Bidirectional sealing ball valve

Abstract

The utility model provides a bidirectional sealing ball valve, which is characterized in that a multi-layer hole structure is arranged in an inner hole of an outlet of a valve body, and a bulge I is arranged on the outer circumference of a valve seat; the inner diameters of the three sections of stepped holes are gradually reduced from the outer end face to the inner end face of an outlet of the valve body, the largest first hole is used for installing the check ring at the outermost end, the second hole is used for moving and adjusting the first protrusion, and the smallest third hole is matched with the outer diameter of the valve seat. And then the valve seat and the spherical crown are sequentially taken out. Furthermore, the check ring is in threaded connection with the first hole, so that the size of the outlet is increased, the full-bore requirement is met, water loss can be reduced, and more energy is saved. The distance between the valve seat and the check ring and the distance between the valve seat and the inner end face of the second hole are further designed, so that the two-way sealing ball valve has a good two-way sealing function, the position of the valve seat is axially adjustable, and the production and machining precision and the technological assembly difficulty of the spherical crown and the valve seat in the main seal are reduced.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and more specifically, to a bidirectional sealing ball valve. Background Technology

[0002] Ball valves, including eccentric hemispherical valves and rotary ball valves, play a crucial role in industrial fluid control systems due to their excellent sealing and regulating properties. Traditional eccentric hemispherical and rotary ball valves typically have a unidirectional sealing structure with a reduced diameter, making them suitable only for pipelines with a single media flow direction. This results in poor energy efficiency and an inability to achieve bidirectional sealing. In the main sealing assembly, the valve seat is pressed against the spherical crown sealing surface by a retaining ring to form a seal, preventing media leakage. Since the axial position of the valve seat is not adjustable, ensuring proper contact between the sealing surfaces requires high machining precision. If, after initial assembly, the contact between the spherical crown and valve seat does not meet sealing requirements, the gap between them must be measured, and the valve seat disassembled for reprocessing, measurement, and trial assembly. This may involve multiple rework attempts to ensure the main seal passes pressure testing, which is detrimental to production and assembly.

[0003] The patent, authorized by CN210687065U and entitled "Utility Model Patent for a Bidirectional Sealing Eccentric Ball Valve," describes a valve body with a stepped outlet end to limit the valve seat position. A groove is provided at the corresponding mounting location on the outer ring of the valve seat at the outlet end. Multiple first set screws are arranged at the corresponding locations on the outer ring of the valve seat within the groove. These first set screws extend beyond the outer ring of the valve seat, into the groove, and can move axially along the valve body within the groove, following the valve seat. Regardless of whether the medium flows in the forward or reverse direction, the movable valve seat can promptly compensate for any deformation of the hemisphere under the pressure of the medium flow, ensuring the eccentric ball valve maintains a good sealing condition and preventing sealing defects. While this patent's technical solution effectively achieves bidirectional sealing, it has the following shortcomings: the eccentric ball valve's crown and seat are easily damaged components that frequently require replacement. As shown in the patent's drawings, the outer diameter of the valve seat 2 is larger than the inner diameter of the valve body outlet end, and the set screw 4 protrudes into the groove 12. With this structure, when repairing or replacing the ball crown and valve seat, the drive unit, valve cover, valve stem, valve body and other components must be removed from the top of the valve before the ball crown and valve seat can be taken out, which makes maintenance inconvenient. Utility Model Content

[0004] The technical problem to be solved by this utility model is to address the shortcomings of existing bidirectional sealing ball valves, especially eccentric hemispherical valves and rotary ball valves, such as inconvenient disassembly of the ball crown and valve seat, small valve outlet area, and large water loss. The present invention provides a bidirectional sealing ball valve that is easy to disassemble, energy-saving, and has good bidirectional sealing performance.

