A high and low temperature alternating pure metal double - direction sealed ball valve

Abstract

The present invention discloses a high and low temperature alternating pure metal bi-directional seal ball valve, which comprises a valve body provided with a valve cavity, a sphere located in the valve cavity and hermetically fitted with the valve cavity via a valve seat seal pair. The top of the sphere is connected to a valve stem. The valve seat seal pair includes an annular valve seat. A plurality of shoulders are provided on the outer circumferential wall of the valve seat. One side of the inner wall of the valve seat close to the sphere is tangent to the sphere. The flow passage is transitioned to the valve cavity through N-level stepped holes. The Nth shoulder is inserted into the Nth-level hole body, and a spring compensation type metal seal ring A is arranged therebetween. The spring compensation type metal seal ring A is at least in a compressed state in the direction parallel to the axis of the flow passage. The present invention realizes floating seal through a seal ring with an elastic compensation function, meets the dimensional compensation required due to temperature changes, overcomes high temperature expansion deformation and low temperature shrinkage deformation whether it is high temperature, low temperature or high and low temperature alternation, and can effectively ensure the tight seal of the ball valve under various changing working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of ball valves, and particularly relates to a high and low temperature alternating pure metal two-way sealing ball valve. Background Art

[0002] Ball valves have good flow capacity and sealing performance, and their valves are widely used in industries such as petroleum, petrochemical, chemical, energy, and minerals. A ball valve mainly includes a ball serving as a valve core, a valve stem driving the ball to rotate, and a valve body that is sealingly matched with the ball through a valve seat sealing pair. A fluid passage perpendicular to its rotation axis is provided on the ball. With the change of the production process of the working conditions of the ball valve and the improvement of the utilization rate of the ball valve, the working conditions of the ball valve are becoming more and more harsh, which is mainly reflected in high temperature, low temperature, and high and low temperature alternation. For these harsh working conditions, the sealing requirements for ball valves are becoming more and more strict. For example, flexible graphite is not allowed to be used as an auxiliary seal for high-temperature ball valves in photovoltaic power generation. The existence of industry barriers in the valve industry severely restricts the research and development and production of valves.

[0003] At present, several widely used ball valves on the market all have different defects, which are specifically as follows:

[0004] 1. For a ball valve with a non-metallic graphite ring as an auxiliary seal, since the non-metallic graphite ring is prone to oxidation at temperatures above 650°C, and the shrinkage coefficients of metal and non-metal materials are different under high temperature, low temperature, or high and low temperature alternation, its size is not sensitive to temperature changes, and it cannot compensate for the dimensional changes of the metal at low temperatures, resulting in easy leakage of the seal; for some manufacturers, the valve seat has no elastic sealing element and directly uses a non-metallic graphite ring as wear compensation. While there are the above-mentioned defects, the requirements for the size of the non-metallic graphite ring and the size of its sealing part are also increased indirectly, which is likely to cause two extremes of large and small assembly torques, and the first-pass assembly qualification rate is low; [[ID=Y15]]

[0005] 2. For a ball valve using an H-type valve seat, due to the increase in the number of sealing points, the requirements for machining form and position tolerances, flatness, and roughness are high, and the first-pass assembly qualification rate is low; the torque is also relatively large, indirectly increasing the cost;

[0006] 3. For a ball valve using bellows sealing, welding is required, the number of processes increases and the cost increases, and an auxiliary seal is still needed during the assembly process to meet the sealing requirements;

[0007] 4. For a ball valve with a non-metallic graphite ring or a metal ring used for valve stem sealing, the graphite ring sealing has the same defects as in item 1; metal rings are generally used for static seals, and the sealing form is preferably surface-to-line contact. When used in the valve stem part, it becomes line-to-line contact sealing. Coupled with the fact that the valve stem itself will move up and down due to the internal medium pressure, from a safety perspective, the leakage risk is high;

[0008] These ball valves only meet the single high-temperature or low-temperature cut-off requirements and do not meet the requirement of simultaneous cut-off under two working conditions of high and low temperature transformation.

[0009] To solve the sealing problem at high and low temperatures, the prior art CN108331936A discloses a high and low temperature self - adapting valve seat structure and a ball valve equipped with this valve seat structure. By setting a spring in the valve seat sealing pair used to seal between the ball and the valve cavity, the elastic property of the spring is utilized to compensate for the dimensional changes during high and low temperature variations, so as to ensure the sealing performance between the ball and the valve cavity. However, in this kind of ball valve, the telescopic direction of the spring is parallel to the fluid flow direction inside the valve body, and it can only compensate for the dimensional changes at the sealing part in the fluid flow direction, and no dimensional compensation can be carried out in other directions. Especially when the valve stem moves up and down due to the internal medium pressure, its sealing effect is poor. Moreover, the sealing structure adopted by this kind of ball valve is complex, with a large number of components, resulting in high processing costs, assembly costs, and difficulties and high costs in later maintenance. Summary of the Invention

[0010] The purpose of the present invention is to provide a high and low temperature alternating pure metal two - way sealing ball valve, which solves the above - mentioned technical problems such as the complex sealing structure, numerous components, high production cost, and high maintenance cost of the existing ball valves for high and low temperature alternation. A high and low temperature alternating pure metal two - way sealing ball valve designed by the present invention redesigned a valve seat sealing pair for between the ball and the valve cavity, so that dimensional compensation required due to temperature changes can be achieved on both sides of the ball, thus enabling true zero - leakage two - way sealing for high and low temperature transformation; at the same time, the structure of the present invention is simple, with a small number of components, facilitating its pre - production, assembly, and later maintenance, and greatly reducing the production cost and maintenance cost of the ball valve.

