Thermal insulation pipe of prefabricated optical fiber and manufacturing method

Abstract

The invention discloses a prefabricated optical fiber thermal insulation pipe and a manufacturing method, the prefabricated optical fiber thermal insulation pipe comprises a working steel pipe arranged at the core part of the thermal insulation pipe, the outer side of the working steel pipe is provided with an outer protection pipe, the diameter of the outer protection pipe is greater than that of the working steel pipe, so that an interlayer gap is formed between the outer protection pipe and the working steel pipe; an interlayer gap is formed in the working steel pipe, a threading pipe is arranged in the interlayer gap, optical fibers are arranged in the threading pipe, the threading pipe is fixed through a fixing device, the fixing device is fixedly arranged on the outer side wall of the working steel pipe, and a foaming tool is further arranged in the interlayer gap. The problem that the thermal insulation performance of the heat supply pipeline cannot be accurately monitored is solved, and the problems that the thermal insulation pipe and the optical fiber are not laid synchronously, the optical fiber laid outside the thermal insulation pipe is prone to being damaged during pipe ditch backfilling, and the monitoring effect is inaccurate due to the fact that the optical fiber is prone to being influenced by cushion layer water seepage and other factors are solved.

Description

Technical Field

[0001] This invention belongs to the field of heating pipe technology, specifically relating to a pre-insulated pipe with pre-fabricated optical fibers and its manufacturing method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the explosive growth in heating demand in cold regions, the heat loss problem caused by the aging and outdated technology of old heating pipelines has become increasingly prominent. In addition, there is a large gap in heating coverage in new areas, creating an urgent need for large-scale construction of long-distance heating pipelines.

[0004] Long-distance pipelines face several challenges during extended operation: harsh natural environments continuously erode the pipelines; external factors such as third-party construction and geological subsidence can also easily cause pipeline damage or aging. When these problems occur, not only does it lead to a significant reduction in heating efficiency and substantial heat loss, but it also significantly increases pipeline operation and maintenance costs, severely impacting the economic benefits and energy transmission stability of centralized heating systems, and hindering accurate monitoring of the insulation performance of new heating pipelines. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a pre-insulated pipe with pre-fabricated optical fibers and a manufacturing method thereof. This solves the issues of inability to accurately monitor the insulation performance of heating pipelines, and addresses the problems of asynchronous laying of the insulation pipe and optical fiber, as well as the ease with which laying optical fibers outside the insulation pipe can cause damage during trench backfilling, and the inaccurate monitoring results due to water seepage from the underlayment and other factors.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a pre-fabricated optical fiber insulation pipe, comprising: a working steel pipe disposed in the core of the insulation pipe, an outer protective pipe disposed on the outside of the working steel pipe, the diameter of the outer protective pipe being larger than the diameter of the working steel pipe, thereby forming an interlayer gap between the outer protective pipe and the working steel pipe; a threading pipe disposed in the interlayer gap, an optical fiber disposed in the threading pipe, the threading pipe being fixed by a fixing device, the fixing device being fixedly disposed on the outer side wall of the working steel pipe, and a foaming fixture disposed in the interlayer gap.

[0007] As a further implementation, the fixing device is a fixing bracket or a conduit clamp. The fixing bracket is used to directly fix the conduit onto the working steel pipe, and the conduit clamp fixes the conduit by pre-tightening it.

[0008] As a further implementation, the fixing bracket is a fixing slot bracket or a quick-fixing buckle; the fixing slot bracket includes a conduit slot, a base and a fixing hole; the conduit slot is disposed above the base, the fixing hole is disposed at the lower part of the base, and the base is disposed on the outer wall of the working steel pipe through the fixing hole.

[0009] As a further implementation, the conduit clamp includes a conduit clamp, a pre-tightening spring, and a pipe end fixing clamp; there are two pipe end fixing clamps, which are respectively disposed at both ends of the working steel pipe; one end of the pre-tightening spring is connected to the pipe end fixing clamp, and the other end is connected to the conduit clamp; the conduit clamp is used to clamp the conduit and pre-tighten it by means of the pre-tightening spring.

