A seal pair structure and a concealed regulating valve

Abstract

The application provides a sealing pair structure and a hidden regulating valve, and relates to the field of regulating valves.The sealing pair structure comprises a valve core and a valve seat, the valve core comprises a valve core main body, a sealing section, an isolation section and an adjusting section which are sequentially connected, the adjusting section is used for reducing the flow rate of fluid medium flowing to the sealing section, the isolation section comprises a flow guide area which is arranged to be inclined from top to bottom with respect to the axial direction of the valve core main body and an isolation area which is connected with the sealing section, the bottom outer diameter of the flow guide area is smaller than the top outer diameter of the flow guide area, the flow guide area is used for guiding the medium to flow away from the axial direction, and the sealing surface of the sealing section is located in a flow blind area which is formed after the medium is deflected by the flow guide area.The application guides the medium to deviate before the medium reaches the sealing pair by arranging the flow guide area and the isolation area, so that the direct flushing, cavitation and flashing of the medium to the sealing section are avoided, and the problem that the sealing surface is rapidly abraded due to the fact that the sealing pair is directly exposed to the medium impact path in the prior art is solved.

Description

Technical Field

[0001] This utility model relates to the field of control valves, and more specifically, to a sealing pair structure and a concealed control valve. Background Technology

[0002] In modern industrial automation control systems, control valves, as key actuators in fluid delivery pipelines, play a crucial role in precisely regulating the flow rate, pressure, and temperature of the medium. Their core working principle involves an actuator driving the valve stem, which in turn causes the valve core to move axially within the valve seat, thereby altering the throttling area of ​​the fluid passage and achieving precise control of process parameters. In this dynamic regulation process, the performance of the sealing pair between the valve core and the valve seat directly determines the valve's closing tightness, regulation accuracy, and service life; however, traditional control valve sealing structures face severe challenges in practical applications. First, because the medium (especially flashing, cavitation, and erosion) directly erodes and corrodes the sealing surface, the valve core and valve seat sealing pair is highly susceptible to wear, cavitation, or carbon deposits. This physical damage disrupts the smoothness of the sealing pair, creating pits, which can lead to internal leakage, severely impacting system efficiency and even causing equipment shutdown.

[0003] For example, the Chinese invention patent (publication number: CN110805697A) discloses an "integral self-protecting sealing surface structure for a regulating valve," which, according to its description, includes a valve stem, a sleeve, a valve core, a valve seat, a valve cover, and a valve body. The valve seat is located at the lowest point inside the valve body, and the valve core is located inside the valve body, above the valve seat. The lower end of the valve stem passes through the valve cover and extends into the valve body to connect with the valve core. A valve core protection device is fixedly connected to the outside of the valve core, and a sleeve is located outside the valve core protection device. This invention reduces the direct scouring effect of the medium on the valve core sealing surface, effectively reducing the erosion and wear of the sealing surface, thereby reducing the frequency of repair or replacement of the valve core sealing surface, extending its service life, and economically reducing maintenance costs. The aforementioned patent can corroborate the deficiencies of the existing technology.

[0004] Therefore, we have made improvements to this by proposing a sealing pair structure and a concealed regulating valve. Utility Model Content

[0005] The purpose of this invention is to solve the problem that the sealing surface of the regulating valve is directly eroded and corroded by the medium, which leads to easy wear, cavitation or carbon deposits on the valve core and valve seat sealing surface.

