Small-bore cryogenic stop valve

Abstract

The utility model discloses a kind of small-bore cryogenic stop valve, it is related to valve technical field, including valve body and the bonnet connected on valve body, the inside of the bonnet is threadedly connected with valve stem, the inside fixed connection of the valve body has valve seat, the present application is cooperated by inserting rod and torsion spring and extension handle, it has played the effect of extending hand wheel lever arm, more labor-saving effect when rotating valve stem, the problem that the force required when personnel operate valve can increase due to the friction coefficient of material increases under low temperature when cryogenic stop valve is used is solved, it is favorable for personnel to conveniently open and close cryogenic stop valve, the present application is cooperated triangular sealing strip and semicircular sealing strip by sealing cone platform and triangular groove and semicircular groove, form multiple sealing measures, increase the contact area and complexity of sealing, to improve sealing performance, the problem that metal can shrink under low temperature state and affect sealing effect of cryogenic stop valve is solved, it is favorable for improving the sealing performance of cryogenic stop valve.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically to a small-diameter cryogenic shut-off valve. Background Technology

[0002] A cryogenic shut-off valve is a valve in which the valve disc, the closing element, moves along the center line of the valve seat. According to this movement of the valve disc, the change in the valve seat opening is directly proportional to the valve disc stroke. Because the valve stem of this type of valve has a relatively short opening or closing stroke and has a very reliable shut-off function, and because the change in the valve seat opening is directly proportional to the valve disc stroke, it is very suitable for regulating flow.

[0003] 1. Due to the increased friction coefficient of materials at low temperatures and the change in the fitting precision between valve components, the torque required to operate the valve may increase, making manual operation of the valve difficult and possibly exceeding the operator's capabilities, resulting in inconvenience for personnel when opening and closing low-temperature shut-off valves;

[0004] 2. Because cryogenic shut-off valves need to be in a low-temperature state to transport liquids during use, and the metal of the cryogenic shut-off valve will shrink at low temperatures, affecting the sealing effect, resulting in poor sealing performance of the cryogenic shut-off valve.

[0005] 3. Because the sudden pressure change in the valve body when the cryogenic shut-off valve is closed can cause liquid backflow, the backflow will cause the liquid flow through the valve to be inconsistent with the expected value, and the backflow liquid will also impact the sealing surface of the valve disc and valve seat, which will accelerate the wear of the sealing surface and reduce the sealing performance. At present, there are no measures to prevent liquid backflow when the cryogenic shut-off valve is used, resulting in poor practical performance of the cryogenic shut-off valve. Utility Model Content

[0006] To address the above problems, this utility model provides a small-diameter cryogenic shut-off valve, which solves the aforementioned issues.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a small-diameter cryogenic shut-off valve, comprising a valve body and a valve cover connected to the valve body, wherein a valve stem is internally threaded to the valve cover, a valve seat is fixedly connected to the inside of the valve body, a sealing ring is fixedly connected to the inside of the valve seat, and a triangular sealing strip and a semi-circular sealing strip are provided on the outside of the sealing ring.

[0008] The valve stem is provided with a valve disc on the outside, and a circular groove is provided inside the valve disc. The valve disc has a sealing cone, and a triangular groove and a semi-circular groove are provided on the outside of the sealing cone. A flow cylinder is fixedly connected to the bottom of the sealing cone, and a number of flow holes are provided on the outer wall of the flow cylinder.

[0009] A handwheel is fixedly connected to the top of the valve stem. A groove is provided on the circular edge of the handwheel. A fixed shaft is connected inside the groove. A torsion spring is provided outside the fixed shaft. An extended handle is provided outside the fixed shaft.

[0010] Preferably, a protective shell is fixedly connected to the top of the handwheel, an adjustment plate is provided inside the protective shell, an adjustment handle is connected to the top of the adjustment plate, and the outside of the adjustment handle penetrates through the top of the protective shell.

[0011] Preferably, the bottom of the adjustment plate is fixedly connected to two insert rods, the outside of which penetrates the bottom of the protective shell and the top of the groove.

[0012] Preferably, the insert rod is inserted into the interior of the extension grip, and the insert rod positions the extension grip.

