Valve stem protection device

Abstract

This utility model belongs to the field of valve protection technology and discloses a valve stem protection device, including a sleeve, a top cover, and a positioning plate. The sleeve is made of transparent material and has an axially penetrating receiving cavity inside. The inner wall of the receiving cavity has an axially extending limiting groove. The bottom end of the sleeve has a first external thread, which is screwed into the thread groove of a handwheel. The valve stem extends vertically into the receiving cavity. The outer wall of the sleeve opposite to the limiting groove has a scale line for measuring the valve stem displacement. The top side wall of the sleeve has a breather hole communicating with the receiving cavity. The top cover is detachably connected to the sleeve for opening or closing the receiving cavity. The positioning plate is located in the receiving cavity and has a slider that slides with the limiting groove, with the slider pointing vertically to the scale line. The valve stem is located below the positioning plate and is rotatably connected to the positioning plate. By rotating the handwheel, the valve stem can drive the positioning plate to slide axially along the sleeve. This utility model can protect the valve stem from environmental corrosion and has accurate opening indication.

Description

Technical Field

[0001] This utility model relates to the field of valve protection technology, and in particular to a valve stem protection device. Background Technology

[0002] In oil and gas field development operations, the manifold system, as a key unit for fluid transport and control, primarily relies on gate valves for fluid shut-off. For applications with relatively ample space, rising stem gate valves are a common choice due to their structural characteristics. The core component of this type of valve is the gate, whose movement trajectory is perpendicular to the fluid flow direction. A handwheel drives the valve stem nut to rotate, utilizing a threaded transmission mechanism to move the valve stem axially forward and backward, thereby controlling the raising and lowering of the associated gate and ultimately achieving the valve's opening and closing function.

[0003] However, when a rising stem gate valve is opened, its stem is directly exposed to the air. Due to limitations in conditions, most oil and gas stations are located outdoors, making them susceptible to wind, sand, and rain. The exposed grease on the valve stem easily deteriorates and corrodes, causing valve jamming and inconvenience. This is especially true for valves on large-diameter, high-pressure pipelines; once the valve stem threads corrode, the operation becomes significantly more difficult, making opening and closing challenging and shortening equipment lifespan. Furthermore, the valve stem threads are part of the valve's transmission and operating mechanism and cannot be protected against corrosion by painting. While applying grease to the stem can slow corrosion, the grease container can detach and pollute the surrounding environment. The exposed stem is also vulnerable to external damage such as impacts. Moreover, rising stem gate valves lack precise opening indication during operation; operators can only roughly estimate the valve opening by observing changes in the length of the exposed stem, making accurate flow control difficult.

[0004] Therefore, there is an urgent need to propose a valve stem protection device to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a valve stem protection device that can solve the problems of existing rising stem gate valves where the valve stem is easily corroded by the environment and lacks accurate opening indication during operation.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A valve stem protection device is used to protect the valve stem of a rising stem gate valve. The valve stem passes through the valve cover and has a trapezoidal thread. A handwheel is fixed above the valve cover by a bearing and engages with the trapezoidal thread of the valve stem. The top of the handwheel has a threaded groove. The valve stem protection device includes:

[0008] The sleeve is made of transparent material and has an axially extending receiving cavity inside. The inner wall of the receiving cavity has an axially extending limiting groove. The bottom end of the sleeve has a first external thread and is screwed into the thread groove of the handwheel through the first external thread. The valve stem extends vertically into the receiving cavity. The outer wall of the sleeve has a scale line for measuring the displacement of the valve stem on the side opposite to the limiting groove. The top side wall of the sleeve has a vent hole that communicates with the receiving cavity.

[0009] A top cover, detachably connected to the sleeve, is used to open or close the receiving cavity;

[0010] A positioning plate is located inside the receiving cavity and is provided with a slider that slides in conjunction with the limiting groove. The slider points vertically to the scale line. The valve stem is located below the positioning plate and is rotatably connected to the positioning plate. By rotating the handwheel, the valve stem can drive the positioning plate to slide along the sleeve axis.

[0011] Preferably, the positioning plate includes a circular base and at least two sliders. The sliders are evenly spaced around the edge of the circular base. At least two limiting grooves are provided on the inner wall of the sleeve. The sliders and the limiting grooves are slidably engaged in a one-to-one correspondence, and one of the sliders points to the scale line.

