Prefabricated assembly for gas conveying pipe of assembly type quick-insertion flow divider
The design of the clamping assembly solves the problem of inconvenient connection between metal pipes and the gas supply pipe of the distributor, achieving fast and reliable connection and sealing effect, and simplifying the installation process.
Patent Information
- Application Number
- CN202423319219.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-12-31
AI Technical Summary
In the existing technology, the connection methods between metal pipes and the gas supply pipe of the distributor are inconvenient. Welding, threaded connection and crimping connection all require tools, which makes the connection inconvenient and inefficient.
The pipe clamping assembly, including a clamping sleeve and a sealing ring, uses a tapered section and a clamping claw structure design to allow the pipe end to be easily inserted and clamped into the connection end of the fitting, achieving circumferential sealing without the need for tools.
It enables quick and reliable connection between pipes and connecting pipes, improves connection efficiency, ensures sealing effect, and simplifies the installation process.
Smart Images
Figure CN223499083U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of gas distribution pipe assembly technology, and more specifically, to a prefabricated assembly of a prefabricated gas distribution pipe for a quick-connect splitter. Background Technology
[0002] Currently, when connecting metal pipes to the gas distribution pipes of a distributor, the ends of the pipes are often connected and fixed using welding, threaded connections, or crimping connections, and circumferentially sealed. However, welding requires a welding machine to weld and fix the pipe ends to the sidewall of the distributor pipe, resulting in inconvenience. Similarly, threaded connections require threads to be made on the outer wall of the pipe ends and a threaded connector to be fixed to the sidewall of the distributor pipe, connecting the pipe ends to the threaded connector. This also presents the inconvenience of connecting the pipe ends to the distributor pipe. Similarly, crimping connections require the use of crimping tools to connect the pipe ends to fittings on the sidewall of the distributor pipe, which also presents the inconvenience of connecting the pipe ends to the distributor pipe. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide a prefabricated assembly of a quick-connect splitter gas pipe, which has the advantages of convenient connection between the connecting pipe and the metal pipe and high connection efficiency.
[0004] This utility model provides a prefabricated assembly of a quick-connect splitter gas pipe, including a connecting pipe and at least two pipe fittings spaced apart along the length of the connecting pipe; one end of the connecting pipe is connected to a connector, and the other end of the connecting pipe is connected to a plug; one end of the pipe fitting is welded and fixed to the side wall of the connecting pipe and communicates with the connecting pipe, and the other end of the pipe fitting forms a connecting end and is provided with a pipe clamping assembly; when the end of the pipe made of metal material passes through the pipe clamping assembly and is inserted into the connecting end of the pipe fitting, the pipe clamping assembly is used to clamp the pipe and perform circumferential sealing on the pipe and the pipe fitting.
[0005] By adopting the above structure, this utility model allows the pipe end, made of metal material, to pass through the pipe clamping assembly and be inserted into the connecting end of the pipe fitting. The pipe clamping assembly can clamp the pipe and provide a circumferential seal for the pipe and the pipe fitting, thus enabling the pipe to be easily connected to the connecting pipe without the need for any tools. This provides the advantages of convenient connection and high connection efficiency between the connecting pipe and the metal pipe.