[0006] To achieve the above-mentioned objectives and improve the aforementioned problems, this utility model provides a sealing pair structure and a concealed regulating valve, including a valve core and a valve seat. The valve core includes a valve core body, a sealing section, an isolation section, and an regulating section connected in sequence. The regulating section is used to reduce the flow velocity of the fluid medium towards the sealing section. The isolation section includes a guide zone that is inclined at the top and bottom relative to the axial direction of the valve core body, and an isolation section connected to the sealing section. The guide zone is used to guide the medium to avoid scouring, cavitation, and flashing of the sealing section. The bottom outer diameter of the guide zone is smaller than the top outer diameter of the guide zone. The guide zone is used to guide the medium to flow away from the axis. The sealing surface of the sealing section is located in the flow blind zone formed after the medium is deflected by the guide zone. As a preferred technical solution of this application, the valve seat includes a valve seat body, an installation cavity is provided inside the valve seat body, the valve core body slides inside the installation cavity, a plurality of flow diversion holes penetrating the valve seat body are provided on the periphery of the installation cavity, a first buffer cavity is provided below the installation cavity, a sealing surface that mates with the sealing section is provided at the top of the first buffer cavity, an adjustment cavity is provided below the first buffer cavity, a slow flow port is provided at the bottom of the valve seat body, a first perforated plate is provided inside the slow flow port, and a plurality of first slow flow holes are provided on the first perforated plate.

[0007] As a preferred technical solution of this application, the adjustment section includes a first buffer zone, a first adjustment zone, and a flow-facing zone. The first buffer zone, the first adjustment zone, and the flow-facing zone are connected sequentially in the axial direction of the valve core body. The outer surfaces of the first buffer zone and the first adjustment zone are inclined at the top and bottom, with the inclination angle of the outer surface of the first buffer zone being greater than that of the outer surface of the first adjustment zone. An arc-shaped transition is provided between the first buffer zone and the first adjustment zone.

[0008] As a preferred technical solution of this application, a plurality of the diversion holes form a plurality of through hole groups arranged vertically, the through hole group including a plurality of through holes arranged in a ring, and the upper edge of the through hole group coincides with the lower edge of the adjacent through hole group.

[0009] As a preferred technical solution of this application, the adjustment section includes a plurality of second adjustment zones arranged axially. The top of the second adjustment zone is connected to a second buffer zone. A connecting section is provided between adjacent adjustment sections. The top and bottom of the connecting section are respectively connected to the adjacent second adjustment zone and the second buffer zone. The connection between the connecting section and the adjacent second adjustment zone and the second buffer zone is transitioned by an arc surface. A lower shaft is fixedly connected to the bottom of the lowest second adjustment zone. The lower shaft slides through the middle of the first perforated plate.

[0010] As a preferred technical solution of this application, the number of regulating cavities is the same as that of regulating sections, the regulating sections are located inside the regulating cavities, a third buffer cavity is provided between adjacent regulating cavities, the bottom of the regulating cavities is inclined, and the lowest regulating cavity is connected to the slow flow port.

[0011] As a preferred technical solution of this application, a second buffer chamber is provided inside the valve seat body. The second buffer chamber is connected to the diversion hole. The medium enters the second buffer chamber, is buffered, and then is discharged from the diversion hole.

[0012] As a preferred technical solution of this application, the isolation section further includes a centralized cavity opened in the middle of the isolation area. The bottom of the centralized cavity is provided with a conveying channel extending into the lower shaft. The lower shaft is provided with a plurality of adjustment holes at equal intervals on its circumferential side. The adjustment holes are connected to the bottom of the conveying channel. The centralized cavity is provided with a plurality of dispersion channels at equal intervals on its circumferential side.

[0013] As a preferred technical solution of this application, the end of the dispersion channel is provided with a fan-shaped dispersion cavity. The fan-shaped structure allows the medium discharged from the dispersion cavity to disperse and cover the entire annular range. The end of the dispersion cavity is inclined away from the sealing section.