[0011] The technical solution adopted by the present invention is as follows:

[0012] A high and low temperature alternating pure metal two - way sealing ball valve includes a valve body provided with a valve cavity, a ball located in the valve cavity and sealingly cooperating with the valve cavity via a valve seat sealing pair, the top of the ball is connected to a valve stem, the valve seat sealing pair is located at the end where the flow channel of the ball valve communicates with the valve cavity, the valve seat sealing pair includes an annular valve seat, the valve seat is made of pure metal, and its axis coincides with the axis of the flow channel;

[0013] A plurality of shoulders are provided on the outer circumferential wall of the valve seat, the radius of the shoulders increases successively as it approaches the axis of the valve stem, and they are the first shoulder, the second shoulder... and the Nth shoulder in sequence, and the inner wall of the valve seat on the side close to the ball is tangent to the ball;

[0014] The flow channel transitions to the valve cavity through N - level stepped holes, the radius of the stepped holes increases successively as it approaches the axis of the valve stem, and they are the first - level hole body, the second - level hole body... and the Nth - level hole body in sequence;

[0015] The Nth shoulder is inserted into the Nth hole body, and a spring-compensated metal seal ring A is arranged between at least one end of the shoulder and the bottom of the hole of the mating hole body. The axis of the spring-compensated metal seal ring A coincides with the axis of the flow channel, and both sides thereof are in contact with the end of the shoulder and the bottom of the hole of the hole body respectively, and it is in a compressed state at least in the direction parallel to the axis of the flow channel.

[0016] Furthermore, the spring-compensated metal seal ring A includes an outer elastic metal ring A and an inner compensation spring ring A whose axes both coincide with the axis of the flow channel. The cross-section of the outer elastic metal ring A is V-shaped, and both sides thereof are in contact with the end of the shoulder and the bottom of the hole of the mating hole body respectively. The inner compensation spring ring A is installed in the V-shaped annular groove of the outer elastic metal ring A and is in contact with both side walls of the V-shaped annular groove.

[0017] Furthermore, the valve body is divided into a left valve body and a right valve body by a plane perpendicular to the axis of the flow channel. The valve cavity is correspondingly divided into a left valve cavity located on the left valve body and a right valve cavity located on the right valve body. The center of the sphere is located in the left valve cavity, and the top of the left valve body protrudes upward to form a neck in sealing fit with the valve stem.

[0018] The left valve body is detachably connected to the right valve body through a fastener, and a spring-compensated metal seal ring B for sealing the dividing part between the left valve body and the right valve body is arranged between the left valve body and the right valve body.

[0019] Furthermore, an annular groove is arranged on the surface of the left valve body in contact with the right valve body, and the axis of the annular groove coincides with the axis of the flow channel.

[0020] The spring-compensated metal seal ring B is located in the annular groove, and the spring-compensated metal seal ring B assembly includes an outer elastic metal ring B and an inner compensation spring ring B whose axes both coincide with the axis of the flow channel. The cross-section of the outer elastic metal ring B is C-shaped, and both sides thereof are in contact with the bottom of the annular groove and the right valve body respectively. The inner compensation spring ring B is installed in the C-shaped annular groove of the outer elastic metal ring B and is inscribed in the side walls of the C-shaped annular groove.

[0021] Furthermore, the neck is sealed with the valve stem through a valve stem seal pair. The valve stem seal pair includes a gland, a gasket ring and a spring-compensated metal seal ring C which are all sleeved on the valve stem. The middle part of the neck is in transitional fit with the valve stem, and an upper annular space is formed between the upper side of the neck and the valve stem.

[0022] The gasket ring and the spring-compensated metal seal ring C are both installed in the upper annular space, and there are two spring-compensated metal seal rings C, which are respectively located on the upper and lower sides of the gasket ring. The bottom end of the gland is inserted into the upper annular space and presses the gasket ring and the spring-compensated metal seal ring C against the middle part of the neck, and the gland is detachably connected to the left valve body through a fastener.

[0023] Furthermore, the spring-compensated metal seal ring C includes an outer elastic metal ring C and an inner compensation spring ring C whose axes coincide with the axis of the valve stem. The cross-section of the outer elastic metal ring C is C-shaped, and a contact ring with an axis coinciding with the axis of the valve stem is provided on its inner ring. The top end of the contact ring is connected to the outer elastic metal ring C, and the inner ring of the contact ring is tangent to the valve stem. The inner compensation spring ring C is installed in the C-shaped ring groove of the outer elastic metal ring C and is inscribed in the groove wall of the C-shaped ring groove.

[0024] Furthermore, right-angle grooves for installing the spring-compensated metal seal ring C are provided at the bottom of the gland and the gasket ring and on the side close to the valve stem.

[0025] Furthermore, a lower annulus is formed between the lower side of the neck and the valve stem. The lower side of the side wall of the valve stem protrudes outward to form a receiving ring. A bushing is installed in the lower annulus. The bushing is sleeved on the valve stem, and its upper and lower ends are in contact with the middle part of the neck and the receiving ring respectively.

[0026] Furthermore, the valve stem is connected to the flattened side of the sphere.

[0027] Furthermore, there are two valve seat sealing pairs, which are respectively located at the ends where the inlet and outlet channels of the ball valve communicate with the valve cavity.

[0028] Due to the adoption of this technical solution, the beneficial effects of the present invention are:

[0029] 1. A high and low temperature alternating pure metal bi-directional sealing ball valve of the present invention uses a spring compensation type metal sealing ring for sealing between the ball and the valve cavity. With its unique all-metal structure design, the structure is bi-directional sealing and has no non-metal sealing elements, which is different from both the existing single-directional sealing floating ball valve technology and the existing bi-directional sealing floating ball valve technology. The present invention improves the original static seal to a dynamic load seal. It not only improves the wear resistance of the valve seat sealing pair through the material properties of the metal, but also realizes floating seal through the sealing ring with elastic compensation function, meeting the dimensional compensation required due to temperature changes. Whether it is high temperature, low temperature or high and low temperature alternating, it overcomes the high temperature expansion deformation and low temperature shrinkage deformation, can effectively ensure the tight seal of the ball valve under high temperature, low temperature and high and low temperature change working conditions, improves the service life cycle of the ball valve, and can highly adapt to the working conditions of the ball valve that needs to rotate for operation. For example, when under high temperature working conditions, the pure metal valve seat sealing pair can well adapt to the high temperature annulus, is not easy to oxidize, and can effectively ensure the high sealing performance between the ball and the valve cavity at high temperature; when under low temperature working conditions, due to the basic characteristic of "thermal expansion and contraction", the valve seat sealing pair will shrink and the size will decrease. At this time, the sealing ring will compensate for the "shrunk" size of the component under "cold shrinkage" based on the elastic force accumulated by its own compression deformation during installation, so that both the inner and outer sides of the valve seat sealing pair are in sealing contact with the ball and the valve cavity at low temperature, that is, both the inner and outer sides of the valve seat sealing pair maintain high sealing performance with the ball and the valve cavity.