[0006] In one possible implementation, the tube clamping assembly includes a ferrule and a sealing ring. A first annular step is provided on the inner wall of the tube fitting's connecting end. The sidewall of the first annular step forms an annular conical portion that gradually tapers from the inside out. The sealing ring abuts against the first annular step, with its outer edge tightly sealing against the inner wall of the conical portion and its inner edge tightly sealing against the outer peripheral wall of the tube. The inner end of the ferrule is inserted into the connecting end of the tube fitting and can move axially relative to the connecting end. An anti-disengagement structure is provided between the ferrule and the connecting end of the tube fitting. The inner end of the ferrule forms several claws spaced apart circumferentially around the ferrule, with the inner ends of the claws abutting against the outer end of the conical portion. On the inner wall, several clamps are used to grip the pipe material passing through the clamp. With this clamping assembly, when connecting the pipe end to the fitting, the clamp is first squeezed towards the fitting. As the clamp is squeezed and moves inward relative to the fitting's connection, the tapered portion gradually contracts from the inside out, which is equivalent to gradually expanding from the outside in. This allows the inner end of each clamp to expand outward along the radial direction of the clamp. Then, the pipe end can pass through the clamp and sealing ring and be inserted into the fitting's connection. After the pipe passes through the clamp, the clamps grip the outer wall of the pipe, and then the clamp is released. When the pipe is subjected to an outward pulling force... Or, when the pipe is subjected to the thrust of air pressure flowing through the fitting, i.e., when the pipe is about to detach from the fitting, several claws grip the outer wall of the pipe, allowing the pipe to move synchronously with the clamping sleeve away from the fitting. Furthermore, because the tapered portion gradually contracts from the inside out, as the clamping sleeve moves outward, the cooperation between the claws and the tapered portion further tightens the grip on the pipe, effectively preventing the pipe from detaching from the fitting's connection end, thus achieving a reliable connection between the pipe and the fitting. Additionally, because the outer edge of the sealing ring is tightly sealed against the inner wall of the tapered portion, and the inner edge of the sealing ring is tightly sealed against the outer circumference of the pipe, this ensures a secure connection. This ensures that the sealing ring reliably seals the gap between the pipe and the fitting. When the pipe needs to be separated from the fitting, the ferrule is first squeezed towards the side closer to the fitting. As the ferrule is squeezed and moves inward relative to the connection end of the fitting, the tapered part gradually contracts from the inside out, which is equivalent to the tapered part gradually expanding from the outside in. This allows the inner end of the claw to have space to expand outward along the radial direction of the ferrule. Then, the pipe can be pulled away from the side away from the fitting. Because the inner end of the claw has space to expand outward along the radial direction of the ferrule, several claws can release their grip on the pipe, allowing the pipe to be pulled out of the ferrule, thus achieving the separation of the pipe and the fitting.
[0007] In one possible implementation, an annular chamfered surface is provided on the inner wall of the connecting end of the pipe fitting. The inner end of the annular chamfered surface is connected to the outer end of the tapered portion. The annular chamfered surface is used to guide and cooperate with the inner ends of several claws so that the several claws can be inserted into the inner side of the tapered portion. With this structure, when the inner end of the ferrule is inserted into the connecting end of the pipe fitting, the annular chamfered surface can cooperate and guide with the inner ends of several claws so that the several claws can be inserted into the inner side of the tapered portion.
[0008] In one possible implementation, each jaw has a protruding, serrated abutment on the outer wall of its inner end, which abuts against the inner wall of the outer end of the conical portion. With this structure, the inner end of each jaw can reliably abut against the inner wall of the outer end of the conical portion under the action of the abutment. Furthermore, since each abutment is a protruding, serrated structure, the friction between the inner end of the jaw and the conical portion can be reduced when the ferrule moves relative to the connection end of the pipe fitting.
[0009] In one possible implementation, each claw has a protrusion on its outer side wall, and the outer end of the pipe fitting has an annular constriction. The annular constriction is used to abut against the protrusion on the claw to prevent the ferrule from axially disengaging from the pipe fitting's connection end. By adopting this structure, the ferrule can be effectively prevented from disengaging from the pipe fitting's connection end. In addition, after the inner end of the ferrule is inserted into the pipe fitting's connection end, the outer end of the pipe fitting's connection end is constricted by a constriction device to form the aforementioned annular constriction.
[0010] In one possible implementation, an annular protrusion is provided on the outer wall of the outer end of the sleeve. The annular protrusion is used to abut against the finger so that the finger can squeeze the sleeve towards the tube. With this structure, when the sleeve is squeezed towards the tube, the finger can abut against the annular protrusion, thereby facilitating the finger to squeeze the sleeve towards the tube.
