A back argon protection device for pipe tungsten electrode argon arc welding

Abstract

The application discloses a back argon filling protection device for pipeline tungsten electrode argon arc welding, which comprises a main air inlet pipe which can be placed in the inside of a pipeline to be welded, a first end of the main air inlet pipe is connected with an argon source through a hose, a second end of the main air inlet pipe is detachably connected with a screw rod, and a baffle which can enter the inside of the pipeline to be welded is arranged at the end of the screw rod away from the main air inlet pipe; an air outlet pipe ring is arranged on the main air inlet pipe, the inside of the air outlet pipe ring is communicated with the inside of the main air inlet pipe through a plurality of thin pipes, and a plurality of air holes are arranged on the air outlet pipe ring; two elastic sealing pads are arranged on the main air inlet pipe and located on the two sides of the air outlet pipe ring, the two elastic sealing pads are respectively away from the air outlet pipe ring by a predetermined distance, the diameters of the two elastic sealing pads are larger than the diameter of the pipeline to be welded, and the two elastic sealing pads are placed in the two pipelines to be welded so as to isolate the weld from the inside of the pipelines located on the two sides of the weld. The device is simple in manufacturing, installation and removal, and can greatly improve construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of metal pipe welding technology, and in particular to an argon purging protection device for pipe tungsten inert gas welding. Background Technology

[0002] In the welding of high-pressure pipelines, boiler pipelines, and sealed containers, the most reliable method for ensuring quality during manual operation is manual tungsten inert gas (TIG) welding. However, during the welding process, some pipe materials, due to their high content of elements such as nickel and chromium, are prone to high-temperature oxidation when exposed to external air at high welding temperatures. This can lead to weld performance failing to meet expectations. For example, this can occur when welding titanium pipes, stainless steel pipes, and Inconel pipes. To ensure the quality of pipeline welding, argon gas purging must be used during the welding process to prevent the metal on the back of the weld from oxidizing due to contact with air at high temperatures.

[0003] Currently, the argon purging method used for welding such pipes is full-pipe argon purging (i.e., sealing from both ends of the pipe joint to ensure the entire pipe is filled with argon). This method not only consumes a huge amount of argon, but the back-purging protection is also ineffective due to the long pipe length, easily affecting the quality of pipe flaw detection and causing frequent rework. Multiple reworks can render some materials unusable, increasing material and labor costs and significantly impacting our construction reputation. To improve welding quality, ensure construction schedule, and significantly reduce material and labor costs, the most effective solution is to improve the back-purging device.

[0004] The existing argon backfill protection devices for argon arc welding are complex to manufacture and have certain limitations in use. Some devices use gaskets that are only suitable for straight pipe welding and not for pipe bends. Some devices use inflatable airbags for sealing, but they do not take into account whether they are heat-resistant. To avoid the airbags being destroyed by high temperatures, the length of the pipe protection must be extended. At the same time, many protection devices only take into account the welding protection and do not take into account the ease of dismantling after welding.

[0005] Therefore, the existing argon purging protection devices behind pipeline tungsten inert gas welding need to be improved. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes an improved argon purging protection device for pipeline tungsten inert gas (TIG) welding. This improvement solves the technical problems of the existing argon purging protection devices being complex to manufacture, installed in the pipeline before welding, and removed from the pipeline after welding, as well as having limited applicability to a wide range of pipelines.

[0007] This invention discloses an argon purging protection device for pipeline tungsten inert gas welding, comprising:

[0008] A main air inlet pipe that can be placed inside the pipe to be welded, the first end of the main air inlet pipe being connected to an argon gas source via a hose, the second end of the main air inlet pipe being detachably connected to a lead screw, and the end of the lead screw away from the main air inlet pipe being provided with a baffle that can enter the inside of the pipe to be welded;

[0009] An exhaust pipe ring is sleeved on the main intake pipe. The interior of the exhaust pipe ring is connected to the interior of the main intake pipe through several thin tubes. An air hole is provided on the exhaust pipe ring.