[0030] 2. For a high and low temperature alternating pure metal bi-directional sealing ball valve of the present invention, when the spring compensation type metal sealing ring A is not only in a compressed state in the direction of the flow channel axis but also in the direction of the valve stem axis, when the valve stem itself moves up and down due to the internal medium pressure, the spring compensation type metal sealing ring A limits the position of the ball in the axial direction of the valve stem, thereby reducing or even eliminating the frequency and amplitude of the valve stem moving up and down due to the medium pressure. Thus, the present invention can achieve dimensional compensation required due to temperature changes within 360 degrees on both sides of the ball, and then can achieve true zero leakage of bi-directional sealing under high and low temperature changes.

[0031] 3. Compared with the existing technology, for a high and low temperature alternating pure metal bi-directional sealing ball valve of the present invention, there are only two sealing components between the ball and the valve cavity: the valve seat and the spring compensation type metal sealing ring A. Its structure is simple, the number of components is small, it has elastic seal compensation, and the performance is stable under temperature changes; moreover, the valve seat and the spring compensation type metal sealing ring A can be separately disassembled and replaced, which is convenient for disassembly and assembly, facilitating pre-production, assembly and later maintenance, improving work efficiency, and greatly reducing the production cost and maintenance cost of the ball valve.

[0032] 4. The present invention relates to a high-low temperature alternating pure metal bidirectional sealed ball valve, which directly adopts a V-shaped metal ring for sealing in the valve seat sealing pair without a non-metallic sealing gasket, and provides elastic compensation while realizing dynamic load sealing, integrating the sealing and elastic compensation functions. The V-shaped metal ring provides elastic compensation and realizes sealing, thereby achieving bidirectional sealing; at the same time, a spring is loaded inside the V-shaped metal ring for elastic force compensation, fully considering the sealing and elastic compensation functions of the V-shaped metal ring, providing pre-pressure elastic compensation for the ball and the valve seat, and realizing sealing between the valve seat and the valve body: the V-shaped metal ring in the valve seat sealing pair is always in close contact with the valve cavity wall and the valve seat during valve operation, and the medium will not enter the valve seat sealing pair and affect the sealing; at the same time, the V-shaped opening of the medium entering the V-shaped metal ring expands, increasing the pressure between the V-shaped metal ring and the valve cavity wall and the valve seat, thereby improving the sealing force and ensuring good sealing performance, and the higher the medium pressure, the tighter the seal, that is, the sealing force increases with the increase of medium pressure;

[0033] 5. This invention provides a high-low temperature alternating pure metal bidirectional sealing ball valve. Regardless of whether the medium pressure enters the valve from the left or right valve body, it can load the pressure inside the spring-compensated metal sealing ring A, causing the outer elastic metal ring A to closely fit the valve seat and the valve cavity wall, achieving a bidirectional tight seal without being restricted by the installation direction, providing a better user experience.

[0034] 6. The present invention provides a high-low temperature alternating pure metal bidirectional sealed ball valve. The valve body is configured as a component consisting of a left valve body and a right valve body that are detachable from each other. This allows all components to be replaced individually on-site, facilitating the assembly of components such as the valve seat seal pair and the ball head, as well as the subsequent maintenance and replacement of worn components. During operation, the failed component can be replaced in a targeted manner. For example, if the valve seat and ball seal fail, there is no need to replace the entire valve. This improves the assembly convenience of the present invention, implements the concept of simple, fast and economical maintenance, and reduces maintenance costs, saving users time and money.

[0035] 7. This invention discloses a high-low temperature alternating pure metal bidirectional sealing ball valve with a unique valve body sealing design. The left and right valve bodies are sealed with a spring-compensated metal sealing ring B. The spring-compensated metal sealing ring B is internally loaded with a spring for elastic force compensation. This can effectively resist high-temperature creep of the material of the bolts fastening the left and right valve bodies. Under working conditions, the sealing area is compensated and sealed, ensuring a tight seal between the left and right valve bodies without the risk of leakage.

[0036] 8. The two-way sealed ball valve made of pure metal with high and low temperature alternating of the present invention adopts an anti-blowout structure at the valve stem, and the valve stem is installed in an inside-to-outside manner. Its unique design of the valve stem seal pair first adopts a spring-compensated metal sealing ring at the dynamic load sealing part of the valve stem packing of the ball valve. A spring-compensated metal sealing ring is used for the seal between the valve stem and the valve body, without non-metal sealing elements. A spring is loaded inside the spring-compensated metal sealing ring for elastic force compensation, which has an elastic function, can meet the use under high temperature and various corrosion conditions, has strong versatility, and is suitable for batch processing and harsh working conditions. Brief Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. The proportional relationship of each component in the drawings of this specification does not represent the proportional relationship in actual material selection and design. It is only a schematic diagram of the structure or position, where:

[0038] Figure 1 is the structural schematic diagram of the present invention;

[0039] Figure 2 is Figure 1 the enlarged view of part A in

[0040] Figure 3 is Figure 1 the enlarged view of part B in

[0041] Figure 4 is Figure 1 the enlarged view of part C in

[0042] Figure 5 is the structural schematic diagram of the spring-compensated metal sealing ring A;

[0043] Figure 6 is the structural schematic diagram of the spring-compensated metal sealing ring B;

[0044] Figure 7 is the structural schematic diagram of the spring-compensated metal sealing ring C;

[0045] Figure 8 is the structural schematic diagram of the spring-compensated metal sealing ring A in the pre-compressed state;

[0046] Figure 9 is the structural schematic diagram of the spring-compensated metal sealing ring A under the medium pressure state.

[0047] Explanation of the reference numerals in the drawings:

[0048] 1 - valve cavity, 2 - valve body, 201 - left valve body, 202 - right valve body;

[0049] 3 - sphere, 4 - valve stem, 5 - valve seat;

[0050] 6 - spring - compensated metal seal ring A, 601 - outer elastic metal ring A, 602 - inner compensation spring ring A;

[0051] 7 - neck, 8 - spring - compensated metal seal ring B, 801 - outer elastic metal ring B, 802 - inner compensation spring ring B;

[0052] 9 - annular groove, 10 - gland, 11 - spacer ring;

[0053] 12 - spring - compensated metal seal ring C, 1201 - outer elastic metal ring C, 1202 - inner compensation spring ring C, 1203 - contact ring;

[0054] 13 - right - angled groove, 14 - bushing. Specific embodiments

[0055] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the following further details the present invention in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Usually, the components of the embodiments of the present invention described and illustrated in the drawings here can be arranged and designed in various different configurations.

