Low temperature emergency shut-off valve with easy maintenance

Abstract

The utility model discloses a low temperature emergency stop valve convenient to maintain, including the valve body, the both sides of valve body all are installed with the connecting end, be provided with the valve ball in the valve body, the top of valve ball is connected with the valve rod, the outer of valve rod is from below to above with the extension sleeve, independent packing gland, be equipped with the sealing ring between independent packing gland and extension sleeve, the top of independent packing gland is installed with the fireproof blocking mechanism, the top of fireproof blocking mechanism is installed with single -action pneumatic actuator, and single -action pneumatic actuator is installed with fusible plug and fusible plug protection cover, and fusible plug protection cover is located the outside of fusible plug, and the valve rod in independent packing gland is from below to above with valve rod seal, packing, packing gland, spring washer, gland nut, stop cap in proper order, and gland nut is connected with valve rod thread. The utility model discloses maintenance convenience promotion, and the higher sealed reliability is more superior in economy.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a low-temperature emergency shut-off valve that is easy to maintain. Background Technology

[0002] Emergency shut-off valves are critical safety devices in cryogenic transport and storage systems, used to quickly cut off fluid flow in emergencies such as leaks, fires, or abnormal pressure to prevent the accident from escalating. Cryogenic conditions place extremely high demands on the valve's sealing performance, material selection, and structural design.

[0003] To address the challenges of cryogenic conditions, existing cryogenic valves (including emergency shut-off valves) commonly employ an extended sleeve structure. This involves adding a slender, extended neck structure between the valve body and the top actuator, keeping the valve stem stuffing box away from the cryogenic valve body, reducing cold transfer, ensuring the extended neck flange operates at ambient temperature, and preventing cryogenic embrittlement. However, this traditional structure still has inherent drawbacks. The sealing component (stuffing box) between the top of the extended sleeve structure and the valve stem is usually machined integrally with the extended sleeve structure itself or is a non-separable, one-piece structure. This design introduces the following problems: 1. Incomplete cold energy isolation: Although there is some isolation, the cold energy of the cryogenic medium will still be conducted to some extent to the sealing area at the top through the valve stem and cylinder wall. For extremely low temperature or demanding operating conditions, this may still lead to a decrease in packing performance.

[0004] 2. Extremely inconvenient maintenance: When the packing wears out or needs to be replaced, the entire structure and all components above it (such as the actuator) must be removed from the valve body. This operation is labor-intensive, time-consuming, and costly, and the valve's overall insulation structure is easily damaged during disassembly.

[0005] 3. Disadvantages of integrated design: Any damage to the sealing components may mean that the entire expensive component needs to be replaced, rather than just the cheap packing ring, which is not economical.

[0006] Therefore, how to further optimize the top sealing structure based on the existing structure to achieve more thorough heat insulation, lower maintenance costs and higher reliability is an urgent problem to be solved in this field. Utility Model Content

[0007] To solve the above problems, this utility model provides a low-temperature emergency shut-off valve that is easy to maintain.

[0008] To solve the above-mentioned technical problems, the technical solution of this utility model is: a low-temperature emergency shut-off valve that is easy to maintain, including a valve body, with connecting ends installed on both sides of the valve body, a valve ball installed inside the valve body, a valve stem connected to the top of the valve ball, an extension sleeve and an independent stuffing box fitted outside the valve stem from bottom to top, a sealing ring between the independent stuffing box and the extension sleeve, a fireproof blocking mechanism installed on the top of the independent stuffing box, a single-acting pneumatic actuator installed on the top of the fireproof blocking mechanism, a fusible plug and a fusible plug protective cover installed on the single-acting pneumatic actuator, the fusible plug protective cover being located outside the fusible plug, and a valve stem seal, packing, packing gland, spring washer, gland nut and stop cover sequentially fitted on the valve stem inside the independent stuffing box from bottom to top, the gland nut being threadedly connected to the valve stem.

[0009] Furthermore, the bottom end of the extension sleeve is connected to the valve body, and the top end of the extension sleeve is connected to the independent stuffing box.

[0010] Furthermore, the fire-prevention mechanism is connected to the top of the valve stem via an internal connecting rod, the upper end of which is inserted into the center slot of the cylinder of the single-acting pneumatic actuator.

[0011] Furthermore, the top of the independent stuffing box is connected to the fire-stopping mechanism by bolt one, and the bottom of the independent stuffing box is connected to the extension sleeve by bolt two.

[0012] Furthermore, the single-acting pneumatic actuator is connected to the air compressor via pneumatic piping.

[0013] Furthermore, there are two sets of packing and packing glands.

[0014] Furthermore, there are two spring washers.

[0015] Furthermore, the stop cover is fitted over the pressure cap nut.

[0016] The beneficial effects of this utility model are: 1. Improved maintenance convenience: When it is necessary to inspect or replace the packing, simply loosen the gland nut and bolts of the independent stuffing box, and the maintenance work can be completed independently and quickly without removing the extension sleeve, which greatly shortens downtime and reduces labor and spare parts costs.

[0017] 2. Enhanced sealing reliability: The compact design of the independent stuffing box, along with the use of a sealing ring, further improves the sealing effect. At the same time, it reduces the risk of accidental damage to the sealing surface during overall disassembly.

[0018] 3. Better economic efficiency: It avoids the waste of replacing the entire extension neck assembly due to damage to local sealing elements. Only the individual stuffing gland needs to be maintained or replaced, which significantly reduces the cost over the entire life cycle.