[0010] Two elastic sealing gaskets are fitted onto the main air inlet pipe and located on both sides of the air outlet pipe annulus. The two elastic sealing gaskets are respectively spaced a predetermined distance from the air outlet pipe annulus. The diameter of the two elastic sealing gaskets is larger than the diameter of the pipe to be welded. The two elastic sealing gaskets are placed inside the two pipes to be welded to isolate the weld from the inside of the pipe located on both sides of the weld.

[0011] According to one embodiment of the present invention, an exhaust port is provided on the side of the main air inlet pipe away from the argon source, and the elastic sealing gasket away from the argon source is disposed between the outlet pipe annulus and the exhaust port.

[0012] According to one embodiment of the present invention, the elastic sealing gasket is a high-density sponge pad or a high-elasticity sponge pad.

[0013] According to one embodiment of the present invention, the diameter of the elastic sealing gasket is 2-3 mm larger than the diameter of the pipe to be welded, and the thickness of the elastic sealing gasket is 38-42 mm.

[0014] According to one embodiment of the present invention, the diameter of the main intake pipe is 18-22 mm, the length of the main intake pipe is ≥650 mm, and the outer diameter of the outlet pipe annulus is 80-100 mm.

[0015] According to one embodiment of the present invention, the predetermined distance between the two elastic sealing gaskets and the vent pipe annulus is 240-260 mm.

[0016] According to one embodiment of the present invention, the diameter of the vent hole is 3 to 5 mm.

[0017] According to one embodiment of the present invention, one end of the lead screw is provided with an external thread, and the second end of the main intake pipe is provided with an internal thread that matches the external thread to realize a detachable connection between the lead screw and the main intake pipe.

[0018] According to one embodiment of the present invention, the shape of the baffle is any one of a circle, rhombus, rectangle, square or polygon.

[0019] According to one embodiment of the present invention, the number of capillaries is three.

[0020] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0021] The argon-filled back-end protection device for tungsten inert gas (TIG) welding of pipelines provided by this invention utilizes a detachable screw rod connected to the second end of the main inlet pipe. Before installation, the screw rod can be removed from the main inlet pipe, elastic sealing gaskets are installed on both sides of the outlet annulus of the main inlet pipe, and then the screw rod is reconnected to the second end of the main inlet pipe. A flexible hose connected to the argon source is inserted into one end of a pipe and exits through the weld joint at the other end, connecting to the first end of the main inlet pipe. When the weld joints of two pipes to be welded are joined, the two elastic sealing gaskets of the assembled protection device can be directly placed inside the two pipes, thus avoiding the cumbersome and complex installation process caused by inserting the assembled protection device entirely into the pipe. A baffle plate at one end of the screw rod prevents the elastic sealing gaskets, which are far from the argon source, from falling into the welded pipe. This facilitates the removal of the assembled protection device from the pipe by simply dragging the flexible hose after welding, simplifying the removal of the post-weld protection device. Furthermore, the protection device is simple to manufacture.

[0022] Furthermore, the protective device provided by this invention is applicable not only to welding straight pipes together but also to welding straight pipes to elbows, expanding the range of applications for the protective device. The protective device provided by this invention is simple to manufacture, install, and dismantle, which greatly improves construction efficiency and significantly reduces argon gas consumption. It is suitable for welding various types of pipes and has a wide range of applications. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of an argon purging protection device for pipeline tungsten inert gas welding disclosed in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0026] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0027] like Figure 1 As shown, an embodiment of the present invention discloses a back-filling argon protection device 100 for pipeline tungsten inert gas welding, comprising:

[0028] A main air inlet pipe 10 can be placed inside the pipe to be welded. The first end 11 of the main air inlet pipe 10 is connected to an argon gas source through a hose. The second end 12 of the main air inlet pipe 10 is detachably connected to a lead screw 60. The end of the lead screw away from the main air inlet pipe is provided with a baffle 70 that can enter the inside of the pipe to be welded.

[0029] An exhaust pipe ring 30 is sleeved on the main intake pipe 10. The inside of the exhaust pipe ring 30 is connected to the inside of the main intake pipe 10 through several thin tubes 40. An air hole 31 is provided on the exhaust pipe ring 30.

