An Argon Purging Protection Device and Method for Welding Austenitic Stainless Steel Pipes

Abstract

This invention discloses an argon-filled protection device and method for welding austenitic stainless steel pipes. The device includes a first partition section, a second partition section, and a gas supply structure. The first and second partition sections are connected by a flexible connector. The first partition section divides the pipe and can drive the second partition section to move within the pipe. During the movement, the second partition section does not divide the pipe. The device moves to a target position within the pipe, and a magnetic component outside the pipe activates the second partition section to seal the pipe. After sealing the pipe, the pipe between the first and second partition sections becomes an isolation section. The leakage point is located on the isolation section, and the gas supply structure provides argon-filled replacement protection for the isolation section. This invention allows the device to move within the pipe and uses magnetic force to activate the second partition section to separate the pipe, without distance limitations. It is suitable for segmented isolation argon-filled protection and maintenance welding protection of long-distance pipelines.

Description

Technical Field

[0001] This invention relates to the technical field of argon purging protection devices for pipelines, specifically to an argon purging protection device and method for welding austenitic stainless steel pipelines. Background Technology

[0002] To improve the sulfuric acid corrosion resistance of the tail gas washing equipment and pipes in the Consovo process unit, some equipment and pipelines are made of S31254 super austenitic stainless steel. However, elements such as sulfur (S) and phosphorus (P) in the S31254 pipe base material and welding materials easily form low-melting-point eutectics with nickel (Ni) in the material, leading to welding cracks. Furthermore, due to limitations in construction site conditions, the argon purging protection at some weld joints is ineffective, resulting in poor weld quality. These factors necessitate frequent repair welding of leaking pipelines during use. As is well known, the main alloying elements such as chromium (Cr) and nickel (Ni) in corrosion-resistant high-alloy metals or bimetallic composite pipe materials such as stainless steel and nickel-based alloys are easily oxidized at high temperatures. Therefore, effective back-side protection measures must be taken during welding to prevent over-oxidation of the weld root and heat-affected zone, which would affect the mechanical and corrosion resistance properties of the weld joint.

[0003] Regarding argon gas protection at the back, there is currently a whole-pipe filling method, which involves sealing both ends of the pipe and filling the entire pipe with argon gas for protection. This method is simple to operate, but the longer the pipe, the more argon gas is required. Overall, the argon gas consumption is too large and uneconomical. For the reasons mentioned above, researchers began to study segmented pipeline isolation, isolating the leak point into a section called the isolation section, and then only purging the isolated section with argon. This can significantly reduce the consumption of argon gas. This is mentioned in CN201810335128.3 Welding method for stainless steel pipes with argon purging protection on the back and CN201721681401.3 An argon purging protective cover. However, these technologies all require manual assistance from one end of the pipeline to assist the operation of the argon purging protection device. For example, using a rigid support to send the protection device to the target position and inflating the gas bladder of the protection device to separate the pipeline. This actually requires the welding point to be close to the pipe opening. For existing installations, the distance between the pipeline opening and the leak point is uncertain and can be quite long. Due to the limitation of the support rod length, the argon purging protection device cannot be sent to the target position at a distance. That is, the existing installation is not suitable for argon purging protection of long pipelines. This situation is particularly prominent during maintenance welding. Summary of the Invention

[0004] The technical problem this invention aims to solve is that existing argon purging protection devices for pipelines are not suitable for long pipelines and cannot be delivered to distant target locations. The purpose of this invention is to provide an argon purging protection device and method for welding austenitic stainless steel pipelines. This device can move inside the pipeline and uses magnetic force to activate a second partition section to separate the pipeline. The activation of the second partition section is achieved manually from outside the pipe, without distance limitations, and is suitable for segmented isolation argon purging and maintenance welding protection of long-distance pipelines.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides an argon-filled protection device for welding austenitic stainless steel pipes. The device includes a first partition section, a second partition section and a gas supply structure. The first partition section and the second partition section are spaced apart by a certain distance and connected by a flexible connector.

[0007] The first dividing section divides the pipeline, and the first dividing section can drive the second dividing section to move inside the pipeline. During the movement, the second dividing section does not divide the pipeline. The device moves to the target position inside the pipeline, and uses a magnetic component outside the pipeline to activate the second dividing section to block the pipeline. After the pipeline is blocked, the pipeline between the first dividing section and the second dividing section becomes the isolation section. The leakage point is located on the isolation section, and the isolation section is protected by argon purging through a gas supply structure. The activation of the second dividing section is achieved manually outside the pipeline with magnetic assistance.

[0008] The pipe of this invention is made of S31254 super austenitic stainless steel.

