Airtightness detection machine for steel pipe welding position

Abstract

This invention relates to the field of airtightness testing technology, specifically to an airtightness testing machine for welded sections of steel pipes. The machine includes: a machine base, and a first support frame, a second support frame, and a fixed plate fixed to the machine base. A first drive module is mounted on the first support frame, and a second drive module is mounted on the second support frame. A bidirectional clamping assembly is mounted on the fixed plate, and symmetrically arranged clamping plates are connected to the bidirectional clamping assembly. A sealing and pressurizing mechanism is mounted on the first drive module, capable of sealing both sides of the steel pipe and performing a pressurizing pumping action into the steel pipe. An airtightness testing mechanism is mounted on the second drive module, and a tester is connected to the airtightness testing mechanism. A through groove is formed at the bottom of the tester. When the sealing and pressurizing mechanism creates positive pressure inside the steel pipe, the airtightness testing mechanism guides the tester to seal and adhere to the steel pipe for airtightness testing of that area.

Description

Technical Field

[0001] This invention relates to the field of airtightness testing technology, specifically an airtightness testing machine for steel pipe welded positions. Background Technology

[0002] Steel pipes, as an important engineering material, are widely used in fluid transportation, pressure vessels, structural support, and other fields. Among them, straight seam welded pipes, which are made by rolling and welding steel strips or plates, have welds whose quality directly determines the overall performance and safety of the steel pipe.

[0003] If defects such as porosity, slag inclusions, or lack of fusion exist in the weld, leakage channels will be formed, seriously affecting the airtightness of the steel pipe. For pipelines transporting flammable, explosive, toxic, or expensive media, even minor leaks can lead to safety accidents, environmental pollution, or economic losses. Therefore, rigorous airtightness testing of welded steel pipes, especially their welds, is an indispensable and critical quality control step in the production process.

[0004] Currently, commonly used methods for testing the air tightness of steel pipes include hydrostatic testing and bubble method. However, neither hydrostatic testing nor bubble method can accurately locate tiny leaks on the weld, and drainage and drying are required after testing, resulting in low efficiency.

[0005] To address this, the airtightness of the steel pipe can be tested by sealing both ends and performing a negative pressure test on the external weld area. However, due to the different diameters of the test steel pipes, the negative pressure test piece needs to be disassembled and replaced according to the curvature of the steel pipe. Even if a test piece of the corresponding size is replaced, there may be machining tolerances, leading to incomplete sealing and thus causing deviations in the test results. Summary of the Invention

[0006] The purpose of this invention is to provide a steel pipe weld site airtightness testing machine to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A steel pipe weld site airtightness testing machine, comprising:

[0009] The machine base, and a first support frame, a second support frame, and a fixing plate fixed on the machine base, wherein a first drive module is provided on the first support frame and a second drive module is provided on the second support frame;

[0010] Also includes:

[0011] A bidirectional clamping assembly is disposed on the fixed plate, and symmetrically arranged clamping plates are connected to the bidirectional clamping assembly;

[0012] A sealing and pressurizing mechanism is installed on the first drive module. The sealing and pressurizing mechanism can seal both sides of the steel pipe and perform a pressurizing pumping action into the steel pipe.

[0013] An airtightness testing mechanism is installed on the second drive module. A tester is connected to the airtightness testing mechanism. A through groove is formed at the bottom of the tester. The airtightness testing mechanism can drive the tester to move to a position that fits against the outer wall of the steel pipe and perform an airtightness test on the steel pipe.

[0014] As a further aspect of the present invention: the bidirectional clamping assembly includes a baffle fixed on the fixed plate, a guide post fixed on the baffle, a guide sleeve symmetrically arranged sliding on the guide post, the guide sleeve being fixedly connected to the clamping plate, and a double-headed cylinder fixed on the guide post and fixedly connected to the guide sleeve.