[0011] In one possible implementation, an annular groove is provided in the middle of the inner end face of the sealing ring. The sealing ring located inside the groove gradually contracts inward along the axial direction of the sealing ring to form an annular contraction portion. The inner edge of the annular contraction portion is tightly sealed against the outer wall of the pipe. The sealing ring located outside the groove gradually expands outward along the axial direction of the sealing ring to form an annular expansion portion. The outer edge of the annular expansion portion is tightly sealed against the inner wall of the conical portion. With this structure, when the end of the pipe and the connection end of the fitting are connected by the pipe clamping assembly, when there is fluid pressure in the fitting and the pipe, the fluid pressure can act on the inner wall of the groove. Because the sealing ring located inside the groove gradually contracts inward along the axial direction of the sealing ring to form an annular contraction portion... The annular contraction section allows fluid pressure to act on it, further tightening the annular contraction section against the outer wall of the pipe. The greater the fluid pressure, the better the seal between the annular contraction section and the pipe, thus further improving the sealing effect between the sealing ring and the pipe. Similarly, the annular expansion section, located outside the opening groove, gradually expands outward along its axial direction, allowing fluid pressure to act on it and further tightening the annular expansion section against the inner wall of the conical section. The greater the fluid pressure, the better the seal between the annular expansion section and the conical section, thus further improving the sealing effect between the sealing ring and the conical section, and ultimately enhancing the sealing effect of the sealing ring on the gap between the pipe and the fitting.
[0012] In one possible implementation, a second annular step is provided on the inner wall of the fitting's connection end; when the end of the pipe passes through the clamping assembly and is inserted into the connection end, the second annular step is used to abut against the end of the pipe; by adopting this structure, when the end of the pipe passes through the clamping assembly and is inserted into the connection end, the second annular step can abut against the end of the pipe, thereby limiting the connection end of the pipe and fitting, and indicating to the installer that the connection end of the fitting and pipe has been inserted in place.
[0013] In one possible implementation, the connector is welded to one end of the connecting pipe and circumferentially sealed; the plug is welded to the other end of the connecting pipe and circumferentially sealed; by adopting this method, the connector can be reliably connected to one end of the connecting pipe and circumferentially sealed to that end, and the plug can be reliably connected to the other end of the connecting pipe and circumferentially sealed to that end. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of this utility model;
[0015] Figure 2 for Figure 1 A magnified structural diagram of point A in the middle;
[0016] Figure 3 This is a cross-sectional view of the card sleeve.
[0017] Figure 4 This is a cross-sectional view of the sealing ring. Detailed Implementation
[0018] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.
[0019] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.
[0020] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0021] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0022] See Figure 1-4 As shown in the embodiment of this application, a prefabricated assembly of a prefabricated gas pipe for a quick-connect splitter is disclosed, including a connecting pipe 1 and at least two pipe fittings 2 spaced apart along the length of the connecting pipe 1; one end of the connecting pipe 1 is connected to a connector 3, and the other end of the connecting pipe 1 is connected to a plug 4; one end of the pipe fitting 2 is welded and fixed to the side wall of the connecting pipe 1 and communicates with the connecting pipe 1, and the other end of the pipe fitting 2 forms a connecting end and is provided with a pipe clamping assembly 5; when the end of the pipe made of metal material passes through the pipe clamping assembly 5 and is inserted into the connecting end of the pipe fitting 2, the pipe clamping assembly 5 is used to clamp the pipe and perform circumferential sealing on the pipe and the pipe fitting 2.
