Low-leakage structure for valve rod of all-welded fixed ball valve

Abstract

The utility model discloses an all-welded fixed ball valve rod low-leakage structure, and relates to the technical field of ball valve assemblies. A supporting ring is fixed to the lower portion in the shaft sleeve, the lifting piston is arranged at the top end of the supporting ring, supporting rods are fixed to the top end of the lifting piston in an annular array mode, a pushing disc is fixed to the top ends of all the supporting rods, and the top end of the shaft sleeve is in threaded connection with the nut. A valve rod is movably connected in the nut in a penetrating mode and vertically penetrates through the supporting ring, a pressing disc is fixed to the upper portion of the peripheral side of the valve rod and abuts against the inner top of the nut, and an elastic sleeve is movably connected in the shaft sleeve between the pressing disc and the pushing disc. Through the arrangement of the shaft sleeve, the nut, the lifting piston, the valve rod and the elastic sleeve, the problems that the sealing effect between the all-welded ball valve rod and the ball valve shell is not good enough, and the valve rod is not convenient to replace are solved.

Description

Technical Field

[0001] This utility model belongs to the field of ball valve assembly technology, and in particular relates to a low-leakage structure for a fully welded fixed ball valve stem. Background Technology

[0002] All-welded ball valves are widely used in petroleum, chemical, and natural gas industries. They are made of welded steel pipes and come in both spherical and cylindrical structures. Spherical valve bodies typically have only one weld seam, while cylindrical valve bodies have two. They feature explosion-proof design, and some products also have anti-blowout design to prevent the valve stem from being ejected due to improper operation. However, they still have the following drawbacks in practical use:

[0003] During the use of fully welded ball valves, the valve stem extends out of the valve housing and connects to the rotary control handle. The position where the valve stem extends out of the ball valve is prone to leakage due to internal pressure, resulting in poor valve sealing performance.

[0004] Secondly, during the installation process, the valve stem is connected to the shaft seal inside the housing. However, the connection with the shaft seal and other sealing structures requires an interference fit, which makes the operation of cooling or heating the components more complicated. Furthermore, replacing the valve stem can easily damage the shaft seal and other structures, making the operation inconvenient. Utility Model Content

[0005] The purpose of this utility model is to provide a low-leakage structure for a fully welded fixed ball valve stem. By setting a bushing, nut, lifting piston, valve stem, and elastic sleeve, it solves the problems of insufficient sealing effect between the valve stem and the ball valve shell, and inconvenient valve stem replacement in a fully welded ball valve.

[0006] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution: a low-leakage structure for a fully welded fixed ball valve stem, comprising a bushing, a nut, a lifting piston, a valve stem, and an elastic sleeve. A support ring is fixed to the lower part of the bushing, and a lifting piston is disposed at the top of the support ring. Support rods are fixed in a circular array at the top of the lifting piston, and a pusher disc is fixed to the top of all the support rods. A nut is threaded to the top of the bushing, and a valve stem is movably connected through the nut. The valve stem is vertically inserted... A pressure plate is fixed to the upper part of the valve stem through the support ring, and the pressure plate abuts against the top of the nut. An elastic sleeve is movably connected in the bushing between the pressure plate and the push plate. During operation, the bushing houses the lifting piston, valve stem and elastic sleeve. The nut closes the top of the bushing. When the lifting piston is lifting, it pushes the support rod and the push plate, and then squeezes the elastic sleeve, so that the elastic sleeve is pressed tightly against the valve stem and the bushing, sealing the gap between the bushing and the valve stem. The elastic sleeve, after being squeezed, seals the gap between the bushing and the valve stem.

[0007] Furthermore, the bottom end of the bushing is fixedly connected to the valve body, and a limit ring is fixed on the upper part of the bushing's periphery. The bottom end of the nut abuts against the limit ring. When the valve stem rotates, the valve body controls the flow of fluid in the two pipes it is connected to, and the limit ring on the bushing restricts the position of the nut.

[0008] The nut has handles fixed in a ring array around its periphery, and a movable hole is opened in the center of the top of the nut. The valve stem passes through the movable hole and extends out of the top of the nut. When the nut is working, rotating the handles causes the nut to rotate, and the valve stem is movably connected in the movable hole on the nut.