[0009] The working principle is as follows:

[0010] Most current pressurization protection methods use the whole-pipe argon filling method, which involves sealing both ends of the pipeline and filling the entire pipeline with argon for protection. This method is simple to operate, but the longer the pipeline, the more argon is required, resulting in excessive argon consumption and making it uneconomical. Some methods use segmented isolation, isolating the leak point into a section, and then only argon-filled protection is applied to the isolated section. This can significantly reduce argon consumption. This is mentioned in CN201810335128.3 Welding method for stainless steel pipelines with back argon filling protection and CN201721681401.3 An argon-filled protective cover. However, these technologies all require manual assistance from one end of the pipeline to operate the argon filling protection device. For example, using a rigid support to move the protection device to the target position and pressurizing the gas bladder of the protection device to isolate the pipeline. This requires the welding point to be close to the pipe opening, making it unsuitable for long pipelines.

[0011] Therefore, this invention designs an argon-filled protection device suitable for welding austenitic stainless steel pipes over long distances. The device can move inside the pipe and uses magnetic force to activate the second partition section to separate the pipe. The activation of the second partition section is achieved manually from outside the pipe and is not limited by distance. This invention is suitable for segmented isolation argon filling and maintenance welding protection of long-distance pipes.

[0012] Furthermore, the first partition section adopts the form of a pipeline pig, with its outer rubber sheet tightly attached to the pipe wall to seal the gas. Moreover, when the pipeline is pressurized, a pressure difference is generated between the front and rear ends of the first partition section, which will drive the first partition section to move within the pipeline.

[0013] The first dividing section is provided with a first magnetic component. The shape of the first magnetic component can be spherical, square, or strip-shaped. It is not limited to direct fixed installation or movable connection. For example, when the shape of the first magnetic component is strip-shaped, it is implemented as follows: the first dividing section has a through hole in the central axis, the first magnetic component passes through the through hole, and the end of the first magnetic component is provided with a locking component.

[0014] When the device is in use, a second magnetic component is installed outside the pipe. The second magnetic component works in conjunction with the first magnetic component to locate the first sealing section through magnetic induction. The magnetic force between the first and second magnetic components is adjusted by adjusting the load on the second magnetic component, thereby fixing the first sealing section in the pipe.

[0015] Furthermore, the second magnetic component is an electromagnet, and the first magnetic component is an iron rod.

[0016] Furthermore, the flexible connector is a rope or a universal joint.

[0017] Furthermore, the second dividing section includes a tapered expansion section and a rubber expansion ring. The rubber expansion ring is sleeved outside the tapered expansion section. When the rubber expansion ring moves axially along the tapered expansion section, it expands and adheres tightly to the pipe, thus playing a dividing role.

[0018] A third magnetic element is provided inside the rubber expansion ring, and a fourth magnetic element is provided outside the pipe to cooperate with the third magnetic element. The rubber expansion ring is guided to move along the conical neck by the magnetic force between the fourth magnetic element outside the pipe and the third magnetic element inside the rubber expansion ring.

[0019] It should be noted that the first and third magnetic components inside the pipe do not generate magnetic force between each other.

[0020] Furthermore, the rubber expansion ring comprises two annular rubber rings, which are fixedly connected and bonded together with strong adhesive.

[0021] A slot is provided on the opposite surface of the two rubber rings that are fixedly connected, and the third magnetic component is fitted and built into the slot.

[0022] Furthermore, limiting mechanisms are provided at both ends of the tapered expansion section, with a first limiting mechanism provided at the large outer diameter end of the tapered expansion section and a second limiting mechanism provided at the small outer diameter end of the tapered expansion section.

[0023] Furthermore, the gas supply structure employs an external gas supply device connected to a gas pipe to supply gas to the isolation section; the gas pipe extends through the conical expansion section and then reaches a position close to the first separation section, which facilitates the replacement of gas in the separation section;

[0024] When the device moves inside the pipeline, the second partition drags the air pipe along with it. Once the first partition reaches the target position, air can be supplied directly. After the replacement is successful, the second partition is activated by the fourth magnetic component to block the pipeline.