[0030] Two elastic sealing gaskets 50 are fitted onto the main air inlet pipe 10 and located on both sides of the air outlet pipe annulus 30. The two elastic sealing gaskets 50 are respectively spaced at a predetermined distance from the air outlet pipe annulus 30. The diameter of the two elastic sealing gaskets 50 is larger than the diameter of the pipe to be welded. After the two elastic sealing gaskets 50 are placed inside the two pipes to be welded, they isolate the weld from the inside of the pipe located on both sides of the weld.

[0031] The pipeline tungsten inert gas (TIG) welding back-filling argon protection device 100 provided in the above embodiments of the present invention, via a lead screw 60 detachably connected to the second end 12 of the main inlet pipe 10, allows for pre-installation removal of the lead screw 60 from the main inlet pipe 10. Elastic sealing gaskets 50 are then installed on both sides of the outlet annulus 30 of the main inlet pipe 10 before the lead screw 60 is reconnected to the second end 12 of the main inlet pipe 10. A flexible hose connected to the argon source passes through one end of a pipe and exits through the weld joint at the other end, connecting to the first end 11 of the main inlet pipe 10. Finally, when the weld joints of two pipes to be welded are joined, the assembled hose is directly connected to the main inlet pipe 10. The two elastic sealing gaskets 50 of the protective device 100 can be placed inside the two pipes, thus avoiding the cumbersome and complicated installation process caused by inserting the assembled protective device 100 entirely into the pipe. A baffle 70 at one end of the screw 60 prevents the elastic sealing gaskets 50, which are far from the argon source, from falling into the welded pipe. This facilitates the removal of the assembled protective device 100 from the pipe by simply dragging the hose after welding, simplifying the disassembly of the protective device 100 after welding. Furthermore, the protective device 100 is simple to manufacture. In addition, the protective device 100 provided by this invention is suitable not only for welding straight pipes but also for welding straight pipes to elbows, expanding its applicability to various pipe types.

[0032] In the above embodiment, when the two elastic sealing gaskets 50 are placed inside the two pipes to be welded, the vent pipe ring 30 can be placed at the weld joint of the two pipes to be welded, which helps to improve the protective effect of argon gas on the welding position. Furthermore, the vent pipe ring 30 has evenly distributed vent holes 31, which facilitates the uniform ejection of argon gas from the vent pipe ring 30. The diameter of the elastic sealing gasket 50 can be adjusted and manufactured according to the diameter of the pipes to be welded, offering the advantages of convenience and simplicity.

[0033] In some embodiments, a plurality of vent holes 31 are uniformly arranged on the vent pipe annulus 30. This facilitates the uniform ejection of argon gas and improves the protective effect of argon gas during welding.

[0034] In some embodiments, an exhaust port 80 is provided on the side of the main inlet pipe 10 away from the argon source, and an elastic sealing gasket 50 away from the argon source is disposed between the outlet pipe annulus 30 and the exhaust port 80. Because argon is continuously injected into the pipe during welding, as the weld becomes shorter, the gas pressure within the sealing area formed by the two elastic sealing gaskets 50 gradually increases. If the gas pressure is not reduced when sealing the weld, the increased argon pressure within the sealing area will directly escape from the final weld seal, ultimately preventing normal sealing of the pipe's root pass. To avoid affecting normal pipe welding and considering a suitable final filling pressure range, an exhaust port 80 is provided on the side of the main inlet pipe 10 away from the argon source in this embodiment. This allows the exhaust port to naturally release pressure when the pressure within the sealing area increases, preventing pressure increases within the sealing area and greatly improving the stability of the argon protection effect.

