Low-pressure packing type high-pressure gate valve

Abstract

The invention belongs to the technical field of valves, and discloses a low-pressure packing type high-pressure gate valve which comprises a valve body, a gate plate and a packing device, and the packing device comprises a boundary penetrating body, a front-end packing plug, a rear-end packing plug, a tightening plug, a blocking ball, a first elastic piece and a second elastic piece; the boundary penetrating body is provided with a through groove, the front end packing plug and the rear end packing plug are arranged in the through groove in a sliding mode, the tightening plug is fixedly connected to the rear end of the through groove, the outer side of the front end packing plug is matched with the front end of the through groove in a sealing mode, the outer side of the rear end packing plug is matched with the tightening plug in a sealing mode, and the first elastic piece is arranged between the front end packing plug and the rear end packing plug. A bent flow channel is formed in the front end packing plug, the blocking ball is movably arranged in the bent flow channel, a fifth sealing face is arranged at the contact position of the bent flow channel and the blocking ball, and the second elastic piece is arranged between the blocking ball and the rear end packing plug. The rear end packing plug is provided with a first flow channel, the tight plug is provided with a second flow channel, and the bending flow channel, the first flow channel and the second flow channel are sequentially communicated.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a low-pressure sealing type high-pressure gate valve. Background Technology

[0002] High-pressure gate valves, as key control components in fluid transport systems, are widely used in industries such as petroleum, chemical, and power. Their sealing performance and ease of operation directly affect the safety, stability, and reliability of the system. Under sub-equilibrium conditions, the sealing fit between the valve body and the gate is crucial for ensuring the valve's functionality, while the energy storage characteristics of the valve body's sealing ring play a decisive role in the sealing effect and operational performance.

[0003] Existing high-pressure gate valves, under sub-equilibrium conditions, exhibit the following problems due to improper selection of the energy storage type of the valve body sealing ring:

[0004] Firstly, when a large energy-storing valve body sealing ring is used, the sealing ring can push the metal sealing surface of the valve body to fit tightly against the metal sealing surface of the gate. Although a seal can be achieved under the rated working pressure, this sealing structure completely isolates the flow channel pressure from the valve cavity pressure, forming a significant pressure difference ΔP. This pressure difference leads to a significant increase in the switching torque required to open the valve, increasing the difficulty of operation. Furthermore, during repeated opening and closing, the metal sealing surfaces of the valve body and the gate are prone to wear and deformation due to continuous high-pressure contact and relative friction, which in turn leads to a gradual decline in sealing performance, affecting the valve's service life and the system's sealing performance.

[0005] Secondly, if a smaller, energy-storing valve body sealing ring is selected, its driving force is insufficient to ensure a tight seal between the valve body's metal sealing surface and the gate's metal sealing surface, making it difficult to achieve a reliable sealing effect under rated operating pressure. More critically, in a sub-equilibrium state where the flow channel pressure gradually increases, pressure will continuously be forced into the valve cavity through the pressure breakthrough point of a conventional valve. Since a purely metal seal at this location is insufficient to block pressure transmission, the pressure in the valve cavity cannot reach equilibrium with the pressure within the flow channel. This phenomenon directly leads to inaccurate pressure detection data during actual production, thereby affecting the system's pressure control accuracy and potentially posing a threat to the safety and stability of industrial production.

[0006] Therefore, there is an urgent need to develop a low-pressure sealing high-pressure gate valve to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to solve or at least alleviate some or all of the above-mentioned problems. Therefore, the purpose of this invention is to provide a low-pressure sealing high-pressure gate valve that, while ensuring reliable sealing between the valve body and the metal sealing surface of the gate, reduces the switching torque when the gate is opened, improving operational convenience; it also blocks pressure transmission between the flow channel and the valve cavity, balancing the pressure in the valve cavity with the pressure in the flow channel, ensuring the accuracy of pressure detection data, and improving the system pressure control precision.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A low-pressure sealing type high-pressure gate valve includes a valve body and a gate. The valve body has a flow channel and a valve cavity communicating with the flow channel. The gate is disposed in the valve cavity. The gate has a flow groove for communicating with the flow channel when the gate is opened.