[0005] A bidirectional sealing ball valve includes a valve body and a valve seat, a ball, a ball crown, and a retaining ring located within the valve body. The ball crown is fixed to the ball, and the retaining ring is fixed to the outlet of the valve body. The valve seat, limited by the retaining ring, ensures a seal when the valve is under forward pressure, as the sealing surface of the valve seat contacts and presses against the sealing surface of the ball crown. The inner hole of the valve body outlet has a multi-layered hole structure, consisting of three sections with gradually decreasing inner diameters from the outer end face to the inner end face of the valve body outlet. The multi-layered hole structure includes a first hole, a second hole, and a third hole. The retaining ring is located in the first hole, and its width is equal to the depth of the first hole. The retaining ring is fixed to the valve body. The valve seat has a protrusion located in the second hole, with a gap between the protrusion and the inner end face of the second hole, allowing the protrusion to move within the second hole when the valve is under reverse pressure. The outer diameter of the valve seat is equal to the inner diameter of the third hole.

[0006] For example, in practical applications such as eccentric hemispherical valves and rotary ball valves used in ring-shaped pipe networks, the valves need to withstand pressure in both directions. Existing eccentric hemispherical valves generally only have unidirectional pressure-bearing capabilities. Under forward pressure, the ball crown and valve seat are pressed together for sealing, and a limiting structure at the valve outlet withstands the pressure. Under reverse pressure, because the valve seat in existing technologies cannot move, the ball crown is compressed, causing it to detach from the valve seat, thus failing to achieve reverse sealing. The valve of this application has bidirectional sealing capabilities. Forward sealing: When the valve is under forward pressure, the valve seat, limited by the retaining ring, forms a sealing pair with the ball crown to prevent media leakage. Reverse sealing: When the valve is under reverse pressure, the retaining ring remains stationary, and the valve seat can move within the second hole. Under the reverse medium pressure, the valve seat presses forward against the ball crown to form a sealing pair to prevent media leakage.

[0007] This invention designs the outlet inner hole surface with a multi-layered hole structure; the three-layered stepped structure actually consists of three layers of inner holes, with the diameter increasing towards the outlet. The retaining ring is located in the outermost first hole, and the outer diameter of the valve seat is equal to the outer diameter of the third hole. A protrusion on the outer diameter of the valve seat is located in the second hole. When replacing the valve seat and ball crown, disassembly can be performed from the side without removing the drive device, valve cover, valve stem, valve body, and other components from above. Specifically, the retaining ring is removed from the side first, and then the valve seat is taken out, which is convenient and quick, solving the technical problem of the difficulty in disassembling the sealing pair of existing eccentric hemispherical valves.

[0008] Furthermore, the gap between the first protrusion and the inner end face of the second hole is greater than the stroke of the first protrusion in the second hole. When the valve is under reverse pressure, the retaining ring remains stationary, and the valve seat presses forward against the ball crown under the action of reverse medium pressure to form a sealing pair to prevent medium leakage. At this time, the first protrusion does not contact the inner end face of the second hole, which can prevent the valve seat from advancing forward under the action of medium pressure without being limited, which is conducive to a tighter contact between the valve seat and the ball crown and a better sealing effect.

[0009] Furthermore, the outer circular surface of the valve seat is provided with a stepped structure, which consists of a second protrusion, a first protrusion, and a first groove, arranged sequentially from the outer end face of the valve body outlet to the inner end face. The second and first protrusions are located in the second hole, and the outer diameters of the second and first protrusions are equal. A groove, called the second groove, is formed between the second and first protrusions. The first groove is located on the valve seat, corresponding to the third hole. Sealing components are placed in the first and second grooves. Sealing grooves on both sides of the first protrusion prevent impurities (such as mud and sand) from entering, avoiding impurities from entering the movement space of the first protrusion (i.e., between the first protrusion and the inner end face of the second hole), thus affecting the tight sealing between the ball crown and the valve seat.