[0013] Preferably, the lower end of the valve stem is provided with an adjusting cylinder, which is disposed inside the circular groove.

[0014] Preferably, the triangular sealing strip and the semi-circular sealing strip are respectively disposed inside the triangular groove and the semi-circular groove.

[0015] Preferably, a packing shell is connected to the top of the valve cover, and the outside of the valve stem is disposed inside the packing shell.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] 1. This application uses a torsion spring to rotate an extended handle out of the handwheel, which extends the lever arm of the handwheel and makes it easier to rotate the valve stem. This solves the problem that the force required to operate the low-temperature shut-off valve increases due to the increased friction coefficient of the material at low temperatures, making it easier for personnel to open and close the low-temperature shut-off valve.

[0018] 2. This application uses a sealing cone, triangular groove and semi-circular groove in conjunction with triangular sealing strip and semi-circular sealing strip to form multiple sealing measures between the sealing surfaces, increasing the sealing contact area and complexity, solving the problem that the metal of the low-temperature shut-off valve will shrink at low temperature and affect the sealing effect, which is beneficial to improving the sealing performance of the low-temperature shut-off valve.

[0019] 3. This application sets the space of the circular groove to be larger than that of the adjusting cylinder to reduce the friction of the valve stem rotation. At the same time, the circular groove can also be used to prevent liquid backflow. Furthermore, the flow cylinder will drive the valve disc to descend quickly and close the valve seat to prevent liquid backflow. This solves the problem that current cryogenic shut-off valves do not have measures to prevent liquid backflow during use, which is beneficial to improving the practical performance of cryogenic shut-off valves. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a schematic cross-sectional view of the overall structure of this utility model;

[0022] Figure 3 This is a cross-sectional view of the valve body of this utility model;

[0023] Figure 4 This is a partial structural schematic diagram of the present invention;

[0024] Figure 5 This is a schematic diagram of the sealing ring structure of this utility model;

[0025] Figure 6 This is a schematic diagram of the handwheel structure of this utility model.

[0026] The diagram shows the following components: 1. Valve body; 2. Valve cover; 3. Packing housing; 4. Valve stem; 5. Adjusting cylinder; 6. Valve seat; 7. Sealing ring; 8. Triangular sealing strip; 9. Semi-circular sealing strip; 10. Triangular groove; 11. Semi-circular groove; 12. Sealing cone; 13. Valve disc; 14. Circular groove; 15. Flow cylinder; 16. Handwheel; 17. Fixed shaft; 18. Torsion spring; 19. Extended handle; 20. Protective shell; 21. Adjusting plate; 22. Adjusting handle; 23. Insert rod. Detailed Implementation

[0027] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0028] Please see Figures 1 to 6A small-diameter cryogenic shut-off valve includes a valve body 1 and a valve cover 2 connected to the valve body 1. A valve stem 4 is internally threaded onto the valve cover 2. A valve seat 6 is fixedly connected internally to the valve body 1. A sealing ring 7 is fixedly connected internally to the valve seat 6. The upper end face of the sealing ring 7 is also conical. The sealing ring 7 is provided with a triangular sealing strip 8 and a semi-circular sealing strip 9. The triangular sealing strip 8 and the semi-circular sealing strip 9 are made of silicone rubber. Silicone rubber has good low-temperature toughness and can maintain elasticity at low temperatures, adapting to the working environment of the small-diameter cryogenic shut-off valve and ensuring a sealing effect. When the cryogenic shut-off valve is closed, the valve disc 13... As the dynamic sealing cone 12 descends, its conical surface tightly fits against the conical surface of the sealing ring 7. Note that at this time, the triangular sealing strip 8 and the semi-circular sealing strip 9 on the sealing ring 7 will be squeezed and inserted into the triangular groove 10 and the semi-circular groove 11 of the sealing cone 12. In this way, the conical surface of the sealing cone 12 and the conical surface of the sealing ring 7 are tightly fitted. The triangular groove 10 and the semi-circular groove 11, along with the triangular sealing strip 8 and the semi-circular sealing strip 9, cooperate to form multiple sealing measures between the sealing surfaces, increasing the contact area and complexity of the seal, thereby improving the sealing performance and reducing the possibility of media leakage.