[0012] Preferably, the valve stem protection device further includes a positioning bolt, the valve stem has a smooth section at the top, the positioning plate has an adapter hole that is clearance-fitted with the smooth section, the valve stem has a threaded hole on the top surface, and the positioning bolt is screwed into the threaded hole and abuts against the top surface of the positioning plate.

[0013] Preferably, the bottom of the sleeve is provided with a drain port that communicates with the receiving cavity.

[0014] Preferably, the top cover includes a cover body and a connecting part connected to each other. The cover body is used to close the opening at the top of the sleeve, the connecting part is provided with an internal thread, and the outer wall of the top of the sleeve is provided with a second external thread that matches the internal thread.

[0015] Preferably, the outer surface of the top cover is provided with a sealing groove, and a rubber sealing strip is embedded in the sealing groove. When the top cover is closed on the sleeve, the rubber sealing strip is deformed by pressure and forms an interference seal with the inner wall of the receiving cavity.

[0016] Preferably, the breathing hole is provided with a breathable membrane, the pore size of which is 0.2-5 micrometers.

[0017] Preferably, the bottom end face of the sleeve is provided with an annular sealing gasket, which is pressed against the bottom surface of the threaded groove when the sleeve is tightened.

[0018] Preferably, the scale lines include main scale lines and sub-scale lines, the main scale lines and the sub-scale lines are arranged alternately at equal intervals of 5mm in the vertical direction, and the main scale lines and the sub-scale lines are set with different colors.

[0019] Preferably, the sleeve is made of transparent acrylic material.

[0020] The beneficial effects of this utility model are:

[0021] This invention provides a valve stem protection device. A sleeve, sealed to the handwheel's threaded groove via a first external thread, encloses the valve stem within a cavity, effectively isolating it from external environmental factors such as wind, sand, and rain. This prevents the grease on the valve stem from deteriorating, avoids corrosion, reduces valve jamming, extends valve life, minimizes operational difficulties caused by valve stem corrosion, and improves production efficiency. When the handwheel is turned to drive the valve stem axially, the rotatable connection between the valve stem and the positioning plate prevents torque interference to the positioning plate caused by the valve stem's rotation during lifting. Simultaneously, the slider on the positioning plate and the limiting groove on the inner wall of the sleeve cooperate to form a stable guiding structure. When the valve stem moves the positioning plate, the limiting groove's constraint on the slider further restricts the positioning plate's movement trajectory, ensuring it can only move along the axial direction of the sleeve, effectively preventing tilting or offset during movement. Furthermore, since the slider points to the scale line, the operator can accurately obtain the valve stem's displacement by observing the relative position of the slider and the scale line, avoiding parallax caused by viewing angle deviations. In addition, the breather hole can maintain the pressure balance within the containment chamber, ensuring the normal operation of the device; the removable top cover facilitates the maintenance and lubrication of the valve stem, making operation convenient and improving the ease of equipment maintenance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the valve stem protection device described in an embodiment of the present invention;

[0023] Figure 2 This is a cross-sectional view of the sleeve and top cover described in an embodiment of the present utility model;

[0024] Figure 3 This is a schematic diagram of the positioning plate described in an embodiment of the present utility model;

[0025] Figure 4 This is a schematic diagram of the valve stem and positioning bolt described in an embodiment of this utility model.

[0026] In the picture:

[0027] 1. Sleeve; 10. Receiving cavity; 11. Breathing hole; 12. Scale line; 13. Limiting groove; 14. Drain outlet;

[0028] 2. Top cover; 21. Cover body; 22. Connecting part;

[0029] 3. Positioning plate; 30. Adapter hole; 31. Slider; 32. Circular base;

[0030] 4. Positioning bolts;

[0031] 5. Annular sealing gasket;

[0032] 100. Valve stem; 101. Threaded hole;

[0033] 200. Handwheel. Detailed Implementation

[0034] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar parts or parts having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0035] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] In the description of this utility model, unless otherwise expressly specified and limited, "above" or "below" the first feature can include the feature and the first feature being in direct contact, or it can include the feature and the first feature not being in direct contact but being in contact through another feature between them. Furthermore, "above," "over," and "on top" of the first feature includes the feature being directly above or diagonally above the first feature, or simply indicates that the feature is at a higher horizontal level than the first feature. "Below," "below," and "under" the first feature includes the feature being directly below or diagonally below the first feature, or simply indicates that the feature is at a lower horizontal level than the first feature.