[0035] In some embodiments, the elastic sealing gasket 50 is a high-density sponge pad or a high-elasticity sponge pad. In this embodiment, compared to harder plastic materials, the high-density sponge pad or high-elasticity sponge pad can deform to make the protective device suitable for welding pipe bends and straight pipes, and the protective device can be easily removed as a whole after welding. Compared to airbag seals and asbestos seals, the high-density sponge pad or high-elasticity sponge pad is less susceptible to damage from welding heat transfer. It can be placed inside the pipe to be welded, which helps to significantly reduce the sealing area protected by argon gas, thereby greatly reducing gas consumption. Moreover, because the sponge pad is elastic, it can fit tightly against the inner wall of the pipe to achieve a good sealing effect, while also being relatively easy and inexpensive to remove, thus helping to reduce costs.

[0036] In some embodiments, the diameter of the elastic sealing gasket 50 is 2-3 mm larger than the diameter of the pipe to be welded, and the thickness of the elastic sealing gasket 50 is 38-42 mm. In some embodiments, the diameter of the elastic sealing gasket 50 is 2 mm larger than the diameter of the pipe to be welded, and the thickness of the elastic sealing gasket 50 is 40 mm. In the above embodiments, the larger diameter of the elastic sealing gasket 50 than the diameter of the pipe to be welded ensures a tight fit between the elastic sealing gasket 50 and the inner wall of the pipe, preventing argon gas leakage. The thickness of the elastic sealing gasket 50 of 38-42 mm avoids the elastic sealing gasket from being damaged by excessively high temperatures during pipe welding, ensuring the smooth progress of the welding process.

[0037] In some embodiments, the diameter of the main intake pipe 10 is 18-22 mm, the length of the main intake pipe 10 is ≥650 mm, and the outer diameter of the outlet pipe annulus 30 is 80-100 mm. In some embodiments, the diameter of the main intake pipe 10 is 20 mm. In the above embodiments, the protective device provided by the present invention is suitable for welding between pipes with large diameters (e.g., pipe diameter ≥80 mm), which is beneficial for pre-welding installation and post-welding removal of the protective device from the pipe, and is easy to manufacture, and is suitable for welding various types of pipes.

[0038] In some embodiments, the predetermined distance between the two elastic sealing gaskets 50 and the outlet pipe annulus 30 is 240-260 mm. In some embodiments, the predetermined distance between the two elastic sealing gaskets 50 and the outlet pipe annulus 30 is 250 mm. In the above embodiments, the influence of heat transfer on the elastic sealing gaskets during pipe welding can be avoided, preventing the elastic sealing gaskets from being damaged by excessively high temperatures. At the same time, the sealing area protected by welding can be effectively shortened, which can improve the protection effect and significantly reduce the consumption of argon gas.

[0039] In some embodiments, the diameter of the vent hole 80 is 3-5 mm, preferably 4 mm. In this embodiment, when the pressure in the sealed area protected by the weld increases in the later stage of welding, the vent hole 80 can play a role in natural pressure relief, while also ensuring that the pressure in the sealed area is not reduced too much, thus ensuring the stability of the argon pressure in the sealed area and greatly improving the stability of the argon protection effect.

[0040] In some embodiments, one end of the lead screw 60 is provided with an external thread, and the second end of the main intake pipe 10 is provided with an internal thread that matches the external thread to achieve a detachable connection between the lead screw 60 and the main intake pipe 10. In this embodiment, it is beneficial to disassemble and install the lead screw 60 and the main intake pipe 10. When the lead screw 60 is connected to the main intake pipe 10, the second end 12 of the main intake pipe 10 can be sealed, and it is also convenient to install the elastic sealing gasket 50 on the main intake pipe 10. It is also convenient to connect the baffle 70 to the main intake pipe 10, thereby realizing the convenience of installing the protective device in the pipeline before welding and the convenience of removing it from the pipeline after welding.

[0041] In some embodiments, the baffle 70 is shaped as a circle, rhombus, rectangle, square, or polygon. In this embodiment, the baffle 70 blocks the elastic sealing gasket 50, which is far from the argon gas source, to prevent the elastic sealing gasket 50 from falling into the welded pipe. This facilitates the removal of the assembled protective device from the pipe by simply dragging the hose after welding, simplifying the removal of the post-weld protective device and making it easy to manufacture.