[0056] "Connection" in the present invention, unless otherwise emphasized, is a conventional connection method, such as integrally formed, welded, riveted, etc. The specific connection method can be adaptively and preferably selected according to the conventional technical knowledge in the technical field of the present invention. All features disclosed in this specification, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

[0057] The following combines Figures 1 to 9 to make a detailed description of the present invention.

[0058] Embodiment 1

[0059] As Figures 1~9As shown in the figure, a high and low temperature alternating pure metal two-way sealed ball valve of the present invention includes a valve body 2 provided with a valve cavity 1, and a sphere 3 located in the valve cavity 1 and hermetically fitted with the valve cavity 1 through a valve seat sealing pair. The top of the sphere 3 is connected to a valve stem 4. Preferably, the valve stem 4 is connected to the sphere 3 by a flat square. After the sphere is closed, the valve stem 4 does not bear the medium thrust in the valve cavity 1. The top of the valve body 2 protrudes upward to form a neck. The top end of the valve stem 4 passes through the neck and is rotationally and hermetically fitted with the neck. The valve stem 4 is rotated manually or by a driving device to drive the sphere 2 to rotate around the axis of the valve stem 4, so that the sphere 2 rotates within a range of 90°, realizing the opening and closing of the ball valve flow channel. There are two valve seat sealing pairs, which are respectively located at the ends where the inlet and outlet channels of the ball valve communicate with the valve cavity 1. The valve seat sealing pair includes an annular valve seat 5. The valve seat 5 is made of pure metal and its axis coincides with the axis of the flow channel.

[0060] A plurality of shoulders are provided on the outer circumferential wall of the valve seat 5. The radius of the shoulders increases in sequence as they approach the axis of the valve stem 4, and are the first shoulder, the second shoulder... and the Nth shoulder in sequence. Preferably, two shoulders are provided. The side of the inner wall of the valve seat close to the sphere 3 is tangent to the sphere 3. The end with a smaller outer diameter of the valve seat is inserted into the flow channel, and the other end is inserted into the valve cavity.

[0061] The flow channel transitions to the valve cavity 1 through N-level stepped holes. The radius of the stepped holes increases in sequence as they approach the axis of the valve stem 4, and are the first-stage hole body, the second-stage hole body... and the Nth-stage hole body in sequence. Preferably, it is a two-stage stepped hole. The small-diameter end of the two-stage stepped hole communicates with the flow channel, and its large-diameter end communicates with the valve cavity.

[0062] The Nth shoulder is inserted into the Nth-stage hole body, that is, the first shoulder is inserted into the first-stage hole body, the second shoulder is inserted into the second-stage hole body, and a spring compensation type metal sealing ring A6 is provided between the end of at least one shoulder and the bottom of the hole body that cooperates with it. The axis of the spring compensation type metal sealing ring A6 coincides with the axis of the flow channel. The two sides of it are respectively in contact with the end of the shoulder and the bottom of the hole body, and it is at least in a compressed state in the direction parallel to the axis of the flow channel.

[0063] The contact sealing surface between the sphere 3 and the valve seat 5 is treated by the method of supersonic spraying hardening layer. N is a natural number greater than 1.

[0064] Metal sealing rings, as static sealing elements, have sufficient performance verification on equipment such as aerospace, power generation, and pumps. When applied to ball valves as dynamic load sealing components, they have good performance guarantees. In the present invention, a spring compensation type metal sealing ring is used for sealing between the sphere 3 and the valve cavity 1. Its unique all-metal structure design, the structure is a two-way seal, without non-metal sealing elements, which is different from both the existing one-way seal floating ball valve technology and the existing two-way seal floating ball valve technology; the present invention improves the original static seal into a dynamic load seal, not only improving the wear resistance of the valve seat sealing pair through the material characteristics of the metal, but also realizing floating seal through the sealing ring with elastic compensation function, meeting the dimensional compensation required due to temperature changes. Whether it is high temperature, low temperature or high-low temperature alternating, it overcomes the high temperature expansion deformation and low temperature shrinkage deformation, can effectively ensure the tight seal of the ball valve under high temperature, low temperature and high-low temperature change working conditions, improves the service life cycle of the ball valve, and can highly adapt to the working conditions of the ball valve that needs to rotate for operation. For example, when in a high temperature working condition, the pure metal valve seat sealing pair can well adapt to the high temperature annulus, is not easy to oxidize, and can effectively ensure the high sealing performance between the sphere 3 and the valve cavity 1 at high temperature; when in a low temperature working condition, due to the basic characteristic of "thermal expansion and contraction", the valve seat sealing pair will shrink and the size will decrease. At this time, the sealing ring will compensate for the "shrunk" size of the components under "cold shrinkage" based on the elasticity accumulated by the compression deformation force existing during installation, so that both the inner and outer sides of the valve seat sealing pair are in sealing contact with the sphere 3 and the valve cavity 1 at low temperature, that is, both the inner and outer sides of the valve seat sealing pair maintain high sealing performance with the sphere 3 and the valve cavity.

[0065] At the same time, when the spring compensation type metal sealing ring A6 is not only in a compressed state in the direction of the flow channel axis, but also in a compressed state in the direction of the valve stem axis, when the valve stem itself moves up and down due to the internal medium pressure, the spring compensation type metal sealing ring A6 limits the position of the sphere 3 in the axial direction of the valve stem, thereby reducing or even eliminating the frequency and amplitude of the valve stem moving up and down due to the medium pressure. Thus, the present invention can achieve dimensional compensation required due to temperature changes within 360 degrees on both sides of the sphere, and then can achieve true zero leakage of two-way seal for high-low temperature change.

