Nondestructive testing equipment for pipe fusion joint of HDPE double-layer pipe

Abstract

The application belongs to the technical field of pipeline joint detection, and discloses a nondestructive testing equipment for pipeline fusion joint of HDPE double-layer pipe, which comprises a workbench, a protective shell is fixedly connected to the middle of the workbench, and a vacuum air extraction box is fixedly connected to the edge of the workbench. Through the cooperation of the double-tooth ring, the single-tooth ring, the moving plate and the protective shell and other structures, the surface flaw and leakage detection of the fusion pipeline are facilitated. The second gear is driven to rotate by the inner teeth of the double-tooth ring, and the industrial camera is driven to rotate at 360 degrees on the surface of the pipeline in cooperation with the setting of the single-tooth ring, so that non-dead-angle detection is realized. The pipeline is filled with water, and the leakage can be detected. Compared with the reagent detection of the comparative file, the device can form a negative pressure state outside the pipeline by the sealing setting of the sealing sleeve, the fixing cover and the protective shell, cooperate with the vacuum air extraction box, increase the water pressure inside the pipeline, and effectively improve the detection efficiency.

Description

Technical Field

[0001] This invention belongs to the field of pipe joint testing technology, specifically a non-destructive testing device for the fusion joint of HDPE double-layer pipe. Background Technology

[0002] HDPE double-walled pipes typically refer to high-density polyethylene double-walled corrugated pipes. Their structure consists of inner and outer double-walled pipes. The outer layer is corrugated and raised, while the inner layer is a smooth straight pipe, forming a hollow cavity in the middle. The quality of the fusion joints of HDPE pipes directly affects the safety and reliability of the system. Non-destructive testing technology uses non-destructive means to assess whether the fusion joint quality meets the standards and to identify potential problems such as gaps, micropores, and minor local deficiencies that may occur during the fusion process.

[0003] The prior art document, CN118857592A, discloses a pipe joint sealing performance testing device. By installing sealing clamps on both sides of the testing chamber, the elastic sealing ring inside the clamps provides an initial seal with the outer wall of the pipe during installation before gas injection testing. Subsequently, a hot-melted phase change liquid is injected into the clamps. After defoaming and cooling solidification, it seals the pipe and a pair of elastic sealing rings in a solid form, serving as a secondary seal between the pipe and the outer wall. This prevents the final test results from being affected by poor sealing, effectively improving testing accuracy. Furthermore, a bandage soaked in phenolphthalein solution can be wrapped around the connection between the clamps and the pipe to form a leak-detecting wet ring. Simultaneously, ammonia gas is used for gas injection testing. During testing, the presence of a color change in the leak-detecting wet ring allows for simultaneous inspection of the seal between the clamps and the pipe, further improving the accuracy of pipe joint sealing performance testing. Although the above-mentioned device can improve the accuracy of pipe joint sealing detection by observing whether there is a color change in the leak detection ring, long-term testing requires a large amount of reagents, which not only increases operating costs but may also have an impact on the environment. In addition, the pipes need to be thoroughly cleaned before testing to ensure that the leak detection ring can work properly. This process is cumbersome and time-consuming, which significantly reduces the testing efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a non-destructive testing device for the welded joints of HDPE double-layer pipes that improves testing efficiency and adapts to different pipe sizes, as well as the testing of bends and straight pipes, in order to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a non-destructive testing device for pipe fusion joints of HDPE double-layer pipes, comprising a workbench, a protective shell fixedly connected to the center of the workbench, and a vacuum extraction box fixedly connected to the edge of the workbench, and further comprising: A winding detection mechanism, which is located on the protective shell; A sealing support mechanism, which is connected to the protective shell; The coiling detection mechanism includes a double-toothed ring rotatably connected to the inner cavity of a protective shell. The protective shell is a hollow circular ring, and a single-toothed ring is fixedly connected to the center of its inner cavity. The double-toothed ring and the single-toothed ring mesh with a second gear. The protective shell is hollow, with a single-toothed ring fixedly connected to its inner cavity, while the double-toothed ring is rotatably connected to the inner cavity of the protective shell and meshes with the single-toothed ring. Through this cooperative relationship, the double-toothed ring and the single-toothed ring jointly drive the rotation of the second gear, achieving efficient operation of the detection equipment. Simultaneously, a sealing support mechanism is connected to the protective shell to ensure a good sealing state during detection, allowing for control of the internal environment using a vacuum extraction box, thereby improving the accuracy and reliability of the detection. By using a coiling method outside the pipeline, the entire device can flexibly and efficiently perform comprehensive non-destructive testing of pipeline weld joints.