[0025] The above technical solution divides the argon filling protection device into two sections: a first partition section and a second partition section. These two sections are spaced a certain distance apart and connected by flexible connectors such as ropes or universal joints, facilitating their movement within the non-linear pipeline. The first partition section utilizes a pipeline pig-like design; its outer rubber layer adheres tightly to the pipe wall, effectively sealing off the gas. Furthermore, during pressurization, a pressure difference is generated between the front and rear ends of the first partition section, driving its movement within the pipeline. To facilitate the positioning of the first partition section, a magnetic material, such as iron, is incorporated within it. Magnetic materials (such as electromagnets) outside the pipeline are then used to sense and locate the first partition section. The location of the partition section (the pipe is made of stainless steel, which is non-magnetic and will not affect the magnetic force of either section) increases the magnetic force of the magnetic material outside the pipe, thereby enhancing the magnetic force between the first partition section and the magnetic material outside the pipe, thus fixing the first partition section inside the pipe. During the movement of the entire argon purging protection device inside the pipe, the second partition section does not separate the pipe, ensuring that the first partition section drags the subsequent components together. After reaching the target position, the second partition section is guided to seal the pipe by the magnetic material outside the pipe. After sealing, the pipe between the first and second partition sections becomes the isolation section, and the leak point is located on the isolation section. At this point, argon purging and replacement protection can be performed. The key here is how to guide the second partition section to move within the pipeline, specifically as follows: The second partition section includes a tapered expansion section and a rubber expansion ring fitted outside the tapered expansion section. The rubber expansion ring expands and seals the pipeline as it moves axially along the tapered expansion section. A magnetic material, such as iron, is embedded within the rubber expansion ring, and a magnetic material B is placed outside the pipeline. The magnetic force between the external magnetic material B and the embedded magnetic material in the rubber expansion ring guides the rubber expansion ring to move along the tapered expansion neck. To prevent the rubber expansion ring from detaching from the tapered expansion section, limiting mechanisms, such as pins or annular bosses, are installed at both ends of the tapered expansion section. For the gas supply structure, the simplest method is for the first partition section of the argon filling protection device to drag the gas supply pipe through the pipeline. After passing through the tapered expansion section, the gas pipe extends to a position close to the first partition section, facilitating gas replacement within the partition section. Once at the target location, gas can be supplied directly, similar to the gas supply section of many existing argon filling devices. After a certain period of replacement, the second partition section is activated to seal the pipeline.

[0026] Furthermore, the gas supply structure uses a gas tank combined with a gas pipe to supply gas to the isolation section. The gas tank is connected to the second partition section, and the gas tank and the second partition section are connected by a flexible connector. The gas tank is filled with compressed argon gas, and a rubber layer is provided on the outside of the gas tank. During the movement of the device, the first partition section drags the second partition section and the gas tank together in the pipeline.

[0027] Furthermore, a solenoid valve, a battery, and a switch are installed on the air supply pipeline at the bottom of the rubber expansion ring. The solenoid valve is used to open or cut off the air supply to the isolation section of the gas tank, and the switch is used to open and close the solenoid valve.

[0028] The second limiting mechanism is made of magnetic material (magnet) or a magnet is fixed on the second limiting mechanism;

[0029] The switch is installed on the second limiting mechanism. The pressing part of the switch extends out of the second limiting mechanism and faces the rubber expansion ring. When the rubber expansion ring presses against the second limiting mechanism, the pressing part of the switch is pressed and the solenoid valve is closed. When the fourth magnetic component outside the pipeline moves the rubber expansion ring, the rubber expansion ring separates from the second limiting mechanism. The pressing part of the switch is no longer pressed and extends outward. The solenoid valve is activated and opens to start supplying gas.

[0030] The above technical solution takes into account that if the distance between the leak point and the pipe opening is very far, the gas supply pipe will be too long and heavy to be moved through the pipeline by dragging the gas supply pipe through the first dividing section. Therefore, we propose some improvements based on embodiment 1, and the specific modifications are as follows:

[0031] 1. After the second partition section, a gas tank is connected by a flexible connector such as a rope or universal joint. The gas tank is filled with compressed argon gas and a rubber layer is installed on the outside of the gas tank. During the movement, the first partition section drags the second partition section and the gas tank together.

[0032] 2. The most challenging aspect of this modification is activating the argon filling protection device to start supplying argon gas after it reaches the leak point. Metal pipes shield wireless signals, and wireless control carries a high risk of failure. Therefore, we utilize the magnetic force between magnetic materials to achieve this action. Specifically: We install a solenoid valve on the gas supply line, equipped with a power supply device and a switch. The solenoid valve opens or closes the gas supply from the tank, and the switch opens and closes the solenoid valve. The limiting structure on the outer wall of the smaller end of the tapered expansion section is made of magnetic material. It magnetically attracts the magnetic material inside the rubber expansion ring. When the argon filling protection device moves within the pipe, this limiting structure magnetically attracts the magnetic material in the rubber expansion ring, causing the argon filling protection device to... The side wall of the rubber expansion ring is pressed against the limiting structure. The solenoid valve switch is installed on this limiting structure, with the pressing part of the switch extending out of the limiting structure and facing the rubber expansion ring. When the rubber expansion ring presses against the limiting structure, the pressing part of the switch is under pressure, and the solenoid valve is closed. When the magnetic material B outside the pipeline moves the rubber ring (the magnetic force between the magnetic material B and the rubber expansion ring is greater than the magnetic force between the limiting structure and the rubber expansion ring, so the rubber expansion ring can move), the rubber expansion ring and the limiting structure, and the pressing part of the switch are no longer under pressure and extend outward. The solenoid valve is activated and opens, and gas supply begins.