[0066] And compared with the existing technology, there are only two sealing components used between the sphere and the valve cavity in the present invention: the valve seat and the spring compensation type metal sealing ring A6. Its structure is simple, the number of components is small, it has elastic seal compensation, and the performance is stable under temperature changes; and the valve seat 5 and the spring compensation type metal sealing ring A6 can be separately disassembled and replaced, which is convenient for disassembly and assembly, facilitating pre-production, assembly and later maintenance, improving work efficiency, and greatly reducing the production cost and maintenance cost of the ball valve.

[0067] Compared with the prior art, the structure of the present invention is simple, and all components can be produced as standard parts, and existing general mechanical processing equipment can meet the processing requirements.

[0068] Embodiment 2

[0069] Based on Embodiment 1, this embodiment describes the specific implementation structure of the spring-compensated metal seal ring A6.

[0070] As Figure 1 、 Figure 2 、 Figure 5 、 Figure 8 and Figure 9 shown, in the present invention, the spring-compensated metal seal ring A6 includes an outer elastic metal ring A601 and an inner compensation spring ring A602 whose axes coincide with the axis of the flow channel. The cross-section of the outer elastic metal ring A601 is V-shaped, preferably with the opening of the V-shape facing the axis of the flow channel. Its two sides are in contact with the end of the shaft shoulder and the bottom of the hole of the mating hole body respectively. The inner compensation spring ring A602 is installed in the V-shaped annular groove of the outer elastic metal ring A601 and is in contact with the two side walls of the V-shaped annular groove.

[0071] In the present invention, with a unique valve seat sealing pair structure design, a V-shaped metal ring is used as a sealing component in the ball valve seat sealing pair for the first time. The free state of the spring-compensated metal seal ring A6 is as Figure 5 shown; its pre-compressed state when installed in the ball valve is as Figure 8 shown. The two sides of the outer elastic metal ring A601 are in contact with the valve cavity and the valve seat and achieve contact sealing. The contact parts are two circular lines whose axes are located at the axis of the flow channel. At the same time, preferably, the outer ring of the outer elastic metal ring A601 is in contact with the hole wall of the corresponding hole body, and the inner ring of the inner compensation spring ring A602 is in contact with the circumferential side wall at the corresponding shaft shoulder, so that the spring-compensated metal seal ring A6 is compressed in the direction parallel to the axis of the valve stem and the direction parallel to the axis of the flow channel, so as to perform floating sealing on the sphere 3 in any direction within the space range through the spring-compensated metal seal ring A6 and ensure excellent sealing performance; preferably, both ends of the outer elastic metal ring A601 are bent inward, and the convex surfaces of the bent parts are in contact with the valve cavity and the valve seat respectively, so as to improve the force environment between the outer elastic metal ring A601 and the corresponding contact surfaces and avoid surface damage such as scratches on the valve cavity and the valve seat when the sharp corners at the ends of the outer elastic metal ring A601 are in contact with the valve cavity and the valve seat; when working, when there is a pressure medium inside the ball valve, its force is as Figure 9As shown, in addition to the pre-tightening force provided by the pre-compressive deformation of the spring-compensated metal sealing ring itself to ensure excellent sealing performance, when the pressure medium enters the V-shaped ring groove, it pushes the two sides of the outer elastic metal ring A601 outward, thereby increasing the force on the contact parts between the two sides of the outer elastic metal ring A601 and the valve cavity and the valve seat, further enhancing the sealing performance. At the same time, when the pressure medium enters the V-shaped ring groove, it can also push up the inner compensation spring ring A602, thereby increasing the extrusion force between the inner compensation spring ring A602 and the outer elastic metal ring A601, and then further enhancing the sealing performance.

[0072] The cross-sectional shape of the outer elastic metal ring A601 can be various, such as C-shaped, U-shaped, Y-shaped, etc., as long as it has an annular groove for installing the inner compensation spring ring A602. The inner compensation spring ring A602 can adopt a spiral spring connected end to end to form a ring, or an elastic metal ring, etc., and the specific implementation structure is not limited.

[0073] In the present invention, a V-shaped metal ring (outer elastic metal ring A601) is directly used as a seal in the valve seat sealing pair, without a non-metallic gasket. While achieving dynamic load sealing, it provides elastic compensation, integrating the sealing and elastic compensation functions. The V-shaped metal ring not only provides elastic compensation but also realizes sealing, achieving two-way sealing. At the same time, a spring (inner compensation spring ring A602) is loaded inside the V-shaped metal ring for elastic force compensation, fully considering the sealing and elastic compensation functions of the V-shaped metal ring. It not only provides pre-compressive elastic compensation for the sphere 3 and the valve seat 5, but also seals the valve seat 5 and the valve body 2: The V-shaped metal ring in the valve seat sealing pair always fits tightly with the valve cavity wall and the valve seat during the operation of the valve, and the medium will not enter the valve seat sealing pair to affect the sealing. At the same time, the V-shaped orifice inside the V-shaped metal ring expands when the medium enters, increasing the pressure between the V-shaped metal ring and the valve cavity wall and the valve seat, enhancing the sealing force and ensuring good sealing performance. Moreover, the higher the medium pressure, the tighter the sealing, that is, the sealing force increases with the increase of the medium pressure.

[0074] When the ball valve designed by the present invention is in use, regardless of whether the medium pressure enters the valve from the left valve body 201 or the right valve body 202, the pressure can be loaded inside the spring-compensated metal sealing ring A6, prompting the outer elastic metal ring A601 to fit tightly with the valve seat 5 and the valve cavity wall, achieving two-way tight sealing, without being restricted by the installation direction, bringing a better experience to the user.

[0075] Embodiment 3

[0076] This embodiment further explains the structure of the valve body 2 on the basis of the above embodiment.

[0077] As Figure 1As shown, in the present invention, the valve body 2 is divided into a left valve body 201 and a right valve body 202 by a plane perpendicular to the flow channel axis. The valve cavity 1 is correspondingly divided into a left valve cavity located on the left valve body 201 and a right valve cavity located on the right valve body 202. The center of the sphere 3 is located in the left valve cavity, and the top of the left valve body 201 is convex to form a neck 7 that seals with the valve stem 4.

[0078] The left valve body 201 is detachably connected to the right valve body 202 via fasteners, and a spring-compensated metal sealing ring B8 is provided between the left valve body 201 and the right valve body 202 to seal the portion separating the left valve body 201 and the right valve body 202 .

