Precise sealing structure for gate valve and gate valve body for natural gas

Abstract

The utility model belongs to natural gas conveying equipment technical field especially relates to natural gas valve, the utility model provides a kind of precision sealing structure and natural gas valve body for gate valve, it include: sealing ring, with the arc-shaped surface of contact for with spheroid sealing contact;At least one compensation ring groove is opened on the end surface of the sealing ring;Several elastic compensation members are provided in the compensation ring groove;Wherein, the elastic compensation member is configured to be able to provide the sealing ring with the elastic force that its arc-shaped surface of contact tends to the spheroid;The utility model is provided with at least one compensation ring groove with elastic compensation member built-in on its end surface, when sealing ring arc-shaped surface of contact is deformed due to abrasion or aging, elastic compensation member can continuously exert force, drive sealing ring displacement to spheroid, automatically compensate wear gap, maintain stable sealing specific pressure;Realized the continuous, automatic elastic pre-tightening of sealing ring, let arc-shaped surface of contact always adhere to spheroid.

Description

Technical Field

[0001] This utility model belongs to the field of natural gas transmission technology, specifically relating to natural gas valves, and more particularly to gate valve bodies for natural gas. Background Technology

[0002] Natural gas, as a clean energy source, relies on long-distance pipelines and urban gas networks as critical infrastructure for maintaining societal operations. As a core opening and closing control component in this system, the buried ball valve, unlike conventional valves, is required to have a maintenance-free lifespan typically ranging from 15 to 30 years and extremely high operational reliability due to its underground location.

[0003] However, during long-term static periods, the valve seat seal ring will experience stress relaxation under the long-term static compressive load, resulting in a decrease in the initial sealing pressure applied to the ball. After the valve is opened, the stress-relaxed and sticky seal ring cannot fully restore its original shape, resulting in permanent deformation (also known as compression permanent deformation).

[0004] When the valve is closed again, the deformed sealing ring cannot fit tightly against the curved surface of the ball, resulting in insufficient sealing contact width and specific pressure, which leads to media leakage.

[0005] Therefore, how to prevent the sealing ring from failing to fit the spherical surface when it is stationary for a long time is a technical problem that urgently needs to be solved in this field.

[0006] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Utility Model Content

[0007] This disclosure provides at least one precision sealing structure for gate valves to solve the technical problem that the sealing ring cannot fit with the spherical surface when it is stationary for a long time.

[0008] In a first aspect, embodiments of this disclosure provide a precision sealing structure for a gate valve, comprising: a sealing ring having an arcuate contact surface for sealing contact with a ball; at least one compensation ring groove is provided on the end face of the sealing ring; a plurality of elastic compensation members are provided in the compensation ring groove; wherein the elastic compensation members are configured to provide the sealing ring with an elastic force that causes the arcuate contact surface to tend toward the ball.

[0009] In one alternative embodiment, the cross-section of the compensation ring groove is a right trapezoid, and its inclined surface is closer to the arc-shaped mating surface than its bottom surface.

[0010] In one alternative implementation, the elastic compensation element is a columnar structure.

[0011] In one optional embodiment, the elastic compensation member includes at least one hollow segment and at least one solid segment; the hollow segment and the solid segment are integrally connected alternately; the outer diameter of the hollow segment at its central position is larger than the diameter of the solid segment.

[0012] In one optional embodiment, the arc-shaped mating surface is provided with at least one annular groove, the cross-section of which is V-shaped or U-shaped.

[0013] Secondly, this disclosure also provides a gate valve body for natural gas, comprising: a valve seat; a ball disposed within the valve seat; and a sealing structure disposed within the valve seat on both sides of the ball; the sealing structure comprising: a pair of sealing rings having arc-shaped contact surfaces for sealing contact with the ball; and at least one annular groove provided on the arc-shaped contact surface, the cross-section of the annular groove being V-shaped or U-shaped.

[0014] In one optional embodiment, at least one compensation ring groove is formed on the end face of the sealing ring, and a plurality of elastic compensation members are provided in the compensation ring groove; wherein, the elastic compensation members are configured to provide the sealing ring with an elastic force that causes the arcuate contact surface to tend toward the sphere.