[0033] Furthermore, the gas supply structure uses a gas cylinder to supply gas to the isolation section, the gas cylinder is located in the first partition section, and the gas cylinder is made of a magnetically conductive material;

[0034] It also includes a solenoid valve and a switch, wherein the solenoid valve is electrically connected to the switch, and the outlet of the solenoid valve is located in an isolation section.

[0035] To simplify the device, the gas cylinder from Embodiment 2 can be integrated into the first partition section. The gas cylinder is made of a magnetically conductive material, eliminating the need for the ferrous magnetically conductive material in the first partition section. The solenoid valve outlet is located within the isolation section, thus eliminating the need for a gas pipe.

[0036] Secondly, the present invention provides a method for using an argon-filled protective device for welding austenitic stainless steel pipes. This method, applied to the aforementioned argon-filled protective device for welding austenitic stainless steel pipes, includes the following steps:

[0037] Step 1: Move the device to the leak point: Insert the device into the pipe from one end opening, seal the pipe and pressurize it. The gas pushes the first partition section to move inside the pipe, while simultaneously moving the entire device. A second magnetic component is installed at the leak point outside the pipe. When the first partition section reaches the position corresponding to the second magnetic component, the magnetic force between the second magnetic component and the first magnetic component in the first partition section fixes the first partition section in place inside the pipe, preventing it from moving forward.

[0038] Step 2, Inflation and Replacement: Inflate the pressure protection device with argon gas through the gas tube (located at the opening at one end of the pipeline). The argon gas will replace the air between the first and second partition sections. (Of course, to reduce the replacement time, it is recommended to reduce the gas in the pipeline to normal pressure or draw a negative pressure first).

[0039] Step 3: Move the fourth magnetic component in the pipeline. Utilize the magnetic force between the fourth magnetic component and the third magnetic component in the second dividing section of the rubber expansion ring to cause the rubber expansion ring to move axially and expand, thus sealing the pipeline.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] 1. According to the solution of Embodiment 1 of the present invention, the argon purging protection device can move inside the pipeline and use magnetic force to make the second partition section move to separate the pipeline. The movement of the second partition section is assisted by a person outside the pipe and is not limited by distance. It is suitable for segmented isolation argon purging and maintenance welding protection of long-distance pipelines. It solves the problem that the existing argon purging protection device inside the pipeline is not suitable for argon purging protection of long pipelines.

[0042] 2. The solution of Embodiment 2 of the present invention integrates the gas tank and the argon filling protection device, which avoids setting up a long gas supply pipeline, realizes the weight reduction (reduced overall weight) and simplification of the device, and the argon filling position is basically not limited by the pipeline length. Compared with the solution of Embodiment 1, the applicable pipeline length is longer.

[0043] 3. In the solution of Embodiment 3 of the present invention, the ferrous magnetic material (first magnetic component) in the first partition section is eliminated, and the outlet of the solenoid valve is located in the isolation section (between the first partition section and the second partition section), thus eliminating the need for an air pipe; the electrical signal of the switch can be directly connected to the solenoid valve, and the wire can pass directly through the tapered expansion section. The overall structure of this device is simpler.

[0044] 4. The device and method of the present invention are suitable for pressurization protection during welding of austenitic stainless steel pipes, especially for welding of long pipes, and have a wide range of applications in maintenance welding. Attached Figure Description

[0045] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0046] Figure 1 This is an overall structural diagram of Embodiment 1 of the present invention;

[0047] Figure 2 This is a structural diagram (including assembly structure) of the first dividing segment in Embodiment 1 of the present invention;

[0048] Figure 3 This is a structural diagram of the rubber expansion ring in Embodiment 1 of the present invention;

[0049] Figure 4 This is a structural diagram of the second dividing segment in Embodiment 1 of the present invention;

[0050] Figure 5 This is an overall structural diagram of Embodiment 2 of the present invention;

[0051] Figure 6 This is a structural diagram of the second dividing segment in Embodiment 2 of the present invention;

[0052] Figure 7 This is an overall structural diagram of Embodiment 3 of the present invention;

[0053] Figure 8 This is a structural diagram (including assembly structure) of the first dividing segment in Embodiment 3 of the present invention;

[0054] Figure 9 This is a structural diagram of the second dividing segment in Embodiment 3 of the present invention.