[0079] The fastener is preferably a combination of a bolt and a nut. Specifically, the rod end of the bolt is movable through the right valve body 202 and the left valve body 201 in sequence and then threadedly connected to the nut. The fastener can also be a welding rod, a U-shaped clamp or other components, and the specific implementation method is not limited.

[0080] The valve body 2 is configured as a component consisting of a left valve body 201 and a right valve body 202 that are detachable from each other, so that all components can be replaced individually on site, which facilitates the assembly of components such as the valve seat sealing pair and the ball head 3, as well as the subsequent maintenance and replacement of a worn component. During operation, the failed components can be replaced in a targeted manner. For example, when the valve seat and ball seal fail, there is no need to replace the entire valve. This improves the assembly convenience of the present invention, realizes the concept of simple, fast and economical maintenance, reduces maintenance costs, and saves users repair cycles and economic losses.

[0081] The sealing structure between the left valve body 201 and the right valve body 202 is as follows: an annular groove 9 is provided on the surface of the left valve body 201 in contact with the right valve body 202, and the axis of the annular groove 9 coincides with the axis of the flow channel;

[0082] The spring compensation type metal sealing ring B8 is located in the annular groove 9, and the spring compensation type metal sealing ring B8 assembly includes an outer elastic metal ring B801 and an inner compensation spring ring B802, both axes of which coincide with the axis of the flow channel. The cross section of the outer elastic metal ring B801 is C-shaped, and its two sides are respectively in contact with the bottom of the annular groove 9 and the right valve body 202. The inner compensation spring ring B802 is installed in the C-shaped annular groove of the outer elastic metal ring B801 and is inscribed in the groove wall of the C-shaped annular groove.

[0083] The free state of the spring compensation metal seal ring B8 is as follows Figure 6As shown; when it is installed between the left valve body 201 and the right valve body 202, it is in a pre-compressed state, and it bears the extrusion force from the left valve body 201 and the right valve body 202, so that its inner ring bulges inward and its outer ring bulges outward. Both sides of the outer elastic metal ring B801 are in contact with the left valve body 201 and the right valve body 202 and are sealed by contact. The contact parts are two loops with the axis located at the axis of the flow channel. The pre-tightening force possessed by the pre-compression deformation of the spring compensation type metal seal ring B8 itself ensures excellent sealing performance between the left valve body 201 and the right valve body 202.

[0084] In the present invention, with a unique valve body sealing design, the left valve body 201 and the right valve body 202 are sealed by a spring compensation type metal seal ring B8. A spring is loaded inside the spring compensation type metal seal ring B8 for elastic force compensation, which can effectively resist the high-temperature creep of the materials of bolts and the like for fastening the left valve body and the right valve body, and compensate and seal the sealing part under working conditions, ensuring tight sealing between the left valve body and the right valve body without the risk of external leakage.

[0085] Regarding the cooperation between the valve stem 4 and the valve body 2, it is as follows: The neck 7 is sealed with the valve stem 4 through a valve stem seal pair. The valve stem seal pair includes a gland 10, a gasket ring 11, and a spring compensation type metal seal ring C12, all of which are sleeved on the valve stem 4. The middle part of the neck 7 is in transitional fit with the valve stem 4, and an upper annulus is formed between the upper side of the neck 7 and the valve stem 4;

[0086] The gasket ring 11 and the spring compensation type metal seal ring C12 are both installed in the upper annulus. There are two spring compensation type metal seal rings C12, which are respectively located on the upper and lower sides of the gasket ring 11. The bottom end of the gland 10 is inserted into the upper annulus, and the gasket ring 11 and the spring compensation type metal seal ring C12 are pressed against the middle part of the neck 7, and the gland 10 is detachably connected to the left valve body 201 through a fastener.

[0087] Further, the spring compensation type metal seal ring C12 includes an outer elastic metal ring C1201 and an inner compensation spring ring C1202 whose axes all coincide with the axis of the valve stem 4. The cross-section of the outer elastic metal ring C1201 is C-shaped, and a contact ring 1203 with an axis coinciding with the axis of the valve stem 4 is provided on its inner ring. The top end of the contact ring 1203 is connected to the outer elastic metal ring C1201, and the inner ring of the contact ring 1203 is tangent to the valve stem 4; The inner compensation spring ring C1202 is installed in the C-shaped ring groove of the outer elastic metal ring C1201 and is inscribed in the groove wall of the C-shaped ring groove.

[0088] The free state of the spring compensation type metal seal ring C12 is as Figure 7As shown; when it is installed between the valve stem 4 and the neck 7, it is in a pre-stressed state, and it bears the extrusion force from the pressure cover 10, so that its inner ring bulges inward and the outer ring bulges outward, and the contact ring 1203 of the inner ring is tightly embraced on the valve stem 4 to achieve sealing between it and the valve stem; the outer ring is tightly pressed on the gasket 11 or the duck liver 10 to achieve sealing at its outer ring. At the same time, since it is pressurized from top to bottom, a seal is also formed between its upper and lower pressurized parts and the corresponding components. The pre-tightening force of the pre-stressed deformation of the spring-compensated metal sealing ring C12 itself ensures excellent sealing between the valve stem 4 and the neck 7.

[0089] The present invention utilizes a blowout-proof structure at the valve stem, and the valve stem is installed from the inside out. Its unique stem seal design utilizes a spring-compensated metal seal ring for the dynamic seal of the ball valve stem packing for the first time. The spring-compensated metal seal ring seals the valve stem and body, eliminating the need for non-metallic sealing components. The spring-compensated metal seal ring is internally loaded with a spring for force compensation, providing a flexible design that meets high-temperature and various corrosive operating conditions. It is highly versatile and suitable for batch processing and harsh operating conditions.

[0090] The C12 spring-compensated metal seal ring features a self-tightening pre-seal. As media enters the ring, it automatically expands, resulting in a tighter seal at higher media pressures. The C12's dual-spring-compensated metal seal ring design is simpler than existing double-packing non-metallic seals, offering improved wear resistance and a wider range of application options.

[0091] Furthermore, a right-angle groove 13 for installing a spring-compensated metal sealing ring C12 is provided at the bottom of the gland 10 and the gasket 11 and on one side close to the valve stem 4 .

