Elastomeric seal mid-line butterfly valve

Abstract

The utility model discloses a kind of elastic sealing midline butterfly valves, it is related to valve technical field, including snap spring, upper valve body, compression ring, sealing ring, valve stem, valve seat assembly, butterfly plate, lower valve body, support assembly and internal hexagon screw.The utility model forms reliable flange face sealing by micro-curved surface sealing layer and rubber layer cooperation, axial triple sealing structure completely blocks leakage path, double U type sealing ring gives consideration to dustproof and leakproof, and sealing reliability greatly improves;Limiting shaft sleeve accurately positions valve seat, dovetail groove prevents displacement, and elastic support stabilizes valve stem, and multiple structure design avoids the problems such as valve seat displacement and valve stem deviation, to ensure that valve works stably for a long time;Support assembly elastic self-adapting design reduces processing precision requirement, without additional flange gasket reduces material cost, dovetail groove is assembled conveniently to reduce installation difficulty, and comprehensive cost performance is high.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically to a resilient sealing centerline butterfly valve. Background Technology

[0002] Centerline butterfly valves are widely used in pipelines transporting fluids such as water, oil, and gas due to their simple structure, convenient opening and closing, and strong flow capacity. However, existing centerline butterfly valves have significant defects in practical use, which seriously affect their performance and lifespan:

[0003] First, the sealing performance is insufficient. The existing PTFE sealing layer on the surface of the valve seat has extremely poor elasticity, and the sealing pressure relies entirely on the compression and deformation of the underlying rubber. After the valve is installed, the valve seat is deformed by the pressure of the pipeline flange on both sides. Because the two sides are fixed by the flange, the deformation is transferred inward, which changes the sealing surface size between the valve seat and the butterfly plate. This not only reduces the sealing reliability but also increases the valve's opening and closing torque and shortens the overall valve service life.

[0004] Secondly, the valve seat fixing is unreliable. The valve seat is fixed to the valve body only by the "nesting of concave and convex sections" and the "valve stem through the shaft hole", without any additional positioning structure. When the valve is under pressure on one side or during opening and closing, the valve seat is prone to displacement due to uneven force, which can lead to permanent deformation of the sealing surface and abnormal increase in torque, affecting the normal operation of the valve.

[0005] Third, the valve stem positioning accuracy is low. The existing valve stem is limited by a simple structure. When installed vertically, it is easy to deviate from the optimal working position due to its own weight, resulting in uneven contact between the butterfly plate and the valve seat sealing surface, which further aggravates the sealing failure problem. Utility Model Content

[0006] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, this utility model proposes an elastic sealing centerline butterfly valve.

[0007] To achieve the above objectives, this utility model provides the following technical solution: an elastic sealing centerline butterfly valve, comprising a snap ring, an upper valve body, a pressure ring, a sealing ring, a valve stem, a valve seat assembly, a butterfly plate, a lower valve body, a support assembly, and an internal hexagon screw, wherein each component works together to achieve the valve's opening and closing, sealing, and structural stability functions;

[0008] The upper valve body and the lower valve body are fixedly connected by hexagonal screws to form the main load-bearing frame of the valve, while providing installation space and positioning reference for components such as valve seat assembly and butterfly plate, ensuring the assembly accuracy of each component;

[0009] The valve seat assembly includes a sealing layer, a rubber layer, an upper limit bushing, and a lower limit bushing. The upper limit bushing and the lower limit bushing are respectively adapted to the countersunk holes of the upper valve body and the lower valve body to achieve sealing and prevent displacement.

[0010] The cross-section of the valve stem extending into the butterfly plate is a regular polygon, which matches the regular polygonal hole of the butterfly plate to ensure that the valve stem can drive the butterfly plate to rotate synchronously when it rotates, thereby realizing the opening and closing of the valve.

[0011] The butterfly plate and the valve seat assembly are interference-fitted, and the tight fit between the two prevents media leakage and ensures the main sealing function of the valve.

[0012] The support assembly abuts against the lower end of the valve stem, and the snap ring, snap ring fixing groove of the upper valve body, and pressure ring cooperate to limit the upper end of the valve stem.