[0010] As a further implementation, the quick-fixing buckle includes a buckle groove and a screw hole, the screw hole being located at the bottom of the buckle groove and fixed to the outer wall of the working steel pipe by a wooden bracket.

[0011] As a further implementation, there are four pre-tension springs and two pipe-end fixing clamps; each pipe-end fixing clamp consists of two clamping blocks, one end of which is connected by an elastic material, and the other end is provided with a fastener for clamping the two clamping blocks. Each of the two clamping blocks has a semi-circular groove on its opposite side for placing the conduit; each pre-tension spring is fixedly connected to one of the clamping blocks.

[0012] As a further implementation, multiple fixed slot brackets or quick-fixing buckles are provided and are arranged at equal intervals on the outer side wall of the working steel pipe, for the purpose of neatly fixing the conduit to the working steel pipe.

[0013] As a further implementation, the conduit is composed of multiple sections spliced ​​together, and a connector is provided between two adjacent conduit sections. The connector is a straight connector or a plug connector. The straight connector is cylindrical, and two adjacent conduit sections are directly inserted into the straight connector for connection.

[0014] As a further implementation, the connector consists of a socket and a plug, with a bevel at the connection between the socket and the plug to reduce the resistance of threading. The socket is connected to the outer wall of the conduit, and the plug is connected to the inner wall of the conduit.

[0015] Secondly, the present invention also provides a method for manufacturing a pre-fabricated optical fiber insulation tube, comprising the following steps: S1. If a fixed bracket is used to fix the conduit, mark the installation position of the fixed bracket on the outer wall of the working steel pipe, and ensure that multiple brackets are arranged at equal intervals. Install and fix the fixed bracket on the outer wall of the working steel pipe through the fixing holes at the bottom of the base; or install and fix the quick-fixing buckle on the outer wall of the working steel pipe with screws. If conduit clamps are used, install pipe end fixing clamps at both ends of the working steel pipe. First, connect the two clamp blocks to the pipe end fixing clamps through the pre-tightening spring to prepare for the subsequent installation and pre-tightening of the conduit. S2. If a direct connector is used, insert the ends of two adjacent conduit sections directly into the round tube-shaped direct connector; if a plug connector is used, connect the socket to the outer wall of one conduit section and the plug to the inner wall of the other conduit section. S3. Place the assembled conduit into the conduit slot of the fixed slot bracket to fix the conduit on the working steel pipe through the slot. When using conduit clamps, place the conduit in the semi-circular groove of the conduit opening clamp, clamp the conduit with fasteners, and pre-tighten the conduit with a pre-tensioning spring. S4. Place the outer protective tube over the outside of the working steel pipe to form a predetermined interlayer gap between the outer protective tube and the working steel pipe. Use a foaming tool to foam the interlayer gap to fill it with thermal insulation foam material. After the foam material has solidified, the prefabricated fiber optic insulation pipe is completed.

[0016] Compared with the prior art, the advantages and positive effects of this invention are: This invention utilizes a conduit made of carbon nanotubes or graphene-modified plastic tubing embedded in the interlayer gap, with built-in optical fiber. Leveraging the high thermal conductivity of the fiber, it enables rapid and accurate monitoring of the operating status of the insulated pipe, allowing for timely detection of pipe damage, abnormal temperatures, and other issues. A fixing device securely installs the conduit on the outer wall of the working steel pipe, ensuring its stability under complex operating conditions and preventing inaccurate fiber optic monitoring due to displacement. A foaming fixture, combined with subsequent foaming treatment, forms a highly efficient insulation layer in the interlayer gap, significantly reducing heat loss, improving media transport efficiency, reducing energy waste, and meeting the energy-saving and consumption-reducing requirements of centralized heating systems. Simultaneously, it solves the problems of lagging monitoring and poor insulation performance of traditional insulated pipes, as well as the issues of asynchronous installation of the insulated pipe and optical fiber, the potential for damage during trench backfilling when laying optical fiber outside the insulated pipe, and the susceptibility to water seepage from the bedding layer and other factors leading to inaccurate monitoring results.