[0014] A concealed regulating valve includes an upper valve body with a valve body cavity in the middle. A valve seat body is installed inside the valve body cavity. An outlet communicating with the valve body cavity is opened on one side of the upper valve body. A lower valve body is connected to the bottom of the upper valve body. A liquid inlet is opened on the lower valve body, which is vertically connected. A second orifice plate is fixedly installed inside the liquid inlet. A plurality of second slow-flow holes are opened on the second orifice plate. The bottom end of the valve seat body extends through the upper valve body to the top end of the liquid inlet. A first flange is fixedly connected to the bottom end of the lower valve body. The lower valve body and the upper valve body are connected by bolts. The bolts tighten the upper and lower valve bodies so that the bottom end face of the valve seat body abuts against the lower valve body to achieve a seal. A valve shaft is inserted through the top end of the upper valve body. The bottom end of the valve shaft is fixedly connected to the valve core body.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: In the scheme of this application: 1. By setting up a flow guiding zone and an isolation zone, the sealing section is hidden behind the blocking structure, so that the medium is guided away by the flow guiding zone before reaching the sealing pair, avoiding direct scouring, cavitation and flashing of the medium on the sealing section. This solves the problem of rapid wear of the sealing surface caused by the sealing pair being directly exposed to the impact path of the medium in the prior art, and significantly extends the service life of the sealing pair. 2. By setting up a buffer space formed by the first buffer chamber and the guide zone, the medium that passes through the regulating section at high speed is slowed down in the buffer space before flowing through the sealing surface, which further reduces the erosion energy of the medium on the sealing pair and enhances the sealing protection effect. 3. By setting up a multi-stage buffer scheme, including the second orifice plate, the first orifice plate, the slow flow port, the regulating chamber, the third buffer chamber, the first buffer chamber and the diversion orifice, the medium is decelerated and buffered multiple times in the flow path, which effectively reduces the medium flow rate, reduces cavitation and erosion damage to various components, and improves the overall stability and reliability of valve operation. 4. The adjustable section, including the first buffer zone, the first adjustable zone and the flow-facing zone, is axially inclined with the outer side of each zone being larger at the top and smaller at the bottom, and the inclination angle changes step by step. When the adjustable section moves up and down, a cross-sectional difference is formed between it and the adjustable cavity to achieve flow regulation. At the same time, the arc transition between each zone avoids the generation of eddies and local erosion of the medium at abrupt changes, thus solving the problem that flow regulation and sealing protection are difficult to achieve simultaneously in the prior art. 5. Through the two-stage buffer structure of the isolation section, the centralized cavity is located in the middle of the isolation zone. The bottom of the centralized cavity extends into the lower shaft through the conveying channel. Several adjusting holes are evenly spaced on the circumference of the lower shaft, and several dispersing channels and dispersing cavities are evenly spaced on the circumference of the centralized cavity. When the valve core moves upward, the adjusting holes are offset from the first orifice plate. The medium enters the centralized cavity through the adjusting holes and the conveying channel, and then is dispersed from the fan-shaped structure of the dispersing cavity through the dispersing channels before being discharged. This further moves the medium guided by the flow guide area away from the sealing section. The fan-shaped structure of the dispersing cavity ensures that the discharged medium evenly covers the entire annular range, avoiding concentrated impact on local areas. The more the valve core moves upward, the greater the offset, and the more medium enters. The dynamic protection effect is enhanced synchronously with the opening degree, solving the problem that the sealing pair protection effect is fixed in the existing technology and cannot be adaptively adjusted with changes in working conditions. Attached Figure Description

[0016] Figure 1 A schematic diagram of the valve core structure in the first embodiment of the sealing pair structure provided in this application; Figure 2 A front view of the valve core in the first embodiment of the sealing pair structure provided in this application; Figure 3 A schematic diagram of the valve seat in the first embodiment of the sealing pair structure provided in this application; Figure 4 A perspective sectional view of the first embodiment of the sealing pair structure provided in this application; Figure 5 A schematic diagram of the closed state of the first embodiment of the sealing pair structure provided in this application; Figure 6 A schematic diagram of the first configuration of the sealing pair structure provided in this application, showing its open state. Figure 7A front sectional view of the second embodiment of the sealing pair structure provided in this application; Figure 8 A schematic diagram of valve core configuration one in the second configuration of the sealing pair structure provided in this application; Figure 9 A front view of valve core configuration one in the second configuration of the sealing pair structure provided in this application; Figure 10 A perspective sectional view of the valve seat in the second embodiment of the sealing pair structure provided in this application; Figure 11 A front sectional view of the valve seat in the second embodiment of the sealing pair structure provided in this application; Figure 12 A schematic diagram and an enlarged view of point A in the second configuration of the sealing pair structure provided in this application; Figure 13 A cross-sectional view and an enlarged view at point B in the second configuration of the sealing pair structure provided in this application; Figure 14 A cross-sectional view of the dispersion cavity in the second embodiment of the sealing pair structure provided in this application; Figure 15 This is a schematic diagram of the structure of the concealed control valve provided in this application; Figure 16 A perspective sectional view of the concealed control valve provided in this application; Figure 17 A front sectional view of the concealed control valve provided in this application.