[0006] Preferably, the winding detection mechanism further includes a motor fixed to the edge of the protective shell sidewall. The output end of the motor penetrates the protective shell, and a first gear is fixed to the end of the motor. The outer wall of the first gear meshes with a double-toothed ring.

[0007] Preferably, the second gear is rotatably connected to a movable plate via a rotating shaft. One end of the movable plate has an arc-shaped groove, and a ring block is slidably connected to the movable plate via the arc-shaped groove. The sidewall of the ring block is fixed to the inner cavity of the protective shell. After the pipeline is positioned, the motor starts and drives the first gear to rotate, thereby causing the double-toothed ring to mesh and rotate. The teeth inside the double-toothed ring are tightly engaged with the second gear, so that the second gear can achieve a 360-degree circular rotation within the inner cavity of the protective shell. The movable plate is synchronously driven by the rotating shaft, and the end of the movable plate is connected to the ring block via the arc-shaped groove, ensuring that it always faces the center of the protective shell during movement. This allows the industrial camera located at the end of the movable plate to face the pipeline surface in real time and accurately, achieving all-round detection.

[0008] Preferably, a microphone and an industrial camera are fixedly connected to the other end of the movable plate, with the industrial camera facing the axis of the protective shell; the image data captured by the industrial camera is transmitted to an external computer in real time, and intelligent analysis and judgment are performed by dedicated detection software to quickly identify welding defects and improve detection efficiency.

[0009] Preferably, the sealing support mechanism includes a fixed cover fixed to both sides of the protective shell, and the microphone is disposed facing the inside of the fixed cover.

[0010] Preferably, a ventilation pipe is fixedly connected to the side wall of one side of the fixed cover, and the ventilation pipe is fixedly connected to the vacuum extraction box through a pipe.

[0011] Preferably, both of the fixed covers are fixedly connected to a sealing soft sleeve on their outer sides, and a folded rubber ring is fixedly connected to the inner wall of the sealing soft sleeve.

[0012] Preferably, the outer end of the sealing sleeve is secured with a cable tie via a snap ring, and the cable tie is secured with Velcro. If it is necessary to detect whether there is a leak at the weld joint, firstly, clean water is injected into the inside of the bend, and the cable ties on both sides are tightened to ensure that the folded rubber ring fits tightly against the pipe surface, thereby forming a relatively sealed state. Next, the vacuum extraction box is turned on, and air is extracted from the sealed cavity outside the pipe through the extraction pipe to create a negative pressure environment. Under the action of atmospheric pressure, the water pressure inside the pipe increases accordingly. If the industrial camera rotates 360 degrees and finds water droplets on the weld surface of the pipe, it can be determined that there is a risk of leakage; otherwise, it indicates that there is no risk of leakage.

[0013] Preferably, a pair of sliders are slidably connected to both sides of the workbench via sliding grooves. Each slider has a bracket fixed to its top, and each bracket has a stop block fixed to its top. The inner sides of the pair of stop blocks are inclined, and the outer sides of the stop blocks are horizontal. Each stop block is rotatably connected to an arc clamping plate in the middle.