[0013] Preferably, the sealing layer of the valve seat assembly has a micro-curved surface structure, extending outward along the curved surface to the flange faces of the upper and lower valve bodies, forming a non-sealing cavity with the flange faces. The sealing layer is made of PTFE or similar polymer materials through powder sintering, and the rubber layer is formed by injection molding. During installation, the pre-tightening force of the pipe flange bolts will apply pressure to the sealing layer, causing it to deform from the micro-curved surface to a flat surface and extend outward from the flange. At the same time, the bottom rubber layer is compressed and deformed to fill the reserved gap in the valve body groove. The elastic force generated by both constitutes the flange face sealing pressure, eliminating the need for additional flange gaskets, simplifying the installation process and improving sealing reliability.

[0014] Preferably, the valve seat assembly is formed with an inward V-shape on both sides, which can effectively avoid valve seat opening problems caused by inconsistent material shrinkage ratios or improper transportation and storage. After assembly, the inward V-shape structure produces slight deformation and can also provide auxiliary fixing force, enhancing the connection stability between the valve seat assembly and the valve body. The upper limit bushing and the lower limit bushing are processed from PTFE rod material and are fixed together with the sealing layer and the rubber layer by special adhesive during the high-temperature process of rubber layer injection molding, ensuring the structural integrity of the valve seat assembly.

[0015] Preferably, the support assembly includes an upper support plate, a spring, and a lower support plate. The upper and lower support plates are made of copper, and the spring is a stainless steel compression spring with both ends tightly ground flat. The two ends of the spring are fixed to the upper and lower support plates by welding, respectively. When installed vertically, the spring force can counteract the weight of the valve stem, ensuring that the valve stem is always in the optimal working position and avoiding uneven sealing caused by gravity shift. At the same time, the copper support plate has good wear resistance, and the stainless steel spring has stable elasticity, ensuring that the support assembly works reliably for a long time.

[0016] Preferably, the sealing ring is a double U-shaped self-tightening sealing ring, located between the valve body counterbore and the valve stem. This prevents external impurities from entering the shaft hole and affecting the valve stem rotation, and also prevents internal media from leaking out along the gap between the valve stem and the valve body. The axial sealing of the butterfly valve includes: interference fit sealing between the upper and lower end faces of the butterfly plate and the sealing layer, interference fit sealing between the valve stem and the rubber layer, and the seal formed by the valve body counterbore, the double U-shaped self-tightening sealing ring, and the valve stem. The interference fit between the upper and lower end faces of the butterfly plate and the sealing layer of the valve seat assembly can block the axial leakage of the medium, and the interference fit between the valve stem and the rubber layer of the valve seat assembly can further intercept any possible leakage of the medium.

[0017] Preferably, the upper limit bushing and the lower limit bushing are modified convex-shaped structures, and the lower half is wrapped with a rubber layer, so that the outer surface of the rubber layer forms a complete cylindrical surface that fits tightly with the valve body. The part of the upper limit bushing and the lower limit bushing embedded in the rubber layer is a smooth curved surface transition without sharp edges, which can avoid local damage caused by stress concentration and extend the service life of the valve seat assembly.

[0018] Preferably, the valve seat assembly is fitted with the upper valve body and the lower valve body through a dovetail groove. During assembly, it is inserted from the narrow end of the dovetail groove, which facilitates the assembly operation and prevents the valve seat assembly from shifting during use through the barb structure of the dovetail groove, thereby improving the connection stability. The upper limit bushing and the lower limit bushing also act as bearings, reducing the frictional resistance when the valve stem rotates.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. Significantly improved sealing performance: the micro-curved sealing layer and the rubber layer work together to form a reliable flange face seal; the axial triple sealing structure completely blocks the leakage path; and the double U-shaped sealing rings provide both dustproof and leakproof protection, greatly improving sealing reliability.

[0021] 2. Enhanced structural stability: The limiting bushing precisely positions the valve seat, the dovetail groove prevents displacement, and the elastic support stabilizes the valve stem. The multiple structural designs avoid problems such as valve seat displacement and valve stem offset, ensuring long-term stable operation of the valve.