[0019] 4. Retain original advantages: It fully inherits all the advantages of the traditional cryogenic valve extended neck structure in isolating cold air, and enhances its performance on this basis. Attached Figure Description

[0020] Figure 1 This is the front view of this utility model; Figure 2 This is a side view of the present invention; Figure 3 This is a top view of an independent stuffing box; Figure 4 This is a bottom view of an independent stuffing box; Figure 5 This is a magnified view of a section of an independent stuffing box.

[0021] The components are: 1. Single-acting pneumatic actuator; 2. Fireproof shut-off mechanism; 3. Independent stuffing box; 4. Extension sleeve; 5. Valve stem; 6. Valve body; 7. Valve ball; 8. Connecting end; 9. Fusible plug; 10. Fusible plug protective cover; 11. Bolt 1; 12. Bolt 2; 13. Sealing ring; 14. Connecting rod; 15. Packing; 16. Packing gland; 17. Spring washer; 18. Stop cover; 19. Gland nut; 20. Valve stem seal. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-5 The technical solution of this utility model has been clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] The easy-to-maintain cryogenic emergency shut-off valve includes a valve body 6, with connecting ends 8 installed on both sides of the valve body 6. A valve ball 7 is installed inside the valve body 6, and a valve stem 5 is connected to the top of the valve ball 7. An extension sleeve 4 and an independent stuffing box 3 are fitted around the valve stem 5 from bottom to top. A sealing ring 13 is provided between the independent stuffing box 3 and the extension sleeve 4. The bottom end of the extension sleeve 4 is connected to the valve body 6, and the top end of the extension sleeve 4 is connected to the bottom of the independent stuffing box 3 by bolt 2 12. The top of the independent stuffing box 3 is connected to the fireproof shut-off mechanism 2 by bolt 1 11. The fireproof shut-off mechanism 2 is connected via an internal... The connecting rod 14 is connected to the top of the valve stem 5. The upper end of the connecting rod 14 is inserted into the center slot of the cylinder of the single-acting pneumatic actuator 1. The single-acting pneumatic actuator 1 is equipped with a fusible plug 9 and a fusible plug protective cover 10. The fusible plug protective cover 10 is located outside the fusible plug 9. The valve stem 5, located in the independent stuffing box 3, is fitted with a valve stem seal 20, packing 15, packing gland 16, spring washer 17, gland nut 19, and stop cover 18 from bottom to top. The gland nut 19 is threaded to the valve stem 5, and the stop cover 18 is fitted over the gland nut 19. There are two sets of packing 15 and packing gland 16, and two spring washer 17. The single-acting pneumatic actuator 1 is connected to the air compressor through a pneumatic pipeline.

[0024] Routine operation: Controls the air compressor to supply / stop air supply, and drives the valve stem 5 through the single-acting pneumatic actuator 1 to realize the opening, closing and state switching of the valve.

[0025] Maintenance of sealing components: There is no need to disassemble the extension sleeve 4 and the overall structure above the valve body 6. Simply loosen the bolt 11 connecting the independent stuffing box 3 to the fireproof blocking mechanism 2 and the bolt 12 connecting the extension sleeve 4, and remove the stop cover 18, the gland nut 19, the spring washer 17, and the packing gland 16 in sequence to replace / repair vulnerable parts such as the packing 15 and the valve stem seal 20. After maintenance, put the valve stem seal 20, the two sets of packing 15 and the packing gland 16, and the two spring washers 17 on the valve stem 5 in sequence, tighten the gland nut 19 and put on the stop cover 18, and then use bolt 11 and bolt 12 to lock the independent stuffing box 3 to the fireproof blocking mechanism 2 and the extension sleeve 4 to restore use, which greatly shortens downtime and reduces costs.

[0026] The embodiments described above are merely preferred embodiments of this utility model, and not all feasible embodiments of this utility model. For those skilled in the art, any obvious modifications made without departing from the principles and spirit of this utility model should be considered to be included within the scope of protection of the claims of this utility model. Although this utility model has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this utility model. In particular, as long as there is no technical conflict, the features in the embodiments disclosed in this utility model can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this utility model is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A low-temperature emergency shut-off valve that is easy to maintain, characterized in that, The valve includes a valve body with connecting ends on both sides. A valve ball is installed inside the valve body, and a valve stem is connected to the top of the valve ball. An extension sleeve and an independent stuffing box are fitted around the valve stem from bottom to top. A sealing ring is provided between the independent stuffing box and the extension sleeve. A fire-stopping mechanism is installed on the top of the independent stuffing box, and a single-acting pneumatic actuator is installed on the top of the fire-stopping mechanism. A fusible plug and a fusible plug protective cover are installed on the single-acting pneumatic actuator. The fusible plug protective cover is located outside the fusible plug. Inside the independent stuffing box, the valve stem is fitted with, from bottom to top, a valve stem seal, packing, packing gland, spring washer, gland nut, and stop cap. The gland nut is threadedly connected to the valve stem.

2. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, The bottom end of the extension sleeve is connected to the valve body, and the top end of the extension sleeve is connected to the independent stuffing box.

3. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, The fire-prevention mechanism is connected to the top of the valve stem via an internal connecting rod, the upper end of which is inserted into the center slot of the cylinder of the single-acting pneumatic actuator.

4. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, The top of the independent stuffing box is connected to the fireproof blocking mechanism by bolt one, and the bottom of the independent stuffing box is connected to the extension sleeve by bolt two.

5. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, The single-acting pneumatic actuator is connected to an air compressor via a pneumatic pipeline.

6. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, There are two sets of the packing and packing gland.

7. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, There are two spring washers.

8. The easy-to-maintain cryogenic emergency shut-off valve according to claim 1, characterized in that, The stop cover is fitted over the pressure cap nut.

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