[0010] Furthermore, an adjusting rod is also installed on the retaining ring. The end of the adjusting rod can pass through the retaining ring and extend from the other end of the retaining ring, located between the valve seat and the retaining ring, and press against the valve seat. Preferably, the adjusting rod is a set screw, which is installed perpendicular to the retaining ring. The set screw is threaded to the retaining ring, and by rotating the set screw, one end of the set screw can be positioned between the valve seat and the retaining ring, pressing against the valve seat. If a local leakage is found under forward pressure on the valve, the set screw can be adjusted to press the valve seat forward, allowing it to make further contact with the ball crown and achieve a seal.

[0011] Furthermore, after the retaining ring is installed, a gap is reserved between the retaining ring and the valve seat. This gap reduces the requirements for the valve seat's machining process. When the valve seat has machining errors, adjusting the set screw to press against the valve seat ensures that the valve seat and the ball crown make contact and seal under positive pressure.

[0012] Furthermore, a plurality of set screws are evenly arranged on the circumference of the retaining ring.

[0013] Furthermore, the retaining ring is threadedly connected to the first hole. Compared to using screws to connect the retaining ring to the valve body, this application uses a threaded connection to the valve body's inner hole, which increases the valve outlet flow area and meets full-bore design requirements. Generally, when the outlet size is not less than 95% of the inlet size, it is considered in the industry to meet full-bore requirements. A water outlet that meets full-bore requirements can reduce water loss and save energy.

[0014] Furthermore, the first and second protrusions are integrally formed with the valve seat. The prior art uses screws and holes to provide space for the valve seat to move, but this requires machining screw holes on the valve seat, which is more cumbersome.

[0015] Furthermore, the ball valve is an eccentric hemispherical valve or a rotary ball valve.

[0016] This utility model has the following beneficial effects:

[0017] The bidirectional sealing ball valve described in this utility model has the following beneficial effects:

[0018] 1. Easy disassembly of the ball crown and valve seat: A multi-layered hole structure is provided in the inner hole of the valve body outlet. This multi-layered hole structure consists of three stepped holes with gradually decreasing inner diameters from the outer end face to the inner end face of the valve body outlet. The largest first hole is used to install the outermost retaining ring, the second hole is used for adjusting the movement of the protrusion, and the smallest third hole mates with the outer diameter of the valve seat. When disassembling the valve seat and ball crown, only the outermost retaining ring needs to be removed, and then the valve seat and ball crown can be taken out sequentially. Compared with existing technologies, this method is much more convenient in terms of disassembling and installing the valve seat and ball crown.

[0019] 2. Features bidirectional sealing: A protrusion is provided on the outer circumference of the valve seat. This protrusion moves within a second hole. When the valve is under forward pressure, the valve seat, under the pressure and limiting action of the set screw on the retaining ring, forms a sealing pair with the ball crown to prevent media leakage. When the valve is under reverse pressure, the set screw on the retaining ring remains stationary, allowing the valve seat to move within the second hole. Under the reverse medium pressure, the valve seat presses forward against the ball crown to form a sealing pair and prevent media leakage. To ensure a specified clamping force between the valve seat and the ball crown during reverse pressure, the gap between the protrusion and the inner end face of the second hole is greater than the stroke of the protrusion within the second hole. Furthermore, it also features a first groove and a second groove, each containing a sealing component to ensure the sealing of the gap between the protrusion and the inner end face of the second hole, preventing water and impurities from entering.

[0020] 3. Meets full-bore design requirements: The retaining ring is threaded to the first hole. Compared to using screws to connect the retaining ring to the valve body, this application uses a threaded connection to the valve body's inner hole, which increases the valve outlet flow area and meets full-bore design requirements. Generally, when the outlet size is not less than 95% of the inlet size, it is considered to meet full-bore requirements in the industry. A water outlet that meets full-bore requirements reduces water loss and is more energy-efficient.