[0022] 3. Extended service life: PTFE material limit bushing is wear-resistant and corrosion-resistant, smooth curved surface transition reduces stress damage, copper support plate and stainless steel spring are aging-resistant, integrated fixation of various components reduces wear, and the overall valve life is significantly extended.

[0023] 4. Reduced costs and easier installation: The flexible adaptive design of the support components reduces the requirements for machining accuracy; no additional flange gaskets are needed, reducing material costs; the dovetail groove facilitates assembly and reduces installation difficulty; and the overall cost-effectiveness is high. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the overall structure of an elastic sealing centerline butterfly valve according to the present invention;

[0025] Figure 2 This is an enlarged view of point A of the resilient sealing centerline butterfly valve of this utility model;

[0026] Figure 3 This is a schematic diagram of the valve seat assembly structure of an elastically sealed centerline butterfly valve according to this utility model;

[0027] Figure 4 This is a schematic diagram of the support component structure of an elastic sealing centerline butterfly valve according to the present invention;

[0028] Figure 5 This is a comparison diagram of the forming and installation position of the valve seat assembly of an elastic sealing centerline butterfly valve according to this utility model;

[0029] Figure 6 This is an exploded view of an elastic sealing centerline butterfly valve according to this utility model.

[0030] In the diagram: 1. Snap ring; 2. Upper valve body; 3. Pressure ring; 4. Sealing ring; 5. Valve stem; 6. Valve seat assembly; 7. Butterfly plate; 8. Lower valve body; 9. Support assembly; 10. Socket head screw; 6.1. Sealing layer; 6.2. Rubber layer; 6.3. Upper limit bushing; 6.4. Lower limit bushing; 9.1. Upper support plate; 9.2. Spring; 9.3. Lower support plate. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] The embodiments of this utility model will be described below based on its overall structure.

[0033] Please see Figure 1 , Figure 2 and Figure 6An antistatic vacuum feeder includes a snap ring 1, an upper valve body 2, a pressure ring 3, a sealing ring 4, a valve stem 5, a valve seat assembly 6, a butterfly plate 7, a lower valve body 8, a support assembly 9, and hexagon socket screws 10. The upper valve body 2 and the lower valve body 8 are fixedly connected by the hexagon socket screws 10. The valve seat assembly 6 includes a sealing layer 6.1, a rubber layer 6.2, an upper limit bushing 6.3, and a lower limit bushing 6.4. The upper limit bushing 6.3 and the lower limit bushing 6.4 are respectively adapted to the countersunk holes of the upper valve body 2 and the lower valve body 8. The cross-section of the valve stem 5 extending into the butterfly plate 7 is a regular polygon, which matches the regular polygon hole of the butterfly plate 7. The butterfly plate 7 and the valve seat assembly 6 are interference-fitted. The support assembly 9 abuts against the lower end of the valve stem 5. The snap ring 1, the snap ring fixing groove of the upper valve body 2, and the pressure ring 3 cooperate to limit the upper end of the valve stem 5.

[0034] To further explain, the upper valve body 2 and the lower valve body 8 are fixed together by hexagonal socket head cap screws 10, forming the main bearing structure of the valve body. The bushing of the valve seat assembly 6 is adapted to the countersunk hole of the valve body, providing initial positioning for the valve seat. The regular polygonal fit between the valve stem 5 and the butterfly plate 7 ensures effective torque transmission during valve opening and closing. The interference fit between the butterfly plate 7 and the valve seat assembly 6 initially achieves the sealing function. The limiting structure of the support assembly 9, the snap ring 1, and the pressure ring 3 ensures stable operation of the valve stem 5 and prevents axial displacement.

[0035] Please see Figure 2 The sealing layer 6.1 of the valve seat assembly 6 has a micro-curved surface structure and extends outward along the curved surface to the flange surface of the upper valve body 2 and the lower valve body 8, forming an unsealed cavity with the flange surface. The sealing layer 6.1 is made of PTFE or similar polymer materials by powder sintering, and the rubber layer 6.2 is formed by injection molding.

