Fixed ball valve

Abstract

The utility model discloses a fixed ball valve which comprises a ball body, a valve body, valve seats, connectors and a valve rod, a valve cavity is arranged in the valve body, the ball body is rotatably arranged in the valve cavity, the upper portion of the ball body is connected with the valve rod, the two sides of the valve body are respectively provided with one connector, the valve seats are arranged between the ball body and the connectors, and sealing assemblies are arranged between the valve seats and the connectors. The sealing assembly comprises a clamping spring arranged on the valve seat. The first lip-shaped ring is arranged on the valve seat and connected with the clamping spring, and the lip-shaped ring seals the valve seat and the connecting body; and the pair of graphite packings is arranged on the two sides of the first lip-shaped ring correspondingly, and the first lip-shaped ring is protected by the graphite packings. By adopting a multi-sealing structure, the sealing performance and the operation stability are improved, the service life is prolonged, the working conditions of low temperature, strong corrosion and the like are effectively handled, the opening torque is small, the stress stability is enhanced by adopting the split pivot design, and the overall performance is excellent.

Description

Technical Field

[0001] The utility model relates to the technical field of ball valves, and particularly relates to a fixed ball valve. Background Art

[0002] In the prior art, with the rapid development of industries such as petroleum and chemical industry, the demand for valves has gradually increased. Ball valves are widely used because of their advantages such as small fluid resistance, good sealing performance, and rapid opening and closing. Ball valves are divided into floating ball valves and fixed ball valves. Under the same caliber and pound class, floating ball valves are limited due to large operating torque and fast wear of the sealing surface. Fixed ball valves have smaller operating torque, stable sealing performance, and long service life compared to floating ball valves, and are suitable for high-pressure and large-caliber occasions. With the development of technology, higher requirements have also been put forward for fixed ball valves. Summary of the Invention

[0003] According to an embodiment of the utility model, a fixed ball valve is provided, which includes a ball, a valve body, a valve seat, a connection body, and a valve stem. A valve cavity is provided in the valve body. The ball is rotatably arranged in the valve cavity. The upper part of the ball is connected to the valve stem. A connection body is installed on each side of the valve body. A valve seat is installed between the ball and the connection body. A sealing assembly is provided between the valve seat and the connection body. The sealing assembly includes:

[0004] A snap ring, which is arranged on the valve seat;

[0005] A first lip seal, which is arranged on the valve seat and is connected to the snap ring, and the lip seal seals the valve seat and the connection body;

[0006] A pair of graphite packing, which are respectively arranged on both sides of the first lip seal, and the graphite packing protects the first lip seal.

[0007] Further, a second lip seal and a first spiral wound gasket are provided between the valve body and the connection body, and the second lip seal and the first spiral wound gasket are used for sealing between the valve body and the connection body.

[0008] Further, the fixed ball valve further includes: a gland flange, a top flange, and a torque pin;

[0009] The gland flange is arranged on the upper part of the valve body, the top flange is arranged on the upper part of the gland flange, and a third lip seal and a second spiral wound gasket are provided between the valve body and the gland flange;

[0010] The torque pin sequentially penetrates through the top flange and the gland flange and is connected to the valve body;

[0011] The valve stem penetrates through the valve body, the gland flange, and the top flange.

[0012] Further, an exhaust gap is left between the torque pin and the valve body, the gland flange, and the top flange.

[0013] Further, the gland flange and the valve body are connected by the first screw, the top flange, the gland flange and the valve body are connected by the second screw, and a through hole is provided on the top flange, and the through hole is arranged directly above the first screw.

[0014] Further, a first bearing is provided between the valve body and the valve stem, and a second bearing is provided between the top flange and the valve stem.

[0015] Further, a fourth lip seal, a V-shaped packing set and a graphite packing are sequentially provided between the valve stem and the gland flange.

[0016] Further, a pivot is provided at the lower part of the sphere, a bottom flange is provided below the pivot, and a fifth lip seal and a third spiral wound gasket are provided between the bottom flange and the valve body.