[0015] As a further embodiment of the present invention: the sealing and pressurizing mechanism includes a first movable plate disposed on the first drive module, and a support plate is fixed on the first movable plate;

[0016] It also includes an elastic component and a pumping component disposed on the support plate.

[0017] As a further embodiment of the present invention: the elastic component includes a support sleeve fixed on the support plate, a support rod axially sliding inside the support sleeve, a pump cylinder slidably mounted on the support rod, and a first spring sleeved on the support sleeve and the support rod, with the two ends of the first spring abutting against the support plate and the pump cylinder respectively.

[0018] As a further embodiment of the present invention: the pumping assembly includes a piston disc that is slidably and sealingly connected to the pumping cylinder, and a push rod that passes through the pumping cylinder and is fixedly connected to the support plate is fixed on the piston disc.

[0019] As a further embodiment of the present invention: a conical sealing tube is fixed to the end of the pump cylinder, and an air delivery hole is formed on the conical sealing tube.

[0020] As a further embodiment of the present invention: a pressurization chamber is formed between the piston disc and the conical sealing tube, which communicates with the air delivery port.

[0021] As a further embodiment of the present invention: the airtightness detection mechanism includes a second movable plate disposed on the second drive module, a receiving plate fixed on the second movable plate, and a groove formed on the receiving plate.

[0022] As a further embodiment of the present invention: a sliding block is slidably installed in the sliding groove, a hydraulic cylinder fixedly connected to the sliding block is fixed on the second movable plate, a support column is fixed on the sliding block, and a limit ring is fixed on the support column.

[0023] As a further embodiment of the present invention: the support column has symmetrically arranged sliding sleeves that slide axially, and a limiting rod fixedly connected to the tester is fixed on the sliding sleeve. A second spring is sleeved on the support column, and the two ends of the second spring abut against the limiting ring and the sliding sleeve, respectively.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention achieves airtightness detection of steel pipes by combining positive and negative pressure. By pumping gas into the sealed steel pipe through a sealed pressurization mechanism to form a stable positive pressure, a local negative pressure environment is formed outside the weld to be tested by an airtightness detection mechanism. In this way, under the dual action of positive and negative pressure, even if there is an extremely small leak point in the weld, the high-pressure gas will quickly flow through the leak point to the negative pressure area, thereby achieving high-precision and high-sensitivity detection of minute leak defects.

[0025] The initial seal is achieved by the deformation of the conical sealing tube, and the continuous compression of the first spring simultaneously increases the squeezing force on the sealing tube during the pumping process, forming an effective adaptive sealing mechanism. This effectively prevents seal failure that may occur when the detection pressure increases, and ensures the high stability of the detection pressure inside the steel pipe.

[0026] The use of positive and negative gas pressure testing effectively avoids the problem of low testing efficiency caused by the need for drainage and drying processes in water pressure testing and bubble method. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of one embodiment of a steel pipe welded area airtightness testing machine.

[0028] Figure 2 This is a structural schematic diagram from another angle in one embodiment of a steel pipe welded position airtightness testing machine.

[0029] Figure 3 This is a schematic diagram of the internal structure of a steel pipe welded position airtightness testing machine in one embodiment.

[0030] Figure 4 This is a schematic diagram of the airtightness testing mechanism in one embodiment of a steel pipe welding position airtightness testing machine.

[0031] Figure 5 This is an exploded structural diagram of the airtightness testing mechanism in one embodiment of a steel pipe welded position airtightness testing machine.

[0032] Figure 6This is a schematic diagram showing the connection relationship between the bidirectional clamping assembly and the sealing and pressurizing mechanism in one embodiment of a steel pipe welding position airtightness testing machine.

[0033] Figure 7 This is a schematic diagram of the sealing and pressurizing mechanism in one embodiment of a steel pipe welding position airtightness testing machine.

[0034] Figure 8 This is a schematic diagram of the bidirectional clamping assembly in one embodiment of a steel pipe welded position airtightness testing machine.