[0036] To further explain, when the valve is connected to the pipeline, the preload of the pipeline flange bolts applies pressure to the slightly curved surface of the sealing layer 6.1, causing it to deform from the slightly curved surface to a flat surface and extend outwards towards the flange. Simultaneously, the underlying rubber layer 6.2 is compressed, filling the gap left in the valve body groove. The deformation of the sealing layer 6.1 and the elasticity of the rubber layer 6.2 together constitute the sealing pressure of the flange face, achieving reliable flange face sealing without the need for additional flange gaskets. By optimizing the structural form and material process of the sealing layer 6.1 and clarifying the molding method of the rubber layer 6.2, the problem of traditional valve seat sealing pressure relying on single rubber compression and low sealing reliability is solved. At the same time, the installation process of the valve and pipeline is simplified, improving the stability and convenience of the flange face seal.

[0037] Please see Figure 2 When the valve seat assembly 6 is formed, the two sides are inward V-shaped. The upper limit bushing 6.3 and the lower limit bushing 6.4 are made of PTFE rod material and are fixed together with the sealing layer 6.1 and the rubber layer 6.2 by special adhesive during the high temperature process of injection molding of the rubber layer 6.2.

[0038] To further explain, the inward-facing shape enhances the deformation resistance and installation stability of the valve seat assembly 6. The integrated fixing design of the upper limit bushing 6.3 and the lower limit bushing 6.4 with the sealing layer 6.1 and the rubber layer 6.2 strengthens the structural strength of the valve seat assembly 6, avoids sealing failure or increased torque due to bushing loosening, and extends the service life of the valve seat.

[0039] Please see Figure 4 The support assembly 9 includes an upper support plate 9.1, a spring 9.2 and a lower support plate 9.3. The upper support plate 9.1 and the lower support plate 9.3 are made of copper. The spring 9.2 is a stainless steel compression spring with both ends tightly ground flat. The two ends of the spring 9.2 are fixed to the upper support plate 9.1 and the lower support plate 9.3 respectively by welding.

[0040] To further explain, the elastic support structure solves the problem of easy displacement due to gravity caused by simple limiting of the valve stem 5 in traditional valves, ensuring accurate positioning of the valve stem 5. This, in turn, ensures uniform contact between the butterfly plate 7 and the valve seat sealing surface, improving sealing reliability. Meanwhile, the selection of copper support plates and stainless steel springs ensures that the support component 9 is wear-resistant and aging-resistant, extending its service life.

[0041] Please see Figure 1 , Figure 3 and Figure 6 The sealing ring 4 is a double U-shaped self-tightening sealing ring, located between the valve body counterbore and the valve stem 5. The axial sealing of the butterfly valve includes: the interference fit seal between the upper and lower end faces of the butterfly plate 7 and the sealing layer 6.1, the interference fit seal between the valve stem 5 and the rubber layer 6.2, and the seal formed by the valve body counterbore, the double U-shaped self-tightening sealing ring 4 and the valve stem 5.

[0042] To further explain, the triple axial sealing structure design completely blocks the path of media leakage, solving the problem of single sealing point and easy leakage in traditional centerline butterfly valves. The design of the double U-shaped self-tightening sealing ring 4 takes into account both dustproof and leak-proof functions, further improving the sealing reliability and service life of the valve.

[0043] Please see Figure 3 The upper limit bushing 6.3 and the lower limit bushing 6.4 are modified convex-shaped structures, and the lower half is wrapped by the rubber layer 6.2, so that the outer surface of the rubber layer 6.2 forms a complete cylindrical surface. The part of the upper limit bushing 6.3 and the lower limit bushing 6.4 embedded in the rubber layer 6.2 is a smooth curved surface transition.

[0044] To further explain, by optimizing the bushing structure, the fit and positioning accuracy between the valve seat assembly 6 and the valve body are improved, and the impact of installation clearance on sealing performance is reduced; the smooth curved surface transition design solves the stress concentration problem caused by the sharp corners of traditional bushings, extends the service life of the valve seat assembly 6, and ensures long-term stable operation of the valve.