[0037] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0038] like Figures 1-3As shown, this utility model provides a valve stem protection device for protecting the valve stem 100 of a rising stem gate valve. The lower section of the valve stem 100 passes through the valve cover and is provided with a trapezoidal thread. The handwheel 200 is fixed above the valve cover by a bearing and engages with the trapezoidal thread of the valve stem 100. The top of the handwheel 200 is provided with a threaded groove. The valve stem protection device includes a sleeve 1, a top cover 2, and a positioning plate 3. The sleeve 1 is made of transparent material and has an axially extending receiving cavity 10 inside. The inner wall of the receiving cavity 10 has an axially extending limiting groove 13. The bottom end of the sleeve 1 has a first external thread and is screwed into the threaded groove of the handwheel 200 through the first external thread. The valve stem 100 extends vertically into the receiving cavity 10. The outer wall of the sleeve 1 has a scale line 12 for measuring the displacement of the valve stem 100 on the side opposite to the limiting groove 13. The top side wall of the sleeve 1 has a breather hole 11 communicating with the receiving cavity 10. The top cover 2 is detachably connected to the sleeve 1 and is used to open or close the receiving cavity 10. The positioning plate 3 is located in the receiving cavity 10 and has a slider 31 that slides with the limiting groove 13. The slider 31 points vertically to the scale line 12. The valve stem 100 is located below the positioning plate 3 and is rotatably connected to the positioning plate 3. By rotating the handwheel 200, the valve stem 100 can drive the positioning plate 3 to slide axially along the sleeve 1.

[0039] The sleeve 1 is sealed within the receiving cavity 10 by the threaded groove of the handwheel 200 via the first external thread, effectively isolating the valve stem 100 from external environmental factors such as wind, sand, and rain, preventing the grease on the valve stem 100 from deteriorating, avoiding corrosion of the valve stem 100, reducing valve opening and closing jamming, extending valve service life, reducing operational difficulties caused by valve stem 100 corrosion, and improving production efficiency. When the handwheel 200 is turned to drive the valve stem 100 to move axially, the valve stem 100 is rotatably connected to the positioning plate 3, thus avoiding torque interference to the positioning plate 3 caused by the valve stem 100's own rotation during lifting and lowering. At the same time, the slider 31 on the positioning plate 3 cooperates with the limiting groove 13 on the inner wall of the sleeve 1 to form a stable guiding structure. When the valve stem 100 drives the positioning plate 3 to move, the constraint effect of the limiting groove 13 on the slider 31 further restricts the movement trajectory of the positioning plate 3, allowing it to move only along the axial direction of the sleeve 1, effectively preventing the positioning plate 3 from tilting or shifting during movement. Furthermore, since the slider 31 points to the scale line 12, the operator can accurately obtain the displacement of the valve stem 100 by observing the relative position of the slider 31 and the scale line 12, avoiding parallax caused by viewing angle deviation. In addition, the breather hole 11 can maintain the pressure balance in the receiving cavity 10, ensuring the normal operation of the device; the removable top cover 2 facilitates the maintenance and lubrication of the valve stem 100, making operation convenient and improving the convenience of equipment maintenance.

[0040] Specifically, sleeve 1 is made of transparent acrylic material. This material has a high tensile strength of 70-80MPa, a light transmittance of over 92%, and a haze of less than 1%, ensuring clear and accurate observation of valve stem 100 displacement; its operating temperature range is -40℃ to 90℃, and it has excellent UV resistance and chemical resistance, making it adaptable to various harsh environments; at the same time, the material is lightweight and has no risk of breakage, greatly improving the safety and convenience of installation and maintenance.

[0041] Specifically, the wall thickness of sleeve 1 is 6-9mm. This ensures sufficient structural strength while maintaining good light transmission.

[0042] Specifically, a breathable membrane is provided at the breathing hole 11, and the pore size of the breathable membrane is 0.2-5 micrometers. The microporous structure of the breathable membrane has selective permeability characteristics, allowing only gas molecules to pass through while effectively blocking liquid water and solid particles. While maintaining the air pressure balance inside and outside the containment cavity 10, it prevents external moisture and particles from entering the containment cavity 10.