[0017] The image shows: 1. Valve core body; 2. Sealing section; 3. Isolation section; 31. Guide zone; 32. Isolation zone; 33. Regulating hole; 34. Conveying channel; 35. Centralized cavity; 36. Dispersing channel; 37. Dispersing cavity; 4. Adjustment section; 4-1A, First buffer zone; 4-2A, First adjustment zone; 4-3A, Upstream zone; 4-1B, Second buffer zone; 4-2B, Second adjustment zone; 5. Connecting section; 6. Lower shaft; 7. Valve seat body; 8. First buffer chamber; 9. Sealing surface; 10. Diverter orifice; 11. Flow-slowing port; 12. Adjusting chamber; 13. Second buffer chamber; 14. Third buffer chamber; 15. First orifice plate; 16. Upper valve body; 17. Lower valve body; 18. Insulated steam flange; 19. Valve body cavity; 20. Outlet; 21. Inlet; 22. Second orifice plate; 23. Throttling orifice plate; 24. Stuffing box; 25. Valve shaft. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0020] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] Example 1 Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 A sealing pair structure includes a valve core and a valve seat. The valve core is composed of a valve core body 1, a sealing section 2, an isolation section 3, and an adjusting section 4 connected in sequence. The adjusting section 4 is used to reduce the flow velocity of the fluid medium towards the sealing section 2. The isolation section 3 includes a guide area 31 that is inclined at the top and lower relative to the axial direction of the valve core body 1, and an isolation area 32 connected to the sealing section 2. The guide area 31 is used to guide the medium to avoid the medium from causing erosion, cavitation, and flashing of the sealing section 2. The bottom outer diameter of the guide area 31 is smaller than the top outer diameter of the guide area 31. The isolation area 32 is used to prevent the medium from accelerating and damaging the valve core when the opening is small. The guide area 31 is used to guide the medium to flow away from the axis. The medium flowing from bottom to top is guided by the guide area 31 and flows to all sides, avoiding the medium from directly impacting the sealing section 2, thereby avoiding the sealing section 2 from being corroded. The isolation area 32 separates the guided medium from the sealing section 2. The sealing surface of the sealing section 2 is located in the flow blind area formed after the medium is deflected by the guide area 31.

[0023] Furthermore, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the valve seat includes a valve seat body 7, with an installation cavity inside the valve seat body 7. The valve core body 1 slides inside the installation cavity. Several diversion holes 10 penetrating the valve seat body 7 are opened on the periphery of the installation cavity. A first buffer cavity 8 is opened below the installation cavity. A sealing surface 9 that cooperates with the sealing section 2 is provided at the top of the first buffer cavity 8. The first buffer cavity 8 and the guide area 31 cooperate to form a large buffer space. After the medium passes through the regulating section 4 at high speed, it enters the first buffer cavity 8, which slows down the flow rate of the medium to achieve the effect of protecting the sealing section 2. A regulating cavity 12 is provided below the first buffer cavity 8. A slow flow port 11 is opened at the bottom of the valve seat body 7. A first orifice plate 15 is provided inside the slow flow port 11. Several first slow flow holes are opened on the first orifice plate 15. The first buffer cavity 8 and the slow flow port 11 are connected through the regulating cavity 12. The inner diameter of the regulating cavity 12 is smaller than the inner diameter of the first buffer cavity 8 and the slow flow port 11. An inclined surface transition is provided between the top of the slow flow port 11 and the regulating cavity 12.