[0015] In one alternative embodiment, the cross-section of the compensation ring groove is a right trapezoid, and its inclined surface is closer to the arc-shaped mating surface than its bottom surface.

[0016] In one alternative implementation, the elastic compensation element is a columnar structure.

[0017] In one optional embodiment, the elastic compensation member includes at least one hollow segment and at least one solid segment; the hollow segment and the solid segment are integrally connected alternately; the outer diameter of the hollow segment at its central position is larger than the diameter of the solid segment.

[0018] The beneficial effect of this utility model is that it provides a precision sealing structure for gate valves: By setting at least one compensation ring groove with a built-in elastic compensation element on its end face, when the arc-shaped contact surface of the sealing ring is deformed due to wear or aging, the elastic compensation element can continuously apply force to drive the sealing ring to move towards the ball, automatically compensate for the wear gap, and maintain a stable sealing pressure; it realizes the continuous and automatic elastic pre-tightening of the sealing ring, realizes the self-compensation function of the sealing ring for wear and deformation, and keeps the arc-shaped contact surface in contact with the ball. By setting an integrated structure with alternating hollow and solid sections, a combination of rigidity and flexibility is achieved to adapt to various working conditions; by setting annular grooves and their V-shaped or U-shaped cross sections, a multi-level sealing barrier is formed, reducing the risk of leakage.

[0019] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.

[0020] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A perspective view of a gate valve body for natural gas provided in an embodiment of this disclosure; Figure 2 A perspective view of the sealing structure provided in the embodiments of this disclosure; Figure 3 A cross-sectional view of the sealing structure provided in an embodiment of this disclosure; Figure 4 A perspective view of the elastic compensation component provided in an embodiment of this disclosure.

[0023] In the picture: 1. Valve seat; 2. Sphere; 3. Sealing structure; 31. Sealing ring; 32. End face; 33. Compensating ring groove; 34. Arc-shaped mating surface; 35. Elastic compensation component; 351. Solid section; 352. Hollow section; 36. Annular groove. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of the components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0026] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0027] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise clearly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0028] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0029] Research has revealed the following drawbacks of existing technologies: During long-term static periods, the valve seat seal ring experiences stress relaxation under static compressive loads, leading to a decrease in the initial sealing pressure applied to the ball. After the valve is opened, the stress-relaxed and sticky seal ring cannot fully recover its original shape, resulting in permanent deformation (also known as compression permanent deformation).

[0030] When the valve is closed again, the deformed sealing ring cannot fit tightly against the curved surface of the ball, resulting in insufficient sealing contact width and specific pressure, which leads to media leakage.

[0031] Therefore, how to prevent the sealing ring from failing to fit the spherical surface when it is stationary for a long time is a technical problem that urgently needs to be solved in this field.

[0032] The shortcomings of the above solutions are the result of the utility model inventor's practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as contributions made by the utility model inventor to this disclosure.

[0033] 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.

[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] like Figures 1 to 4 As shown, some embodiments provide a precision sealing structure for a gate valve, including: a sealing ring 31 having an arcuate contact surface 34 for sealing contact with a ball 2; the sealing ring 31 is the core component of the sealing structure 3 and is made of a polymer (such as polytetrafluoroethylene PTFE, reinforced nylon or rubber composite material) which has good elasticity, wear resistance and chemical stability.

[0036] The sealing ring 31 is designed with an arc-shaped contact surface 34, which is precision machined so that its radius of curvature matches the curvature of the outer surface of the ball 2 to ensure that surface contact rather than line contact is achieved during initial installation and valve closure, thereby providing a uniform sealing pressure.

[0037] The presence of the arc-shaped contact surface 34 allows the sealing ring 31 to tightly wrap around the sphere 2, reducing the leakage path of the medium. Under long-term static conditions, the material of the sealing ring 31 will experience stress relaxation due to continuous pressure, causing the contact pressure between the arc-shaped contact surface 34 and the sphere 2 to gradually decrease. In this embodiment, through the optimized design of the arc-shaped contact surface 34, combined with other compensation mechanisms, stress relaxation is effectively counteracted, and the stability of the sealing interface is maintained. The smoothness and geometric accuracy of the arc-shaped contact surface 34 directly affect the sealing effect. Therefore, CNC grinding or polishing processes are often used during manufacturing to ensure that the surface roughness is lower than Ra 0.8μm, in order to minimize friction and adhesion risks.