[0043] In this embodiment, the breathable membrane is made of corrosion-resistant polytetrafluoroethylene material, which can work stably for a long time in a temperature range of -40℃ to 150℃.

[0044] Specifically, such as Figure 1 As shown, scale line 12 includes main scale lines and sub-scale lines. The main scale lines and sub-scale lines are arranged alternately at 5mm intervals along the vertical direction, and the main scale lines and sub-scale lines are set with different colors. The main scale lines and sub-scale lines use different colors and are arranged alternately at fixed intervals to form a clear visual contrast, allowing operators to quickly distinguish scale markings of different precision. When the positioning plate 3 moves to the 80mm position of scale line 12, it indicates that the current valve opening is 80%.

[0045] In this embodiment, the main scale line is red, and the secondary scale line is black. The red and black color scheme creates a strong visual contrast, making it easy for operators to quickly and accurately determine the valve opening in complex working conditions. The ergonomic color scheme ensures that key scale points are clearly indicated in emergency situations, while also meeting the requirements for scale clarity during daily fine adjustments.

[0046] Specifically, such as Figure 1 As shown, the bottom of the sleeve 1 is provided with a drain port 14 that communicates with the receiving cavity 10. When a small amount of water enters the receiving cavity 10 through the breather hole 11, the drain port 14 can drain the water in time, preventing the valve stem 100 from rusting due to long-term water retention.

[0047] Specifically, such as Figure 2As shown, an annular sealing gasket 5 is provided on the bottom end face of the sleeve 1. When the sleeve 1 is tightened, the annular sealing gasket 5 is pressed against the bottom surface of the threaded groove. By providing an annular sealing gasket at the bottom of the sleeve 1, a reliable sealing interface is formed between the sleeve 1 and the handwheel 200, effectively preventing external dust, moisture and other contaminants from entering the sleeve and protecting the valve stem 100 from corrosion.

[0048] Optionally, the top cover 2 includes a cover body portion 21 and a connecting portion 22 connected together. The cover body portion 21 is used to close the opening at the top of the sleeve 1, and the connecting portion 22 is provided with an internal thread. The outer wall at the top of the sleeve 1 is provided with a second external thread that matches the internal thread. The threaded engagement provides a reliable mechanical connection, ensuring that the top cover 2 remains stable under vibration conditions. The precise threaded pair design makes disassembly and maintenance operations more convenient, and the sealing effect can be optimized by adjusting the tightening force.

[0049] Optionally, the outer surface of the top cover 2 is provided with a sealing groove, and a rubber sealing strip is embedded in the sealing groove. When the top cover 2 is closed on the sleeve 1, the rubber sealing strip is deformed under pressure, forming an interference fit with the inner wall of the receiving cavity 10. The radial pressure formed by the interference fit ensures a reliable seal in the entire circumference, effectively preventing external dust, moisture and other contaminants from entering the receiving cavity 10; secondly, the elastic properties of the rubber material can adaptively compensate for the machining errors of the parts and the deformation due to thermal expansion and contraction, maintaining long-term stable sealing performance.

[0050] Specifically, such as Figure 3 As shown, the positioning plate 3 includes a circular base 32 and at least two sliders 31. The sliders 31 are evenly spaced around the edge of the circular base 32. At least two limiting grooves 13 are provided on the inner wall of the sleeve 1. The sliders 31 slide in a one-to-one correspondence with the limiting grooves 13, and one of the sliders 31 points to the scale line 12. The evenly distributed guiding constraint force further ensures that the positioning plate 3 always moves in parallel, thereby ensuring accurate and reliable readings.

[0051] Specifically, such as Figure 3 and Figure 4 As shown, the valve stem protection device also includes a positioning bolt 4. The valve stem 100 has a smooth section at its top, and the positioning plate 3 has a transition hole 30 that is clearance-fitted with the smooth section. The valve stem 100 has a threaded hole 101 on its top surface. The positioning bolt 4 is screwed into the threaded hole 101 and abuts against the top surface of the positioning plate 3. The smooth section of the valve stem 100 and the transition hole 30 of the positioning plate 3 are clearance-fitted, ensuring that the valve stem 100 does not cause the positioning plate 3 to rotate during rotation, thus preventing torsional friction from affecting the linear movement of the slider 31 within the limiting groove. The positioning bolt 4 is screwed into the threaded hole 101 at the top of the valve stem 100 and abuts against the positioning plate 3, ensuring that the valve stem 100 can stably drive the positioning plate 3 to move synchronously downwards during descent, without causing relative displacement between the positioning plate 3 and the valve stem 100 due to vibration or external interference.