[0010] The low-pressure sealing type high-pressure gate valve also includes a sealing device, which is installed on the gate plate and includes a boundary crossing body, a front sealing plug, a rear sealing plug, a tight plug, a blocking ball, a first elastic element, and a second elastic element.

[0011] The boundary crossing body is disposed on the gate plate. The boundary crossing body has a through groove that penetrates the side wall of the flow channel. The front end sealing plug and the rear end sealing plug are both slidably disposed in the through groove. The parallel plug is fixedly connected to the rear end of the through groove. The front end sealing plug has a first sealing surface on its outer side. The front end of the through groove has a second sealing surface that seals with the first sealing surface. The rear end sealing plug has a third sealing surface on its outer side. The parallel plug has a fourth sealing surface that seals with the third sealing surface. The first elastic element is disposed between the front end sealing plug and the rear end sealing plug.

[0012] The front end sealing plug has a bent flow channel, the blocking ball is movably disposed in the bent flow channel, a fifth sealing surface is provided at the contact point between the bent flow channel and the blocking ball, and the second elastic element is disposed between the blocking ball and the rear end sealing plug;

[0013] The rear end seal has a first flow channel, and the tight plug has a second flow channel. The bent flow channel, the first flow channel, and the second flow channel are connected in sequence.

[0014] In some alternative embodiments, the sealing device further includes a pressure block and a blocking seat, the pressure block abutting against the rear end sealing plug, the blocking seat abutting against the blocking ball, and the second elastic member disposed between the pressure block and the blocking ball.

[0015] In some optional embodiments, both the pressure block and the blocking seat have through holes and are connected to each other, and the blocking seat has an opening groove on the side near the blocking ball.

[0016] In some optional embodiments, the end of the rear end packer near the front end packer is provided with a first sealing groove, and the end of the front end packer near the rear end packer is slidably sealed with the first sealing groove.

[0017] In some optional embodiments, at least one of the outer wall of the front sealing block and the inner wall of the first sealing groove is provided with a first receiving groove, and a first sealing ring is provided in the first receiving groove.

[0018] In some optional embodiments, a second sealing groove is provided at one end of the parallel plug near the rear end sealing plug, and the end of the rear end sealing plug near the parallel plug slides and seals with the second sealing groove.

[0019] In some optional embodiments, at least one of the outer wall of the plug and the inner wall of the second sealing groove is provided with a second receiving groove, and a second sealing ring is provided in the second receiving groove.

[0020] In some optional embodiments, at least one of the outer wall of the plug and the inner wall of the through groove is provided with a third receiving groove, and a third sealing ring is provided in the third receiving groove.

[0021] In some optional embodiments, both the first sealing surface and the second sealing surface are tapered surfaces; and / or,

[0022] Both the third sealing surface and the fourth sealing surface are conical surfaces.

[0023] In some alternative embodiments, the threaded plug is connected to the rear end of the through groove.

[0024] The beneficial effects of this invention are:

[0025] This invention provides a low-pressure sealing high-pressure gate valve, comprising a valve body and a gate. The valve body has a flow channel and a valve cavity communicating with the flow channel. The gate is disposed within the valve cavity, wherein the gate has a flow groove for communicating with the flow channel when the gate is open. The low-pressure sealing high-pressure gate valve also includes a sealing device mounted on the gate, comprising a boundary through-body, a front sealing plug, a rear sealing plug, a tight plug, a blocking ball, a first elastic element, and a second elastic element. The boundary through-body is disposed on the gate and has a through groove penetrating the side wall of the flow channel. The front and rear sealing plugs are slidably disposed within the through groove, and the tight plug is fixedly connected to the rear end of the through groove. The front sealing plug has a first sealing surface on its outer side, and the through groove has a second sealing surface that seals with the first sealing surface at its front end. The rear sealing plug has a second sealing surface on its outer side. A third sealing surface is provided on the side, and a fourth sealing surface that seals with the third sealing surface is provided in a tight-fitting manner. A first elastic element is provided between the front end sealing plug and the rear end sealing plug to provide a pre-tightening force for pressing the first sealing surface of the front end sealing plug against the second sealing surface at the front end of the through groove, and a pre-tightening force for pressing the third sealing surface of the rear end sealing plug against the fourth sealing surface of the tight-fitting plug. A bent flow channel is provided inside the front end sealing plug, and a blocking ball is movably disposed in the bent flow channel. A fifth sealing surface is provided at the contact point between the bent flow channel and the blocking ball. A second elastic element is provided between the blocking ball and the rear end sealing plug to provide a pre-tightening force for pressing the blocking ball against the fifth sealing surface of the bent flow channel. A first flow channel is provided in the rear end sealing plug, and a second flow channel is provided in the tight-fitting plug. The bent flow channel, the first flow channel, and the second flow channel are connected in sequence.