[0017] According to the fixed ball valve of the embodiment of the present invention, a multi-sealing structure is adopted to improve the sealing performance and operation stability, extend the service life, effectively cope with working conditions such as low temperature and strong corrosion, have a small opening torque, and the split pivot design enhances the force stability, and the overall performance is excellent.

[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further explanation of the claimed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic cross-sectional view of a fixed ball valve according to an embodiment of the present invention;

[0020] Figure 2 is Figure 1 an enlarged view of part A in

[0021] Figure 3 is Figure 1 an enlarged view of part B in

[0022] Figure 4 is a schematic top view of a torque pin of a fixed ball valve according to an embodiment of the present invention;

[0023] Figure 5 is a schematic side view of a torque pin of a fixed ball valve according to an embodiment of the present invention;

[0024] Figure 6 is a schematic top view of a fixed ball valve according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the drawings, and the present invention will be further elaborated.

[0026] First, it will be combined with Figures 1 to 6Describe a fixed ball valve according to an embodiment of the present utility model, which is used in industries such as petroleum and chemical industry, and has a wide range of application scenarios.

[0027] As Figures 1 to 6 shown, the fixed ball valve according to the embodiment of the present utility model includes a ball 1, a valve body 2, a valve seat 3, a connector 4 and a valve stem 5. A valve cavity is provided in the valve body 2. The ball 1 is rotatably arranged in the valve cavity. The upper part of the ball 1 is connected to the valve stem 5. A connector 4 is installed on each side of the valve body 2. A valve seat 3 is installed between the ball 1 and the connector 4. The valve stem 5 drives the ball 1 to rotate in the valve cavity to control the on-off of the fluid. A sealing assembly is provided between the valve seat 3 and the connector 4. The sealing assembly includes: a snap ring 61, which is arranged on the valve seat 3; a first lip seal 62, which is arranged on the valve seat 3 and is in contact with the snap ring 61, and the lip seal seals the valve seat 3 and the connector 4; a pair of graphite packing 63, which are respectively arranged on both sides of the first lip seal 62. The graphite packing 63 protects the first lip seal 62, and the graphite packing 63 can prevent adverse media in the pipeline from damaging the first lip seal 62, ensuring the sealing effect of the first lip seal 62. The API 6D standard stipulates that the cavity relief pressure of the ball valve shall not exceed 33% of the rated pressure of the valve. The existing fixed ball valve realizes the separation of the valve seat 3 from the ball 1 by increasing the area difference between the static pressure surface of the first lip seal 62 and the sealing surface of the valve seat 3 (i.e., the sealing surface between the valve seat 3 and the ball 1), and relieves pressure at the sealing surface of the valve seat 3. The disadvantage of this solution is that the opening torque of the valve will increase significantly, resulting in the failure of the strength check of the valve stem 5, and a larger output torque of the valve actuator is required to meet the opening and closing of the valve, increasing the cost of the valve actuator used. If the area difference between the lip seal and the sealing surface of the valve seat 3 is not increased, when the cavity pressure increases to a certain level, the cavity medium will relieve pressure through the lip seal itself instead of through the separation of the valve seat 3 from the ball 1, which will cause the lip seal to fail and permanently lose its sealing performance. In this embodiment, by adding a snap ring 61, there is no need to deliberately increase the area difference between the static pressure surface of the first lip seal 62 and the sealing surface of the valve seat 3, so the static pressure surface of the first lip seal 62 is reduced, and the area difference between the static pressure surface of the lip seal of the valve seat 3 and the sealing surface of the valve seat 3 is reduced, thereby effectively reducing the valve torque.