[0014] Preferably, a pair of sliders are threaded together with a bidirectional threaded rod. Both sides of the bidirectional threaded rod are rotatably connected to the bottom of the worktable. A second motor is fixed to the bottom edge of the worktable, and the output end of the second motor is fixed to the end of the bidirectional threaded rod. When inspecting the welded part of the bent pipe, the operation steps are relatively simple and efficient. The operator needs to pass the bent pipe through the sealing sleeve and the fixing cover to ensure that the welded part is accurately located in the middle of the protective shell. Then, the second motor is started, driving the bidirectional threaded rod to rotate, so that the sliders on both sides move closer to each other. This movement is connected to the arc clamp plate through the bracket, so that the arc clamp plate gradually moves closer and finally abuts against the surface of the bent pipe. At this time, the arc clamp plate automatically adjusts the angle, closely fits the pipe wall, and effectively fixes the position of the bent pipe, providing a stable foundation for subsequent inspection work. When facing the inspection requirements of straight pipes, the arc clamp plate is rotated to a horizontal state and abuts against the surface of the stop block. The straight pipe is inserted into the middle of the protective shell and kept horizontal for inspection.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention facilitates the detection of surface defects and leaks in welded pipes by incorporating a combination of a double-toothed ring, a single-toothed ring, a movable plate, and a protective shell. The inner teeth of the double-toothed ring engage and rotate the second gear. Combined with the single-toothed ring, the second gear rotates 360 degrees within the protective shell, causing an industrial camera to rotate 360 ​​degrees across the pipe surface for inspection. This allows for comprehensive inspection of the welded surface without blind spots. Furthermore, filling the pipe with water allows for leak detection. Compared to reagent-based testing methods, this device, through its sealed design with a soft sleeve, a fixed cover, and a protective shell, along with a vacuum extraction box, creates negative pressure outside the pipe, increasing the water pressure inside and effectively improving detection efficiency.

[0016] This invention, through the combination of a stop block and an arc clamp, facilitates the detection of both straight and bent pipe joints. The arc clamp is rotatable and is tilted inwards to match the stop block, while the stop block is horizontally positioned outwards. Therefore, when detecting a bent pipe, the supports on both sides drive the arc clamps closer together until a pair of arc clamps abut against the surface of the bent pipe. The arc clamps automatically rotate to the corresponding angle to fit against the pipe wall, fixing the position of the bent pipe. When detecting a straight pipe, the arc clamps are rotated outwards to a horizontal position and abut against the surface of the stop block, allowing the straight pipe to be placed horizontally. With the addition of a sealing sleeve, folding rubber ring, and cable ties, it can also accommodate measurements of different pipe diameters. This adaptability enhances the applicability of the device, enabling it to detect different pipe sizes and both bent and straight pipes. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side view of the structure of the present invention; Figure 3 This is a top view of the structure of the present invention; Figure 4 This is a schematic diagram showing the structural fit between the fixing cover and the protective shell of the present invention; Figure 5 This is a schematic diagram showing the structural fit between the double-toothed ring and the protective shell of the present invention; Figure 6 For the present invention Figure 5 A magnified view of the structure at point A in the middle; Figure 7 This is a schematic diagram showing the structural fit between the arc clamp and the stop block of the present invention; Figure 8 For the present invention Figure 7 A magnified schematic diagram of the structure at point B in the middle; Figure 9 This is a schematic diagram showing the structural fit between the movable plate and the ring block of the present invention.

[0018] In the picture: 100. Workbench; 200. Vacuum extraction box; 300. Protective shell; 400. Coiling detection mechanism; 410. Motor 1; 420. First gear; 430. Double toothed ring; 440. Single toothed ring; 450. Second gear; 460. Moving plate; 470. Rotating shaft; 480. Arc groove; 490. Industrial camera; 4100. Microphone; 4110. Ring block; 500. Sealing support mechanism; 510. Fixing cover; 520. Sealing soft sleeve; 530. Cable tie; 540. Exhaust pipe; 550. Arc clamp plate; 560. Stop block; 570. Bracket; 580. Slider; 590. Bidirectional threaded rod; 5100. Motor 2; 5110. Folding rubber ring. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figures 1 to 9 As shown, this invention provides a non-destructive testing device for the welded joints of HDPE double-layer pipes, including a workbench 100, a protective shell 300 fixedly connected to the middle of the workbench 100, and a vacuum extraction box 200 fixedly connected to the edge of the workbench 100, and further including: The winding detection mechanism 400 is located on the protective shell 300; A sealing support mechanism 500 is connected to the protective shell 300; The winding detection mechanism 400 includes a double-toothed ring 430 rotatably connected to the inner cavity of the protective shell 300. The protective shell 300 is configured as a hollow ring shape. A single-toothed ring 440 is fixed at the center of the inner cavity of the protective shell 300. The double-toothed ring 430 and the single-toothed ring 440 are meshed together with a second gear 450.