[0026] When the low-pressure packing type high-pressure gate valve is in its initial unused state, the flow channel pressure F1=0, the valve cavity pressure F2=0, the pre-tightening force of the first elastic element on the front and rear packing plugs is F3, the pre-tightening force of the second elastic element on the blocking ball is F4, the sealing pre-tightening force between the first and second sealing surfaces is F5=F3+F4, and the sealing pre-tightening force between the third and fourth sealing surfaces is F6=F3+F4.

[0027] When the low-pressure isolation type high-pressure gate valve is in operation, the flow channel pressure F1 rises from 0 to F under the action of the construction pressure. 1-1 , of which F 1-1 ≤F5, the first sealing surface and the second sealing surface maintain a sealing fit, so that the flow channel pressure and the valve cavity pressure are isolated from each other, and the valve cavity pressure F2=0 is maintained.

[0028] When the flow channel pressure F1 changes from F 1-1 Boost to F 1-2 Where, F5 < F 1-2≤F4+F5, the flow channel pressure will push the front end packer to move closer to the rear end packer, causing the sealing fit between the first sealing surface and the second sealing surface to fail. A circulation cavity is formed between the outer side of the front end packer and the inner wall of the through groove, and the fluid enters the circulation cavity. The sealing fit between the third sealing surface and the fourth sealing surface, as well as the sealing fit between the blocking ball and the fifth sealing surface, can prevent the fluid from entering the valve cavity, so that the flow channel pressure and the valve cavity pressure are isolated from each other, and the valve cavity pressure F2=0 is maintained.

[0029] When the flow channel pressure F1 changes from F 1-2 Boost to F 1-3 , of which F 1-3 >F4+F5, the flow channel pressure will push the blocking ball towards the rear end of the sealing block. The fluid sequentially enters the valve chamber through the circulation chamber, the bent flow channel, the first flow channel, and the second flow channel. The flow channel pressure thus invades the valve chamber until the valve chamber pressure F2 tends to balance, i.e., F2=F 1-3 -F5.

[0030] When the valve chamber pressure F2 is in a critical equilibrium state, due to the instability of the flow channel pressure F1, the preload force F3 of the first elastic element, and the preload force F4 of the second elastic element under pressure fluctuations, the valve chamber pressure F2 will be slightly greater than F4. The valve chamber pressure F2 pushes the rear end seal to compress the first elastic element, causing the preload force F3 of the first elastic element to increase to F4. 3-1 Then, the front end packer is pushed back to the position where the first sealing surface and the second sealing surface are sealed together. At this time, the pressure in the circulation chamber, the preload force F3 of the first elastic element and the preload force F4 of the second elastic element reach the necessary specific pressure required for the sealing and cooperation of the first sealing surface and the second sealing surface under the action of the valve chamber pressure F2, and form a blockage between the flow channel pressure and the valve chamber pressure again, so that the valve chamber pressure and the flow channel pressure reach a balance, preventing the pressure difference between the flow channel pressure and the valve chamber pressure from being too large, thereby preventing the switching torque required when the gate is opened from being too large, and preventing the valve chamber pressure fluctuation from causing inaccurate pressure detection data.