[0021] 4. A gap exists between the first protrusion and the inner end face of the second hole, and a gap is reserved between the retaining ring and the valve seat. A set screw is installed on the retaining ring, and the end of the set screw can extend into the gap between the retaining ring and the valve seat. This design allows the valve seat position to be axially adjustable, reducing the manufacturing precision and assembly difficulty of the ball crown and valve seat in the main seal. Attached Figure Description

[0022] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0023] Figure 1 This is a structural diagram of the eccentric hemispherical valve described in Example 1;

[0024] Figure 2 for Figure 1Enlarged view at point A;

[0025] Figure 3 This is a structural diagram of the retaining ring.

[0026] The serial numbers are: 1-drive device, 2-valve cover, 3-valve body, 4-valve stem, 5-retaining ring, 5a-screw hole of set screw, 6-valve seat, 6a-protrusion one, 6b-protrusion two, 6c-groove one, 6d-groove two, 7-spherical crown, 8-inlet, 9-outlet, 10-inner end face of second hole, 11-set screw, 12-threaded connection, 13-gap between retaining ring and valve seat. Detailed Implementation

[0027] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0028] Example 1

[0029] A bidirectional sealing ball valve, wherein the ball valve is an eccentric hemispherical valve, such as Figure 1 The diagram shows an eccentric hemispherical valve. From top to bottom, the eccentric hemispherical valve includes a drive unit 1, a valve cover 2, and a valve body 3. A valve stem 4 is connected to the drive unit 1 and passes through the valve cover 2 to connect with the ball, driving the ball inside the valve body 3 to rotate. A ball crown 7 is mounted on the ball via fasteners. A valve seat 6 and a retaining ring 5 are also installed inside the valve body 3. In the existing technology, when inspecting the ball crown 7 and valve seat 6, it is necessary to disassemble the drive unit 1, valve cover 2, and valve body 3 sequentially before the ball crown 7 and valve seat 6 can be removed, making maintenance extremely inconvenient.

[0030] like Figure 1 As shown, in the pipeline network, point 8 is the fluid inlet 8, and point 9 is the fluid outlet 9. When the fluid flows from inlet 8 to outlet 9, the valve is under forward pressure, and the ball crown 7 presses against the valve seat 6. A retaining ring 5 is fixed at outlet 9, which acts as a limiting structure to withstand the pressure. When the fluid flows from outlet 9 to inlet 8, the valve is under reverse pressure, and the fluid pressure presses against the ball crown 7. In existing technologies, both the retaining ring 5 and the valve seat 6 are fixed. In this case, the sealing surfaces of the ball crown 7 and the valve seat 6 will separate, and a seal cannot be achieved under reverse pressure.

[0031] To ensure that the eccentric hemispherical valve has both good bidirectional sealing function and can be quickly and easily disassembled, this application provides a novel bidirectional sealing ball valve, such as... Figure 1 and Figure 2As shown, the valve includes a valve body 3 and a valve seat 6, a ball, a ball crown 7, and a retaining ring 5 located within the valve body 3. The ball crown 7 is fixed to the ball, and the retaining ring 5 is fixed to the outlet 9 of the valve body 3. The valve seat 6 is limited by the retaining ring 5 so that when the valve is under forward pressure, the sealing surface of the valve seat 6 contacts and presses against the sealing surface of the ball crown 7 to form a seal. The inner hole of the outlet 9 of the valve body 3 has a multi-layer hole structure, which consists of three sections of holes with gradually decreasing inner diameters from the outer end face to the inner end face of the outlet 9 of the valve body 3. The multi-layer hole structure includes a first hole, a second hole, and a third hole. The retaining ring 5 is located in the first hole, and the width of the retaining ring 5 is equal to the depth of the first hole. The retaining ring 5 is fixed to the valve body 3. The valve seat 6 is provided with a protrusion 6a, which is located in the second hole. There is a gap between the protrusion 6a and the inner end face of the second hole so that when the valve is under reverse pressure, the protrusion 6a can move in the second hole. The outer diameter of the valve seat 6 is equal to the inner diameter of the third hole.

[0032] The inner end face 10 of the second hole mentioned in this application refers to the radial end face at the transition between the second hole and the third hole.