[0092] Furthermore, a lower annulus is formed between the lower side of the neck 7 and the valve stem 4. The lower side of the side wall of the valve stem 4 protrudes outward to form a receiving ring. A shaft sleeve 14 is installed in the lower annulus. The shaft sleeve 14 is sleeved on the valve stem 4, and its upper and lower ends are respectively in contact with the middle part of the neck 7 and the receiving ring. The surfaces of the shaft sleeve 14 and the valve stem 4 are hardened to resist hard pressure and wear.

[0093] Example 4

[0094] This embodiment illustrates the production process implementation method of the present invention.

[0095] In the present invention, the production process is mainly as follows: blank - heat treatment - surface treatment - rough machining - heat treatment - fine machining - assembly - normal temperature pressure test - heat treatment - high and low temperature pressure test - surface treatment - finished product.

[0096] The specific facilities and processes are as follows:

[0097] 1. Parts Manufacturing

[0098] 1. Valve body 2 (left valve body 201 and right valve body 202):

[0099] (1) First, cast or forge the blanks of the left valve body 201 and the right valve body 202. After the casting or forging of the blanks is completed, each material is subjected to corresponding heat treatment according to the temperature and time specified in the Fe-C phase diagram to change the material phase and eliminate stress.

[0100] (2) Shot peening and pickling treatment on the surface of the casting.

[0101] (3) Rough machine the surfaces that need to be machined according to the drawing requirements, leaving a single-sided allowance of 2 - 3 mm for rough machining.

[0102] (4) Conduct heat treatment again according to the temperature and time specified in the Fe-C phase diagram.

[0103] (5) Finish machine according to the drawing requirements.

[0104] 2. Metal sealing ring

[0105] (1) Manually grind the surfaces of the contact parts of the spring-compensated metal sealing ring A6, spring-compensated metal sealing ring B8, and spring-compensated metal sealing ring 12 as the sealing parts, with the surface roughness not higher than Ra0.2.

[0106] (2) Deburr and clean after processing.

[0107] 3. Sphere 3, valve seat 5

[0108] (1) First, cast or forge the blanks of the sphere 3 and the valve seat 5. After the casting or forging of the blanks is completed, each material is subjected to corresponding heat treatment according to the temperature and time specified in the Fe-C phase diagram to change the material phase and eliminate stress.

[0109] (2) Rough machine the surfaces that need to be machined according to the drawing requirements, leaving a single-sided allowance of 2 - 3 mm for rough machining, and finish machine the parts that need surface hardening to the size before spraying.

[0110] (3) Sandblasting treatment on the surface hardening parts of the ball seat sealing surface.

[0111] (4) Surface hardening treatment of the ball seat sealing surface, and the hardening treatment can be carried out by means such as spray welding, spraying, laser cladding, etc.

[0112] (5) Conduct heat treatment again according to the temperature and time specified in the Fe-C phase diagram.

[0113] (6) Rough grinding of the ball seat sealing surface.

[0114] (7) Finish machine according to the drawing requirements.

[0115] (8) Manually finish grind the ball seat sealing surface.

[0116] Two assembly processes

[0117] 1. Deburr and clean the surfaces of each component part.

[0118] 2. Assemble the ball valve according to the assembly drawing.

[0119] (1) Install the shaft sleeve into the valve body.

[0120] (2) Install the valve stem into the valve body.

[0121] (3) Install the spring-compensated metal seal ring A6 and the valve seat into the valve body.

[0122] (4) Align the ball with the flat side of the valve stem and install it into the valve body.

[0123] (5) Install the spring-compensated metal seal ring B8 into the annular groove 9 of the left valve body 201, cover the right valve body 201, and pre-tighten the bolts at the joint of the left valve body 201 and the right valve body 201. The bolts should be tightened diagonally.

[0124] (6) Install the spring-compensated metal seal ring 12, the spacer ring, the spring-compensated metal seal ring 12, and the gland onto the outside of the valve stem in sequence, and pre-tighten the bolts of the gland part.

[0125] (7) Use a tooling handle to pre-open and pre-close the valve.

[0126] (8) Tighten the bolts of each part.

[0127] (9) Test the valve torque.

[0128] 3. Conduct a normal temperature inspection, test the leakage rate of the ball valve, and the test medium is gas or liquid; after the test, the liquid inside the ball valve needs to be dried or baked.

[0129] 4. After passing the normal temperature test, conduct an overall heat treatment at the operating temperature + 30°C as required by the project. The heat treatment requirement is a holding time of 25mm / 2h.

[0130] 5. Test the leakage rate of the valve at high temperature, and the test medium is gas.

[0131] 6. Air-cool.

[0132] 7. Conduct a normal temperature inspection, test the leakage rate of the ball valve, and the test medium is gas or liquid. After the test, the liquid inside the ball valve needs to be dried or baked.

[0133] 8. Surface treatment of the ball valve. Paint the surface of carbon steel valves, and do not treat the surface of stainless steel valves.

[0134] 9. Store the qualified finished products in the warehouse.

[0135] The valve has a pure metal sealing structure. The materials of the spring-compensated metal sealing rings A6, B8, and 12 can be selected according to different service temperatures and different media. Their surfaces are hardened to resist hard pressure and wear. These sealing rings have strong versatility and long service life. Metal parts such as the valve body 2, valve seat 5, ball 3, valve stem 4, gland 10, etc. can be made of various materials according to the actual working conditions.

[0136] After the left valve body and the right valve body are assembled, they are in metal-to-metal contact. Based on the mechanism of forced sealing, the spring-compensated metal sealing ring B8 is added to increase elastic compensation, improving the temperature change range of the valve and solving the problem of external leakage.

[0137] In terms of technology, all sealing contact parts adopt the mechanical processing + automated grinding process to improve the surface finish of the sealing surface. Its advantages are wear resistance and corrosion resistance, and it can be applied to various harsh working conditions of high and low temperatures and high pressures.

[0138] The external drive device transmits torque to the ball 3 through the valve stem 4 to realize the opening and closing of the flow channel hole. When the ball valve is closed, no matter from which end of the flow channel the pressure enters the valve interior, the pressure can be applied to the spring-compensated metal sealing ring A6, prompting the spring-compensated metal sealing ring A6 to closely fit the valve seat 5 and the left valve body 201 and the right valve body 202, achieving two-way tight sealing.