[0031] By adopting the low-pressure sealing high-pressure gate valve provided in this embodiment, the switching torque when the gate is opened can be reduced, improving the ease of operation, while ensuring reliable sealing between the valve body and the metal sealing surface of the gate. It also blocks the pressure transmission between the flow channel and the valve cavity, balancing the pressure in the valve cavity with the pressure in the flow channel, ensuring the accuracy of pressure detection data, and improving the system pressure control precision. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0033] Figure 1 This is an axial sectional view of the low-pressure sealing high-pressure gate valve described in an embodiment of the present invention;

[0034] Figure 2 yes Figure 1 Sectional view at point AA;

[0035] Figure 3 This is a schematic diagram of the sealing device described in the embodiment of the present invention when the flow channel pressure is not greater than F1-2;

[0036] Figure 4 This is a schematic diagram of the sealing device described in the embodiment of the present invention when the flow channel pressure is greater than F1-2.

[0037] In the picture:

[0038] 1. Valve body; 11. Flow channel; 12. Valve cavity;

[0039] 2. Gate; 21. Flow channel;

[0040] 3. Sealing device; 31. Boundary crossing body; 311. Through groove; 312. Second sealing surface; 32. Front end sealing plug; 321. First sealing surface; 322. Bent flow channel; 3221. Third flow channel; 3222. Fourth flow channel; 323. Fifth sealing surface; 33. Rear end sealing plug; 331. Third sealing surface; 332. First flow channel; 333. First sealing groove; 34. Tight plug; 341. Fourth sealing surface; 342. Second flow channel; 343. Second sealing groove; 35. Blocking ball; 36. First elastic element; 37. Second elastic element; 38. Pressure block; 39. Blocking seat; 391. Opening groove; 40. First sealing ring; 41. Second sealing ring; 42. Third sealing ring;

[0041] 5. Circulation chamber. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] In this invention, the terms "comprising," "including," "having," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0044] In this invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following related objects have an "and / or" relationship.

[0045] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," "fixed," "combined," "coupled," and "installed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection via an intermediate medium; or the internal communication of two components or the interaction between two components. As examples, a direct connection refers to two parts or components being connected together without the need for an intermediate medium, while an indirect connection refers to two parts or components each being connected to at least one intermediate medium, with the connection achieved through the intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0046] In this invention, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​not using relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0047] In this invention, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0048] In this invention, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientations or positional relationships shown in the accompanying drawings. They are used solely for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, in the context, it should be understood that when an element is mentioned as being "upper" or "lower" than another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as "upper side," "lower side," "left side," "right side," "front side," and "rear side" not only represent positive orientation but can also be understood as lateral orientation. For example, "above," "on top of," "upper side of," and "above" the first feature "above" or "on the second feature" includes the first feature being directly above, to the upper left, to the upper right, to the upper front, and to the upper rear of the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature. The terms "below," "under," "below," and "below" for "first feature" and "second feature" include situations where the first feature is directly below, to the lower left, to the lower right, in front of, or behind the second feature, or simply indicate that the first feature is at a lower horizontal level than the second feature. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no specific meaning.

[0049] like Figures 1-4 As shown, this embodiment provides a low-pressure sealing type high-pressure gate valve, including a valve body 1 and a gate 2. The valve body 1 has a flow channel 11 and a valve cavity 12 communicating with the flow channel 11. The gate 2 is disposed in the valve cavity 12, wherein the gate 2 has a flow groove 21, which is used to communicate with the flow channel 11 when the gate 2 is open. The gate 2 has a closed position that blocks the flow channel 11 and an open position that opens the flow channel 11. When the gate 2 is in the closed position, the gate 2 is sealed with the valve body 1 to block the flow channel 11. When the gate 2 is in the open position, the flow groove 21 communicates with the flow channel 11.