[0024] Example 2 The first form of the sealing pair structure, specifically, is as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the regulating section 4 includes a first buffer zone 4-1A, a first regulating zone 4-2A, and a flow-facing zone 4-3A. The first buffer zone 4-1A, the first regulating zone 4-2A, and the flow-facing zone 4-3A are connected sequentially in the axial direction of the valve core body 1. The outer surfaces of the first buffer zone 4-1A and the first regulating zone 4-2A are inclined at the top and at the bottom, with the inclination angle of the outer surface of the first buffer zone 4-1A being greater than that of the outer surface of the first regulating zone 4-2A. An arc-shaped transition is provided between the first buffer zone 4-1A and the first regulating zone 4-2A. The first regulating zone 4-2A and the flow-facing zone 4-3A are used to regulate the flow medium of the valve. When the valve core body 1 moves up and down, a cross-sectional difference is formed between the regulating section 4 and the regulating chamber 12, thereby achieving the effect of flow regulation.

[0025] Furthermore, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, several diversion holes 10 form multiple through hole groups arranged vertically. Each through hole group includes several through holes arranged in a ring. The upper edge of the through hole group coincides with the lower edge of the adjacent through hole group, so that the communication interface of the valve core body 1 can be increased steplessly when it slides up and down in the mounting cavity without any stuttering. The through holes of the adjacent through hole groups are staggered.

[0026] Example 3 The second form of the sealing pair structure, specifically, is as follows: Figure 7 , Figure 8 and Figure 9As shown, the adjustment section 4 includes multiple second adjustment zones 4-2B arranged axially. The top of the second adjustment zone 4-2B is connected to a second buffer zone 4-1B. A connecting section 5 is provided between adjacent adjustment sections 4. The top and bottom of the connecting section 5 are connected to the adjacent second adjustment zone 4-2B and the second buffer zone 4-1B, respectively. The connection between the connecting section 5 and the adjacent second adjustment zone 4-2B and the second buffer zone 4-1B is transitioned by an arc surface. A lower shaft 6 is fixedly connected to the bottom of the lowest second adjustment zone 4-2B. The lower shaft 6 slides through the middle of the first orifice plate 15 to improve the stability of the valve core body 1 moving up and down.

[0027] Furthermore, such as Figure 7 , Figure 10 and Figure 11 As shown, the number of regulating cavities 12 is the same as that of regulating sections 4. Regulating sections 4 are located inside regulating cavities 12. When regulating sections 4 move up and down, they regulate the flow rate of the medium passing through regulating cavities 12. A third buffer cavity 14 is provided between adjacent regulating cavities 12. The third buffer cavity 14 buffers and decelerates the medium passing through regulating cavities 12. The bottom of regulating cavities 12 is inclined. The lowest regulating cavity 12 is connected to the slow flow port 11.

[0028] Furthermore, such as Figure 10 and Figure 11 As shown, a second buffer chamber 13 is provided inside the valve seat body 7. The second buffer chamber 13 is located above the sealing surface 9. The second buffer chamber 13 is connected to the diversion hole 10. The medium enters the second buffer chamber 13 for buffering and is then discharged from the diversion hole 10.

[0029] Example 4 The sealing pair structure provided in Example 3 is further optimized, specifically, as follows: Figure 12 and Figure 13As shown, the isolation section 3 also includes a centralized cavity 35 located in the middle of the isolation zone 32. A conveying channel 34 extending into the lower shaft 6 is provided at the bottom of the centralized cavity 35. Several adjusting holes 33 are evenly spaced on the circumferential side of the lower shaft 6, communicating with the bottom of the conveying channel 34. Several dispersing channels 36 are evenly spaced on the circumferential side of the centralized cavity 35. When the valve core body 1 moves upward, it drives the lower shaft 6 upward. The adjusting holes 33 are offset from the first orifice plate 15, and the medium enters through the adjusting holes 33 and passes through the conveying channel 34 into the centralized cavity 35. Then, it enters the dispersion chamber 37 through the dispersion channel 36. After being dispersed by the fan-shaped structure of the dispersion chamber 37, it is discharged, allowing the medium guided by the guide zone 31 to move further away from the sealing section 2. The more the valve core body 1 moves upward, the more the adjustment hole 33 is offset from the first orifice plate 15, and the more medium enters the adjustment hole 33. As a result, more medium rushes towards the isolation zone 32, and more medium is discharged from the dispersion chamber 37, thus better resisting and deflecting the impact of the medium. In this embodiment, the lower shaft 6 is slidably inserted in the middle of the first orifice plate 15 without penetrating the first orifice plate 15.