[0035] Figure 9 This is a schematic diagram of the partial sealing and pressurizing mechanism in one embodiment of a steel pipe welded position airtightness testing machine.

[0036] Figure 10 This is an exploded structural diagram of a portion of the sealing and pressurizing mechanism in one embodiment of a steel pipe welded position airtightness testing machine.

[0037] In the diagram: 1. Machine base; 2. First support frame; 3. Second support frame; 4. First drive module; 5. First movable plate; 6. Support plate; 7. Support sleeve; 8. Support rod; 801. Fixing ring; 9. Pump cylinder; 10. Push rod; 11. Piston disc; 12. First spring; 13. Fixing plate; 14. Baffle; 15. Guide column; 16. Guide sleeve; 17. Clamping plate; 18. Double-headed cylinder; 19. Second drive module; 20. Second movable plate; 21. Receiving plate; 2101. Slide groove; 22. Sliding block; 23. Support column; 2301. Limiting ring; 24. Sliding sleeve; 25. Second spring; 26. Limiting rod; 27. Tester; 2701. Through groove; 28. Conical sealing tube; 2801. Air inlet; 29. ​​Hydraulic cylinder. Detailed Implementation

[0038] 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.

[0039] Furthermore, elements in this invention are referred to as being "fixed to" or "set on" another element, which may be directly on the other element or may also include an intervening element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or may also include an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0040] Please see Figures 1-10 In this embodiment of the invention, a steel pipe weld site airtightness testing machine includes:

[0041] The machine base 1, and the first support frame 2, the second support frame 3, and the fixing plate 13 fixed on the machine base 1. The first support frame 2 is provided with a first drive module 4, and the second support frame 3 is provided with a second drive module 19.

[0042] Also includes:

[0043] A bidirectional clamping assembly is disposed on the fixed plate 13, and symmetrically arranged clamping plates 17 are connected to the bidirectional clamping assembly;

[0044] A sealing and pressurizing mechanism is installed on the first drive module 4. The sealing and pressurizing mechanism can seal both sides of the steel pipe and perform a pressurizing pumping action into the steel pipe.

[0045] An airtightness testing mechanism is installed on the second drive module 19. A tester 27 is connected to the airtightness testing mechanism. A through groove 2701 is formed at the bottom of the tester 27. The airtightness testing mechanism can drive the tester 27 to move to a position that fits against the outer wall of the steel pipe and perform an airtightness testing action on the steel pipe.

[0046] Specifically, during the production of steel pipes, steel sheets are bent and then welded together. To ensure the airtightness of the steel pipe, airtightness testing of the welded areas is required. To do this, the steel pipe to be tested is placed between clamping plates 17 and clamped and fixed by the bidirectional clamping assembly. After clamping, the first drive module 4 controls the sealing and pressurizing mechanism to move towards both ends of the steel pipe. Under the action of the sealing and pressurizing mechanism, both ends of the steel pipe are first sealed and then pressurized, maintaining a sealed positive pressure state inside the steel pipe. At this time, under the action of the second drive module 19, the airtightness testing mechanism controls the tester 27 to move to the weld seam. At the starting point, directly above the tester, the airtightness testing mechanism will control the tester 27 to move to a position that is tightly fitted to the outer wall of the steel pipe, so that the through groove 2701 connects with the weld in that area, and the weld in that area is enclosed within the tester 27. At this time, a negative pressure can be formed inside the tester 27. Under the dual action of the positive pressure inside the steel pipe and the negative pressure inside the tester 27, the weld in that area is tested. If the weld airtightness is good, the pressure inside the tester 27 will not change. If the weld airtightness is poor, the pressure inside the tester 27 will increase. After the weld in that area is tested, the tester 27 is controlled to move to the next area to be tested, and the subsequent welds are tested for airtightness in sequence until the test is completed.