[0050] The low-pressure packing type high-pressure gate valve also includes a packing device 3, which is installed on the gate plate 2. The packing device 3 includes a boundary through-body 31, a front packing plug 32, a rear packing plug 33, a tight plug 34, a blocking ball 35, a first elastic element 36, and a second elastic element 37. The boundary through-body 31 is disposed on the gate plate 2 and has a through-groove 311 that passes through the side wall of the flow channel 21. The front packing plug 32 and the rear packing plug 33 are slidably disposed within the through-groove 311, and the tight plug 34 is fixedly connected to the rear end of the through-groove 311. The front packing plug 32 has a first sealing surface 321 on its outer side, the through-groove 311 has a second sealing surface 312 that seals with the first sealing surface 321 at its front end, the rear packing plug 33 has a third sealing surface 331 on its outer side, and the tight plug 34 has a fourth sealing surface 341 that seals with the third sealing surface 331. The first elastic element 36 is disposed between the front packing plug 32 and the rear packing plug 33. Between 3, a pre-tightening force is provided to press the first sealing surface 321 of the front end seal 32 against the second sealing surface 312 at the front end of the through groove 311, and a pre-tightening force is provided to press the third sealing surface 331 of the rear end seal 33 against the fourth sealing surface 341 of the plug 34; a bent flow channel 322 is provided inside the front end seal 32, and the blocking ball 35 is movably disposed in the bent flow channel 322. A first sealing surface 341 is provided at the contact point between the bent flow channel 322 and the blocking ball 35. The fifth sealing surface 323 is provided, and the blocking ball 35 can be sealed with the fifth sealing surface 323. The second elastic element 37 is provided between the blocking ball 35 and the rear end sealing plug 33 to provide a pre-tightening force to press the blocking ball 35 and the fifth sealing surface 323 of the bent flow channel 322 into tight fit. The rear end sealing plug 33 has a first flow channel 332 and the tight plug 34 has a second flow channel 342. The bent flow channel 322, the first flow channel 332 and the second flow channel 342 are connected in sequence.

[0051] like Figure 3 As shown, when the low-pressure packing type high-pressure gate valve is in its initial unused state, the pressure in the flow channel 11 is F1=0, the pressure in the valve chamber 12 is F2=0, the pre-tightening force of the first elastic element 36 on the front end packing plug 32 and the rear end packing plug 33 is F3, the pre-tightening force of the second elastic element 37 on the blocking ball 35 is F4, the sealing pre-tightening force between the first sealing surface 321 and the second sealing surface 312 is F5=F3+F4, and the sealing pre-tightening force between the third sealing surface 331 and the fourth sealing surface 341 is F6=F3+F4.

[0052] When the low-pressure isolation type high-pressure gate valve is in operation, the pressure F1 in the flow channel 11 rises from 0 to F under the action of the construction pressure. 1-1 , of which F 1-1 ≤F5, the first sealing surface 321 and the second sealing surface 312 maintain a sealing fit, so that the pressure of the flow channel 11 and the pressure of the valve cavity 12 are isolated from each other, and the pressure of the valve cavity 12 is kept at F2=0.

[0053] When the pressure F1 in flow channel 11 is from F 1-1 Boost to F 1-2 Where, F5 < F 1-2 ≤F4+F5, the pressure in the flow channel 11 will push the front sealing plug 32 to move closer to the rear sealing plug 33, causing the sealing fit between the first sealing surface 321 and the second sealing surface 312 to fail. A circulation cavity 5 is formed between the outer side of the front sealing plug 32 and the inner wall of the through groove 311, and the fluid enters the circulation cavity 5. The sealing fit between the third sealing surface 331 and the fourth sealing surface 341, as well as the sealing fit between the blocking ball 35 and the fifth sealing surface 323, can prevent the fluid from entering the valve cavity 12, so that the pressure in the flow channel 11 and the pressure in the valve cavity 12 are isolated from each other, and the pressure in the valve cavity 12 is kept at F2=0.