[0029] It should be further explained that a triangular groove 10 and a semi-circular groove 11 are chosen here instead of two grooves of the same shape because the semi-circular groove 11 has a large contact area with the silicone rubber, which allows the silicone rubber to deform evenly under stress and fully fill the gap; the triangular groove 10 has a wedge-shaped effect, which makes the compression of the silicone rubber stronger when the valve disc 13 is closed, and can generate a higher sealing specific pressure. The combination of the two can enhance the sealing effect from different angles. In addition, because the cryogenic shut-off valve is used in a low-temperature environment, the flow of the medium and pressure changes will affect the seal. The semi-circular groove 11 makes the silicone rubber deform smoothly, which is beneficial to cope with pressure fluctuations; the self-tightening characteristic of the triangular groove 10 can better prevent leakage when the pressure rises. Different groove shapes can adapt to various working conditions, and this combination can also extend the service life of the cryogenic shut-off valve.

[0030] A valve disc 13 is provided on the outside of the valve stem 4. A circular groove 14 is provided inside the valve disc 13. A sealing cone 12 is provided on the outside of the sealing cone 12. A triangular groove 10 and a semi-circular groove 11 are provided on the outside of the sealing cone 12. A flow cylinder 15 is fixedly connected to the bottom of the sealing cone 12. Several flow holes are provided on the outer wall of the flow cylinder 15. When the cryogenic shut-off valve is closed, the sudden change in pressure inside the valve body 1 will cause liquid backflow. When the valve stem 4 is rotated to close the cryogenic shut-off valve, the flow cylinder 15 will first enter the valve seat 6. The valve stem 4 will first drive the adjusting cylinder 5 to descend inside the circular groove 14. It should be noted that the circular groove 14 and the adjusting cylinder 5 will have a certain... With a certain amount of space, if backflow occurs at this time, it will force the valve disc 13 to descend. Because of the space between the circular groove 14 and the adjusting cylinder 5, the descent of the valve disc 13 is not affected by the valve stem 4. The valve disc 13 drives the sealing cone 12 to descend and fit tightly with the sealing ring 7 to seal and prevent liquid backflow. Then, the operator continues to rotate the valve stem 4 so that the bottom of the adjusting cylinder 5 fits tightly with the inner bottom of the circular groove 14, thereby completing the closure of the cryogenic shut-off valve. At the same time, it also prevents liquid backflow when closing the valve. When liquid backflows, it will enter the interior of the flow cylinder 15 and generate pressure to accelerate the descent of the valve disc 13.

[0031] By setting the space of the circular groove 14 to be larger than that of the adjusting cylinder 5, the rotational friction of the valve stem 4 can be reduced. At the same time, the circular groove 14 can also be used to prevent liquid backflow. Furthermore, the cooperation between the flow cylinder 15 and the flow hole can prevent backflow first when liquid backflow occurs. Then, the flow cylinder 15 will drive the valve disc 13 to descend rapidly and close with the valve seat 6 to prevent liquid backflow. This solves the problem that the current low-temperature shut-off valve does not have measures to prevent liquid backflow during use, which is conducive to improving the practical performance of the low-temperature shut-off valve.

[0032] A handwheel 16 is fixedly connected to the top of the valve stem 4. By rotating the handwheel 16, the valve stem 4 is driven to rotate. Because the valve stem 4 is threadedly connected to the valve cover 2, the valve stem 4 will rise and fall synchronously when rotating, thereby driving the adjusting cylinder 5 and the valve disc 13 to rise and fall, so as to open and close the low temperature shut-off valve. The handwheel 16 has a groove on its round edge. A fixed shaft 17 is connected inside the groove. A torsion spring 18 is provided outside the fixed shaft 17. An extension handle 19 is provided outside the fixed shaft 17.

[0033] A protective shell 20 is fixedly connected to the top of the handwheel 16. An adjusting plate 21 is provided inside the protective shell 20. An adjusting handle 22 is connected to the top of the adjusting plate 21. The outside of the adjusting handle 22 penetrates the top of the protective shell 20.