[0038] At least one compensation ring groove 33 is provided on the end face 32 of the sealing ring 31; the compensation ring groove 33 is an annular groove, the axis of which is parallel to the central axis of the sealing ring 31, and the groove depth and width are precisely calculated according to the size of the sealing ring 31 and the expected compensation amount.

[0039] The core function of the compensation groove 33 is to accommodate the elastic compensation component 35 and provide structural space for the elastic recovery of the sealing ring 31. Its cross-section is designed as a right trapezoid, in which the inclined surface is closer to the arc-shaped mating surface 34 than the bottom surface. This asymmetrical design has important mechanical significance: the inclined surface of the right trapezoid generates a radial component force when subjected to internal pressure, pushing the sealing ring 31 to move towards the sphere 2. When the elastic compensation component 35 expands or extends in the groove, the guiding effect of the inclined surface can convert part of the axial elastic force into radial sealing force, directly enhancing the pressing effect of the arc-shaped mating surface 34 on the sphere 2.

[0040] In addition, the right-angled trapezoidal structure is easier to process than rectangular or semi-circular grooves, and the stress distribution is more uniform, reducing stress concentration at the root of the groove and preventing the sealing ring 31 from cracking under long-term cyclic load. The depth and angle of the compensation ring groove 33 have been optimized by finite element analysis. The depth is usually 1 / 5 to 1 / 3 of the thickness of the sealing ring 31, and the slope angle is between 45° and 60° to balance the compensation force and structural strength.

[0041] The compensation ring groove 33 is provided with a plurality of elastic compensation elements 35; wherein, the elastic compensation elements 35 are configured to provide elastic force to the sealing ring 31 to make its arc-shaped contact surface 34 tend to the sphere 2; the cross-section of the compensation ring groove 33 is a right trapezoid, and its inclined surface is closer to the arc-shaped contact surface 34 than the bottom surface.

[0042] The elastic compensator 35 has a columnar structure. It is disposed within the compensation ring groove 33 and configured to provide an elastic force to the sealing ring 31, causing its arc-shaped contact surface 34 to tend towards the sphere 2. The columnar structure can be made of a metal spring (such as a stainless steel helical spring) or a high-performance elastomer (such as silicone rubber or fluororubber). The columnar structure provides a uniform axial elastic force. When the sealing ring 31 shrinks in volume due to stress relaxation, the restoring force of the elastic compensator 35 pushes the sealing ring 31 towards the sphere 2, compensating for the sealing gap caused by permanent deformation. The columnar structure design allows it to store a large amount of elastic potential energy under compression and exhibits a low stress decay rate during long-term static placement (e.g., the relaxation rate of high-quality spring steel is less than 5%). The elastic modulus and pre-compression of the elastic compensator 35 need to be customized according to the expected deformation of the sealing ring 31 to ensure continuous and effective compensation throughout the valve's entire lifespan.

[0043] The elastic compensator 35 includes at least one hollow segment 352 and at least one solid segment 351; the hollow segment 352 and the solid segment 351 are integrally connected alternately; the outer diameter of the hollow segment 352 at its central position is larger than the diameter of the solid segment 351; the elastic compensator 35 further includes at least one hollow segment 352 and at least one solid segment 351, which are integrally connected alternately; this design combines the advantages of flexibility and rigidity: the solid segment 351 provides a stable support matrix to ensure that the elastic compensator 35 does not buckle under high pressure; the hollow segment 352 reduces local stiffness and increases elastic deformation capacity through its hollow structure; when the sealing ring 31 is compressed, the hollow segment 352 is more likely to undergo radial expansion, thereby applying a more uniform force to the inclined surface of the compensating ring groove 33.