[0054] like Figure 4 As shown, when the pressure F1 in flow channel 11 changes from F 1-2 Boost to F 1-3 , of which F 1-3 >F4+F5, the pressure in flow channel 11 will push the blocking ball 35 towards the rear sealing plug 33. The fluid will sequentially enter the valve chamber 12 through the circulation chamber 5, the bent flow channel 322, the first flow channel 332, and the second flow channel 342. The pressure in flow channel 11 will thus invade the valve chamber 12 until the pressure F2 in the valve chamber 12 tends to be balanced, that is, F2=F 1-3 -F5.

[0055] When the pressure F2 in valve chamber 12 is at a critical equilibrium state, due to the instability of the pressure F1 in flow channel 11, the preload F3 of the first elastic element 36, and the preload F4 of the second elastic element 37 under pressure fluctuations, the pressure F2 in valve chamber 12 will be slightly greater than F4. The pressure F2 in valve chamber 12 pushes the rear sealing plug 33 to compress the first elastic element 36, causing the preload F3 of the first elastic element 36 to increase to F4. 3-1 Then, the front end sealing plug 32 is pushed back to the position where the first sealing surface 321 and the second sealing surface 312 are sealed together. At this time, the pressure in the circulation chamber 5, the pre-tightening force F3 of the first elastic element 36 and the pre-tightening force F4 of the second elastic element 37 reach the necessary specific pressure required for the sealing and cooperation of the first sealing surface 321 and the second sealing surface 312 under the action of the valve chamber 12 pressure F2, and form a blockage between the pressure of the flow channel 11 and the pressure of the valve chamber 12 again, so that the pressure of the valve chamber 12 and the pressure of the flow channel 11 are balanced, preventing the pressure difference between the pressure of the flow channel 11 and the pressure of the valve chamber 12 from being too large, thereby preventing the switching torque required when the gate 2 is opened from being too large, and preventing the pressure fluctuation of the valve chamber 12 from causing inaccurate pressure detection data.

[0056] In summary, by adopting the low-pressure sealing high-pressure gate valve provided in this embodiment, the switching torque of the gate 2 when it is opened can be reduced, improving the ease of operation, while ensuring reliable sealing between the metal sealing surfaces of the valve body 1 and the gate 2; the pressure transmission between the flow channel 11 and the valve cavity 12 is blocked, so that the pressure in the valve cavity 12 is balanced with the pressure in the flow channel 11, ensuring the accuracy of the pressure detection data and improving the system pressure control precision.

[0057] It should be noted that in this embodiment, the boundary crossing body 31 is part of the gate plate 2. The through groove 311 is formed on the gate plate 2. The front sealing plug 32, the rear sealing plug 33, the tight plug 34, the blocking ball 35, the first elastic element 36, and the second elastic element 37 are all installed in the through groove 311, so that the sealing device 3 is integrated on the gate plate 2. In other embodiments, the boundary crossing body 31 is an independent component. The gate plate 2 has a mounting hole on the side wall of the through flow groove 21. The boundary crossing body 31 is installed in the mounting hole. This design makes the sealing device 3 an independent unit, which is convenient to assemble the sealing device 3 separately and then install it into the gate plate 2.

[0058] The bent flow channel 322 includes a third flow channel 3221 and a fourth flow channel 3222 that are connected. The third flow channel 3221 extends axially along the front end sealing plug 32, and the fourth flow channel 3222 penetrates the outer wall of the front end sealing plug 32. When the pressure of the flow channel 11 pushes the front end sealing plug 32 to move closer to the rear end sealing plug 33, a circulation cavity 5 is formed between the outer side of the front end sealing plug 32 and the inner wall of the through groove 311. The fourth flow channel 3222 is connected to the circulation cavity 5, so that the fluid can enter the valve cavity 12 in sequence through the circulation cavity 5, the bent flow channel 322, the first flow channel 332 and the second flow channel 342.

[0059] like Figure 3 and Figure 4 As shown, in some optional embodiments, the sealing device 3 further includes a pressure block 38 and a blocking seat 39. The pressure block 38 abuts against the rear sealing plug 33, and the blocking seat 39 abuts against the blocking ball 35. A second elastic member 37 is disposed between the pressure block 38 and the blocking ball 35. The pressure block 38 and the blocking seat 39 are used to fix the second elastic member 37.