[0030] Furthermore, such as Figure 12 , Figure 13 and Figure 14 As shown, the end of the dispersion channel 36 is provided with a fan-shaped dispersion cavity 37. The fan-shaped structure allows the medium discharged from the dispersion cavity 37 to disperse and cover the entire annular range. The end of the dispersion cavity 37 is inclined away from the sealing section 2.

[0031] Please refer to Figure 8 , Figure 11 , Figure 15 , Figure 16 and Figure 17A concealed regulating valve includes an upper valve body 16 and a lower valve body 17. The upper valve body 16 has a valve body cavity 19 in its middle. A valve seat body 7 is installed inside the valve body cavity 19. An outlet 20 communicating with the valve body cavity 19 is provided on one side of the upper valve body 16. A vertically penetrating inlet 21 is provided on the lower valve body 17. A second orifice plate 22 is fixedly installed inside the inlet 21, and several second slow-flow holes are provided on the second orifice plate 22. The bottom end of the valve seat body 7 extends through the upper valve body 16 to the top end of the inlet 21. A first flange is fixedly connected to the bottom end of the lower valve body 17. The lower valve body 17 and the upper valve body 16 are connected by bolts. The bolts tighten the upper valve body 16 and the lower valve body 17 so that the bottom surface of the valve seat body 7 abuts against... The lower valve body 17 achieves sealing, and the top of the upper valve body 16 is provided with a valve shaft 25. The bottom end of the valve shaft 25 is fixedly connected to the valve core body 1. The regulating valve is installed through the first flange. When the regulating valve is in the open state, the medium enters from the inlet 21, passes through the second orifice plate 22, and completes the first buffer between the second orifice plate 22 and the first orifice plate 15. Then the medium passes through the first orifice plate 15 and enters the slow flow port 11 to complete the second buffer. Then the medium is decelerated between the regulating chamber 12 and the regulating section 4 and completes the third buffer in the third buffer chamber 14. The medium further enters the first buffer chamber 8 to complete the fourth buffer. Finally, it is discharged through the diversion hole 10 into the valve body cavity 19 to converge, and then discharged through the outlet 20.

[0032] Furthermore, such as Figure 16 and Figure 17 As shown, a throttling orifice plate 23 located at the end of the outlet 20 is installed on one side of the upper valve body 16. Several third slow-flow holes are opened on the throttling orifice plate 23. The medium discharged through the outlet 20 is decelerated again by passing through the throttling orifice plate 23.

[0033] Furthermore, such as Figure 15 , Figure 16 and Figure 17 As shown, an insulated steam flange 18 is inserted on the other side of the upper valve body 16. The insulated steam flange 18 includes a through pipe that is transversely inserted into the upper valve body 16 and a second flange fixedly connected to the end of the through pipe. The inner end of the through pipe is connected to the valve body cavity, and the outer end is connected to a steam pipe through the second flange to introduce high-temperature steam for circulating heating in the valve body jacket. A stuffing box 24 is provided between the valve shaft 25 and the upper valve body 16. The stuffing box 24 is made of polytetrafluoroethylene and is used to enhance the sealing between the valve shaft 25 and the upper valve body 16.