[0017] This invention provides two fixing devices: a fixed bracket and a conduit clamp, increasing the flexibility of conduit fixing methods. The fixed bracket provides stable direct support for the conduit, suitable for conventional installation scenarios. The conduit clamp, fixed by pre-tightening, allows adjustment of the clamping force according to actual working conditions, ensuring conduit stability even under complex conditions such as pipeline vibration and changes in medium flow velocity, meeting different installation scenarios and engineering needs, and guaranteeing the stable operation of the fiber optic monitoring system. The conduit slot of the fixed bracket is adapted to the conduit, tightly securing it and effectively limiting its horizontal displacement. The base is firmly connected to the working steel pipe through fixing holes and connectors, ensuring stable and reliable conduit installation. This structure facilitates the installation and disassembly of the conduit, simplifying later maintenance and repair, while ensuring the stability of the conduit's position, providing a reliable foundation for fiber optic monitoring and ensuring that the fiber optic cable can accurately sense the pipeline's operating status.

[0018] The pre-tensioning spring in the conduit clamp of this invention provides continuous clamping force, and the clamping force can be adjusted according to actual needs to achieve adjustable fixation of the conduit. The pipe end fixing clamp, in conjunction with the pre-tensioning spring and the conduit clamp, not only firmly fixes the conduit but also ensures its straightness, making it particularly suitable for longer, fixed-length insulation pipes. When the insulation pipe is long, a hydraulic or screw device can be used to enhance the fixing effect. During the foaming process, it prevents the conduit from shifting or loosening due to abnormal local stress, ensuring the stability of the conduit during long-distance laying and guaranteeing the accuracy and reliability of fiber optic monitoring. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a radial cross-sectional view of the insulation pipe of the present invention; Figure 2 This is a structural diagram of the fixing slot bracket of the present invention; Figure 3 This is a diagram of the quick-fixing buckle structure of the present invention; Figure 4 This is a structural diagram of the direct header interface of the present invention; Figure 5 This is a diagram showing the installation structure of the conduit clamp of the present invention; Figure 6 This is a diagram showing the installation structure of the connector of the present invention.

[0021] In the diagram: 1. Outer protective tube; 2. Foaming fixture; 3. Working steel pipe; 4. Conduit; 5. Base; 6. Conduit slot; 7. Fixing hole; 8. Clip slot; 9. Screw hole; 10. Straight head; 11. Pipe end clamp; 12. Conduit clamp; 13. Preload spring; 14. Socket; 15. Spigot. Detailed Implementation

[0022] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. Example 1 This embodiment discloses a pre-fabricated optical fiber insulation pipe, such as... Figures 1-6 As shown, it includes: a working steel pipe 3 disposed in the core of the insulation pipe, an outer protective pipe 1 disposed on the outside of the working steel pipe 3, the diameter of the outer protective pipe 1 being larger than the diameter of the working steel pipe 3, so that an interlayer gap is formed between the outer protective pipe 1 and the working steel pipe 3; a conduit 4 disposed in the interlayer gap, an optical fiber disposed in the conduit 4, the conduit 4 being a plastic pipe made of carbon nanotubes or other graphene modified formula, having a high thermal conductivity, facilitating rapid optical fiber response, the conduit 4 being fixed by a fixing device, the fixing device being fixedly disposed on the outer wall of the working steel pipe 3, ensuring the stable position of the conduit 4 in the interlayer gap, and preventing its displacement due to medium flow or external force; a foaming fixture 2 is also disposed in the interlayer gap. Fiber optics are used to achieve rapid and accurate monitoring of the operating status of the insulation pipe; the fixing device ensures the stability of the conduit 4, providing a guarantee for the accuracy of fiber optic monitoring; the foaming fixture 2, in conjunction with subsequent foaming treatment, gives the insulation pipe good insulation performance, solving the problem that traditional insulation pipes cannot quickly and accurately monitor their internal operating status. At the same time, it ensures the stability of each component and good insulation performance during use, avoiding energy waste and reduced media transport efficiency caused by heat loss.