[0044] The outer diameter of the hollow section 352 at its center position is larger than that of the solid section 351. This "drum-shaped" design allows the hollow section 352 to preferentially contact the groove wall during compression, generating a leverage effect and amplifying the pushing force on the sealing ring 31. In addition, the integral connection of the hollow section 352 and the solid section 351 (such as through precision casting or molding) avoids interface stress concentration and improves fatigue life. This structure is particularly suitable for working conditions with large temperature differences, because the difference in the coefficient of thermal expansion between different sections can be absorbed by the deformation of the hollow section 352, reducing the impact of thermal stress on sealing performance.

[0045] At least one annular groove 36 is provided on the arc-shaped mating surface 34. The cross-section of the annular groove 36 is V-shaped or U-shaped. The annular groove 36 serves as a secondary sealing structure and has multiple functions: First, the V-shaped or U-shaped groove forms a labyrinthine flow channel between the sealing interfaces. When the medium attempts to leak, the flow channel increases the flow resistance and reduces the leakage rate. Second, the groove can store grease or sealing grease to lubricate the surface of the ball 2 when the valve is actuated, reducing friction and wear. Third, the sharp edge of the V-shaped groove (usually 60°-90°) can generate high specific pressure during low-pressure sealing, achieving a soft seal. The rounded corner of the U-shaped groove provides a gentler stress distribution and is suitable for high-pressure applications. The depth and width of the annular groove 36 are calculated, with a typical depth of 0.1-0.3 mm, to avoid weakening the main structure of the sealing ring 31; multiple grooves can be arranged in parallel to form a multi-level sealing barrier, further improving reliability; in addition, the grooves can also accommodate tiny debris generated when the sealing ring 31 deforms, preventing it from scratching the surface of the sphere 2.

[0046] Some embodiments provide a gate valve body for natural gas, including: a valve seat 1; a ball 2 disposed within the valve seat 1; and a sealing structure 3 disposed within the valve seat 1 on both sides of the ball 2; the sealing structure 3 includes: a pair of sealing rings 31 having arcuate contact surfaces 34 for sealing contact with the ball 2; the arcuate contact surfaces 34 are provided with at least one annular groove 36, the cross-section of the annular groove 36 being V-shaped or U-shaped.

[0047] At least one compensation ring groove 33 is provided on the end face 32 of the sealing ring 31, and a plurality of elastic compensation members 35 are provided in the compensation ring groove 33; wherein, the elastic compensation members 35 are configured to provide the sealing ring 31 with an elastic force that causes its arc-shaped contact surface 34 to tend toward the sphere 2.

[0048] The cross-section of the compensation ring groove 33 is a right trapezoid, and its inclined surface is closer to the arc-shaped contact surface 34 than the bottom surface; the elastic compensation member 35 is a columnar structure; or the elastic compensation member 35 includes at least one hollow segment 352 and at least one solid segment 351; the hollow segment 352 and the solid segment 351 are alternately and integrally connected; the outer diameter of the hollow segment 352 at its central position is larger than the diameter of the solid segment 351.

[0049] Overall workflow: When the valve is closed, the arc-shaped mating surface 34 of the sealing ring 31 is tightly fitted with the ball 2 under the initial preload, forming the main seal. As time progresses, the material of the sealing ring 31 experiences stress relaxation, and the specific pressure between the arc-shaped mating surface 34 and the ball 2 decreases. At this time, the elastic compensating element 35 in the compensating ring groove 33 continuously releases elastic potential energy, transmitting the force to the sealing ring 31 through the inclined surface of the groove, pushing it to move towards the ball 2, compensating for the gap caused by relaxation. The hollow section 352 and the solid section 351 of the elastic compensating element 35 deform together to adapt to different pressure conditions: low... Under pressure, the hollow section 352's flexibility provides gentle compensation; under high pressure, the solid section 351 ensures overall stability; simultaneously, the annular groove 36 on the arc-shaped mating surface 34 plays an auxiliary sealing role, and the V-shaped or U-shaped structure hinders the flow of the medium and stores lubricant; when the valve is opened and then closed again, the immediate response of the elastic compensation element 35 can quickly eliminate the gap caused by the permanent deformation of the sealing ring 31, ensuring that the sealing contact width and specific pressure always meet the requirements; the entire process achieves dynamic compensation, enabling the sealing structure 3 to maintain high reliability during the maintenance-free period.