[0023] The tube clamping assembly 5 includes a clamping sleeve 51 and a sealing ring 52. A first annular step 21 is provided on the inner wall of the connecting end of the tube fitting 2. The sidewall of the first annular step 21 forms an annular conical portion 22, which gradually tapers from the inside out. The sealing ring 52 abuts against the first annular step 21, with its outer edge tightly sealing against the inner wall of the conical portion 22, and its inner edge tightly sealing against the outer peripheral wall of the tube. The inner end of the clamping sleeve 51 is inserted into the connecting end of the tube fitting 2 and can move axially relative to the connecting end of the tube fitting. An anti-disengagement structure is provided between the clamping sleeve 51 and the connecting end of the tube fitting 2. The inner end of the clamping sleeve 51 forms several claws 511 spaced apart in the circumferential direction around the clamping sleeve 51. The inner end of the jaw 511 abuts against the inner wall at the outer end of the tapered portion 22. Several jaws 511 are used to grip the pipe material passing through the sleeve 51. By employing this pipe clamping assembly, when connecting the end of the pipe material to the connection end of the fitting, the sleeve is first squeezed towards the side closest to the fitting. As the sleeve is squeezed and moves inward relative to the connection end of the fitting, the tapered portion gradually contracts from the inside out, which is equivalent to gradually expanding from the outside in. This allows the inner end of each jaw to expand outward along the radial direction of the sleeve. Then, the end of the pipe material can pass through the sleeve and the sealing ring and be inserted into the connection end of the fitting. After the pipe material passes through the sleeve, several jaws grip the outer wall of the pipe material, and then the sleeve is released. That is, when the pipe is subjected to an outward pulling force, or the thrust of the air pressure flowing through the fitting, i.e., when the pipe is about to detach from the fitting, several claws grip the outer wall of the pipe, allowing the pipe to move the ferrule synchronously away from the fitting. Furthermore, because the conical part gradually contracts from the inside out, during the outward movement of the ferrule, the cooperation between the claws and the conical part further tightens the grip on the pipe, effectively preventing the pipe from detaching from the fitting's connection end, thus achieving a reliable connection between the pipe and the fitting. Additionally, because the outer edge of the sealing ring is tightly sealed against the inner wall of the conical part, and the inner edge of the sealing ring is tightly sealed against the outer circumference of the pipe... The sealing ring reliably seals the gap between the pipe and the fitting. When the pipe needs to be separated from the fitting, the ferrule is first squeezed towards the side closer to the fitting. As the ferrule is squeezed and moves inward relative to the connection end of the fitting, the tapered part gradually contracts from the inside out, which is equivalent to the tapered part gradually expanding from the outside in. This allows the inner end of the claw to have space to expand outward along the radial direction of the ferrule. Then, the pipe can be pulled away from the side away from the fitting. Because the inner end of the claw has space to expand outward along the radial direction of the ferrule, several claws can release their grip on the pipe, allowing the pipe to be pulled out of the ferrule, thus achieving the separation of the pipe and the fitting.
[0024] An annular chamfered surface 23 is provided on the inner wall of the connecting end of the pipe fitting 2. The inner end of the annular chamfered surface 23 is connected to the outer end of the tapered part 22. The annular chamfered surface 23 is used to cooperate with the inner ends of several claws 511 for guidance so that several claws 511 can be inserted into the inner side of the tapered part 22. With this structure, when the inner end of the sleeve is inserted into the connecting end of the pipe fitting, the annular chamfered surface can cooperate with the inner ends of several claws for guidance so that several claws can be inserted into the inner side of the tapered part.
[0025] Each jaw 511 has a protruding, serrated abutment portion 512 on the outer wall of its inner end. The abutment portion 512 abuts against the inner wall of the outer end of the conical portion 22. With this structure, the inner end of each jaw can reliably abut against the inner wall of the outer end of the conical portion under the action of the abutment portion. In addition, since each abutment portion is a protruding, serrated structure, the friction between the inner end of the jaw and the conical portion can be reduced when the ferrule moves relative to the connection end of the pipe fitting.