[0139] The above is only the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of by those skilled in the art within the technical scope disclosed by the present invention without creative labor should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the claims.

Claims

1. A high and low temperature alternating pure metal bi-directional sealed ball valve, comprising a valve body (2) provided with a valve cavity (1), and a sphere (3) located in the valve cavity (1) and hermetically fitted with the valve cavity (1) through a valve seat sealing pair. The top of the sphere (3) is connected to a valve rod (4), and is characterized in that: The seat sealing pair is located at the end where the flow passage of the ball valve communicates with the valve chamber (1). The seat sealing pair includes an annular seat (5), and the seat (5) is made of pure metal and its axis coincides with the axis of the flow passage. A plurality of shoulders are provided on the outer circumferential wall of the seat (5), and the radius of the shoulders increases successively as it approaches the axis of the valve stem (4), and they are the first shoulder, the second shoulder to the Nth shoulder in sequence. The inner wall of the seat (5) on the side close to the sphere (3) is tangent to the sphere (3). The flow passage transitions to the valve chamber (1) through an N-stage stepped hole, and the radius of the stepped hole increases successively as it approaches the axis of the valve stem (4), and they are the first-stage hole body, the second-stage hole body to the Nth-stage hole body in sequence. The Nth shoulder is inserted into the Nth-stage hole body, and a spring-compensated metal seal ring A (6) is provided between the end of at least one shoulder and the bottom of the hole body that mates with it. The axis of the spring-compensated metal seal ring A (6) coincides with the axis of the flow passage, and its two sides are respectively in contact with the end of the shoulder and the bottom of the hole body, and it is at least in a compressed state in the direction parallel to the axis of the flow passage. The valve body (2) is divided into a left valve body (201) and a right valve body (202) by a plane perpendicular to the axis of the flow passage. The valve chamber (1) is correspondingly divided into a left valve chamber on the left valve body (201) and a right valve chamber on the right valve body (202). The center of the sphere (3) is located in the left valve chamber, and the top of the left valve body (201) protrudes upward to form a neck (7) that is sealingly fitted with the valve stem (4). The left valve body (201) is detachably connected to the right valve body (202) by fasteners, and a spring-compensated metal seal ring B (8) for sealing the dividing part between the left valve body (201) and the right valve body (202) is provided between the left valve body (201) and the right valve body (202). The neck (7) is sealed with the valve stem (4) through a valve stem sealing pair. The valve stem sealing pair includes a gland (10), a spacer ring (11) and a spring-compensated metal seal ring C (12) that are all sleeved on the valve stem (4). The middle part of the neck (7) is in transitional fit with the valve stem (4), and an upper annulus is formed between the upper side of the neck (7) and the valve stem (4). The spacer ring (11) and the spring-compensated metal seal ring C (12) are both installed in the upper annulus, and there are two spring-compensated metal seal rings C (12), which are respectively located on the upper and lower sides of the spacer ring (11). The bottom end of the gland (10) is inserted into the upper annulus, and the spacer ring (11) and the spring-compensated metal seal ring C (12) are pressed against the middle part of the neck (7), and the gland (10) is detachably connected to the left valve body (201) by fasteners. The spring-compensated metal seal ring C (12) includes an outer elastic metal ring C (1201) and an inner compensation spring ring C (1202) whose axes coincide with the axis of the valve stem (4). The cross-section of the outer elastic metal ring C (1201) is C-shaped, and a contact ring (1203) with an axis coinciding with the axis of the valve stem (4) is provided on its inner ring. The top end of the contact ring (1203) is connected to the outer elastic metal ring C (1201), and the inner ring of the contact ring (1203) is tangent to the valve stem (4); the inner compensation spring ring C (1202) is installed in the C-shaped ring groove of the outer elastic metal ring C (1201) and is inscribed in the groove wall of the C-shaped ring groove. The valve stem (4) is connected to the sphere (3) in a flat-square manner.

2. The high and low temperature alternating pure metal two-way sealed ball valve according to claim 1, characterized in that: The spring-compensated metal seal ring A (6) includes an outer elastic metal ring A (601) and an inner compensation spring ring A (602) whose axes coincide with the axis of the flow passage. The cross-section of the outer elastic metal ring A (601) is V-shaped, and its two sides are respectively in contact with the end of the shaft shoulder and the bottom of the hole body that mates with it. The inner compensation spring ring A (602) is installed in the V-shaped ring groove of the outer elastic metal ring A (601) and is in contact with the two side groove walls of the V-shaped ring groove.

3. A high and low temperature alternating pure metal two-way sealed ball valve according to claim 1, characterized in that: An annular groove (9) is provided on the surface of the left valve body (201) that contacts the right valve body (202), and the axis of the annular groove (9) coincides with the axis of the flow passage; the spring-compensated metal seal ring B (8) is located in the annular groove (9), and the spring-compensated metal seal ring B (8) includes an outer elastic metal ring B (801) and an inner compensation spring ring B (802) whose axes coincide with the axis of the flow passage. The cross-section of the outer elastic metal ring B (801) is C-shaped, and its two sides are respectively in contact with the bottom of the annular groove (9) and the right valve body (202). The inner compensation spring ring B (802) is installed in the C-shaped ring groove of the outer elastic metal ring B (801) and is inscribed in the groove wall of the C-shaped ring groove.

4. A high-low temperature alternating pure metal double-sealed ball valve according to claim 1, characterized in that: Right-angle grooves (13) for installing the spring-compensated metal seal ring C (12) are provided at the bottom of the gland (10) and the gasket ring (11) and on the side close to the valve stem (4).

5. A high and low temperature alternating pure metal double-sealed ball valve according to any one of claims 1 to 4, characterized in that: A lower annulus is formed between the lower side of the neck (7) and the valve stem (4). The lower side of the side wall of the valve stem (4) protrudes outward to form a receiving ring. A bushing (14) is installed in the lower annulus. The bushing (14) is sleeved on the valve stem (4), and its upper and lower ends are respectively in contact with the middle part of the neck (7) and the receiving ring.

6. A high and low temperature alternating pure metal double-sealed ball valve according to claim 1, characterized in that: There are two valve seat sealing pairs, which are respectively located at the ends where the inlet and outlet flow passages of the ball valve communicate with the valve cavity (1).

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