[0047] Please see Figures 1-3 , Figure 6 , Figure 8The bidirectional clamping assembly includes a baffle 14 fixed on the fixed plate 13, a guide post 15 fixed on the baffle 14, a guide sleeve 16 symmetrically arranged and slidably mounted on the guide post 15, the guide sleeve 16 being fixedly connected to the clamping plate 17, and a double-headed cylinder 18 fixedly mounted on the guide post 15 and fixedly connected to the guide sleeve 16.

[0048] Please see Figures 1-3 , Figure 6 , Figure 7 , Figure 9 , Figure 10 The sealing and pressurizing mechanism includes a first movable plate 5 disposed on the first drive module 4, and a support plate 6 fixed on the first movable plate 5; it also includes an elastic component and a pumping component disposed on the support plate 6. The elastic component includes a support sleeve 7 fixed on the support plate 6, a support rod 8 axially sliding inside the support sleeve 7, a pumping cylinder 9 slidably mounted on the support rod 8, and a first spring 12 sleeved on the support sleeve 7 and the support rod 8. The two ends of the first spring 12 abut against the support plate 6 and the pumping cylinder 9, respectively. The pumping component includes a piston disc 11 slidably and sealingly connected inside the pumping cylinder 9, and a push rod 10 fixed on the piston disc 11 that penetrates the pumping cylinder 9 and is fixedly connected to the support plate 6.

[0049] A conical sealing tube 28 is fixed at the end of the pump cylinder 9. An air delivery hole 2801 is formed on the conical sealing tube 28. A pressurization chamber that communicates with the air delivery hole 2801 is formed between the piston disc 11 and the conical sealing tube 28.

[0050] Please see Figure 6 In detail, the conical sealing tube 28 is made of rubber. The central axis of the conical sealing tube 28 coincides with the central reference plane of the two sets of clamping plates 17. The first drive module 4 is composed of a motor, a bidirectional lead screw, and a guide rail. The first movable plate 5 is threadedly connected to the bidirectional lead screw and slidably connected to the guide rail. Therefore, when the motor controls the bidirectional lead screw to rotate, it can drive the two first movable plates 5 to slide radially along the guide rail, and the two first movable plates 5 will move towards each other or away from each other.

[0051] Please see Figure 9In the initial state, under the action of the first drive module 4, the two first movable plates 5 are located at the end of their stroke in the direction away from each other, that is, the distance between the two conical sealing tubes 28 is the largest. The end of the support rod 8 is fixed with a fixing ring 801. The pump cylinder 9 is located at the end of its stroke in the direction away from the support plate 6 and is in contact with the fixing ring 801, that is, the distance between the pump cylinder 9 and the support plate 6 is the largest. The extension of the first spring 12 in its natural state is greater than the maximum distance between the pump cylinder 9 and the support plate 6. Therefore, the first spring 12 is in a pre-compressed state and always provides the pump cylinder 9 with a thrust in the direction away from the support plate 6. At this time, under the action of the push rod 10, the distance between the piston disc 11 and the conical sealing tube 28 is the largest, so that the volume of the pressurization chamber is the largest. Under the action of the double-headed cylinder 18, the distance between the two clamping plates 17 is the largest.

[0052] When it is necessary to perform airtightness testing on steel pipes, the steel pipe to be tested can be placed between two sets of clamping plates 17. Under the action of the double-headed cylinder 18, the two guide sleeves 16 are driven to slide along the axial direction of the guide column 15 and move towards each other. The guide sleeves 16 will drive the clamping plates 17 to move until the clamping plates 17 are in contact with the outer circumference of the steel pipe. Under the action of the clamping plates 17, the steel pipe is clamped and the weld of the steel pipe is facing the tester 27.

[0053] Subsequently, under the action of the first drive module 4, the two first movable plates 5 are controlled to move toward each other. Under the action of the first spring 12, the pump cylinder 9 and the support plate 6 move synchronously, that is, the distance between the pump cylinder 9 and the support plate 6 remains unchanged, thereby driving the two conical sealing tubes 28 to move toward each other. When the conical sealing tube 28 is inserted into the end of the steel pipe, the conical sealing tube 28 will deform until the conical sealing tube 28 is tightly fitted with the two ends of the steel pipe. At this time, the inside of the steel pipe is in a sealed state.