[0021] The above-described scheme employs a protective shell 300 fixedly connected to the center of the workbench 100. The protective shell 300 is a hollow ring, with a single-toothed ring 440 fixedly connected to its inner center. A double-toothed ring 430 is rotatably connected to the inner cavity of the protective shell 300, meshing with the single-toothed ring 440. Through this cooperative relationship, the double-toothed ring 430 and the single-toothed ring 440 jointly drive the rotation of the second gear 450, achieving efficient operation of the testing equipment. Simultaneously, a sealing support mechanism 500 is connected to the protective shell 300, ensuring a good sealing condition during testing. This allows for control of the internal environment using a vacuum extraction chamber 200, thereby improving the accuracy and reliability of the testing. This structural design enables the entire device to flexibly and efficiently perform comprehensive non-destructive testing of pipe weld joints.

[0022] like Figures 5 to 9 As shown, the winding detection mechanism 400 also includes a motor 410 fixed to the edge of the side wall of the protective shell 300. The output end of the motor 410 passes through the protective shell 300 and a first gear 420 is fixed to the end. The outer wall of the first gear 420 meshes with a double toothed ring 430. A second gear 450 is rotatably connected to a movable plate 460 through a rotating shaft 470. One end of the movable plate 460 is provided with an arc-shaped groove 480. A ring block 4110 is slidably connected to the movable plate 460 through the arc-shaped groove 480. The side wall of the ring block 4110 is fixed to the inner cavity of the protective shell 300. A microphone 4100 and an industrial camera 490 are fixed to the other end of the movable plate 460 respectively. The industrial camera 490 is set facing the axis of the protective shell 300.

[0023] The above scheme involves inspecting for weld defects after pipe positioning. Motor 410 starts, driving the first gear 420 to rotate, which in turn causes the double-toothed ring 430 to mesh and rotate. The teeth inside the double-toothed ring 430 closely engage with the second gear 450, allowing the second gear 450 to rotate 360 ​​degrees within the inner cavity of the protective shell 300. The moving plate 460 is synchronously driven via the rotating shaft 470, and its end is connected to the ring block 4110 via an arc-shaped groove 480, ensuring that it always faces the center of the protective shell 300 during movement. This design allows the industrial camera 490, located at the end of the moving plate 460, to face the pipe surface accurately and in real time, achieving omnidirectional inspection. The image data captured by the industrial camera 490 is transmitted in real time to an external computer, where dedicated inspection software performs intelligent analysis and judgment, quickly identifying weld defects. This process not only improves inspection efficiency but also enhances the stability and accuracy of the inspection.

[0024] like Figure 2 , Figure 3 and Figure 7As shown, the sealing support mechanism 500 includes fixed covers 510 fixed to both sides of the protective shell 300, with the microphone 4100 facing inwards from the fixed cover 510; a ventilation pipe 540 is fixedly connected to the side wall of one fixed cover 510, and the ventilation pipe 540 is fixedly connected to the vacuum extraction box 200 via a pipe; a sealing sleeve 520 is fixedly connected to the outer sides of both fixed covers 510, and a folded rubber ring 5110 is fixedly connected to the inner wall of the sealing sleeve 520; a cable tie 530 is snapped onto the outer side of the end of the sealing sleeve 520 by a snap ring, and the cable tie 530 is secured by Velcro; the two sides of the workbench 100 are connected to... A pair of sliders 580 are slidably connected via a slide groove. Each slider 580 has a bracket 570 fixed to its top, and each bracket 570 has a stop block 560 fixed to its top. The inner sides of the two stop blocks 560 are inclined, and the outer sides of the stop blocks 560 are horizontal. An arc clamp plate 550 is rotatably connected to the middle of each stop block 560. The pair of sliders 580 are threaded together with a bidirectional threaded rod 590. Both sides of the bidirectional threaded rod 590 are rotatably connected to the bottom of the worktable 100. A second motor 5100 is fixed to the bottom edge of the worktable 100, and the output end of the second motor 5100 is fixed to the end of the bidirectional threaded rod 590.