[0009] An outer sealing sleeve is fixed to the periphery of the lifting piston. The bottom end of the outer sealing sleeve is supported on the support ring and is movably connected inside the bushing. An inner sealing ring is fixed to the inner ring of the lifting piston and is movably connected to the periphery of the valve stem. The lifting piston seals the gap between itself and the bushing through the outer sealing sleeve and the gap between itself and the lifting piston through the inner sealing ring.

[0010] A pin is fixed to the bottom end of the valve stem, and an installation block is fixed to the top end of the valve stem. The pin on the valve stem is movably connected to the valve core inside the valve body, and the installation block is connected to the valve handle.

[0011] The elastic sleeve is hollow inside and is filled with a rubber filler disc. The elastic sleeve is movably connected to the periphery of the valve stem. The elastic sleeve and the rubber filler disc cooperate to seal the gap between the valve stem and the bushing when compressed.

[0012] This invention has the following advantages: By setting up a bushing, nut, lifting piston, valve stem, and elastic sleeve, it solves the problem of insufficient sealing effect between the valve stem and the valve shell of a fully welded ball valve. When the valve stem enters the bushing, it presses against the pressure plate on the valve stem as the nut is screwed onto the bushing. The pressure plate is then pressed down until it presses against the elastic sleeve, squeezing the rubber filling disc inside the elastic sleeve. This compresses the elastic sleeve and the rubber filling disc, pressing them against the circumference of the bushing and the valve stem, sealing the gap between them. After the fluid pressure inside the valve body is transmitted to the bushing, it pushes the lifting piston, which in turn pushes the support rod. The support rod then pushes the push plate, increasing the pressure exerted by the push plate on the elastic sleeve and the rubber filling disc, thus increasing the sealing effect between the elastic sleeve and the valve stem. This results in a better sealing effect between the valve stem and the valve shell of the fully welded ball valve.

[0013] This invention solves the problem of inconvenient valve stem replacement in fully welded ball valves by setting up a bushing, nut, and valve stem. When installing the valve stem, simply rotate the handle on the outside of the nut to unscrew the nut from the top of the bushing. Then, insert the mounting block on the valve stem into the top of the bushing. The valve stem then passes through the elastic sleeve, enters the push plate, passes through the inner sealing ring inside the lifting piston, and finally extends into the valve body. The pin block is movably connected to the valve core in the valve body. After completion, the open end of the nut faces the top of the bushing, and the valve stem passes through the outer sealing sleeve on the nut. Then, rotate the handle to rotate the nut onto the bushing, where it abuts against the limiting ring, completing the valve stem installation. For disassembly, simply rotate the handle to unscrew the nut from the bushing and pull out the valve stem, making valve stem removal much easier. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a three-dimensional view of the structure of a low-leakage structure for a fully welded fixed ball valve stem, after partial cross-section.

[0016] Figure 2 This is a three-dimensional structural diagram of the bushing.

[0017] Figure 3 This is a three-dimensional view of the nut section after it has been cut open.

[0018] Figure 4 This is a three-dimensional structural diagram of the lifting piston.

[0019] Figure 5 This is a three-dimensional structural diagram of the valve stem.

[0020] Figure 6 This is a three-dimensional view of the structure after the elastic sleeve is cut open.

[0021] Figure 7 This is a three-dimensional view of the assembly structure of a low-leakage structure for a fully welded fixed ball valve stem.