[0060] Furthermore, both the pressure block 38 and the blocking seat 39 are provided with through holes, and the two are connected to each other, thereby improving fluid flow efficiency; the blocking seat 39 is provided with an opening groove 391 on the side near the blocking ball 35. The opening groove 391 is used to release pressure, avoid the blocking ball 35 and the blocking seat 39 from being too tightly fitted, prevent sticking, ensure that the blocking ball 35 can flexibly respond to pressure changes and accurately realize on / off control; and can quickly release locally accumulated pressure, avoid excessive system pressure fluctuations, make the fluid flow in the through holes of the pressure block 38 and the blocking seat 39 smoother, and improve the sensitivity of overall pressure regulation.

[0061] Optionally, the first elastic element 36 and the second elastic element 37 include, but are not limited to, springs or elastic rubber tubes, which are not limited here.

[0062] In some optional embodiments, a first sealing groove 333 is provided at the end of the rear packer 33 near the front packer 32, and the end of the front packer 32 near the rear packer 33 slides and seals with the first sealing groove 333, thereby ensuring the sealing between the front packer 32 and the rear packer 33 and preventing fluid leakage from causing packer failure.

[0063] Furthermore, at least one of the outer wall of the front sealing plug 32 and the inner wall of the first sealing groove 333 is provided with a first receiving groove, and a first sealing ring 40 is provided in the first receiving groove, which further improves the sealing performance between the front sealing plug 32 and the rear sealing plug 33.

[0064] In some optional embodiments, a second sealing groove 343 is provided at one end of the parallel plug 34 near the rear end sealing plug 33. The end of the rear end sealing plug 33 near the parallel plug 34 slides and seals with the second sealing groove 343, thereby ensuring the sealing between the rear end sealing plug 33 and the parallel plug 34 and preventing fluid leakage from causing sealing failure.

[0065] Furthermore, at least one of the outer wall of the plug 34 and the inner wall of the second sealing groove 343 is provided with a second receiving groove, and a second sealing ring 41 is provided in the second receiving groove, which further improves the sealing performance between the rear sealing plug 33 and the plug 34.

[0066] In some optional embodiments, at least one of the outer wall of the plug 34 and the inner wall of the through groove 311 is provided with a third receiving groove, and a third sealing ring 42 is provided in the third receiving groove to ensure the sealing between the plug 34 and the boundary through body 31 and prevent fluid leakage from causing the sealing failure.

[0067] For example, the first sealing ring 40, the second sealing ring 41 and the third sealing ring 42 are all O-rings.

[0068] In some optional embodiments, both the first sealing surface 321 and the second sealing surface 312 are conical surfaces. On the one hand, the two conical surfaces contact to form a line seal, which further enhances the sealing performance by means of the hydraulic self-tightening effect and effectively blocks fluid leakage; on the other hand, the conical surface has a guiding function, which can compensate for assembly deviations and slight wear, adapt to high-pressure conditions, and provide uniform contact stress, thereby reducing component damage.

[0069] Similarly, both the third sealing surface 331 and the fourth sealing surface 341 are conical surfaces, which helps to improve sealing reliability, effectively block fluid leakage, compensate for assembly deviations and slight wear, adapt to high-pressure conditions and have uniform contact stress, and reduce component damage. These features will not be elaborated here.