[0055] Figure reference numerals and corresponding component names:

[0056] 1-First dividing section, 11-Through hole, 12-First magnetic component, 13-Locking component, 2-Second dividing section, 21-Conical expansion section, 22-Rubber expansion ring, 211-First limiting mechanism, 212-Second limiting mechanism, 221-Third magnetic component, 222-Rubber ring, 2221-Groove, 3-Gas tank, 4-Flexible connector, 51-Solenoid valve, 52-Battery, 53-Switch, 6-Gas pipe. Detailed Implementation

[0057] In the following, the terms “comprising” or “may include” as used in various embodiments of the invention indicate the presence of an inventive function, operation, or element, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in various embodiments of the invention, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0058] In various embodiments of the invention, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0059] The expressions used in the various embodiments of the present invention (such as "first," "second," etc.) may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used for the purpose of distinguishing one element from other elements. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, a first element may be referred to as a second element without departing from the scope of the various embodiments of the present invention, and similarly, a second element may also be referred to as a first element.

[0060] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0061] The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the invention pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the invention.

[0062] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0063] Example 1

[0064] like Figures 1 to 4 As shown, the present invention provides an argon-filled protection device for welding austenitic stainless steel pipes, such as... Figure 1 As shown, the argon filling protection device includes a first partition section 1, a second partition section 2, and a gas supply structure. The first partition section 1 and the second partition section 2 are spaced a certain distance apart and connected by a flexible connector 4, which facilitates their movement in a non-linear pipeline. The flexible connector 4 is a rope or a universal joint.

[0065] The first dividing section 1 divides the pipeline, and the first dividing section 1 can drive the second dividing section to move inside the pipeline. During the movement, the second dividing section does not divide the pipeline. The device moves to the target position inside the pipeline, and the second dividing section 2 is activated by a magnetic component outside the pipeline to block the pipeline. After the pipeline is blocked, the pipeline between the first dividing section 1 and the second dividing section 2 becomes the isolation section. The leakage point is located on the isolation section, and the isolation section is protected by argon purging through a gas supply structure. The activation of the second dividing section 2 is achieved manually outside the pipeline with magnetic assistance.

[0066] like Figure 2As shown, the first sealing section 1 adopts the form of a pipeline pig, i.e., it is cylindrical, with its outer rubber sheet tightly attached to the pipe wall to seal off gas. Furthermore, when pressurized into the pipeline, a pressure difference is generated between the two ends of the first sealing section 1, which drives the first sealing section 1 to move within the pipeline. In addition, the device of this invention uses magnetic induction to locate the position of the first sealing section 1. Specifically, the first sealing section 1 has a through hole 11 in its central axial direction, through which a first magnetic element 12 passes, and a locking element 13 is provided at the end of the first magnetic element 12. In this embodiment, the first magnetic element 12 is an iron rod with a threaded end, and the locking element 13 is a nut. The first magnetic element 12 passes through the through hole 11 and is locked to the nut through the threaded end. An electromagnet A is installed outside the pipeline. Since the pipe is made of stainless steel and is non-magnetic, it will not affect the magnetic force between the first magnetic component 12 (iron rod) and the electromagnet A outside the pipe; the second magnetic component works in conjunction with the first magnetic component 12 to achieve the positioning of the first sealing section 1 through magnetic induction; by adjusting the load of the electromagnet A, the magnetic force between the first magnetic component 12 (iron rod) and the electromagnet A can be adjusted, thereby fixing the first sealing section 1 in the pipe.

