High-frequency soft-seal self-adjusting cock valve structure

Abstract

The utility model relates to the technical field of plug valve, especially to a high frequency soft seal self -adjusting plug valve structure. It includes the valve body, the plug of being placed in the valve body, the valve cover subassembly, still be provided with the sealing assembly in the valve cover subassembly inside, still be provided with the sleeve for cooperation plug rotation in the valve body inner wall, be provided with three layer lock glue structure on the sleeve, still include the adjustment assembly of being placed in the valve cover subassembly and can adjust the up and down displacement of plug, and set up between the stretch spring of plug bottom and the valve body bottom inner wall. The utility model has the beneficial effect that: this technical scheme is through setting adjustment assembly and stretch spring, in the cooperation of both, makes the plug valve in the frequent operation process can according to the sealing surface wear amount automatic adjustment sealing force, significantly reduces the internal leakage problem caused by the sealing surface stress reduction.

Description

Technical Field

[0001] This utility model relates to the field of plug valve technology, and in particular to a high-frequency soft-seal self-adjusting plug valve structure. Background Technology

[0002] Plug valves, as important fluid control devices, are widely used in petrochemical, natural gas transportation, and other industrial fields. However, in practical applications, the design of traditional plug valves faces many challenges, especially under high-frequency operation and long-term running conditions, where their sealing performance and service life often fail to meet requirements.

[0003] The prior art, as disclosed in patent announcement number CN2025105502746, "A Plug Structure and a Petroleum Plug Valve," reveals a specific structure where frequent opening and closing of the valve leads to continuous wear of the soft sealing material (such as PTFE or rubber), and a gradual decrease in the initial assembly preload, resulting in media leakage. To address this issue, traditional methods typically rely on manual disassembly and adjustment of gaskets or bolts after shutdown to restore sealing performance. However, this method is not only costly to maintain but also severely impacts production continuity. Furthermore, the prior art often employs a hot-fitting process (interference fit) to assemble key components (such as valve seat sleeves), but this high-temperature heating process can easily cause localized deformation or changes in the metallographic structure of the metal parts. This leads to residual stress generated by cooling and shrinkage after assembly, further accelerating stress relaxation on the sealing surface and significantly shortening the valve's service life.

[0004] Therefore, it is necessary to design a high-frequency soft-seal self-adjusting plug valve structure to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a high-frequency soft-seal self-adjusting plug valve structure to overcome the aforementioned shortcomings of the existing technology.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A high-frequency soft-seal self-adjusting plug valve structure includes a valve body, a plug placed inside the valve body, a valve stem assembly for driving the plug to rotate to achieve the opening and closing of the valve body, and a valve cover assembly installed to the upper end of the valve body by bolts and nested outside the valve stem assembly. A sealing assembly is also provided inside the valve cover assembly. The valve cover assembly is characterized in that a sleeve for cooperating with the rotation of the plug is provided on the inner wall of the valve body; the sleeve is provided with a three-layer locking structure. It also includes an adjustment component placed inside the valve cover assembly and capable of adjusting the up-and-down displacement of the valve stem, and a tension spring disposed between the bottom of the valve stem and the inner wall of the bottom of the valve body.

[0007] Preferably, the adjusting component is disposed above the sealing component, and a pressure ring is further disposed between the adjusting component and the sealing component; the sealing component is located above the plug and cooperates with the pressure ring and the valve cover assembly.

[0008] Preferably, the sealing assembly is composed of a wedge ring, a V-shaped gasket, a metal diaphragm, and a central graphite layer, forming a multi-layered sealing assembly.

[0009] Preferably, the wedge-shaped ring is tightly fitted to the V-shaped gasket through its inclined surface; the metal diaphragm covers the V-shaped gasket.

[0010] Preferably, the adjusting assembly includes a positioning sleeve embedded in the valve cover assembly, an online adjusting bolt embedded in the positioning sleeve and capable of moving up and down, and a double-layer disc spring structure placed between the online adjusting bolt and the pressure ring.

[0011] Preferably, the double-layer disc spring structure includes a disc spring pressure plate and multiple disc springs, the disc spring pressure plate is placed at the bottom of the online adjusting bolt, and the multiple disc springs are placed between the disc spring pressure plate and the pressure ring.

[0012] Preferably, the sleeve is installed into the valve body using a cold-fitting process.