[0022] Figure label:

[0023] 1. Bushing; 101. Valve body; 102. Limiting ring; 103. Support ring; 2. Nut; 201. Movable hole; 202. Handle; 3. Lifting piston; 301. Outer sealing sleeve; 302. Inner sealing ring; 303. Support rod; 304. Push plate; 4. Valve stem; 401. Pin block; 402. Pressure plate; 403. Mounting block; 5. Elastic sleeve; 501. Rubber filler plate. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model. Specific Implementation Example 1

[0026] Please see Figure 1-5 This utility model discloses a low-leakage structure for a fully welded fixed ball valve stem, comprising a bushing 1, a nut 2, a lifting piston 3, a valve stem 4, and an elastic sleeve 5. A support ring 103 is fixed to the lower part of the bushing 1, connecting the valve stem 4 within the bushing 1. The support ring 103 provides support for the lifting piston 3 and the outer sealing sleeve 301 within the bushing 1. The lifting piston 3 is positioned at the top of the support ring 103. When subjected to pressure from the pressure released within the ball valve, the lifting piston 3 pushes upward, generating compressive pressure. Support rods 303 are fixed in a circular array at the top of the lifting piston 3, supporting a pusher disc 304 on the lifting piston 3. The pusher disc 304 is fixed to the top of all the support rods 303. 04. Under the push of the lifting piston 3, the push plate 304 squeezes the elastic sleeve 5. The top of the bushing 1 is threaded with a nut 2, which closes the top of the bushing 1. The valve stem 4 is movably connected inside the nut 2. When the valve stem 4 rotates, it drives the valve body 101 to open and close. The valve stem 4 passes vertically through the support ring 103. The upper part of the circumference of the valve stem 4 is fixed with a pressure plate 402, and the pressure plate 402 abuts against the top of the nut 2, restricting the position between the valve stem 4 and the bushing 1. The elastic sleeve 5 is movably connected inside the bushing 1 between the pressure plate 402 and the push plate 304. After being pressed, the elastic sleeve 5 squeezes the inner wall of the bushing 1 and the circumference of the valve stem 4, fully sealing the bushing 1 and the valve stem 4.

[0027] Specifically, the bottom end of the bushing 1 is fixedly connected to the valve body 101, the upper part of the bushing 1 is fixedly fixed with a limit ring 102, and the bottom end of the nut 2 abuts against the limit ring 102. The two ends of the valve body 101 are fixedly connected to the pipeline for conveying fluid to control the flow of fluid. The bushing 1 above the limit ring 102 is threaded. After the nut 2 is screwed onto the bushing 1, the position of the threaded connection is restricted by the limit ring 102.

[0028] Furthermore, the nut 2 is fixed with handles 202 in a ring array around its periphery, and a movable hole 201 is provided at the center of the top of the nut 2. The valve stem 4 passes through the movable hole 201 and extends out of the top of the nut 2. The handles 202 on the nut 2 provide a rotating gripping function, and the nut 2 is movably connected to the valve stem 4 through the movable hole 201.

[0029] Furthermore, a pin block 401 is fixed at the bottom of the valve stem 4, and an mounting block 403 is fixed at the top of the valve stem 4. The pin block 401 at the bottom of the valve stem 4 is movably connected to the pin port on the valve core inside the valve body 101. The mounting block 403 is installed on the handle of the ball valve. Turning the handle will drive the valve stem 4 to rotate.

[0030] The operation process of this embodiment is as follows: When it is necessary to install the valve stem 4, directly rotate the handle 202 on the outside of the nut 2 to unscrew the nut 2 from the top of the bushing 1. Then, first send the mounting block 403 on the valve stem 4 into the top of the bushing 1. Then, the valve stem 4 passes through the elastic sleeve 5 and enters the push plate 304. Then, it passes through the inner sealing ring 302 in the lifting piston 3 and finally extends into the valve body 101. The pin block 401 is movably connected to the valve core in the valve body 101. After completion, the open end of the nut 2 can be facing the top of the bushing 1. Pass the valve stem 4 through the outer sealing sleeve 301 on the nut 2. Then, rotate the handle to drive the nut 2 to rotate and screw onto the bushing 1. After it abuts against the limiting ring 102, the installation of the valve stem 4 is completed. When disassembling, directly rotate the handle to unscrew the nut 2 from the bushing 1 and pull out the valve stem 4 to complete the disassembly of the valve stem 4. Specific Implementation Example 2

[0032] Please see Figure 1-7 Based on the first specific embodiment, an outer sealing sleeve 301 is fixed to the periphery of the lifting piston 3. The bottom end of the outer sealing sleeve 301 is supported on the support ring 103, and the outer sealing sleeve 301 is movably connected inside the bushing 1. An inner sealing ring 302 is fixed to the inner ring of the lifting piston 3. The inner sealing ring 302 is movably connected to the periphery of the valve stem 4. The outer sealing sleeve 301 on the lifting piston 3 is supported on the support ring 103 inside the bushing 1. During operation, this ensures that the gap between the bushing 1 and the valve stem 4 is fully sealed.