[0025] Using the above method, the operation steps for inspecting the welded section of the bend are relatively simple and efficient. The operator must pass the bend through the sealing sleeve 520 and the fixing cover 510, ensuring the welded section is accurately located in the center of the protective shell 300. Then, the motor 5100 is started, driving the bidirectional threaded rod 590 to rotate, causing the sliders 580 on both sides to move closer together. This movement is connected to the arc clamp 550 via the bracket 570, causing the arc clamp 550 to gradually approach and eventually abut against the surface of the bend. At this time, the arc clamp 550 automatically adjusts its angle, tightly fitting the pipe wall, effectively fixing the bend's position and providing a stable foundation for subsequent inspection work. If it is necessary to detect whether there is a leak at the welded section, first, clean water is injected into the bend, and the cable ties 530 on both sides are tightened to ensure the folded rubber ring 5110 is tightly fitted against the pipe surface, thus forming a relatively sealed state. Next, the vacuum extraction box 200 is turned on, and air is extracted from the sealed cavity outside the pipe through the extraction pipe 540 to create a negative pressure environment. Under atmospheric pressure, the water pressure inside the pipe increases. If the industrial camera 490 rotates 360 degrees and detects water droplets on the welded surface of the pipe, a leakage risk is identified; otherwise, no leakage risk is detected. Furthermore, combined with the sound collection by the microphone 4100, the sound of flowing water can serve as an auxiliary basis for judgment when the gap is small, avoiding missed detections due to reliance solely on machine vision and improving the accuracy and reliability of the inspection. When inspecting straight pipes, the arc clamp 550 is rotated to a horizontal position, abutting against the surface of the stop block 560. Then, the straight pipe is passed through the sealing sleeve 520 and the fixing cover 510, inserted into the middle of the protective shell 300, ensuring the welded part of the pipe is aligned with the protective shell 300, and the other end of the pipe is attached to another arc clamp 550, keeping it horizontal. At this time, the cooperation between the double-toothed ring 430 and the single-toothed ring 440 still plays a crucial role, causing the second gear 450 to drive the moving plate 460, allowing the industrial camera 490 to perform a 360-degree circular inspection. The process for detecting defects on the outer wall is the same as that for bends. However, when detecting leaks, pressurized gas is filled into the straight pipe and kept sealed. The sound receiver 4100 can be used to determine whether there is a wind sound leak, ensuring the diversity and reliability of the detection methods.

[0026] Working principle and usage process of this invention: First, when the welded section is a pipe bend, if it is necessary to inspect for defects at the welded section, the bend must be passed through the sealing sleeve 520 and the fixing cover 510, so that the welded section is located in the middle of the protective shell 300. Then, the motor 5100 is started to drive the bidirectional threaded rod 590 to rotate, which in turn causes the sliders 580 on both sides to move closer to each other. This, in turn, causes the arc clamps 550 to move closer to each other through the brackets 570 on both sides, until a pair of arc clamps 550 abut against the surface of the bend. The arc clamps 550 automatically rotate to the corresponding angle to fit against the pipe wall, fixing the position of the bend for easy pipe inspection. Secondly, when detecting defects on the welded surface, the motor 410 drives the first gear 420 to rotate, which in turn meshes and rotates the double-toothed ring 430. The inner teeth of the double-toothed ring 430 mesh with and drive the second gear 450 to rotate. Combined with the single-toothed ring 440, the second gear 450, located between the double-toothed ring 430 and the single-toothed ring 440, rotates 360 degrees in a circular motion within the inner cavity of the protective shell 300. The rotating shaft 470 synchronously drives the moving plate 460. Since the end of the moving plate 460 is slidably connected to the ring block 4110 through the arc-shaped groove 480, the moving plate 460 is limited during movement, ensuring its end always faces the center of the protective shell 300. Therefore, the industrial camera 490 located at the end of the moving plate 460 can synchronously rotate 360 ​​degrees towards the pipe surface at the center of the protective shell 300 for inspection. The industrial camera 490 transmits the inspection images to an external computer in real time, and the inspection software intelligently judges the weld defects, effectively improving inspection efficiency and stability. Furthermore, to detect leaks at the weld joint, clean water is injected into the bend, and the cable ties 530 on both sides are tightened to ensure the folded rubber ring 5110 fits tightly against the pipe surface, creating a relatively sealed state between the sealing sleeve 520, the fixing cover 510, and the cavity in the middle of the protective shell 300. Next, the vacuum extraction box 200 is opened, and air is extracted from the sealed cavity outside the pipe through the extraction pipe 540, creating a negative pressure outside the pipe. Under atmospheric pressure, this increases the water pressure inside the pipe. If the industrial camera 490 rotates 360 degrees and detects water droplets on the weld surface, it indicates a potential leak; otherwise, there is no leak risk. At this time, a microphone 4100 can be used to collect internal sounds. If the gap is small, the hissing sound can serve as an auxiliary judgment, avoiding missed detections when relying solely on machine vision and effectively improving detection accuracy. Finally, when the pipe to be welded is a straight pipe, rotate the arc clamp 550 outward to a horizontal position and abut it against the surface of the stop block 560. Then, pass the straight pipe through the sealing sleeve 520 and the fixing cover 510, insert it into the middle of the protective shell 300, align the welded part of the pipe with the protective shell 300, and place the other side of the pipe onto another arc clamp 550, keeping it horizontal. Similarly, the cooperation of the double toothed ring 430 and the single toothed ring 440 causes the second gear 450 to drive the moving plate 460, allowing the industrial camera 490 at the end to rotate 360 ​​degrees for detection. The detection of defects on the outer wall is the same as for the bent pipe. When performing leakage detection, pressurized gas can be injected into the straight pipe through a gap, and the pipe can be kept sealed. At this time, the presence of wind noise leakage can be mainly determined by the receiver 4100.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A non-destructive testing device for pipe fusion joints of HDPE double-layer pipes, comprising a workbench (100), a protective shell (300) fixedly connected to the middle of the workbench (100), and a vacuum extraction box (200) fixedly connected to the edge of the workbench (100), characterized in that: Also includes: A winding detection mechanism (400) is located on the protective shell (300); A sealing support mechanism (500) is connected to the protective shell (300); The winding detection mechanism (400) includes a double-toothed ring (430) rotatably connected to the inner cavity of the protective shell (300). The protective shell (300) is configured as a hollow ring shape. A single-toothed ring (440) is fixedly connected to the center of the inner cavity of the protective shell (300). The double-toothed ring (430) and the single-toothed ring (440) are meshed together with a second gear (450).

2. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 1, characterized in that: The winding detection mechanism (400) also includes a motor (410) fixed to the edge of the side wall of the protective shell (300). The output end of the motor (410) passes through the protective shell (300) and the end is fixed with a first gear (420). The outer wall of the first gear (420) meshes with a double toothed ring (430).

3. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 2, characterized in that: The second gear (450) is rotatably connected to a movable plate (460) via a rotating shaft (470). One end of the movable plate (460) is provided with an arc groove (480). The movable plate (460) is slidably connected to a ring block (4110) via the arc groove (480). The side wall of the ring block (4110) is fixed to the inner cavity of the protective shell (300).

4. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 3, characterized in that: The other end of the movable plate (460) is fixed with a microphone (4100) and an industrial camera (490), respectively, with the industrial camera (490) facing the axis of the protective shell (300).

5. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 4, characterized in that: The sealing support mechanism (500) includes a fixed cover (510) fixed to both sides of the protective shell (300), and the microphone (4100) is disposed facing the interior of the fixed cover (510).

6. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 5, characterized in that: A ventilation pipe (540) is fixedly connected to the side wall of the fixed cover (510) on one side, and the ventilation pipe (540) is fixedly connected to the vacuum extraction box (200) through a pipe.

7. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 6, characterized in that: Both of the fixed covers (510) are fixedly connected to the outer sides of a sealing soft sleeve (520), and a folded rubber ring (5110) is fixedly attached to the inner wall of the sealing soft sleeve (520).

8. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 7, characterized in that: The outer end of the sealing sleeve (520) is secured with a cable tie (530) by a snap ring, and the cable tie (530) is secured by Velcro.

9. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 8, characterized in that: The workbench (100) has a pair of sliders (580) slidably connected to both sides via sliding grooves. Each slider (580) has a bracket (570) fixed to its top. Each bracket (570) has a stop block (560) fixed to its top. The inner sides of the pair of stop blocks (560) are inclined, and the outer sides of the stop blocks (560) are horizontal. Each stop block (560) has an arc clamp plate (550) rotatably connected to its middle.

10. The non-destructive testing equipment for pipe fusion joints of HDPE double-layer pipes according to claim 9, characterized in that: A pair of sliders (580) are threaded together with a bidirectional threaded rod (590). Both sides of the bidirectional threaded rod (590) are rotatably connected to the bottom of the worktable (100). A second motor (5100) is fixed to the bottom edge of the worktable (100). The output end of the second motor (5100) is fixed to the end of the bidirectional threaded rod (590).

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