[0024] As a further implementation, the fixing device is either a fixing bracket or a pipe clamp for the conduit 4. The fixing bracket is used to directly fix the conduit 4 to the working steel pipe 3, while the pipe clamp for the conduit 4 fixes the conduit 4 by pre-tightening it. Specifically, different forms of fixing devices provide diverse options for fixing the conduit 4 to adapt to different installation scenarios and needs. The function of the fixing bracket is to directly fix the conduit 4 to the working steel pipe 3, providing reliable support for the conduit 4 through a stable connection with the working steel pipe 3. The pipe clamp for the conduit 4 achieves fixation by pre-tightening the conduit 4, which allows adjustment of the fixing force according to the actual situation, enhancing the fixing effect.

[0025] As a further implementation, the fixing bracket is a fixing slot bracket or a quick-fixing buckle; the fixing slot bracket includes a conduit slot 6, a base 5, and a fixing hole 7; the conduit slot 6 is located above the base 5 and is adapted to the conduit 4, which can tightly lock the conduit 4 and prevent the conduit 4 from moving in the horizontal direction; the fixing hole 7 is located at the lower part of the base 5, and the base 5 is fixed to the outer wall of the working steel pipe 3 through the fixing hole 7 and in conjunction with the connector, effectively limiting the displacement of the conduit 4, ensuring the stable installation of the conduit 4 on the working steel pipe 3, and thus ensuring the normal operation of the fiber optic monitoring system.

[0026] As a further implementation, the conduit 4 clamp includes a conduit clamp 12, a pre-tightening spring 13, and a pipe end fixing clamp 11. There are two pipe end fixing clamps 11, which are respectively set at both ends of the working steel pipe 3. One end of the pre-tightening spring 13 is connected to the pipe end fixing clamp 11, and the other end is connected to the conduit clamp 12. The elastic force of the pre-tightening spring 13 can provide a continuous clamping force to the conduit clamp 12. The conduit clamp 12 is used to tighten the conduit clamp 12 and pre-tighten it through the pre-tightening spring 13. Through the pre-tightening action of the pre-tightening spring 13, the clamping force on the conduit 4 can be adjusted according to actual needs. The conduit 4 clamp, together with the pre-tightening spring 13 and the pipe end fixing clamp, continuously applies tension to the conduit 4 to ensure the straightness of the conduit 4. If the insulation pipe is long, the pre-tightening spring 13 can be replaced with a hydraulic or screw device.

[0027] As a further implementation, the quick-fixing buckle is an existing standard part. The quick-fixing buckle includes a buckle groove 8 and a screw hole 9. The screw hole 9 is located at the bottom of the buckle groove 8 and is fixed to the outer side wall of the working steel pipe 3 by a wooden bracket. The screw hole 9 facilitates the use of screws or other connectors to firmly connect the quick-fixing buckle to the wooden bracket and the working steel pipe 3, thereby solving the problem that the quick-fixing buckle, as a standard part, cannot be adapted to the insulation pipe.

[0028] As a further implementation, there are four pre-tightening springs 13 and two pipe-end fixing clamps 11. Each pipe-end fixing clamp 11 consists of two clamping blocks. One end of each clamping block is connected by an elastic material, and the other end is provided with a fastener for clamping the two clamping blocks. Semi-circular grooves are provided on opposite sides of each clamping block for placing the conduit 4. Each pre-tightening spring 13 is fixedly connected to one of the clamping blocks, achieving uniform pre-tightening and reliable fixing of the conduit 4, thereby enhancing the stability and reliability of the conduit 4 fixing.

[0029] As a further implementation, multiple fixed slot brackets or quick-fixing buckles are provided and are arranged at equal intervals on the outer side wall of the working steel pipe 3 to neatly fix the conduit 4 onto the working steel pipe 3. Through the coordinated action of multiple fixing devices, the conduit 4 can be neatly fixed onto the working steel pipe 3, so that the conduit 4 maintains a neat and orderly arrangement in the interlayer gap. This ensures that the conduit 4 is subjected to uniform force on the working steel pipe 3, avoiding the problem of misalignment or loosening of the conduit 4 due to excessive or insufficient local force during the injection of foaming adhesive, which would lead to difficulties in the subsequent fiber optic installation.