[0045] Please see Figure 1 The valve seat assembly 6 is fitted with the upper valve body 2 and the lower valve body 8 through a dovetail groove. During assembly, it is inserted from the narrow end of the dovetail groove. The upper limit bushing 6.3 and the lower limit bushing 6.4 simultaneously act as bearings to reduce the frictional resistance when the valve stem 5 rotates.

[0046] To further explain, the dovetail groove fit structure solves the problems of unreliable fixing and easy displacement of traditional valve seats, improving the installation stability of valve seat assembly 6. The bushing also functions as a bearing, reducing the rotational friction resistance of valve stem 5, lowering the valve opening and closing torque, improving operational convenience, and at the same time avoiding wear caused by direct friction between valve stem 5 and valve body, extending the service life of valve stem 5.

[0047] Working Principle: During assembly, slowly push the valve seat assembly 6 into the countersunk hole of the lower valve body 8 from the narrow end of the dovetail groove, ensuring that the outer cylindrical surface of the valve seat assembly 6 fits tightly with the countersunk hole without any looseness. Then, place the butterfly plate 7 into the valve seat assembly 6, aligning the regular polygonal hole of the butterfly plate 7 with the regular polygonal shaft end of the valve stem 5, and insert the valve stem 5 upwards from the bottom of the lower valve body 8 until the upper end of the valve stem 5 extends beyond the mounting surface of the upper valve body. Place the support assembly 9 into the mounting groove at the bottom of the lower valve body 8, so that the upper support plate 9.1 abuts against the lower end of the valve stem 5, and fix the lower support plate 9.3 to the lower valve body 8 with screws. Cover the lower valve body 8 with the upper valve body 2, so that the countersunk hole of the upper valve body matches the upper limit bushing 6.3 of the valve seat assembly 6, insert the hexagon socket screw 10 and tighten it to ensure a tight valve body connection. Slide the pressure ring 3 onto the valve stem 5, so that it fits against the top surface of the upper valve body 2, and then snap the retaining ring 1 into the retaining ring fixing groove of the upper valve body, abutting against the pressure ring 3. The sealing ring 4 is inserted into the gap between the counterbore of the valve body and the valve stem 5, ensuring that the sealing ring 4 completely fits the hole wall and the surface of the valve stem 5, and the assembly is completed.

[0048] During installation, align the valve flange face with the pipe flange face, ensuring that the flange holes correspond one-to-one. Insert the flange bolts and gradually tighten them, using a diagonal tightening method to ensure uniform stress on the flange face. At this time, the sealing layer 6.1 of the valve seat assembly 6 changes from a slightly curved surface to a flat surface under flange pressure, and the rubber layer 6.2 is compressed and deformed, forming a reliable flange face seal together with the sealing layer 6.1, without the need for additional flange gaskets. After installation, the operator applies torque through the operating mechanism at the upper end of the valve stem 5, i.e., the handwheel or handle. The valve stem 5, due to its regular polygonal fit with the butterfly plate 7, drives the butterfly plate 7 to rotate synchronously. At this time, the upper limit bushing 6.3 and the lower limit bushing 6.4 act as bearings, reducing the frictional resistance of the valve stem 5 rotation. The spring 9.2 of the support assembly 9 always provides vertical support for the valve stem 5, preventing the valve stem 5 from shifting due to rotation or gravity. As the butterfly plate 7 rotates, the interference fit between it and the sealing layer 6.1 of the valve seat assembly 6 gradually dissipates, and the medium begins to flow along the valve passage until the butterfly plate 7 rotates to the fully open position, reaching the maximum flow rate. Reverse rotation of the valve stem 5 causes the butterfly plate 7 to rotate in the opposite direction, gradually approaching the valve seat assembly 6. When the butterfly plate 7 rotates to the closed position, the upper and lower end faces of the butterfly plate 7 re-form an interference fit with the sealing layer 6.1, and the first seal takes effect. If a small amount of medium permeates, the interference fit between the valve stem 5 and the rubber layer 6.2 forms a second seal. Simultaneously, the double U-shaped self-tightening sealing ring 4 self-tightens under the pressure of the medium, forming a third seal and completely blocking medium leakage.