[0034] The sealing pair structure and concealed regulating valve provided by this utility model are used as follows: During operation, the actuator is connected to the top of the upper valve body 16. The medium enters from the inlet 21 at the bottom of the lower valve body 17, passes through the second orifice plate 22 and the first orifice plate 15 in sequence for two buffering and rectification processes, and then enters the slow flow port 11. Subsequently, it enters the regulating chamber 12. The regulating section 4 is located inside the regulating chamber 12. When the valve shaft 25 drives the valve core body 1 to move up and down, the annular flow cross section between the first buffer zone 4-1A, the first regulating zone 4-2A, and the flow-facing zone 4-3A of the regulating section 4 and the inner wall of the regulating chamber 12 changes accordingly, thereby realizing stepless flow regulation. In the multi-stage scheme, the medium is decelerated through the multi-stage regulating chamber 12 and the third buffer chamber 14, and the pressure is reduced step by step. After passing through the regulating chamber 12, the medium enters the first buffer chamber 8, forming an annular buffer space between it and the guide zone 31. After impacting the inclined conical surface of the guide zone 31, the medium is guided to deflect in all directions. The sealing section 2 is in the flow "blind zone" after deflection. The main flow of the medium bypasses the sealing surface and flows around it without directly eroding the sealing surface. The isolation zone 32 is located above the guide zone 31, further separating the deflected medium from the sealing section 2 to achieve "hidden" sealing protection. In the scheme of embodiment 4, when the valve core body 1 moves upward to open the valve, the lower shaft 6 rises accordingly, and the adjusting hole 33 on it is offset from the first orifice plate 15. Under the pressure difference drive, part of the medium enters the conveying channel 34 through the adjusting hole 33, flows upward into the concentration cavity 35 in the middle of the isolation zone 32, and then sprays out along the annular path from the fan-shaped dispersion cavity 37 through the dispersion channel 36, forming an annular gas / liquid curtain on the outside of the guide zone 31, which generates a reverse push against the mainstream medium, making it further away from the sealing section 2. The more the valve core body 1 moves upward, the larger the offset area of ​​the adjusting hole 33, the faster the spraying medium speed, and the protective effect is adaptively enhanced. When the valve is closed, the adjusting hole 33 returns to the bottom of the first orifice plate 15 and is blocked, and the path is automatically closed. After being deflected and pushed, the medium is decelerated and homogenized by the second buffer chamber 13, and then flows into the valve body chamber 19 through multiple sets of annular staggered diversion holes 10. After being finally decelerated by the throttling orifice plate 23, it is discharged from the outlet 20. When closed, the valve core body 1 moves down, the regulating section 4 gradually blocks the regulating chamber 12, and the sealing section 2 fits with the sealing surface 9 to achieve a seal. The guide zone 31 continuously deflects the medium throughout the closing process to protect the sealing surface from high-speed jet erosion.

[0035] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A sealing pair structure, characterized in that, The valve includes a valve core and a valve seat. The valve core is composed of a valve core body (1), a sealing section (2), an isolation section (3), and an adjustment section (4) connected in sequence. The adjustment section (4) is used to reduce the flow velocity of the fluid medium to the sealing section (2). The isolation section (3) includes a guide area (31) that is inclined at the top and lower relative to the axial direction of the valve core body (1) and an isolation area (32) connected to the sealing section (2). The bottom outer diameter of the guide area (31) is smaller than the top outer diameter of the guide area (31). The guide area (31) is used to guide the medium to flow away from the axis. The sealing surface of the sealing section (2) is located in the flow blind area formed after the guide area (31) guides the medium to deflect. The valve seat includes a valve seat body (7), an installation cavity is provided inside the valve seat body (7), the valve core body (1) slides inside the installation cavity, a plurality of flow diversion holes (10) penetrating the valve seat body (7) are provided on the periphery of the installation cavity, a first buffer cavity (8) is provided below the installation cavity, a sealing surface (9) that cooperates with the sealing section (2) is provided at the top of the first buffer cavity (8), an adjustment cavity (12) is provided below the first buffer cavity (8), a slow flow port (11) is provided at the bottom of the valve seat body (7), a first orifice plate (15) is provided inside the slow flow port (11), and a plurality of first slow flow holes are provided on the first orifice plate (15).

2. The sealing pair structure according to claim 1, characterized in that, The adjustment section (4) includes a first buffer zone (4-1A), a first adjustment zone (4-2A), and a flow-facing zone (4-3A). The first buffer zone (4-1A), the first adjustment zone (4-2A), and the flow-facing zone (4-3A) are connected sequentially in the axial direction of the valve core body (1). The outer surfaces of the first buffer zone (4-1A) and the first adjustment zone (4-2A) are axially inclined with a larger upper surface and a smaller lower surface. The inclination angle of the outer surface of the first buffer zone (4-1A) is greater than that of the outer surface of the first adjustment zone (4-2A). An arc-shaped transition is provided between the first buffer zone (4-1A) and the first adjustment zone (4-2A).