[0034] Two insert rods 23 are fixedly connected to the bottom of the adjusting plate 21. The outer surface of the insert rods 23 penetrates the bottom of the protective shell 20 and the top of the groove. When the handwheel 16 is not adjusted, the extension handle 19 is retracted and hidden in the groove on the rounded edge of the handwheel 16. At the same time, the adjusting plate 21 naturally descends due to gravity, causing the insert rods 23 to be inserted into the extension handle 19 for positioning and fixation, thereby reducing space occupation. When the handwheel 16 is used, the friction coefficient of the material increases due to the low temperature of the cryogenic shut-off valve, and the force required to turn the handwheel 16 will increase. Therefore, when the operator pulls the adjusting handle 22 upwards, the adjusting plate 21 causes the insert rod 23 to rise and separate from the extended handle 19. At this time, the extended handle 19, under the influence of the torsion spring 18, will rotate outwards from the fixed shaft 17. Then, the operator can use the extended handle 19 to extend the lever arm of the handwheel 16, making it easier to rotate the valve stem 4. This solves the problem that the friction coefficient of the material increases at low temperatures, which increases the force required for the operator to operate the valve, making it inconvenient to open and close the low-temperature shut-off valve. This makes it easier for the operator to open and close the low-temperature shut-off valve.

[0035] The insert 23 is internally inserted into the extension grip 19, and the insert 23 positions the extension grip 19.

[0036] The lower end of the valve stem 4 is provided with an adjusting cylinder 5, which is located inside the circular groove 14.

[0037] The triangular sealing strip 8 and the semi-circular sealing strip 9 are respectively disposed inside the triangular groove 10 and the semi-circular groove 11.

[0038] The top of the valve cover 2 is connected to the packing shell 3. The valve stem 4 is located inside the packing shell 3. The packing shell 3 is a specially designed structure on the valve body to accommodate the packing layer. It is usually located at the part where the valve stem passes through the valve body. The packing layer is axially compressed by components such as the packing gland, so that it forms a seal between the valve stem and the inner wall of the stuffing box. The packing shell 3 and the packing layer inside it are known technologies. Those skilled in the art can and should understand their specific functions and structures, so they will not be described in detail here.

[0039] Example 2: Example 2 is basically the same as Example 1. Example 2 is an optimization of Example 1. The similarities will not be repeated. The difference is that in Example 2, a spring can be set on the outside of the adjustment handle 22, so that the spring will squeeze the adjustment plate 21 until the insertion rod 23 is inserted into the inside of the extension handle 19. In this way, the insertion rod 23 can be kept in normal working position and fixed to the extension handle 19 regardless of the direction of the handwheel 16 of this application.

[0040] When using this utility model:

[0041] First, the operator rotates the handwheel 16, causing the valve stem 4 to rotate. Because the valve stem 4 is threadedly connected to the valve cover 2, the valve stem 4 will rise and fall synchronously when rotating, thereby driving the adjusting cylinder 5 and the valve disc 13 to rise and fall, thus opening and closing the cryogenic shut-off valve. When the cryogenic shut-off valve is closed, the valve disc 13 drives the sealing cone 12 to descend, so that the cone surface of the sealing cone 12 will fit tightly against the cone surface of the sealing ring 7. Note that at this time, the triangular sealing strip 8 and the semi-circular sealing strip 9 on the sealing ring 7 will squeeze and insert into the triangular groove 10 and the semi-circular groove 11 of the sealing cone 12. In this way, the cone surface of the sealing cone 12 and the cone surface of the sealing ring 7 fit tightly against each other. With the cooperation of the triangular groove 10 and the semi-circular groove 11 with the triangular sealing strip 8 and the semi-circular sealing strip 9, multiple sealing measures are formed between the sealing surfaces, increasing the contact area and complexity of the seal, thereby improving the sealing performance and reducing the possibility of media leakage.