[0042] In some embodiments, the number of capillary tubes 40 is three. In this embodiment, the included angle between the three capillary tubes 40 is 60°, and the capillary tubes 40 can provide stable support for the exhaust pipe annulus, allowing gas in the main intake pipe 10 to enter the exhaust pipe annulus.

[0043] The method of using the argon purging protection device behind tungsten inert gas welding of pipelines provided in one embodiment of the present invention is as follows:

[0044] Before welding, the beveling of the pipe is processed using a beveling machine with a beveling angle of 30°. After the beveling is completed, the inner and outer sides of the pipe opening and the beveling surface are ground to about 15mm according to the normal test piece grinding requirements. After grinding, the beveling should be temporarily wrapped with welding tape to avoid oil stains. It should be removed when welding.

[0045] After the pipes are ground, they are assembled. First, a certain number of high-density sponge pads 50 are cut according to the diameter of the pipes to be welded. After the pipes are placed in the assembly position, the screw 60 of the second end 12 of the main air inlet pipe 10 is removed. A high-density sponge pad 50 is installed on each side of the main air inlet pipe 10. The high-density sponge pad 50 away from the argon source is installed between the outlet pipe ring 30 and the exhaust hole 80 (that is, the high-density sponge pad 50 away from the argon source cannot cover the exhaust hole 80 and must expose the exhaust hole 80). Then, the hose connected to the argon source is inserted into one end of a pipe and exited through the weld joint at the other end, and connected to the first end 11 of the main air inlet pipe 10. Then, the hose is tightened to the first end 11 of the main air inlet pipe 10 with a hose clamp so that the protective device can be pulled out by pulling the hose after welding. Then, when the weld joints of the two pipes to be welded are joined, the two high-density sponge pads 50 of the assembled protective device are placed directly in the two pipes.

[0046] Leave a 3-5mm gap between the two pipes to be welded. The positioning welding also requires back gas filling protection. Place the gas outlet ring directly in front of the weld gap, turn on the argon gas source to fill the pipe with argon gas. When argon gas is ejected from the weld, it proves that the air in the pipe has been expelled. Use a welding special sealing bag to stick the gas outlet ring 30, leaving only the position of the positioning welding point to improve the argon gas protection effect. Start welding the positioning points. The positioning point length is 10-15mm, and the number of positioning points is 1-2 points. The current is 90-100A. After positioning, grind the two ends of the positioning point to make a gentle slope to facilitate the joint.

[0047] The current parameters during formal welding are the same as those during positioning point welding. The argon flow rate is 10-12 L / min. After the root pass welding is completed, allow it to cool down appropriately before welding the cover pass. Avoid welding at high temperatures. Argon gas protection is also required during cover pass welding. The argon flow rate is 6-8 L / min, and the welding current is 110-130 A. Avoid welding with high current and low welding speed, which can cause the weld temperature to be too high. After welding, allow the weld to cool down appropriately before stopping the back gas supply. When removing the argon protection device, simply pull the hose connected to the first end 11 of the main air inlet pipe 10. Then, follow the same method to weld the next pipe opening.

[0048] The argon back purging protection device provided in this embodiment of the invention effectively improves the construction welding quality, eliminates the need for rework of the weld, and greatly reduces gas consumption. The device is easy to install and remove, has strong on-site adaptability, and is suitable for welding all pipe joints with a diameter of 80mm or more that require argon back purging protection. It has certain application value.

[0049] In summary, the pipeline tungsten inert gas welding back-filling argon protection device 100 provided in this embodiment of the invention, through the lead screw 60 detachably connected to the second end 12 of the main inlet pipe 10, allows the lead screw 60 to be removed from the main inlet pipe 10 before installation. Elastic sealing gaskets 50 are then installed on both sides of the outlet pipe annulus 30 of the main inlet pipe 10 before the lead screw 60 is reconnected to the second end 12 of the main inlet pipe 10. A flexible hose connected to the argon source passes through one end of a pipe and exits through the weld joint at the other end, connecting to the first end 11 of the main inlet pipe 10. Finally, when the weld joints of the two pipes to be welded are joined, the assembled device can be directly connected. The two elastic sealing gaskets 50 of the assembled protective device 100 can be placed inside the two pipes, thus avoiding the cumbersome and complicated installation process caused by inserting the assembled protective device 100 entirely into the pipes; by setting a baffle 70 at one end of the screw 60, the elastic sealing gasket 50 away from the argon gas source is blocked to prevent the elastic sealing gasket 50 from falling into the welded pipes, which makes it convenient to manually drag the hose after welding to remove the assembled protective device 100 entirely from the pipes, thus simplifying the removal of the protective device 100 after welding, and the protective device 100 is simple to manufacture.