3. The sealing pair structure according to claim 2, characterized in that, A plurality of the diversion holes (10) form a plurality of through hole groups arranged vertically. The through hole group includes a plurality of through holes arranged in a ring. The upper edge of the through hole group coincides with the lower edge of the adjacent through hole group. The through holes of the adjacent through hole groups are staggered.

4. The sealing pair structure according to claim 1, characterized in that, The adjustment section (4) includes a plurality of second adjustment zones (4-2B) arranged axially. The top of the second adjustment zone (4-2B) is connected to a second buffer zone (4-1B). A connecting section (5) is provided between adjacent adjustment sections (4). The top and bottom of the connecting section (5) are respectively connected to the adjacent second adjustment zone (4-2B) and the second buffer zone (4-1B). The connection between the connecting section (5) and the adjacent second adjustment zone (4-2B) and the second buffer zone (4-1B) is transitioned by an arc surface. A lower shaft (6) is fixedly connected to the bottom of the lowest second adjustment zone (4-2B). The lower shaft (6) slides through the middle of the first perforated plate (15).

5. A sealing pair structure according to claim 4, characterized in that, The number of regulating cavities (12) is the same as that of regulating sections (4). The regulating sections (4) are located inside the regulating cavities (12). A third buffer cavity (14) is provided between adjacent regulating cavities (12). The bottom of the regulating cavities (12) is inclined. The lowest regulating cavity (12) is connected to the slow flow port (11).

6. A sealing pair structure according to claim 5, characterized in that, The valve seat body (7) has a second buffer chamber (13) inside. The second buffer chamber (13) is connected to the diversion hole (10). The medium enters the second buffer chamber (13) for buffering and then is discharged from the diversion hole (10).

7. A sealing pair structure according to claim 4, characterized in that, The isolation section (3) also includes a central cavity (35) located in the middle of the isolation area (32). The bottom of the central cavity (35) is provided with a conveying channel (34) extending into the lower shaft (6). The lower shaft (6) is provided with a number of adjustment holes (33) at equal intervals on its circumference. The adjustment holes (33) are connected to the bottom of the conveying channel (34). The central cavity (35) is provided with a number of dispersion channels (36) at equal intervals on its circumference.

8. A sealing pair structure according to claim 7, characterized in that, The end of the dispersion channel (36) is provided with a fan-shaped dispersion cavity (37), and the end of the dispersion cavity (37) is inclined away from the sealing section (2).

9. A concealed regulating valve, comprising a sealing pair structure as described in any one of claims 1-8, characterized in that, The valve includes an upper valve body (16) and a lower valve body (17). The upper valve body (16) has a valve body cavity (19) in its middle. The valve seat body (7) is installed inside the valve body cavity (19). One side of the upper valve body (16) has an outlet (20) communicating with the valve body cavity (19). The lower valve body (17) has a vertically penetrating inlet (21). A second perforated plate (22) is fixedly installed inside the inlet (21). The second perforated plate (22) has several second slow-flow holes. The bottom end of the valve seat body (7) extends through the upper valve body (16) to the top end of the inlet (21). The bottom end of the lower valve body (17) is fixedly connected to the first flange. The lower valve body (17) and the upper valve body (16) are connected by bolts. The bolts tighten the upper valve body (16) and the lower valve body (17) so that the bottom end face of the valve seat body (7) abuts against the lower valve body (17) to achieve a seal. The top end of the upper valve body (16) is provided with a valve shaft (25). The bottom end of the valve shaft (25) is fixedly connected to the valve core body (1).

10. A concealed regulating valve according to claim 9, characterized in that, A throttling orifice plate (23) located at the end of the outlet (20) is installed on one side of the upper valve body (16), and a number of third slow-flow holes are opened on the throttling orifice plate (23).

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