[0049] Although the present invention 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 embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A resilient-sealed centerline butterfly valve, characterized in that, Includes snap ring (1), upper valve body (2), pressure ring (3), sealing ring (4), valve stem (5), valve seat assembly (6), butterfly plate (7), lower valve body (8), support assembly (9), and internal hex screw (10); The upper valve body (2) and the lower valve body (8) are fixedly connected by internal hexagonal screws (10); The valve seat assembly (6) includes a sealing layer (6.1), a rubber layer (6.2), an upper limit bushing (6.3), and a lower limit bushing (6.4), wherein the upper limit bushing (6.3) and the lower limit bushing (6.4) are respectively adapted to the countersunk holes of the upper valve body (2) and the lower valve body (8); The cross-section of the valve stem (5) extending into the butterfly plate (7) is a regular polygon, which fits with the regular polygonal hole of the butterfly plate (7); The butterfly plate (7) is interference-fitted with the valve seat assembly (6); The support assembly (9) abuts against the lower end of the valve stem (5), and the snap ring (1), the snap ring fixing groove of the upper valve body (2) and the pressure ring (3) cooperate to limit the upper end of the valve stem (5).

2. The resilient sealing centerline butterfly valve according to claim 1, characterized in that: The sealing layer (6.1) of the valve seat assembly (6) has a micro-curved surface structure and extends outward along the curved surface to the flange surface of the upper valve body (2) and the lower valve body (8), forming an unsealed cavity with the flange surface. The sealing layer (6.1) is made of PTFE or similar polymer materials by powder sintering, and the rubber layer (6.2) is formed by injection molding.

3. The resilient sealing centerline butterfly valve according to claim 1, characterized in that: When the valve seat assembly (6) is formed, the two sides are inward V-shaped. The upper limit bushing (6.3) and the lower limit bushing (6.4) are formed by processing PTFE rod material, and are fixed together with the sealing layer (6.1) and the rubber layer (6.2) by special adhesive during the high temperature process of injection molding of the rubber layer (6.2).

4. The resilient sealing centerline butterfly valve according to claim 1, characterized in that: The support assembly (9) includes an upper support plate (9.1), a spring (9.2) and a lower support plate (9.3). The upper support plate (9.1) and the lower support plate (9.3) are made of copper. The spring (9.2) is a stainless steel compression spring with both ends tightly ground flat. The two ends of the spring (9.2) are fixed to the upper support plate (9.1) and the lower support plate (9.3) respectively by welding.

5. A resilient sealing centerline butterfly valve according to claim 1, characterized in that: The sealing ring (4) is a double U-shaped self-tightening sealing ring, which is located between the counterbore of the valve body and the valve stem (5). The axial sealing of the butterfly valve includes: the interference fit sealing between the upper and lower end faces of the butterfly plate (7) and the sealing layer (6.1), the interference fit sealing between the valve stem (5) and the rubber layer (6.2), and the seal formed by the counterbore of the valve body, the double U-shaped self-tightening sealing ring (4) and the valve stem (5).

6. A resilient sealing centerline butterfly valve according to claim 1, characterized in that: The upper limit bushing (6.3) and lower limit bushing (6.4) are modified convex-shaped structures, and the lower half is wrapped by the rubber layer (6.2), so that the outer surface of the rubber layer (6.2) forms a complete cylindrical surface. The part of the upper limit bushing (6.3) and lower limit bushing (6.4) embedded in the rubber layer (6.2) is a smooth curved surface transition.

7. A resilient sealing centerline butterfly valve according to claim 1, characterized in that: The valve seat assembly (6) is fitted with the upper valve body (2) and the lower valve body (8) through a dovetail groove. During assembly, it is inserted from the narrow end of the dovetail groove. The upper limit bushing (6.3) and the lower limit bushing (6.4) also act as bearings to reduce the frictional resistance when the valve stem (5) rotates.

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