Mechanical expansion seal plug for heat exchanger tubes

Abstract

The utility model discloses a kind of mechanical expansion type sealing plug for heat exchanger pipeline, including main shaft, sleeve is equipped on the outside of main shaft, and fastening assembly is installed on the side of sleeve of main shaft.The utility model is formed multiple sealing barrier by the annular sealing tooth structure of sleeve outer surface, and can effectively bite into pipe wall, provide very high anti-extrusion capacity and sealing performance, can withstand very high pressure and temperature fluctuation, installation is simple, safe, controllable, installation process only needs to use standard wrench and torque wrench, without fire, safe and fast, by control tightening, can realize standardized, repeatable installation, ensure the quality and sealing effect of every installation, strong adaptability to pipe wall, ensure the sealing effect under non-ideal pipe wall condition, mechanical expansion force is uniformly applied to pipeline inner wall, avoid the thermal damage of welding and the impact damage of knock type plug, effectively protect the integrity of tube sheet.

Description

Technical Field

[0001] This utility model belongs to the field of sealing plug technology, specifically relating to a mechanical expansion sealing plug for heat exchanger pipelines. Background Technology

[0002] In industries such as chemical, power, and petroleum, heat exchangers, boilers, and condensers are critical equipment. These devices typically contain numerous tube bundles. During long-term operation, due to corrosion, erosion, vibration, or material fatigue, some pipes may develop cracks or perforations, leading to leaks. Leaks not only reduce equipment efficiency but can also cause cross-contamination of media and even serious safety accidents. Currently, there are two main methods for handling leaking pipelines: 1. Welding sealing: The leaking pipe opening is sealed by welding. The disadvantages of this method are that it requires hot work, which poses a high risk in flammable and explosive environments, and the approval process is complex. The heat from welding may cause thermal stress damage to the tube sheet, and for certain special materials or confined spaces, welding is difficult to perform and the quality is hard to guarantee. 2. Impact-type plug: This method uses a conical metal plug, which is forcibly driven into the pipe opening using a hammer or other tools, relying on an interference fit to achieve a seal. While simple and quick, this method has poor sealing reliability. Under high pressure or large temperature fluctuations, the plug is prone to loosening or being pushed out by pressure, causing secondary leaks. Furthermore, forceful impacts can also damage the pipe opening and tube sheet.

[0003] To address the problems of complex construction, unreliable sealing, and easy damage to tube sheets caused by existing sealing methods (such as welding and impact plugs), a mechanical expansion sealing plug for heat exchanger pipelines is provided to solve the above problems. Utility Model Content

[0004] In view of the problems mentioned above in the background art, the purpose of this utility model is to provide a mechanically expanding sealing plug for heat exchanger pipes.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by this utility model is as follows: A mechanically expandable sealing plug for heat exchanger pipes includes a main shaft, a sleeve fitted around the outside of the main shaft, and a fastening assembly mounted on one side of the sleeve.

[0006] Further specifying, the spindle includes a tapered working section, a straight connecting section is installed on one side of the tapered working section, and a threaded connecting post is installed on the other side of the straight connecting section. The tapered working section, the straight connecting section, and the threaded connecting post are integrally formed. This structural design facilitates sealing when used with a sleeve.

[0007] Further specifying, the sleeve includes a main body, the main body having a threaded hole matching the threaded connecting post, the main body having a tapered hole matching the tapered working section on one side of the threaded hole, a hexagonal torsion head on one outer side of the main body, and several annular sealing teeth distributed circumferentially on the other outer side of the main body. This structural design allows the sleeve to perfectly fit and embed into the inner wall of the pipe under the wedge force of the spindle.

[0008] Furthermore, the main body and the hexagonal twisting head are integrally formed. This structural design eliminates connection gaps and assembly interfaces between the main body and the hexagonal twisting head, thereby significantly improving the connection strength and overall structural rigidity.

[0009] Further specifying, the fastening assembly includes a hexagonal nut and a spring washer. The hexagonal nut is locked onto the threaded connecting post, and the spring washer is installed between the hexagonal nut and the sleeve. This structural design allows for precise control of the tension applied to the spindle, thereby controlling the degree of sleeve expansion and the clamping force on the tube wall.