[0054] The first movable plate 5 continues to move. Since the conical sealing tube 28 cannot move, the position of the pump cylinder 9 no longer changes. Under the action of the support plate 6, the size of the support sleeve 7 and the support rod 8 will gradually increase and compress the first spring 12. The support plate 6 will also drive the push rod 10 to move, so that the piston disc 11 moves toward the conical sealing tube 28, thereby reducing the volume of the pressurization chamber. Since the steel pipe is in a sealed state, and the pressurization chamber is connected to the internal cavity of the steel pipe through the air supply hole 2801, the air in the pressurization chamber will be pushed into the steel pipe, so that positive pressure is formed inside the steel pipe.

[0055] Since the conical sealing tube 28 is deformable, it ensures that the steel pipe is sealed after it is tightly fitted to the pipe opening. As the support plate 6 and the pump cylinder 9 move in a misaligned manner, it can pump air into the steel pipe after it is sealed to detect whether there is any leakage in the weld area. It can also increase the squeezing force on the conical sealing tube 28 by compressing the first spring 12, thereby ensuring a tighter seal between the conical sealing tube 28 and the steel pipe end. This effectively avoids the sealing failure that may occur due to pressure increase during the pressurization process. When the air pressure inside the steel pipe reaches the preset detection value, the first drive module 4 stops moving. At this time, the inside of the steel pipe is maintained in a stable positive pressure state, providing accurate and stable pressure conditions for subsequent airtightness testing.

[0056] A pressure sensor is installed inside the pump cylinder 9. The pressure sensor can detect the air pressure inside the steel pipe to ensure that the air pressure inside the steel pipe reaches the required value.

[0057] Please see Figures 1-5 The airtightness testing mechanism includes a second movable plate 20 disposed on the second drive module 19. A receiving plate 21 is fixed on the second movable plate 20. A sliding groove 2101 is formed on the receiving plate 21. A sliding block 22 is slidably installed in the sliding groove 2101. A hydraulic cylinder 29 fixedly connected to the sliding block 22 is fixed on the second movable plate 20. A support column 23 is fixed on the sliding block 22. A limit ring 2301 is fixed on the support column 23. A symmetrically arranged sliding sleeve 24 slides axially on the support column 23. A limit rod 26 fixedly connected to the tester 27 is fixed on the sliding sleeve 24. A second spring 25 is sleeved on the support column 23. The two ends of the second spring 25 abut against the limit ring 2301 and the sliding sleeve 24, respectively.

[0058] Furthermore, a key is fixed to the outer circumference of the support column 23, and a keyway is formed on the inner wall of the sliding sleeve 24 to fit the key. Under the action of the key and the keyway, the sliding sleeve 24 can only slide along the axial direction of the support column 23 and will not deviate.

[0059] The second drive module 19 is composed of a motor, a lead screw, and a guide rod. The second movable plate 20 is threadedly connected to the lead screw and slidably connected to the guide rod. When the motor is working, the lead screw drives the second movable plate 20 to slide along the axial direction of the guide rod to adjust the position of the tester 27 in the horizontal direction.

[0060] Please see Figure 4The tester 27 is a sealed box made of rubber. A pressure sensor is installed inside the sealed box to monitor the pressure changes inside the tester 27 in real time. The sealed box is connected to the outside air through the through groove 2701. The tester 27 is in an extended state on both sides. A rigid sealing rod is fixed at the extended position. The rigid sealing rod is fixedly connected to the limiting rod 26.