[0026] Each claw 511 has a protrusion 513 on its outer side wall, and an annular constriction 25 is provided at the outer end of the connecting end of the pipe fitting 2. The annular constriction 25 is used to abut against the protrusion 513 on the claw 511 to prevent the sleeve 51 from axially disengaging from the connecting end of the pipe fitting 2. By adopting this structure, it is possible to effectively avoid the sleeve from disengaging from the connecting end of the pipe fitting. In addition, after the inner end of the sleeve is inserted into the connecting end of the pipe fitting, the outer end of the connecting end of the pipe fitting is constricted by the constriction device to form the above-mentioned annular constriction.
[0027] The outer wall of the outer end of the sleeve 51 is provided with an annular protrusion 514. The annular protrusion 514 is used to abut against the finger so that the finger can squeeze the sleeve 51 towards the tube 2. With this structure, when squeezing the sleeve towards the tube, the finger can abut against the annular protrusion, which makes it easier for the finger to squeeze the sleeve towards the tube.
[0028] A ring-shaped opening groove 521 is provided in the middle of the inner end face of the sealing ring 52. The sealing ring 52 located inside the opening groove 521 gradually contracts inward along the axial direction of the sealing ring 52 to form an annular contraction portion 522. The inner edge of the annular contraction portion 522 is tightly sealed against the outer wall of the pipe. The sealing ring 52 located outside the opening groove 521 gradually expands outward along the axial direction of the sealing ring 52 to form an annular expansion portion 523. The outer edge of the annular expansion portion 523 is tightly sealed against the inner wall of the conical portion 22. With this structure, when the end of the pipe and the connection end of the fitting are connected by the pipe clamping assembly, when there is fluid pressure in the fitting and the pipe, the fluid pressure can act on the inner wall of the opening groove. Because the sealing ring located inside the opening groove gradually contracts inward along the axial direction of the sealing ring, the sealing ring 521 forms an annular contraction portion 522. The inward contraction forms an annular contraction section, allowing fluid pressure to act on it and further tighten the annular contraction section against the outer wall of the pipe. The greater the fluid pressure, the better the sealing effect between the annular contraction section and the pipe, thus further improving the sealing effect between the sealing ring and the pipe. Similarly, as the sealing ring located outside the opening groove gradually expands outward along the axial direction of the sealing ring to form an annular expansion section, fluid pressure is applied to it, allowing the annular expansion section to further tighten against the inner wall of the conical section. The greater the fluid pressure, the better the sealing effect between the annular expansion section and the conical section, thus further improving the sealing effect between the sealing ring and the conical section, and thus improving the sealing effect of the sealing ring on the gap between the pipe and the fitting.
[0029] A second annular step 24 is provided on the inner wall of the connecting end of the pipe fitting 2. When the end of the pipe passes through the pipe clamping assembly 5 and is inserted into the connecting end, the second annular step 24 is used to abut against the end of the pipe. With this structure, when the end of the pipe passes through the pipe clamping assembly and is inserted into the connecting end of the pipe, the second annular step can abut against the end of the pipe, thereby limiting the connection end of the pipe and the fitting and indicating to the installer that the connection end of the fitting and the pipe has been inserted in place.
[0030] The connector 3 is welded and fixed to one end of the connecting pipe 1 and circumferentially sealed; the plug 4 is welded and fixed to the other end of the connecting pipe 1 and circumferentially sealed; by adopting this method, the connector can be reliably connected to one end of the connecting pipe and circumferentially sealed to that end, and the plug can be reliably connected to the other end of the connecting pipe and circumferentially sealed to that end.
[0031] The aforementioned connecting pipes, fittings, joints, plugs, and ferrules are all made of steel, while the aforementioned pipes are made of copper.