[0050] Overall beneficial effects: By setting the sealing ring 31 and its arc-shaped contact surface 34, optimized contact with the ball 2 is achieved, improving the initial sealing accuracy. By setting the compensation annular groove 33 and its right-angled trapezoidal cross section, a guiding mechanism for converting axial elastic force into radial sealing force is obtained, enhancing the compensation efficiency. By setting the elastic compensation element 35 and its columnar structure, a continuous and stable elastic restoring force is provided, counteracting the stress relaxation effect. By setting the alternating integrated structure of hollow section 352 and solid section 351, a compensation characteristic combining rigidity and flexibility is achieved, adapting to various working conditions. By setting the annular groove 36 and its V-shaped or U-shaped cross section, a multi-level sealing barrier is formed, reducing the risk of leakage. In summary, the sealing structure 3 of this embodiment significantly improves the sealing reliability of the buried ball valve under long-term static conditions, extends the maintenance-free period, and reduces operation and maintenance costs.

[0051] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0052] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, 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, and therefore should not be construed as a limitation of this utility model. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as the second element, component, region, layer, or segment.

[0053] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A precision sealing structure for a gate valve, characterized in that, include: The sealing ring (31) has an arc-shaped contact surface (34) for sealing contact with the ball (2). At least one compensation annular groove (33) is provided on the end face (32) of the sealing ring (31). The compensation ring groove (33) is provided with a number of elastic compensation elements (35); The elastic compensator (35) is configured to provide the sealing ring (31) with an elastic force that causes its arcuate contact surface (34) to tend toward the sphere (2).

2. The sealing structure as described in claim 1, characterized in that, The cross-section of the compensation ring groove (33) is a right trapezoid, and its inclined surface is closer to the arc-shaped mating surface (34) than its bottom surface.

3. The sealing structure as described in claim 2, characterized in that, The elastic compensation component (35) has a columnar structure.

4. The sealing structure as described in claim 2, characterized in that, The elastic compensation member (35) includes at least one hollow segment (352) and at least one solid segment (351); The hollow segment (352) and the solid segment (351) are alternately and integrally connected; The outer diameter of the hollow segment (352) at its center position is larger than the diameter of the solid segment (351).

5. The sealing structure as described in claim 4, characterized in that, At least one annular groove (36) is provided on the arc-shaped bonding surface (34), and the cross-section of the annular groove (36) is V-shaped or U-shaped.

6. A gate valve body for natural gas, characterized in that, include: Valve seat (1); A ball (2) is disposed inside the valve seat (1); A sealing structure (3) is provided in the valve seats (1) on both sides of the ball (2); The sealing structure (3) includes: A pair of sealing rings (31) having an arcuate contact surface (34) for sealing contact with the ball (2). At least one annular groove (36) is provided on the arc-shaped bonding surface (34), and the cross-section of the annular groove (36) is V-shaped or U-shaped.

7. The gate valve body for natural gas as described in claim 6, characterized in that, At least one compensation ring groove (33) is provided on the end face (32) of the sealing ring (31), and a plurality of elastic compensation members (35) are provided in the compensation ring groove (33). The elastic compensator (35) is configured to provide the sealing ring (31) with an elastic force that causes the arcuate contact surface (34) to tend toward the sphere (2).

8. The gate valve body for natural gas as described in claim 7, characterized in that, The cross-section of the compensation ring groove (33) is a right trapezoid, and its inclined surface is closer to the arc-shaped mating surface (34) than its bottom surface.

9. The gate valve body for natural gas as described in claim 8, characterized in that, The elastic compensation component (35) has a columnar structure.

10. The gate valve body for natural gas as described in claim 8, characterized in that, The elastic compensation member (35) includes at least one hollow segment (352) and at least one solid segment (351); The hollow segment (352) and the solid segment (351) are alternately and integrally connected; The outer diameter of the hollow segment (352) at its center position is larger than the diameter of the solid segment (351).

Images