cracking, and reduce internal stress. The risk of fusion mesh breakage is mitigated; the buffer composite transition layer 61 resolves the difference in modulus between layers and absorbs interfacial stress to avoid interlayer delamination. Through the synergistic effect of the three, the physical and mechanical properties and environmental resistance of the outer protective pipe 1 are enhanced, making up for the shortcomings of the traditional outer protective pipe 1 in complex environments. It also ensures the long-term stability of the overall structure, provides a stable carrier for the inner thermal fusion components, ensures uniform heating and reliable sealing of the pipeline connection, reduces the risk of groundwater infiltration and damage to the insulation layer, and ultimately expands the application scenarios of the electrothermal fusion sleeve to complex environments such as saline-alkali land and gravel layers, extending service life and reducing later maintenance costs and safety hazards.

[0031] Additionally, refer to Figure 3 and Figure 5 As shown, the inner side of the outer protective tube 1 is provided with a self-healing anti-corrosion component 8, which is used to actively repair minor damage to the outer protective tube 1 and provide double sealing protection.

[0032] The self-healing corrosion protection component 8 includes multiple capsule slots 81 formed on the inner surface of the outer protective tube 1, with microcapsules 82 embedded inside the multiple capsule slots 81, and epoxy resin adhesive 83 encapsulated inside the microcapsules 82.

[0033] Through the above technical solution:

[0034] In use, microcapsules 82 containing epoxy resin adhesive 83 are evenly distributed and encapsulated in the inner layer of the outer protective pipe 1, and the outer layer of the microcapsules 82 is made of a water-swellable material. This structure can achieve active repair and dual sealing synergistic protection of the outer protective pipe 1, addressing the shortcomings of traditional outer protective pipe 1, which has weak long-term anti-aging and impact resistance due to its single material, is prone to cracking due to soil corrosion, sand and gravel impact or stress, and can only passively resist damage. When a small crack appears in the outer protective pipe 1, the microcapsules 82 rupture and release epoxy resin adhesive 83, which cures to form a repair layer to fill the crack and protect the insulation layer. The water-swellable material on the outer layer simultaneously seals the crack, forming a dual physical and chemical protection. This design breaks through the limitations of traditional passive protection, realizes autonomous repair of minor damage, reduces the risk of water ingress into the insulation layer and pipe corrosion, reduces later maintenance costs, extends the service life of the outer protective pipe 1 and the electrothermal fusion sleeve, and improves its applicability and reliability in complex underground environments.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-density polyethylene seamless electrothermal fusion sleeve, characterized in that: The outer protective tube (1) includes a first groove (2) and a second groove (3) at both ends. The first groove (2) is located outside the second groove (3), and a second nickel-chromium alloy electrothermal mesh (5) is embedded inside the first groove (2). A first nickel-chromium alloy electrothermal mesh (4) is embedded inside the second groove (3). The outer protective tube (1) has a reinforcing structure (6) on its outer side to improve the physical and mechanical properties of the outer protective tube (1) and its resistance to damage from complex underground environments. The inner side of the outer protective tube (1) has a self-healing anti-corrosion component (8) to achieve active repair and double sealing protection of minor damage to the outer protective tube (1).

2. The high-density polyethylene seamless electrothermal sleeve according to claim 1, characterized in that: The reinforced structure (6) includes a buffer composite transition layer (61) sleeved on the outer wall of the outer protective tube (1), a glass fiber reinforced bearing layer (62) is provided on the outside of the buffer composite transition layer (61), and an anti-corrosion and wear-resistant composite layer (63) is provided on the outside of the glass fiber reinforced bearing layer (62).

3. The high-density polyethylene seamless electrothermal sleeve according to claim 1, characterized in that: The outer protective tube (1) has a placement groove (9) on its outer wall. Two conductive copper wires (10) are symmetrically connected inside the placement groove (9), and an insulating pad (11) is connected between the two conductive copper wires (10).

4. The high-density polyethylene seamless electrothermal sleeve according to claim 3, characterized in that: The two conductive copper wires (10) are each covered with a protective sleeve (12), and the opening of the placement groove (9) is covered with a protective cover (13).

5. The high-density polyethylene seamless electrothermal sleeve according to claim 4, characterized in that: The outer wall of the reinforced structure (6) is provided with a groove (7), which is located on the outside of the protective cover (13).

6. The high-density polyethylene seamless electrothermal sleeve according to claim 1, characterized in that: The self-healing corrosion protection component (8) includes a plurality of capsule slots (81) formed on the inner surface of the outer protective tube (1), and microcapsules (82) are embedded inside the plurality of capsule slots (81), and epoxy resin adhesive (83) is encapsulated inside the microcapsules (82).

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