[0070] In some alternative embodiments, the plug 34 is threadedly connected to the rear end of the through groove 311. By screwing and tightening the plug 34, the initial sealing preload between the first sealing surface 321 and the second sealing surface 312, as well as the initial sealing preload between the third sealing surface 331 and the fourth sealing surface 341, can be easily adjusted.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A low-pressure sealing type high-pressure gate valve, comprising a valve body (1) and a gate (2), wherein the valve body (1) has a flow channel (11) and a valve cavity (12) communicating with the flow channel (11), and the gate (2) is disposed in the valve cavity (12), characterized in that, The gate (2) is provided with a flow groove (21), which is used to communicate with the flow channel (11) when the gate (2) is opened; The low-pressure sealing high-pressure gate valve also includes a sealing device (3), which is installed on the gate (2) and includes a boundary crossing body (31), a front sealing plug (32), a rear sealing plug (33), a tight plug (34), a blocking ball (35), a first elastic element (36), and a second elastic element (37). The boundary crossing body (31) is disposed on the gate (2). The boundary crossing body (31) has a through groove (311) that passes through the side wall of the flow channel (21). The front end sealing plug (32) and the rear end sealing plug (33) are slidably disposed in the through groove (311). The parallel plug (34) is fixedly connected to the rear end of the through groove (311). The front end sealing plug (32) has a first sealing surface (321) on its outer side. The front end of the through groove (311) has a second sealing surface (312) that seals with the first sealing surface (321). The rear end sealing plug (33) has a third sealing surface (331) on its outer side. The parallel plug (34) has a fourth sealing surface (341) that seals with the third sealing surface (331). The first elastic element (36) is disposed between the front end sealing plug (32) and the rear end sealing plug (33). The front end sealing plug (32) has a bent flow channel (322) inside, the blocking ball (35) is movably disposed in the bent flow channel (322), the contact point between the bent flow channel (322) and the blocking ball (35) is provided with a fifth sealing surface (323), and the second elastic element (37) is disposed between the blocking ball (35) and the rear end sealing plug (33); The rear end sealing plug (33) has a first flow channel (332), and the tight plug (34) has a second flow channel (342). The bent flow channel (322), the first flow channel (332) and the second flow channel (342) are connected in sequence.

2. The low-pressure sealing type high-pressure gate valve according to claim 1, characterized in that, The sealing device (3) further includes a pressure block (38) and a blocking seat (39). The pressure block (38) abuts against the rear sealing plug (33), and the blocking seat (39) abuts against the blocking ball (35). The second elastic element (37) is disposed between the pressure block (38) and the blocking ball (35).

3. The low-pressure sealing high-pressure gate valve according to claim 2, characterized in that, Both the pressure block (38) and the blocking seat (39) are provided with through holes and are connected to each other. The blocking seat (39) has an opening groove (391) on the side near the blocking ball (35).

4. The low-pressure sealing type high-pressure gate valve according to claim 1, characterized in that, The rear end of the packer (33) is provided with a first sealing groove (333) at the end near the front end of the packer (32), and the end of the front end of the packer (32) near the rear end of the packer (33) is in sliding sealing cooperation with the first sealing groove (333).

5. The low-pressure sealing high-pressure gate valve according to claim 4, characterized in that, At least one of the outer wall of the front sealing plug (32) and the inner wall of the first sealing groove (333) is provided with a first receiving groove, and a first sealing ring (40) is provided in the first receiving groove.

6. The low-pressure sealing high-pressure gate valve according to claim 1, characterized in that, The end of the parallel plug (34) near the rear end seal plug (33) is provided with a second sealing groove (343), and the end of the rear end seal plug (33) near the parallel plug (34) slides and seals with the second sealing groove (343).

7. The low-pressure sealing high-pressure gate valve according to claim 6, characterized in that, At least one of the outer wall of the plug (34) and the inner wall of the second sealing groove (343) is provided with a second receiving groove, and a second sealing ring (41) is provided in the second receiving groove.

8. The low-pressure sealing high-pressure gate valve according to claim 1, characterized in that, At least one of the outer wall of the plug (34) and the inner wall of the through groove (311) is provided with a third receiving groove, and a third sealing ring (42) is provided in the third receiving groove.

9. The low-pressure sealing type high-pressure gate valve according to any one of claims 1 to 8, characterized in that, Both the first sealing surface (321) and the second sealing surface (312) are conical surfaces; and / or, Both the third sealing surface (331) and the fourth sealing surface (341) are conical surfaces.

10. The low-pressure sealing high-pressure gate valve according to any one of claims 1 to 8, characterized in that, The plug (34) is threaded to the rear end of the through groove (311).

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