[0067] During the movement of the entire argon purging protection device within the pipeline, the second partition section 2 does not separate the pipeline, ensuring that the first partition section 1 drags the second partition section 2 along with it. Upon reaching the target position, an electromagnet B is used outside the pipeline to guide the second partition section 2 to activate and seal the pipeline. After sealing, the pipeline between the first partition section 1 and the second partition section 2 becomes the isolation section, and the leak point is located on this isolation section. At this point, argon purging protection can be performed. The key here is how to guide the second partition section 2 to activate within the pipeline, as detailed below: Figure 3 , Figure 4The second dividing section 2 includes a tapered expansion section 21 and a rubber expansion ring 22 sleeved outside the tapered expansion section 21. When the rubber expansion ring 22 moves axially along the tapered expansion section 21, it expands and adheres tightly to the pipe, thus serving as a separator. A third magnetic element 221 (magnetic material - iron block) is built into the rubber expansion ring 22. An electromagnet B is set outside the pipe. The magnetic force between the electromagnet B outside the pipe and the third magnetic element 221 (magnetic material - iron block) built into the rubber expansion ring 22 guides the rubber expansion ring 22 to move along the tapered expansion neck 21. Specifically, the rubber expansion ring 22 is made of two annular rubber rings 222 bonded together with strong adhesive. A groove 2221 is provided on the opposite surface of the two rubber rings 222 bonded together. The third magnetic element 221 fits into the groove 2221. To prevent the rubber expansion ring 22 from falling off the conical expansion section 21, limiting mechanisms are provided at both ends of the conical expansion section 21. Specifically, a first limiting mechanism 211 (annular boss) is provided at the end with the larger outer diameter of the conical expansion section 21, and a second limiting mechanism 212 (nut B) is provided at the end with the smaller outer diameter. After the rubber expansion ring 22 is put on the conical expansion section 21, the second limiting mechanism 212 (nut B) is screwed on. In this embodiment, the gas supply structure adopts a conventional gas supply method, which is also the simplest method. Gas is supplied to the isolation section through a long gas pipe. The gas pipe 6 passes through the conical expansion section 21 and extends to a position close to the first dividing section 1. This facilitates the replacement of the gas in the dividing section. When the argon filling protection device moves in the pipeline, the second dividing section 2 drags the gas pipe 6 in the pipeline. When the first dividing section 1 reaches the target position, gas can be supplied directly. After the replacement is qualified, the second dividing section 2 is activated by the electromagnet B to block the pipeline.

[0068] It should be noted that the first and third magnetic components inside the pipe do not generate magnetic force between each other.

[0069] The present invention targets pipes made of S31254 super austenitic stainless steel.

[0070] This invention relates to an argon-filled protection device for welding austenitic stainless steel pipes over long distances. The device can move inside the pipe and uses magnetic force to activate a second partition to separate the pipe. The activation of the second partition is achieved manually from outside the pipe and is not limited by distance. This invention is suitable for segmented isolation argon filling and maintenance welding protection of long-distance pipes.

[0071] The method of using the device of the present invention is as follows:

[0072] Step 1: Move the device to the leak point: Insert the device into the pipe from one end opening, seal the pipe and pressurize it. The gas will push the first partition section to move inside the pipe, and at the same time, it will move the entire device. Place a second magnetic component (electromagnet A) at the leak point outside the pipe. When the first partition section reaches the position corresponding to the second magnetic component (electromagnet A), the magnetic force between the second magnetic component (electromagnet A) and the first magnetic component 12 (iron rod) in the first partition section will fix the first partition section in the pipe and prevent it from moving forward.

[0073] Step 2, Inflation and Replacement: Inflate the pressure protection device with argon gas through the gas tube (located at the opening at one end of the pipeline). The argon gas will replace the air between the first and second partition sections. (Of course, to reduce the replacement time, it is recommended to reduce the gas in the pipeline to normal pressure or draw a negative pressure first).

[0074] Step 3: Move the fourth magnetic component (electromagnet B) in the pipeline. Utilize the magnetic force between the fourth magnetic component (electromagnet B) and the third magnetic component (iron block) in the second dividing section of the rubber expansion ring to cause the rubber expansion ring to move axially and expand, sealing the pipeline.

[0075] Example 2

[0076] like Figure 5 , Figure 6 As shown, the difference between this embodiment and Embodiment 1 is that if the leak point is very far from the pipe opening, the gas supply pipe is too long and too heavy to be moved through the pipeline by the first dividing section 1. Therefore, this embodiment proposes some improvements based on Embodiment 1, and the specific modifications are as follows:

[0077] like Figure 5 As shown, in this embodiment, the gas supply structure uses a gas tank 3 combined with a gas pipe 6 to supply gas to the isolation section. The gas tank 3 is connected to the second partition section 2, that is, after the second partition section 2, a gas tank 3 is connected to a flexible connector 4 such as a universal joint. The gas tank 3 is filled with compressed argon gas, and a rubber layer is provided on the outside of the gas tank 3. During the movement of the device, the first partition section 1 drags the second partition section 2 and the gas tank 3 together in the pipeline.