[0013] The beneficial effects of this utility model are as follows: By setting up an adjustment component and a tension spring, the combined effect of these two components allows the plug valve to automatically adjust the sealing force according to the wear of the sealing surface during frequent operation, significantly reducing internal leakage caused by reduced stress on the sealing surface. The design of the online adjustment bolt and the positioning sleeve enables precise control of the bolt preload, avoiding over-tightening that could damage the sealing material or cause the plug to jam. Compared with the prior art, this utility model solves the problems of seal wear, thermal deformation, stress relaxation, and insufficient adjustment accuracy that exist in traditional plug valves during high-frequency operation and long-term use, ensuring the valve's sealing performance, service life, and operational stability. Attached Figure Description

[0014] Figure 1 This is a schematic cross-sectional view of the overall structure of a high-frequency soft-seal self-adjusting plug valve according to the present invention. Figure 2 This is a partially enlarged schematic diagram of the structure of a high-frequency soft-seal self-adjusting plug valve according to this utility model; Figure 3 This is a partial enlarged view of the sleeve of a high-frequency soft-seal self-adjusting plug valve structure according to this utility model; Figure 4 This is a partial enlarged view of the tension spring in the high-frequency soft-seal self-adjusting plug valve structure of this utility model; In the diagram: 1. Valve body; 2. Plug; 3. Valve stem assembly; 4. Valve cover assembly; 11. Sleeve; 5. Tension spring; 41. Positioning sleeve; 42. Line adjusting bolt; 6. Pressure ring; 43. Disc spring pressure plate; 44. Multiple disc springs; 111. Wedge ring; 112. V-shaped gasket; 113. Metal diaphragm; 114. Zhongdao graphite. Detailed Implementation

[0015] Reference Figures 1 to 4 A high-frequency soft-seal self-adjusting plug valve structure includes a valve body 1, a plug 2 placed inside the valve body 1, a valve stem assembly 3 that drives the plug 2 to rotate to open and close the valve body 1, and a valve cover assembly 4 that is installed to the upper end of the valve body 1 by bolts and nested outside the valve stem assembly 3. A sleeve 11 is also provided on the inner wall of the valve body 1 to cooperate with the rotation of the stopcock 2. The sleeve 11 mainly serves a sealing function and has a three-layer sealing structure. The size of the three-layer sealing structure is calculated based on the maximum and minimum allowable specific pressure of the sleeve 11. The specific implementation steps of the three-layer sealing structure are as follows: first, determine the maximum and minimum allowable specific pressure range of the sleeve 11; second, calculate the key dimensions of the sealing groove based on the specific pressure range; finally, process the three-layer sealing structure to the corresponding position of the sleeve 11, specifically according to the model of the entire valve body. The design of the three-layer sealing structure effectively improves the sealing reliability between the sleeve 11 and the stopcock 2, preventing media leakage due to sealing failure.

[0016] It also includes an adjustment component placed inside the valve cover assembly and capable of adjusting the up and down displacement of the valve cock, and a tension spring 5 disposed between the bottom of the valve cock 2 and the bottom inner wall of the valve body 1; a sealing component is also disposed inside the valve cover assembly; the adjustment component is disposed above the sealing component, and a pressure ring 6 is disposed between the adjustment component and the sealing component; the sealing component is located above the valve cock and cooperates with the pressure ring 6 and the valve cover assembly 4.

[0017] The sealing assembly comprises a wedge ring 111, a V-shaped gasket 112, a metal diaphragm 113, and a central graphite 114, forming a multi-layered sealing assembly. The wedge ring 111, through its inclined surface, fits tightly against the V-shaped gasket 112, enhancing the sealing effect. The metal diaphragm 113 covers the V-shaped gasket 112, further improving the sealing performance. The central graphite 114 fills the remaining gaps in the wedge ring, namely the gaps between the valve stem assembly 4 and the wedge ring 111, the valve cover assembly 4 and the valve body 1, and the gaps between the valve stem assembly 3 and the valve body 1, providing additional sealing protection. The valve cover assembly 4 covers the valve body 1 and is fixed with bolts to ensure the sealing of the entire cavity.

[0018] The adjustment assembly includes a positioning sleeve 41 embedded in the valve cover assembly 4, an online adjustment bolt 42 embedded in the positioning sleeve 41 and capable of moving up and down, and a double-layer disc spring structure placed between the online adjustment bolt 42 and the pressure ring 6. The double-layer disc spring structure includes a disc spring pressure plate 43 and multiple disc springs 44. The disc spring pressure plate 43 is placed at the bottom of the online adjusting bolt 42, and the multiple disc springs 44 are placed between the disc spring pressure plate 43 and the pressure ring 6. The thickness w, free height h, and compression amount Δx of the multiple disc springs 44 are derived through a mathematical model (refer to existing formulas for spring calculation). The compression amount is calculated from the maximum and minimum allowable specific pressure of the sleeve and satisfies the condition that Δx is less than the drop height of the stopcock 2. The disc spring pressure plate 43 limits and fixes the multiple disc springs 44 to ensure that they do not shift or loosen during operation. The online adjusting bolt 42 cooperates with the positioning sleeve 41. The positioning sleeve 41 limits the compression amount when the bolt is pre-tightened, achieving precise control and avoiding over-tightening that could damage the sealing material or cause the stopcock to jam.