[0028] Further, as Figures 1 to 6As shown, in this embodiment, a second lip seal 21 and a first spiral wound gasket 22 are provided between the valve body 2 and the connecting body 4. The second lip seal 21 and the first spiral wound gasket 22 are used for sealing between the valve body 2 and the connecting body 4, providing double sealing to ensure that the valve does not leak. Most of the seals such as the valve stem 5, valve seat 3, valve body 2 and connecting body 4 of existing fixed ball valves use O-ring seals. However, for working media such as low temperature and strong corrosiveness, conventional O-rings cannot meet this requirement, and the cost of special-purpose O-rings is extremely high. A lip seal is a high-performance seal with a PTFE or other high-performance engineering plastic jacket and various springs installed inside, which is fully applicable to working conditions such as low temperature and strongly corrosive media.

[0029] Furthermore, as Figures 1 to 6 shown, in this embodiment, the fixed ball valve further includes: a gland flange 71, a top flange 72 and a torque pin 73; the gland flange 71 is arranged on the upper part of the valve body 2, the top flange 72 is arranged on the upper part of the gland flange 71, and a third lip seal 23 and a second spiral wound gasket 24 are provided between the valve body 2 and the gland flange 71; the torque pin 73 sequentially passes through the top flange 72 and the gland flange 71 and is connected to the valve body 2; the valve stem 5 passes through the valve body 2, the gland flange 71 and the top flange 72. The torque pin 73 has an interference fit with the holes on the valve body 2, the gland flange 71 and the top flange 72. During the opening and closing processes of the valve, the top flange 72 and the gland flange 71 will not shake, making the valve operation more stable and the service life longer.

[0030] Furthermore, as Figures 1 to 6 shown, in this embodiment, an exhaust gap is left between the torque pin 73 and the valve body 2, the gland flange 71 and the top flange 72, which is convenient for the installation of the torque pin 73.

[0031] Furthermore, as Figures 1 to 6 shown, in this embodiment, the gland flange 71 and the valve body 2 are connected by a first screw 74, the gland flange 71, the top flange 72 and the valve body 2 are connected by a second screw 75, and a through hole 76 is provided on the top flange 72, and the through hole 76 is arranged directly above the first screw 74; when tightening the second screw 75, the first screw 74 can be tightened again through the through hole 76 corresponding to the first screw 74 on the top flange 72, making the seal at the mating part of the gland flange 71 and the valve body 2 more reliable.

[0032] Furthermore, as Figures 1 to 6As shown, in this embodiment, a first bearing 81 is provided between the valve body 2 and the valve stem 5, and a second bearing 82 is provided between the top flange 72 and the valve stem 5. Most of the existing fixed ball valves only have one bearing at the valve stem 5. If the height of this bearing is too low, the stability of the valve stem 5 is insufficient when rotating, and the valve stem 5 will hit the gland flange 71 or the top flange 72, causing the valve stem 5 to be strained and the valve torque to increase abnormally, which will shorten the service life of the valve. In this embodiment, a pair of bearings are provided, and the first bearing 81 and the second bearing 82 are used to position and guide the valve stem 5 to ensure that the valve stem 5 will not be excessively tilted, and the valve stem 5 rotates more smoothly, the valve torque is stable, and the service life of the valve is extended. The first bearing 81 is closer to the valve cavity. When the valve is in the closed position, the force arm of the valve stem 5 is small, the bending stress of the valve stem 5 is small, and the diameter of the valve stem 5 required at the first bearing 81 is smaller. Under the condition of meeting the strength of the valve stem 5, the raw material cost of the valve stem 5 and the processing cost of the valve stem 5 hole of the valve body 2 are reduced.

[0033] Further, if Figures 1 to 6 As shown, in this embodiment, a fourth lip ring 83, a V-shaped packing group 84 and a graphite packing 85 are sequentially arranged between the valve stem 5 and the gland flange 71. The existing trunnion ball valve valve stem 5 is generally sealed with only one lip ring and one graphite packing 85. If the lip ring is damaged and fails by the medium, the sealing performance of the graphite packing 85 alone is poor, and the medium will leak out. In this embodiment, the fourth lip ring 83, the V-shaped packing group 84 and the graphite packing 85 form a triple seal to ensure a reliable sealing effect of the valve stem 5. A spacer ring 86 is arranged between the graphite packing 85, the V-shaped packing group 84 and the second bearing 82.