[0078] The most challenging aspect of this modification was activating the argon filling protection device to start supplying argon gas after the leak point. Metal pipes shield wireless signals, and wireless control carries a high risk of failure. Therefore, we opted to utilize the magnetic force between magnetic materials to achieve this action. See details... Figure 6As shown: We install a solenoid valve 51 on the gas supply pipeline, along with a power supply device - battery 52 and a switch 53 for the solenoid valve 51. The solenoid valve 51 is used to open or cut off the external gas supply from the gas tank 3, and the switch 53 is used to open and close the solenoid valve 51. The second limiting mechanism 212 is made of magnetic material (magnet) or a magnet is fixed on the second limiting mechanism 212. The switch 53 is installed on the second limiting mechanism 212. In this embodiment, the second limiting mechanism 212 is a nut B.

[0079] The nut B at the smaller outer diameter end of the tapered expansion section 21 is made of magnetic material—a magnet—or a magnet is fixed on the nut B, so that the nut B and the rubber expansion ring 22 are magnetically attracted. When the argon filling protection device moves in the pipeline, the magnetic nut B and the magnetic block 13 in the rubber expansion ring 22 are magnetically attracted, so that the side wall of the rubber expansion ring 22 presses the nut B tightly. The switch 53 of the solenoid valve 51 is installed on the nut B, and the pressing part of the switch 53 extends out of the nut B and faces the rubber expansion ring 22. When the rubber expansion ring 22 presses the nut B, the pressing part of the switch 53 is pressed, and the solenoid valve 51 is closed. When the fourth magnetic component (electromagnet B) outside the pipeline drives the rubber expansion ring 22 to move, the rubber expansion ring 22 separates from the nut B, the pressing part of the switch 53 is not pressed and extends outward, the solenoid valve 51 is activated and opens, and gas supply begins.

[0080] In this embodiment 2, the gas tank 3 and the argon filling protection device are integrated, which avoids the need to set up a long gas supply pipeline, and realizes the lightweight (reduced overall weight) and simplification of the device. The argon filling position is basically not limited by the pipeline length, and the applicable pipeline length is longer than that of the embodiment 1.

[0081] The method of using the device in this embodiment 2 is as follows:

[0082] The difference between this embodiment and the device in Example 1 lies in the replacement steps. In Example 2, during replacement, the electromagnet B drives the rubber expansion ring to move, thereby triggering the opening of the solenoid valve 51 on the gas supply line to begin replacement. After replacement is complete, the electromagnet B is further used to move the rubber expansion ring to separate the pipeline.

[0083] Example 3

[0084] like Figures 7 to 9 As shown, the difference between this embodiment and embodiment 1 is that the gas supply structure of embodiment 3 uses a gas tank 3 to supply gas to the isolation section. The gas tank 3 is set in the first partition section 1 and is made of a magnetic material (such as iron).

[0085] It also includes a solenoid valve 51 and a switch 53, wherein the solenoid valve 51 is electrically connected to the switch 53, and the outlet of the solenoid valve 51 is located in the isolation section.

[0086] In this embodiment 3, the ferrous magnetic material (first magnetic component 12) in the first partition section 1 is eliminated. The outlet of the solenoid valve 51 is located in the isolation section (between the first partition section 1 and the second partition section 2), thus eliminating the need for the air pipe 6; the electrical signal of the switch 53 can be directly connected to the solenoid valve 51, and the wire can pass directly through the tapered expansion section 21, provided that a sealed connection is used. The overall structure of this device is simpler.

[0087] The method of using the device in this embodiment 3 is the same as that in embodiment 2.

[0088] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An argon-filled protection device for welding austenitic stainless steel pipes, characterized in that, The device includes a first partition section, a second partition section, and a gas supply structure, wherein the first partition section and the second partition section are connected by a flexible connector. The first dividing section separates the pipeline, and the first dividing section can drive the second dividing section to move inside the pipeline. During the movement, the second dividing section does not separate the pipeline. The device moves to the target position inside the pipeline, and the second dividing section is activated by a magnetic component outside the pipeline to block the pipeline. After the pipeline is blocked, the pipeline between the first dividing section and the second dividing section becomes the isolation section. The leak point is located on the isolation section, and the isolation section is protected by argon purging through a gas supply structure. The activation of the second dividing section is achieved manually outside the pipeline with magnetic assistance. The first partition section is in the form of a pipeline pig, with its outer wall tightly attached to the pipe wall to block the gas. When the pipeline is pressurized, a pressure difference is generated between the front and rear ends of the first partition section, which drives the first partition section to move inside the pipeline. The first partition section is equipped with a first magnetic component. When the device is in use, a second magnetic component is installed outside the pipe. The second magnetic component works in conjunction with the first magnetic component to achieve the positioning of the first partition section through magnetic induction. Furthermore, the magnetic force between the first and second magnetic components is adjusted by adjusting the load on the second magnetic component, thereby fixing the first partition section in the pipe. The second dividing section includes a tapered expansion section and a rubber expansion ring. The rubber expansion ring is sleeved outside the tapered expansion section. When the rubber expansion ring moves axially along the tapered expansion section, it expands and fits tightly against the pipe. A third magnetic element is provided inside the rubber expansion ring, and a fourth magnetic element is provided outside the pipe to cooperate with the third magnetic element. The rubber expansion ring is guided to move along the conical expansion section by the magnetic force between the fourth magnetic element outside the pipe and the third magnetic element in the rubber expansion ring.