[0061] Please see Figure 4 In the initial state, under the action of the hydraulic cylinder 29, the sliding block 22 is located at the end of the stroke of the slide groove 2101 facing the second movable plate 20, so that the distance between the tester 27 and the first support frame 2 is maximized. The two sliding sleeves 24 are located at the end of the stroke in the direction away from each other, that is, the distance between the sliding sleeve 24 and the limiting ring 2301 is maximized. The elongation of the second spring 25 in its natural state is greater than the maximum distance between the sliding sleeve 24 and the limiting ring 2301. Therefore, the second spring 25 is in a pre-compressed state and always provides the sliding sleeve 24 with a thrust in the direction away from the limiting ring 2301. The sliding sleeve 24 will control the tester 27 to be in a horizontally unfolded state through the limiting rod 26.

[0062] When it is necessary to perform airtightness testing on the weld of the steel pipe, the steel pipe is clamped by the clamping plate 17 and the two ends of the steel pipe are sealed by the conical sealing pipe 28. After pressurization, the weld can be tested. At this time, under the action of the second drive module 19, the tester 27 is moved to the position above the weld start point by the second movable plate 20. Under the action of the hydraulic cylinder 29, the sliding block 22 is pushed to slide radially along the slide groove 2101 and move away from the second movable plate 20, thereby driving the support column 23 to move. The support column 23 will control the tester 27 to move towards the outer wall of the steel pipe through the sliding sleeve 24 and the limit rod 26.

[0063] When the center of the tester 27 is in contact with the outer wall of the steel pipe, the weld will be connected to the tester 27 under the action of the through groove 2701. At this time, the sliding block 22 continues to move, and the limit rod 26 will control the deformation of the tester 27 through the hard sealing rod and gradually wrap around the outer wall of the steel pipe. During this process, due to the bending of the tester 27, that is, the width of the tester 27 in the horizontal direction decreases, the two sliding sleeves 24 move towards each other and compress the second spring 25. When the tester 27 is completely in contact with the steel pipe, that is, the tester 27 is in the arc-shaped wrapping state, the hydraulic cylinder 29 stops working. At this time, under the action of the through groove 2701, the cavity inside the tester 27 is connected to the weld.

[0064] A negative pressure can be created inside the tester 27 by controlling the air pump. Under the action of the negative pressure in the tester 27 and the positive pressure inside the steel pipe, the weld area of ​​the steel pipe can be tested for air tightness. If the weld of the steel pipe is airtight, the negative pressure state inside the tester 27 will be maintained, and the pressure value detected by the internal air pressure sensor will not change significantly. If there is a leakage defect in the weld, the positive pressure gas inside the steel pipe will continuously flow into the sealed cavity of the tester 27 through the leakage point, causing its internal pressure to rise. The air pressure sensor will detect the pressure change, thereby achieving accurate location and judgment of the leakage point. In this way, through the dual action of positive and negative pressure, the weld in the test area can be tested for air tightness, preventing the problem of inaccurate test results caused by the reduction of positive pressure inside the steel pipe due to leakage points in other locations of the weld.

[0065] During this process, the tester 27 itself is made of rubber and, under the preload of the second spring 25 and the guidance of the sliding sleeve 24, can adapt to the elastic deformation of the outer wall curvature of steel pipes of different diameters, ensuring that its bottom and sides always keep in close contact with the outer wall of the steel pipe, thereby forming a local sealed chamber in the weld inspection area, effectively preventing external gas from seeping in or internal gas from leaking out, and ensuring the stability of the negative pressure testing environment and the accuracy of the test results.

[0066] Because the weld seam is relatively long, it needs to be inspected in sections. After the inspection of the inspection points in a certain area is completed, the hydraulic cylinder 29 controls the tester 27 to separate from the steel pipe, and the internal pressure of the tester 27 returns to normal. The second drive module 19 drives the second movable plate 20 to move along the axial direction of the steel pipe to the next inspection area. By repeating the above inspection process, continuous and automated inspection of the entire weld seam can be achieved. If there is a leak in the pipeline weld seam, when the gas leakage is slow, the gas pressure sensor in the pump cylinder 9 can detect the gas pressure in the steel pipe in real time, and the piston disc 11 is moved slightly by the first drive module 4 to replenish the lost gas pressure. When the gas leakage is fast, the first drive module 4 can be controlled to reset first. After the second drive module 19 moves to the inspection area, the conical sealing pipe 28 is controlled to seal and pressurize, so as to ensure sufficient inspection conditions and thus accurately locate the leak area.