[0050] Furthermore, the protective device 100 provided in this embodiment of the invention is applicable not only to welding straight pipes together but also to welding straight pipes to elbows, expanding the range of applications for the protective device. The protective device provided by this invention is simple to manufacture, install, and dismantle, which greatly improves construction efficiency and significantly reduces argon gas consumption. It is suitable for welding various types of pipes and has a wide range of applications.

[0051] It should be noted that the components or steps in the above embodiments can be interleaved, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of the present invention, and the protection scope of the present invention should not be limited to the above embodiments.

[0052] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0053] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for argon purging protection behind tungsten inert gas welding of pipelines, characterized in that, The argon purging protection device used for pipeline tungsten inert gas welding includes: A main air inlet pipe can be placed inside the pipe to be welded. The first end of the main air inlet pipe is connected to an argon gas source via a hose. The second end of the main air inlet pipe is detachably connected to a lead screw. The end of the lead screw away from the main air inlet pipe is provided with a baffle that can enter the inside of the pipe to be welded. One end of the lead screw is provided with an external thread, and the inside of the second end of the main air inlet pipe is provided with an internal thread that matches the external thread to realize the detachable connection between the lead screw and the main air inlet pipe. An exhaust pipe ring is fitted onto the main intake pipe. The interior of the exhaust pipe ring is connected to the interior of the main intake pipe through three thin tubes. The included angle between the three thin tubes is 60°. Air holes are evenly distributed on the exhaust pipe ring. Two elastic sealing gaskets are fitted onto the main air inlet pipe and located on both sides of the air outlet pipe annulus. The two elastic sealing gaskets are 240-260mm apart from the air outlet pipe annulus. The diameter of the elastic sealing gasket is 2-3mm larger than the diameter of the pipe to be welded. The thickness of the elastic sealing gasket is 38-42mm. The two elastic sealing gaskets are placed inside the two pipes to be welded to isolate the weld from the inside of the pipe located on both sides of the weld. The main inlet pipe is provided with an exhaust hole with a diameter of 3-5 mm on the side away from the argon source, and the elastic sealing gasket away from the argon source is provided between the outlet pipe ring and the exhaust hole. The method for argon purging protection after tungsten inert gas welding of pipelines includes: using a lead screw detachably connected to the second end of the main inlet pipe, the lead screw is first removed from the main inlet pipe before installation. Elastic sealing gaskets are then installed on both sides of the outlet annulus of the main inlet pipe before connecting the lead screw to the second end of the main inlet pipe. A flexible hose connected to the argon source is inserted into one end of a pipe and exits through the weld joint at the other end, connecting to the first end of the main inlet pipe. Then, when the weld joints of the two pipes to be welded are joined, the two elastic sealing gaskets of the assembled protection device are directly placed inside the two pipes. A baffle plate at one end of the lead screw prevents the elastic sealing gaskets, which are far from the argon source, from falling into the welded pipe.

2. The method for argon purging protection behind tungsten inert gas welding of pipelines according to claim 1, characterized in that, The elastic sealing gasket is a high-density sponge pad or a high-elasticity sponge pad.

3. The method for argon purging protection behind tungsten inert gas welding of pipelines according to claim 1, characterized in that, The diameter of the main intake pipe is 18-22mm, the length of the main intake pipe is ≥650mm, and the outer diameter of the outlet pipe ring is 80-100mm.

4. The method for argon purging protection behind tungsten inert gas welding of pipelines according to claim 1, characterized in that, The baffle is circular or polygonal in shape.

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