2. The argon-filled internal protection device for welding austenitic stainless steel pipes according to claim 1, characterized in that, The rubber expansion ring includes two annular rubber rings, which are fixedly connected. A slot is provided on the opposite surface of the two rubber rings that are fixedly connected, and the third magnetic component is fitted and built into the slot.

3. The argon-filled internal protection device for welding austenitic stainless steel pipes according to claim 1, characterized in that, Limiting mechanisms are provided at both ends of the tapered expansion section, a first limiting mechanism is provided at the large outer diameter end of the tapered expansion section, and a second limiting mechanism is provided at the small outer diameter end of the tapered expansion section.

4. The argon-filled protection device for welding austenitic stainless steel pipes according to claim 3, characterized in that, The air supply structure uses an external air supply device connected to an air pipe to supply air to the isolation section; the air pipe extends to a position close to the first partition section after passing through the tapered expansion section. When the device moves inside the pipeline, the second partition drags the air pipe along with it. Once the first partition reaches the target position, air can be supplied directly. After the replacement is successful, the second partition is activated by the fourth magnetic component to block the pipeline.

5. The argon-filled protection device for welding austenitic stainless steel pipes according to claim 3, characterized in that, The gas supply structure uses a gas tank combined with a gas pipe to supply gas to the isolation section. The gas tank is connected to the second partition section, and the gas tank and the second partition section are connected by a flexible connector. The gas tank is filled with compressed argon gas, and a rubber layer is provided on the outside of the gas tank. During the movement of the device, the first partition section drags the second partition section and the gas tank together in the pipeline.

6. The argon-filled protection device for welding austenitic stainless steel pipes according to claim 5, characterized in that, The air supply line at the bottom of the rubber expansion ring is equipped with a solenoid valve, a battery, and a switch. The solenoid valve is used to open or cut off the air supply to the isolation section of the gas tank, and the switch is used to open and close the solenoid valve. The second limiting mechanism is made of magnetic material or a magnet is fixed to the second limiting mechanism; The switch is installed on the second limiting mechanism. The pressing part of the switch extends out of the second limiting mechanism and faces the rubber expansion ring. When the rubber expansion ring presses against the second limiting mechanism, the pressing part of the switch is pressed and the solenoid valve is closed. When the fourth magnetic component outside the pipeline moves the rubber expansion ring, the rubber expansion ring separates from the second limiting mechanism. The pressing part of the switch is no longer pressed and extends outward. The solenoid valve is activated and opens to start supplying gas.

7. The argon-filled internal protection device for welding austenitic stainless steel pipes according to claim 1, characterized in that, The gas supply structure uses a gas cylinder to supply gas to the isolation section. The gas cylinder is located in the first isolation section and is made of magnetically conductive material. It also includes a solenoid valve and a switch, wherein the solenoid valve is electrically connected to the switch, and the outlet of the solenoid valve is located in an isolation section.

8. A method for using an argon-filled protective device for welding austenitic stainless steel pipes, characterized in that, This method is applied to an argon-filled protective device for welding austenitic stainless steel pipes as described in any one of claims 1 to 7, and the method includes the following steps: Step 1: Move the device to the leak point: Insert the device into the pipe from one end opening, seal the pipe and pressurize it. The gas pushes the first partition section to move inside the pipe, while simultaneously moving the entire device. Set a second magnetic component at the leak point outside the pipe. When the first partition section reaches the position corresponding to the second magnetic component, the magnetic force between the second magnetic component and the first magnetic component in the first partition section fixes the first partition section in place inside the pipe. Step 2, inflation and replacement: Argon gas is injected into the inflation protection device through the gas pipe of the inflation protection device. The argon gas will replace the air between the first and second partition sections. Step 3: Move the fourth magnetic component in the pipeline. Utilize the magnetic force between the fourth magnetic component and the third magnetic component in the second dividing section of the rubber expansion ring to cause the rubber expansion ring to move axially and expand, thus sealing the pipeline.

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