[0033] Specifically, the elastic sleeve 5 is hollow inside and is filled with a rubber filling disc 501. The elastic sleeve 5 is movably connected to the periphery of the valve stem 4. When the elastic sleeve 5 is compressed, the rubber filling disc 501 inside presses against the bushing 1 and the valve stem 4.

[0034] The operation process of this embodiment is as follows: During operation, when the valve stem 4 enters the bushing 1, and during the process of screwing the nut 2 onto the bushing 1, it presses against the pressure plate 402 on the valve stem 4, and then presses down the pressure plate 402 until the pressure plate 402 presses against the elastic sleeve 5, squeezing the rubber filling plate 501 inside the elastic sleeve 5, so that the elastic sleeve 5 and the rubber filling plate 501 are squeezed and pressed against the periphery of the bushing 1 and the valve stem 4, sealing the gap between the bushing 1 and the valve stem 4. After the fluid pressure inside the valve body 101 is transmitted to the bushing 1, it pushes the lifting piston 3, and the lifting piston 3 pushes the support rod 303. The support rod 303 pushes the push plate 304, increasing the pressure of the push plate 304 on the elastic sleeve 5 and the rubber filling plate 501, and increasing the sealing effect of the elastic sleeve 5 between the bushing 1 and the valve stem 4.

[0035] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0036] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A low-leakage structure for a fully welded fixed ball valve stem, comprising a bushing (1), a nut (2), a lifting piston (3), a valve stem (4), and an elastic sleeve (5), characterized in that: A support ring (103) is fixed in the lower part of the bushing (1). A lifting piston (3) is provided at the top of the support ring (103). A support rod (303) is fixed in a ring array at the top of the lifting piston (3). A push plate (304) is fixed at the top of all the support rods (303). A nut (2) is threaded to the top of the bushing (1). A valve stem (4) is movably connected through the nut (2). The valve stem (4) passes vertically through the support ring (103). A pressure plate (402) is fixed to the upper part of the circumference of the valve stem (4). The pressure plate (402) abuts against the top of the nut (2). An elastic sleeve (5) is movably connected in the bushing (1) between the pressure plate (402) and the push plate (304).

2. The low-leakage structure of a fully welded fixed ball valve stem according to claim 1, characterized in that: The bottom end of the bushing (1) is fixedly connected to the valve body (101), and a limit ring (102) is fixed on the upper part of the circumference of the bushing (1), and the bottom end of the nut (2) abuts against the limit ring (102).

3. The low-leakage structure of a fully welded fixed ball valve stem according to claim 1, characterized in that: The nut (2) has a handle (202) fixed in a ring array around its periphery. The nut (2) has a movable hole (201) in the center of its top end. The valve stem (4) passes through the movable hole (201) and extends out of the top end of the nut (2).

4. The low-leakage structure of a fully welded fixed ball valve stem according to claim 1, characterized in that: An outer sealing sleeve (301) is fixed on the periphery of the lifting piston (3). The bottom end of the outer sealing sleeve (301) is supported on the support ring (103), and the outer sealing sleeve (301) is movably connected inside the bushing (1). An inner sealing ring (302) is fixed on the inner ring of the lifting piston (3), and the inner sealing ring (302) is movably connected to the periphery of the valve stem (4).

5. The low-leakage structure of a fully welded fixed ball valve stem according to claim 1, characterized in that: A pin block (401) is fixed at the bottom end of the valve stem (4), and an mounting block (403) is fixed at the top end of the valve stem (4).

6. The low-leakage structure of a fully welded fixed ball valve stem according to claim 1, characterized in that: The elastic sleeve (5) is hollow inside and is filled with a rubber filling disc (501). The elastic sleeve (5) is movably connected to the periphery of the valve stem (4).

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