[0030] As a further implementation, the conduit 4 is composed of multiple sections spliced ​​together, and a connector is provided between two adjacent conduit sections 4. The connector is a straight connector 10 or a plug connector. The straight connector 10 is in the shape of a round tube, and two adjacent conduit sections 4 are directly inserted into the straight connector 10 for connection.

[0031] As a further implementation, the connector consists of a socket portion 14 and a plug portion 15. The socket portion 14 is the optical fiber inlet. The design of the connector effectively reduces the resistance of optical fiber threading, protects the optical fiber from damage during the threading process, and improves the quality and efficiency of optical fiber installation. The tight connection structure ensures the stability and sealing of the connection part of the conduit 4. A bevel is provided at the connection between the socket portion 14 and the plug portion 15 to reduce the threading resistance. The socket portion 14 is connected to the outer wall of the conduit 4, and the plug portion 15 is connected to the inner wall of the conduit 4.

[0032] Example 2 This embodiment provides a method for manufacturing a pre-fabricated optical fiber insulation tube, including the following steps: S1. If a fixed bracket is used to fix the conduit 4, mark the installation position of the fixed slot bracket on the outer wall of the working steel pipe 3 to ensure that multiple brackets are arranged at equal intervals. The fixed slot bracket is installed and fixed on the outer wall of the working steel pipe 3 through the fixing hole 7 at the bottom of the base 5; or the quick-fixing buckle is installed and fixed on the outer wall of the working steel pipe 3 by screws. If the conduit 4 clamp is used, install the pipe end fixing clamp 11 at both ends of the working steel pipe 3. First, connect the two clamp blocks to the pipe end fixing clamp 11 through the pre-tightening spring 13 to prepare for the subsequent installation and pre-tightening of the conduit 4. S2. If a direct connector 10 is used for connection, clean the ends of the two adjacent sections of conduit 4 and insert them directly into the round tube-shaped direct connector 10. During the insertion process, ensure that the conduit 4 is inserted in place to ensure a tight connection and smooth inner wall. If a plug connector is used for connection, connect the socket 14 to the outer wall of one section of conduit 4 and the plug 15 to the inner wall of the other section of conduit 4. S3. Place the assembled conduit 4 into the conduit slot 6 of the fixed slot bracket, gently adjust the position of the conduit 4 so that it is fully embedded in the slot, and fix the conduit 4 on the working steel pipe 3 through the limiting effect of the slot. When using the conduit 4 clamp, place the conduit 4 in the semi-circular groove of the pipe end fixing clamp 11, and clamp the conduit 4 with fasteners. The clamping force should ensure that the conduit 4 is firmly fixed, but not too tight to cause the conduit 4 to deform. Use the pre-tensioning spring 13 to pre-tighten the conduit 4. S4. Place the outer protective tube 1 on the outside of the working steel pipe 3 to form a set interlayer gap between the outer protective tube 1 and the working steel pipe 3. Use the foaming tool 2 to foam the interlayer gap so that the interlayer gap is filled with thermal insulation foam material. After the foam material has solidified and formed, the prefabricated fiber optic thermal insulation pipe is completed.

[0033] The proper installation of the fixing device ensures the stable fixation of the conduit 4, providing a reliable foundation for fiber optic monitoring; the correct splicing and fixing method of the conduit 4 ensures the quality and stability of the fiber optic installation; the installation and foaming treatment of the outer protective tube 1 give the insulation tube a good insulation effect, reduce heat loss, and improve energy utilization efficiency.

[0034] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A heat-insulating pipe with pre-fabricated optical fibers, characterized in that, include: A working steel pipe is installed in the core of the insulation pipe. An outer protective pipe is installed on the outside of the working steel pipe. The diameter of the outer protective pipe is larger than that of the working steel pipe, so that a gap is formed between the outer protective pipe and the working steel pipe. A conduit is installed in the gap, and an optical fiber is installed in the conduit. The conduit is fixed by a fixing device, which is fixed on the outer wall of the working steel pipe. A foaming fixture is also installed in the gap.

2. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 1, characterized in that, The fixing device is a fixing bracket or a conduit clamp. The fixing bracket is used to directly fix the conduit onto the working steel pipe, and the conduit clamp fixes the conduit by pre-tightening it.

3. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 2, characterized in that, The fixing bracket is a fixing slot bracket or a quick-fixing buckle; the fixing slot bracket includes a conduit slot, a base and a fixing hole; the conduit slot is located above the base, the fixing hole is located at the bottom of the base, and the base is located on the outer wall of the working steel pipe through the fixing hole.

4. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 2, characterized in that, The conduit clamp includes a conduit clamp, a pre-tightening spring, and a pipe end fixing clamp; there are two pipe end fixing clamps, which are respectively set at both ends of the working steel pipe; one end of the pre-tightening spring is connected to the pipe end fixing clamp, and the other end is connected to the conduit clamp; the conduit clamp is used to clamp the conduit and pre-tighten it by the pre-tightening spring.

5. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 3, characterized in that, The quick-fixing buckle includes a buckle groove and a screw hole. The screw hole is located at the bottom of the buckle groove and is fixed to the outer wall of the working steel pipe by a wooden bracket.

6. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 4, characterized in that, There are four pre-tension springs and two pipe-end fixing clamps. Each pipe-end fixing clamp consists of two clamping blocks. One end of each clamping block is connected by an elastic material, and the other end is provided with a fastener to clamp the two clamping blocks. Each clamping block has a semi-circular groove on its opposite side for placing the conduit. Each pre-tension spring is fixedly connected to one of the clamping blocks.

7. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 5, characterized in that, Multiple fixed slot brackets or quick-fixing buckles are provided and are arranged at equal intervals on the outer side wall of the working steel pipe to neatly fix the conduit onto the working steel pipe.

8. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 1, characterized in that, The conduit is composed of multiple sections spliced ​​together, and a connector is provided between two adjacent sections of the conduit. The connector is either a straight connector or a plug connector. The straight connector is cylindrical, and two adjacent sections of the conduit are directly inserted into the straight connector for connection.

9. The heat-insulating pipe with pre-fabricated optical fiber as described in claim 8, characterized in that, The connector consists of a socket and a plug. A bevel is provided at the connection between the socket and the plug to reduce the resistance of threading. The socket is connected to the outer wall of the conduit, and the plug is connected to the inner wall of the conduit.

10. A method for manufacturing a pre-fabricated optical fiber insulation pipe as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. If a fixed bracket is used to fix the conduit, mark the installation position of the fixed bracket on the outer wall of the working steel pipe, and ensure that multiple brackets are arranged at equal intervals. Install and fix the fixed bracket on the outer wall of the working steel pipe through the fixing holes at the bottom of the base; or install and fix the quick-fixing buckle on the outer wall of the working steel pipe with screws. If conduit clamps are used, install pipe end fixing clamps at both ends of the working steel pipe. First, connect the two clamp blocks to the pipe end fixing clamps through the pre-tightening spring to prepare for the subsequent installation and pre-tightening of the conduit. S2. If a direct connector is used, insert the ends of two adjacent conduit sections directly into the round tube-shaped direct connector; if a plug connector is used, connect the socket to the outer wall of one conduit section and the plug to the inner wall of the other conduit section. S3. Place the assembled conduit into the conduit slot of the fixed slot bracket to fix the conduit on the working steel pipe through the slot. When using conduit clamps, place the conduit in the semi-circular groove of the conduit opening clamp, clamp the conduit with fasteners, and pre-tighten the conduit with a pre-tensioning spring. S4. Place the outer protective tube over the outside of the working steel pipe to form a predetermined interlayer gap between the outer protective tube and the working steel pipe. Use a foaming tool to foam the interlayer gap to fill it with thermal insulation foam material. After the foam material has solidified, the prefabricated fiber optic insulation pipe is completed.

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