[0019] The tension spring 5 is used to compensate for the weakening of sealing force caused by wear of the sealing surface during long-term use. Specifically, the tension spring 5 provides axial force through elastic deformation. When a gap appears between the sealing surface of the plug 2 and the sleeve due to wear, the tension spring 5 can adjust the position of the plug 2 in real time to ensure that the sealing surface always maintains tight contact and prevents internal leakage. The elastic tension parameter of the tension spring 5 is calculated based on the valve's working pressure and the characteristics of the medium to ensure that it can provide sufficient elastic force under different operating conditions.

[0020] In this embodiment, when the valve is closed, the plug 2 and sleeve 11 fit tightly together, forming a sealing pair to prevent the flow of media. At this time, the multi-layer sealing assembly consisting of a wedge ring, V-shaped gasket, metal diaphragm, and central graphite, cooperates with the pressure ring 6 and valve cover assembly 4 to ensure that the media inside the cavity does not leak from the packing or the central channel. The tension spring 5 provides axial force to ensure that the sealing surfaces between the plug 2 and sleeve 11 always maintain tight contact. During frequent valve opening and closing, wear of the sealing surfaces is inevitable. The tension spring 5 compensates for the weakening of the sealing force by adjusting the position of the plug 2 in real time, thus preventing internal leakage. When online adjustment of the sealing force is required, it is achieved by rotating the online adjusting bolt 42. The online adjusting bolt 42 cooperates with the positioning sleeve 41, which limits the compression amount during bolt pre-tightening to ensure adjustment accuracy. During compression, the multiple disc springs 44 release elastic potential energy, pushing the pressure ring 6 downward, thereby increasing the sealing force between the plug 2 and the sleeve 11. Because the multiple disc springs 44 have a self-adjusting function, their elastic deformation can replenish the sealing force in real time when the sealing surface is worn, without the need for frequent manual intervention. In addition, the double-layer disc spring structure design avoids screw loosening and retraction caused by vibration, improving operational stability.

[0021] The advantages of this invention are that, by incorporating an adjusting component and a tension spring, the plug valve can automatically adjust the sealing force based on the wear of the sealing surface during frequent operation, significantly reducing internal leakage caused by reduced stress on the sealing surface. The design of the online adjusting bolt and positioning sleeve enables precise control of the bolt preload, preventing over-tightening that could damage the sealing material or cause the plug to jam. Compared to existing technologies, this invention solves the problems of seal wear, thermal deformation, stress relaxation, and insufficient adjustment accuracy in traditional plug valves during high-frequency operation and long-term use, ensuring the valve's sealing performance, service life, and operational stability.

[0022] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A high-frequency soft-seal self-adjusting plug valve structure, comprising a valve body, a plug disposed within the valve body, a valve stem assembly for driving the plug to rotate to achieve opening and closing of the valve body, and a valve cover assembly installed to the upper end of the valve body by bolts and nested outside the valve stem assembly, wherein a sealing assembly is further provided inside the valve cover assembly, characterized in that: A sleeve for cooperating with the rotation of the valve body is also provided on the inner wall of the valve body; the sleeve is provided with a three-layer locking structure; It also includes an adjustment component placed inside the valve cover assembly and capable of adjusting the up-and-down displacement of the valve stem, and a tension spring disposed between the bottom of the valve stem and the inner wall of the bottom of the valve body.

2. The high-frequency soft-seal self-adjusting plug valve structure according to claim 1, characterized in that: The adjusting component is disposed above the sealing component, and a pressure ring is disposed between the adjusting component and the sealing component; the sealing component is located above the plug and cooperates with the pressure ring and the valve cover assembly.

3. The high-frequency soft-seal self-adjusting plug valve structure according to claim 2, characterized in that: The sealing assembly consists of a wedge ring, a V-shaped gasket, a metal diaphragm, and a central graphite layer, forming a multi-layered sealing assembly.

4. The high-frequency soft-seal self-adjusting plug valve structure according to claim 3, characterized in that: The wedge-shaped ring fits tightly against the V-shaped gasket through its inclined surface; the metal diaphragm covers the V-shaped gasket.

5. The high-frequency soft-seal self-adjusting plug valve structure according to claim 2, characterized in that: The adjustment assembly includes a positioning sleeve embedded in the valve cover assembly, an online adjustment bolt embedded in the positioning sleeve and capable of moving up and down, and a double-layer disc spring structure placed between the online adjustment bolt and the pressure ring.

6. The high-frequency soft-seal self-adjusting plug valve structure according to claim 5, characterized in that: The double-layer disc spring structure includes a disc spring pressure plate and multiple disc springs. The disc spring pressure plate is placed at the bottom of the online adjusting bolt, and the multiple disc springs are placed between the disc spring pressure plate and the pressure ring.

7. The high-frequency soft-seal self-adjusting plug valve structure according to claim 1, characterized in that: The sleeve is installed into the valve body using a cold-fitting process.

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