[0010] The beneficial effects of this utility model are as follows: This utility model forms multiple sealing barriers through several annular sealing tooth structures on the outer surface of the sleeve, which can effectively bite into the pipe wall, providing extremely high resistance to push-out and sealing performance. It can withstand extremely high pressure and temperature fluctuations. The installation is simple, safe, and controllable. The installation process only requires the use of a standard wrench and torque wrench, without the need for open flame, making it safe and quick. By controlling the tightening, standardized and repeatable installation can be achieved, ensuring the quality and sealing effect of each installation. It has strong adaptability to pipe walls. The annealed soft sleeve has good plasticity and can adapt to minor corrosion, pits, or scratches on the pipe wall, ensuring the sealing effect under non-ideal pipe wall conditions. The mechanical expansion force is evenly applied to the inner wall of the pipe, avoiding heat damage from welding and impact damage from hammer-type plugs, effectively protecting the integrity of the tube sheet. Attached Figure Description

[0011] This utility model can be further illustrated by the non-limiting embodiments given in the accompanying drawings; Figure 1 This is a schematic diagram of the axial structure of a mechanical expansion sealing plug for a heat exchanger pipeline according to an embodiment of the present invention. Figure 2 This is a cross-sectional structural diagram of a mechanical expansion sealing plug for a heat exchanger pipeline according to an embodiment of the present invention. Figure 3 This is an exploded structural diagram of a mechanically expanding sealing plug for a heat exchanger pipeline according to an embodiment of the present invention. The symbols for the main components are explained below: Main spindle 1, tapered working section 101, straight connecting section 102, threaded connecting column 103.

[0012] Sleeve 2, body 201, threaded hole 202, tapered hole 203, hexagonal toggle head 204, annular sealing teeth 205.

[0013] Fastening component 3, hexagonal nut 301, spring washer 302. Detailed Implementation

[0014] To enable those skilled in the art to better understand this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0015] Example 1, as Figure 1 As shown, a mechanical expansion sealing plug for heat exchanger pipes has a sleeve 2 sleeved on the outside of the main shaft 1, and a fastening assembly 3 is installed on one side of the sleeve 2 on the main shaft 1.

[0016] In this embodiment, during installation, the pipe opening to be sealed is first inspected and cleaned. If necessary, a slight reaming is performed to remove rust and burrs. Then, thread grease is applied to the spindle 1 to reduce friction and ensure accurate torque transmission. After the sleeve 2 is installed on the spindle 1, it is inserted into the pipe. The spindle 1 or sleeve 2 is fixed with a wrench. The fastening assembly 3 is tightened with a torque wrench. During the tightening process, the fastening assembly 3 applies a pulling force to the spindle 1, causing the spindle 1 to move outward. This creates a strong wedge effect within the sleeve 2. The huge radial force forces the sleeve 2 to undergo plastic expansion, and its outer surface is forcibly pressed into and embedded in the inner wall of the pipe, forming a strong, durable, and high-pressure resistant seal. The entire installation process is fast, safe, and the sealing effect is controllable.

[0017] The main shaft 1 is made of high-strength steel to withstand huge tensile loads, while the sleeve 2 is made of carbon steel with good plasticity and has undergone full annealing treatment. The annealing treatment significantly reduces the hardness of the sleeve 2, giving it excellent ductility and plasticity. During installation, the softer sleeve 2 can undergo controllable plastic deformation under the wedge force of the main shaft 1, perfectly fitting and embedding into the inner wall of the pipe without cracking.

[0018] By tightening the fastening assembly 3 with a torque wrench, the tension applied to the main shaft 1 can be precisely controlled, thereby controlling the expansion of the sleeve 2 and the clamping force on the pipe wall, thus avoiding seal failure or component damage caused by insufficient or excessive installation force.

[0019] Example 2, as Figure 2 and Figure 3As shown, this embodiment adds the following structure based on embodiment 1: the main shaft 1 includes a tapered working section 101, a straight connecting section 102 is installed on one side of the tapered working section 101, and a threaded connecting column 103 is installed on the other side of the straight connecting section 102. The tapered working section 101, the straight connecting section 102 and the threaded connecting column 103 are integrally formed structures.

[0020] In this embodiment, during use, thread grease is first applied to the tapered working section 101 and threaded connecting post 103 of the main shaft 1 to reduce friction and ensure accurate torque transmission. The plug is then inserted into the pipe as a whole. The sleeve 2 or the main shaft 1 is fixed with a wrench. The fastening assembly 3 is tightened with a torque wrench. During the tightening process, the fastening assembly 3 applies a pulling force to the threaded connecting post 103 on the main shaft, causing the threaded connecting post 103 to move outward and drive the tapered working section 101 to generate a strong wedge effect inside the sleeve 2. The huge radial force forces the sleeve 2 to undergo plastic expansion, and its outer surface is forcibly pressed into and embedded in the inner wall of the pipe to form a seal.