[0032] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A prefabricated assembly for a quick-connect splitter gas pipe, characterized in that: It includes a connecting pipe (1) and at least two fittings (2) spaced apart along the length of the connecting pipe (1); one end of the connecting pipe (1) is connected to a connector (3), and the other end of the connecting pipe (1) is connected to a plug (4); one end of the fitting (2) is welded and fixed to the side wall of the connecting pipe (1) and communicates with the connecting pipe (1), and the other end of the fitting (2) forms a connecting end and is provided with a pipe clamping assembly (5); when the end of the pipe made of metal material passes through the pipe clamping assembly (5) and is inserted into the connecting end of the fitting (2), the pipe clamping assembly (5) is used to clamp the pipe and perform circumferential sealing on the pipe and the fitting (2).
2. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 1, characterized in that: The tube clamping assembly (5) includes a clamping sleeve (51) and a sealing ring (52); a first annular step (21) is provided on the inner wall of the connecting end of the tube fitting (2), and the side wall of the first annular step (21) forms an annular conical part (22), which gradually shrinks from the inside to the outside. The sealing ring (52) abuts against the first annular step (21), and the outer edge of the sealing ring (52) is tightly sealed with the inner wall of the conical part (22). The inner edge of the sealing ring (52) is tightly sealed with the outer peripheral wall of the tube. The inner end of the sleeve (51) is inserted into the connecting end of the pipe fitting (2) and can move axially relative to the connecting end of the pipe fitting. An anti-disengagement structure is provided between the sleeve (51) and the connecting end of the pipe fitting (2). The inner end of the sleeve (51) forms a plurality of claws (511) spaced apart around the circumferential direction of the sleeve (51). The inner ends of the plurality of claws (511) abut against the inner wall at the outer end of the tapered part (22). The plurality of claws (511) are used to hold the pipe material passing through the sleeve (51).
3. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 2, characterized in that: The inner wall of the connecting end of the pipe fitting (2) is provided with an annular chamfered surface (23). The inner end of the annular chamfered surface (23) is connected to the outer end of the tapered part (22). The annular chamfered surface (23) is used to cooperate with the inner ends of several claws (511) for guidance so that several claws (511) can be inserted into the inner side of the tapered part (22).
4. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 2, characterized in that: Each of the claws (511) has a protruding and serrated abutment (512) on the outer wall of its inner end, which abuts against the inner wall of the outer end of the conical part (22).
5. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 2, characterized in that: Each of the claws (511) has a protrusion (513) on its outer side wall, and an annular constriction (25) is provided at the outer end of the connecting end of the pipe fitting (2). The annular constriction (25) is used to abut against the protrusion (513) on the claw (511) to prevent the sleeve (51) from axially disengaging from the connecting end of the pipe fitting (2).
6. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 2, characterized in that: The outer wall of the outer end of the sleeve (51) is provided with an annular protrusion (514), which is used to abut against the finger so that the finger can squeeze the sleeve (51) towards the tube (2).
7. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 2, characterized in that: The sealing ring (52) has an annular opening groove (521) in the middle of its inner end face. The sealing ring (52) located inside the opening groove (521) gradually contracts inward along the axial direction of the sealing ring (52) to form an annular contraction part (522). The inner edge of the annular contraction part (522) is tightly sealed against the outer wall of the pipe. The sealing ring (52) located outside the opening groove (521) gradually expands outward along the axial direction of the sealing ring (52) to form an annular expansion part (523). The outer edge of the annular expansion part (523) is tightly sealed against the inner wall of the conical part (22).
8. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 1, characterized in that: The inner wall of the connecting end of the pipe fitting (2) is provided with a second annular step (24); when the end of the pipe passes through the pipe clamping assembly (5) and is inserted into the connecting end, the second annular step (24) is used to abut against the end of the pipe.
9. The prefabricated assembly of the prefabricated gas pipe for the prefabricated quick-connect splitter according to claim 1, characterized in that: The connector (3) is welded to one end of the connecting pipe (1) and circumferentially sealed; the plug (4) is welded to the other end of the connecting pipe (1) and circumferentially sealed.