[0052] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A valve stem protection device for protecting the valve stem (100) of a rising stem gate valve, wherein the valve stem (100) passes through a valve cover and is provided with a trapezoidal thread, and a handwheel (200) is fixed above the valve cover by a bearing and engages with the trapezoidal thread of the valve stem (100), wherein the top of the handwheel (200) is provided with a threaded groove, characterized in that, The valve stem protection device includes: The sleeve (1) is made of transparent material and has an axially penetrating receiving cavity (10) inside. The inner wall of the receiving cavity (10) is provided with an axially extending limiting groove (13). The bottom end of the sleeve (1) is provided with a first external thread and is screwed to the thread groove of the handwheel (200) through the first external thread. The valve stem (100) extends vertically into the receiving cavity (10). The outer wall of the sleeve (1) is provided with a scale line (12) for measuring the displacement of the valve stem (100) on the side opposite to the limiting groove (13). The top side wall of the sleeve (1) is provided with a breathing hole (11) communicating with the receiving cavity (10). Top cover (2), detachably connected to the sleeve (1), for opening or closing the receiving cavity (10); The positioning plate (3) is located in the receiving cavity (10) and is provided with a slider (31) that slides in cooperation with the limiting groove (13). The slider (31) points vertically to the scale line (12). The valve stem (100) is located below the positioning plate (3) and is rotatably connected to the positioning plate (3). By rotating the handwheel (200), the valve stem (100) can drive the positioning plate (3) to slide along the sleeve (1) axially.

2. The valve stem protection device according to claim 1, characterized in that, The positioning plate (3) includes a circular base (32) and at least two sliders (31). The sliders (31) are evenly spaced around the edge of the circular base (32). At least two limiting grooves (13) are provided on the inner wall of the sleeve (1). The sliders (31) and the limiting grooves (13) are slidably engaged in a one-to-one correspondence. One of the sliders (31) points to the scale line (12).

3. The valve stem protection device according to claim 1, characterized in that, The valve stem protection device also includes a positioning bolt (4), the valve stem (100) has a smooth section at the top, the positioning plate (3) has a transition hole (30) that is clearance-fitted with the smooth section, the valve stem (100) has a threaded hole (101) on the top surface, and the positioning bolt (4) is screwed into the threaded hole (101) and abuts against the top surface of the positioning plate (3).

4. The valve stem protection device according to claim 1, characterized in that, The bottom of the sleeve (1) is provided with a drain outlet (14) that communicates with the receiving cavity (10).

5. The valve stem protection device according to claim 1, characterized in that, The top cover (2) includes a cover body (21) and a connecting part (22) connected to each other. The cover body (21) is used to close the top opening of the sleeve (1). The connecting part (22) is provided with an internal thread. The outer wall of the top of the sleeve (1) is provided with a second external thread that matches the internal thread.

6. The valve stem protection device according to claim 1, characterized in that, The outer surface of the top cover (2) is provided with a sealing groove, and a rubber sealing strip is embedded in the sealing groove. When the top cover (2) is closed on the sleeve (1), the rubber sealing strip is deformed by pressure and forms an interference seal with the inner wall of the receiving cavity (10).

7. The valve stem protection device according to claim 1, characterized in that, A breathable membrane is provided at the breathing hole (11), and the pore size of the breathable membrane is 0.2-5 micrometers.

8. The valve stem protection device according to claim 1, characterized in that, The bottom end face of the sleeve (1) is provided with an annular sealing gasket (5). When the sleeve (1) is tightened, the annular sealing gasket (5) is pressed against the bottom surface of the threaded groove.

9. The valve stem protection device according to claim 1, characterized in that, The scale line (12) includes a main scale line and a secondary scale line. The main scale line and the secondary scale line are arranged alternately at equal intervals of 5mm in the vertical direction, and the main scale line and the secondary scale line are set with different colors.

10. The valve stem protection device according to any one of claims 1-9, characterized in that, The sleeve (1) is made of transparent acrylic material.

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