[0033] The gap between the protrusion 6a and the inner end face of the second hole is greater than the travel of the protrusion 6a in the second hole.

[0034] The outer circular surface of the valve seat 6 is provided with a stepped structure, which consists of a second protrusion 6b, a first protrusion 6a, and a first groove 6c, arranged sequentially from the outer end face of the outlet 9 of the valve body 3 to the inner end face. The second protrusion 6b and the first protrusion 6a are located in the second hole, and the outer diameters of the second protrusion 6b and the first protrusion 6a are equal. A second groove 6d is formed between the second protrusion 6b and the first protrusion 6a. The first groove 6c is located on the valve seat 6 at the corresponding position of the third hole. A sealing component is placed in the first groove 6c and the second groove 6d. In this embodiment, the sealing component is an O-ring.

[0035] like Figure 2 As shown, the multi-layered hole structure includes three layers of holes with gradually decreasing inner diameters. The valve seat 6, protrusion 6a, and protrusion 6b are integral and are adapted to the shapes of the second and third holes. Therefore, when inspecting and replacing the valve seat 6 and the ball crown 7, the retaining ring 5 in the first hole and the valve seat 6, which also has a stepped outer surface, can be removed in sequence. Finally, the ball crown 7 can be removed from the inner hole of the outlet 9 of the valve body 3. It is not necessary to disassemble the drive device 1, valve cover 2, valve body 3, and valve stem 4.

[0036] To ensure a good bidirectional sealing function while facilitating disassembly, this application provides a stepped structure on the outer circumferential surface of the valve seat 6. A gap exists between the first protrusion 6a and the inner end face 10 of the second hole. When the valve is under reverse pressure, the first protrusion 6a of the valve seat 6 moves towards the inner end face 10 of the second hole; when under forward pressure, it returns to its original position. To prevent water and other impurities from entering between the first protrusion 6a and the inner end face 10 of the second hole, sealing grooves are provided on both sides of the first protrusion 6a. One sealing component is installed in the second groove 6d between the first protrusion 6a and the second protrusion 6b, and another sealing component is installed in the first groove 6c. The gap between valve seat 6 and the inner end face 10 of the second hole is greater than the stroke of valve seat 6. When the valve is under reverse pressure, the retaining ring 5 does not move. Under the action of reverse medium pressure, valve seat 6 presses forward to tighten the ball crown 7 to form a sealing pair to prevent medium leakage. At this time, the protrusion 6a does not contact the inner end face of the second hole. This can prevent valve seat 6 from moving forward under the action of medium pressure without being limited. It is beneficial for valve seat 6 and ball crown 7 to have a tighter contact and better sealing effect.

[0037] Example 2

[0038] In Example 2, based on Example 1, a set screw 11 is further installed on the retaining ring 5. The set screw 11 is installed perpendicular to the retaining ring 5. Multiple set screws 11 are evenly installed along the circumference of the retaining ring 5, and the set screws 11 are threadedly connected to the retaining ring 5. By rotating the set screw 11, one end of the set screw 11 can be positioned between the valve seat 6 and the retaining ring 5. After installing the set screw 11, if a local leakage is found under forward pressure of the valve, the set screw 11 can be adjusted to press the valve seat 6 forward so that it can further contact the ball crown 7 and achieve a seal. After the retaining ring 5 is installed, a gap (gap 13 between the retaining ring and the valve seat 6) is reserved between the retaining ring 5 and the valve seat 6. When there are manufacturing errors in the valve seat 6 and the ball crown 7, the distance between the valve seat 6 and the inner end face of the second hole can be adjusted by adjusting the set screw 11, that is, adjusting the clamping force between the valve seat 6 and the ball crown 7 to ensure forward sealing performance. Under the pressure of the reverse medium, the valve seat 6 moves forward to press against the ball crown 7, forming a reverse seal. At this time, the set screw 11 on the retaining ring 5 disengages from the valve seat 6. After the reverse seal is completed and the valve is opened, if a forward seal is required according to the operating conditions, the ball crown 7 will push the valve seat 6 backward during the valve closing process. When the valve is closed, the valve seat 6 is held in place by the set screw 11 on the retaining ring 5, so that the valve seat 6 and the ball crown 7 form a sealing pair to complete the forward seal.