[0021] Example 3, as Figure 2 and Figure 3 As shown, this embodiment adds the following structure based on embodiment 1: the sleeve 2 includes a main body 201, the main body 201 is provided with a threaded hole 202 that matches the threaded connecting post 103, the main body 201 is provided with a tapered hole 203 that matches the tapered working section 101 on one side of the threaded hole 202, a hexagonal torsion head 204 is provided on one side of the outer side of the main body 201, and a plurality of annular sealing teeth 205 distributed along the circumferential direction are provided on the other side of the outer side of the main body 201.

[0022] In this embodiment, during use, thread grease is applied to the tapered working section 101 of the spindle 1 and the threaded connecting post 103 to reduce friction and ensure accurate torque transmission. Then, the spindle 1, sleeve 2, and fastening assembly 3 are assembled and inserted into the pipe. A wrench is used to hold the hexagonal torque head 204 on the sleeve 2 or the spindle 1 in place. A torque wrench is used to tighten the fastening assembly 3. During tightening, the fastening assembly 3 applies tension to the threaded connecting post 103 on the spindle, causing the threaded connecting post 103 to... Moving outward, the conical working section 101 is driven to generate a strong wedge effect within the sleeve 2. The conical working section 101 of the main shaft 1 is forcibly pulled into the conical hole 203 of the sleeve 2. Due to the presence of the taper, the axial tension of the main shaft 1 is converted into a huge radial expansion force, which acts on the sleeve 2, forcing the annealed soft sleeve 2 to undergo plastic expansion. The annular sealing teeth 205 on its outer surface are forcibly pressed into and embedded in the inner wall of the pipe, forming a strong, durable, and high-pressure resistant multi-layer metal seal.

[0023] When the sleeve 2 is subjected to force and expands, the annular sealing tooth 205 can concentrate the radial force on a small contact area, generating a great pressure, thereby "biting" or tightly pressing against the inner wall of the pipe. Even if there are slight corrosion pits or longitudinal scratches on the pipe wall, it can form an effective, multi-redundant seal.

[0024] Example 4, as Figure 3 As shown, this embodiment adds the following structure to the embodiment 3: the main body 201 and the hexagonal twisting head 204 are integrally formed.

[0025] In this embodiment, since the main body 201 and the hexagonal twisting head 204 are integrally formed, there are no connection gaps or assembly interfaces between them, which significantly improves the connection strength and overall structural rigidity between the two. This high-strength connection can better withstand various external forces, torques and vibrations generated during operation, avoid problems such as loosening and breakage, and extend service life.

[0026] Example 5, as Figure 2 and Figure 3 As shown, this embodiment adds the following structure based on embodiment 1: the fastening component 3 includes a hexagonal nut 301 and a spring washer 302. The hexagonal nut 301 is locked onto the threaded connecting post 103, and the spring washer 302 is installed between the hexagonal nut 301 and the sleeve 2.

[0027] In this embodiment, during the tightening process, the hexagonal nut 301 applies tension to the main shaft 1 through the spring washer 302. The main shaft 1 moves outward, and its tapered section generates a strong wedge effect in the tapered hole 203 of the sleeve 2, thereby controlling the degree of expansion of the sleeve 2 and the clamping force on the pipe wall.

[0028] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A mechanically expanding sealing plug for heat exchanger pipes, comprising a main shaft (1), characterized in that: A sleeve (2) is fitted on the outside of the main shaft (1), and a fastening assembly (3) is installed on one side of the sleeve (2) of the main shaft (1).

2. The mechanical expansion sealing plug for heat exchanger pipelines according to claim 1, characterized in that: The main shaft (1) includes a tapered working section (101), a straight connecting section (102) is installed on one side of the tapered working section (101), and a threaded connecting column (103) is installed on the other side of the straight connecting section (102). The tapered working section (101), the straight connecting section (102) and the threaded connecting column (103) are integrally formed.

3. A mechanically expanding sealing plug for heat exchanger pipelines according to claim 2, characterized in that: The sleeve (2) includes a body (201), the body (201) has a threaded hole (202) that matches the threaded connecting post (103), the body (201) has a tapered hole (203) that matches the tapered working section (101) on one side of the threaded hole (202), the body (201) has a hexagonal torsion head (204) on one side of the outside of the body (201), and the other side of the outside of the body (201) has a plurality of annular sealing teeth (205) distributed along the circumferential direction.

4. A mechanically expanding sealing plug for heat exchanger pipelines according to claim 3, characterized in that: The main body (201) and the hexagonal twisting head (204) are integrally formed.

5. A mechanically expanding sealing plug for heat exchanger pipelines according to claim 4, characterized in that: The fastening assembly (3) includes a hexagonal nut (301) and a spring washer (302). The hexagonal nut (301) is locked onto the threaded connecting post (103), and the spring washer (302) is installed between the hexagonal nut (301) and the sleeve (2).

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