[0042] Secondly, when the cryogenic shut-off valve is closed, the sudden pressure change inside the valve body 1 will cause liquid backflow. When the operator rotates the valve stem 4 to close the cryogenic shut-off valve, the flow cylinder 15 will first enter the interior of the valve seat 6. The valve stem 4 will first drive the adjusting cylinder 5 to descend inside the circular groove 14. It should be noted that the circular groove 14 and the adjusting cylinder 5 have a certain amount of space. If backflow occurs at this time, it will compress the valve disc 13 to descend. Because of the space between the circular groove 14 and the adjusting cylinder 5, the descent of the valve disc 13 is not affected by the valve stem 4. The valve disc 13 drives the sealing cone 12 to descend and fit tightly with the sealing ring 7 to seal and prevent liquid backflow. Then, the operator continues to rotate the valve stem 4 so that the bottom of the adjusting cylinder 5 fits tightly with the inner bottom of the circular groove 14, thereby completing the closure of the cryogenic shut-off valve. At the same time, it will also prevent liquid backflow when closing the valve. At the same time, when liquid backflow occurs, it will enter the interior of the flow cylinder 15 and generate pressure to accelerate the descent of the valve disc 13.

[0043] Finally, when the handwheel 16 is not adjusted, the extension handle 19 will be stored and hidden in the groove on the round edge of the handwheel 16. At the same time, the adjusting plate 21 will naturally descend under the influence of gravity, so that the insert rod 23 will be inserted into the extension handle 19 and positioned and fixed, thereby reducing the space occupied. When the operator uses the handwheel 16, because the friction coefficient of the material of the low temperature shut-off valve increases, the force required for the operator to turn the handwheel 16 will increase. Therefore, the operator pulls the adjusting handle 22 upward, so that the adjusting plate 21 drives the insert rod 23 to rise and separate from the extension handle 19. At this time, the extension handle 19 will be rotated out of the fixed shaft 17 under the influence of the torsion spring 18. Then the operator can use the extension handle 19 to extend the lever arm of the handwheel 16, making it easier to rotate the valve stem 4.

[0044] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A small-bore cryogenic stop valve, comprising a valve body (1) and a bonnet (2) connected to the valve body (1), an inner part of the bonnet (2) is threadedly connected with a valve stem (4), an inner part of the valve body (1) is fixedly connected with a valve seat (6), characterized in that: A sealing ring (7) is fixedly connected inside the valve seat (6), and a triangular sealing strip (8) and a semi-circular sealing strip (9) are provided on the outside of the sealing ring (7); The valve stem (4) is provided with a valve disc (13) on the outside. The valve disc (13) has a circular groove (14) inside. The valve disc (13) has a sealing cone (12). The sealing cone (12) has a triangular groove (10) and a semi-circular groove (11) on the outside. The bottom of the sealing cone (12) is fixedly connected to a flow cylinder (15). The outer wall of the flow cylinder (15) has several flow holes. A handwheel (16) is fixedly connected to the top of the valve stem (4). The handwheel (16) has a groove on its round edge. A fixed shaft (17) is connected inside the groove. A torsion spring (18) is provided outside the fixed shaft (17). An extension handle (19) is provided outside the fixed shaft (17).

2. The low temperature stop valve according to claim 1, characterized in that: The top of the handwheel (16) is fixedly connected to a protective shell (20). An adjustment plate (21) is provided inside the protective shell (20). An adjustment handle (22) is connected to the top of the adjustment plate (21). The outside of the adjustment handle (22) penetrates the top of the protective shell (20).

3. A low temperature stop valve according to claim 2, wherein: The bottom of the adjustment plate (21) is fixedly connected to two insert rods (23), and the outside of the insert rods (23) penetrates the bottom of the protective shell (20) and the top of the groove.

4. A low temperature stop valve according to claim 3, wherein: The insert (23) is inserted into the interior of the extension grip (19), and the insert (23) positions the extension grip (19).

5. The low temperature stop valve according to claim 1, wherein: The lower end of the valve stem (4) is provided with an adjusting cylinder (5), which is located inside the circular groove (14).

6. A cryogenic stop valve according to claim 1, characterized in that: The triangular sealing strip (8) and the semi-circular sealing strip (9) are respectively disposed inside the triangular groove (10) and the semi-circular groove (11).

7. A low temperature stop valve according to claim 1, wherein: The top of the valve cover (2) is connected to a packing shell (3), and the outside of the valve stem (4) is disposed inside the packing shell (3).

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