[0034] Further, if Figures 1 to 6 As shown, in this embodiment, a pivot 91 is provided at the lower part of the ball 1, a bottom flange 92 is provided below the pivot 91, and a fifth lip ring 93 and a third winding pad 94 are provided between the bottom flange 92 and the valve body 2. The pivot 91 and the bottom flange 92 are connected by a fixing member, which is different from the existing one-piece structure of the pivot 91 and the bottom flange 92. In this embodiment, the pivot 91 and the bottom flange 92 adopt a split structure. When the valve is in the closed position, the split pivot 91 moves slightly and is completely attached to the pivot 91 hole at the bottom of the valve body 2. The force is more stable than that of the one-piece structure, and the overall performance of the valve is more stable.

[0035] The valve body 2 and the connecting body 4 , the valve body 2 and the bottom flange 92 , and the valve body 2 and the gland flange 71 can all be connected by means of fixing parts such as screws.

[0036] Above, refer to Figures 1 to 6 The present invention describes a fixed ball valve according to an embodiment of the present invention, which adopts a multiple sealing structure to improve the sealing performance and operating stability, prolong the service life, effectively cope with low temperature, strong corrosion and other working conditions, has a small opening torque, and a split pivot design to enhance the force stability and has excellent overall performance.

[0037] It should be noted that in this specification, the terms "comprising", "including" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0038] Although the content of the present utility model has been introduced in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation to the present utility model. After those skilled in the art have read the above content, various modifications and alternatives to the present utility model will be obvious. Therefore, the protection scope of the present utility model shall be defined by the appended claims.

Claims

1. A fixed ball valve, comprising a ball, a valve body, a valve seat, a connecting body and a valve stem. A valve cavity is provided in the valve body. The ball is rotatably arranged in the valve cavity. The upper part of the ball is connected to the valve stem. One connecting body is installed on each side of the valve body. The valve seat is installed between the ball and the connecting body. It is characterized in that, A sealing assembly is provided between the valve seat and the connecting body, and the sealing assembly includes: A circlip, which is arranged on the valve seat; A first lip seal, which is arranged on the valve seat and is in contact with the circlip, and the lip seal seals the valve seat and the connecting body; A pair of graphite packing, which are respectively arranged on both sides of the first lip seal, and the graphite packing protects the first lip seal.

2. The fixed ball valve according to claim 1, characterized in that, A second lip seal and a first spiral wound gasket are provided between the valve body and the connecting body, and the second lip seal and the first spiral wound gasket are used for sealing between the valve body and the connecting body.

3. The fixed ball valve according to claim 1, wherein The fixed ball valve further includes: a gland flange, a top flange and a torque pin; The gland flange is arranged on the upper part of the valve body, the top flange is arranged on the upper part of the gland flange, and a third lip seal and a second spiral wound gasket are provided between the valve body and the gland flange; The torque pin sequentially passes through the top flange and the gland flange and is connected to the valve body; The valve stem passes through the valve body, the gland flange and the top flange.

4. The fixed ball valve according to claim 3, wherein, An exhaust gap is left between the torque pin and the valve body, the gland flange and the top flange.

5. The fixed ball valve according to claim 3, characterized in that, The gland flange and the valve body are connected by a first screw, the top flange, the gland flange and the valve body are connected by a second screw, and a through hole is provided on the top flange, and the through hole is arranged directly above the first screw.

6. The fixed ball valve according to claim 3, characterized in that, A first bearing is provided between the valve body and the valve stem, and a second bearing is provided between the top flange and the valve stem.

7. The fixed ball valve according to claim 3, characterized in that, A fourth lip seal, a V-shaped packing set and graphite packing are sequentially provided between the valve stem and the gland flange.

8. The fixed ball valve according to claim 1, characterized in that, A pivot is provided at the lower part of the ball, a bottom flange is provided below the pivot, and a fifth lip seal and a third spiral wound gasket are provided between the bottom flange and the valve body.

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