[0039] Example 3

[0040] Example 3 is an improvement on Example 2, wherein the retaining ring 5 is connected to the first hole via a thread. Compared to using screws to connect the retaining ring 5 to the valve body 3, this application uses a threaded connection to the inner hole of the valve body 3, which increases the flow area of ​​the valve outlet 9 and meets the full-bore design requirements. Generally, when the outlet 9 size is not less than 95% of the inlet 8 size, it is considered in the industry to meet the full-bore requirement. An outlet that meets the full-bore requirement can reduce water loss and save energy.

[0041] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Various modifications and variations can be made to the present utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the scope of the present utility model.

Claims

1. A bidirectional sealing ball valve, comprising a valve body and a valve seat, a ball, a ball crown, and a retaining ring located within the valve body, wherein the ball crown is fixed to the ball, the retaining ring is fixed to the outlet of the valve body, and the valve seat is limited by the retaining ring so that when the valve is under positive pressure, the sealing surface of the valve seat contacts and presses against the sealing surface of the ball crown to form a seal; characterized in that, The inner hole of the valve body outlet has a multi-layer hole structure, which consists of three sections of holes with gradually decreasing inner diameters from the outer end face to the inner end face of the valve body outlet. The multi-layer hole structure includes a first hole, a second hole, and a third hole. The retaining ring is located in the first hole, and the width of the retaining ring is equal to the depth of the first hole. The retaining ring is fixed to the valve body. The valve seat is provided with a protrusion located in the second hole. There is a gap between the protrusion and the inner end face of the second hole, so that the protrusion can move in the second hole when the valve is subjected to reverse pressure. The outer diameter of the valve seat is equal to the inner diameter of the third hole.

2. The bidirectional sealing ball valve according to claim 1, characterized in that, The gap between the first protrusion and the inner end face of the second hole is greater than the stroke of the first protrusion in the second hole.

3. The bidirectional sealing ball valve according to claim 1, characterized in that, The outer circular surface of the valve seat is provided with a stepped structure, which consists of a second protrusion, a first protrusion, and a first groove from the outer end face of the valve body outlet to the inner end face. The second protrusion and the first protrusion are located in the second hole, and the outer diameter of the second protrusion is equal to that of the first protrusion. A groove is formed between the second protrusion and the first protrusion, which is called the second groove. The first groove is opened on the valve seat at the position corresponding to the third hole. Sealing components are placed in the first groove and the second groove.

4. The bidirectional sealing ball valve according to claim 1, characterized in that, An adjusting rod is also installed on the retaining ring. The end of the adjusting rod can pass through the retaining ring and extend from the other end of the retaining ring to be located between the valve seat and the retaining ring and press against the valve seat.

5. The bidirectional sealing ball valve according to claim 4, characterized in that, The adjusting rod is a set screw, which is installed perpendicular to the retaining ring. The set screw is threaded to the retaining ring, and by rotating the set screw, one end of the set screw can be positioned between the valve seat and the retaining ring and press against the valve seat.

6. The bidirectional sealing ball valve according to claim 4, characterized in that, After the retaining ring is installed, a gap is reserved between the retaining ring and the valve seat.

7. The bidirectional sealing ball valve according to claim 1, characterized in that, The retaining ring is threadedly connected to the first hole.

8. The bidirectional sealing ball valve according to claim 3, characterized in that, The first protrusion, the second protrusion, and the valve seat are an integrated structure.

9. The bidirectional sealing ball valve according to claim 1, characterized in that, The ball valve is either an eccentric hemispherical valve or a rotary ball valve.

10. The bidirectional sealing ball valve according to claim 3, characterized in that, The sealing component is an O-ring.

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