[0067] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0068] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A steel pipe weld site airtightness testing machine, comprising: The machine base, and a first support frame, a second support frame, and a fixing plate fixed on the machine base, wherein a first drive module is provided on the first support frame and a second drive module is provided on the second support frame; Its characteristic is that it further includes: A bidirectional clamping assembly is disposed on the fixed plate, and symmetrically arranged clamping plates are connected to the bidirectional clamping assembly; A sealing and pressurizing mechanism is installed on the first drive module. The sealing and pressurizing mechanism can seal both sides of the steel pipe and perform a pressurizing pumping action into the steel pipe. An airtightness testing mechanism is installed on the second drive module. A tester is connected to the airtightness testing mechanism. A through groove is formed at the bottom of the tester. The airtightness testing mechanism can drive the tester to move to a position that fits against the outer wall of the steel pipe and perform an airtightness test on the steel pipe.

2. The airtightness testing machine for steel pipe welded positions according to claim 1, characterized in that, The bidirectional clamping assembly includes a baffle fixed on the fixed plate, a guide post fixed on the baffle, and symmetrically arranged guide sleeves that slide axially on the guide post. The guide sleeves are fixedly connected to the clamping plate, and a double-headed cylinder fixed on the guide post and fixedly connected to the guide sleeve.

3. The airtightness testing machine for steel pipe welded positions according to claim 1, characterized in that, The sealing and pressurizing mechanism includes a first movable plate disposed on the first drive module, and a support plate is fixed on the first movable plate; It also includes an elastic component and a pumping component disposed on the support plate.

4. The airtightness testing machine for steel pipe welded positions according to claim 3, characterized in that, The elastic component includes a support sleeve fixed to the support plate, a support rod axially sliding inside the support sleeve, a pump cylinder slidably mounted on the support rod, and a first spring sleeved on the support sleeve and the support rod, with the two ends of the first spring abutting against the support plate and the pump cylinder, respectively.

5. The airtightness testing machine for steel pipe welded positions according to claim 4, characterized in that, The pumping assembly includes a piston disc that is slidably and sealed within the pumping cylinder, and a push rod that passes through the pumping cylinder and is fixedly connected to the support plate is fixed on the piston disc.

6. The airtightness testing machine for steel pipe welded positions according to claim 5, characterized in that, A conical sealing tube is fixed to the end of the pump cylinder, and an air delivery hole is formed on the conical sealing tube.

7. A steel pipe weld site airtightness testing machine according to claim 6, characterized in that, A pressurized chamber that communicates with the air delivery port is formed between the piston disc and the tapered sealing tube.

8. The airtightness testing machine for steel pipe welded positions according to claim 1, characterized in that, The airtightness detection mechanism includes a second movable plate disposed on the second drive module, a receiving plate fixed on the second movable plate, and a groove formed on the receiving plate.

9. A steel pipe weld site airtightness testing machine according to claim 8, characterized in that, A sliding block is slidably installed in the slid groove, and a hydraulic cylinder fixedly connected to the sliding block is fixed on the second movable plate. A support column is fixed on the sliding block, and a limit ring is fixed on the support column.

10. A steel pipe weld site airtightness testing machine according to claim 9, characterized in that, The support column has symmetrically arranged sliding sleeves that slide axially. A limiting rod that is fixedly connected to the tester is fixed on the sliding sleeve. A second spring is sleeved on the support column, and the two ends of the second spring abut against the limiting ring and the sliding sleeve, respectively.

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