Special hydrogen valve capable of realizing on-line leak hunting

Abstract

The utility model discloses a hydrogen special valve capable of online leak hunting, which relates to the technical field of valves and comprises a valve body, a valve cover and a support, the valve cover is mounted on the valve body, the support is mounted on the valve cover, a valve rod is arranged in the valve cover, the valve rod is inserted into the valve body and penetrates through the valve cover and the support deep in the valve cover, and the valve rod is inserted into the valve body and penetrates through the valve cover. According to the technical scheme provided by the utility model, the corrugated pipe is adopted as the main seal of the valve, the packing seal is adopted as the auxiliary seal, and the double-layer seal design is adopted, so that media are prevented from leaking out, and the reliability of the valve is improved. And the welding of the corrugated pipe and the sealing of the filler are separated and do not influence each other. Even if the corrugated pipe is damaged or the welding position of the corrugated pipe has a quality problem, the filler can still play a sealing role, so that the safety is relatively high due to double guarantee.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a special hydrogen valve capable of online leak detection. Background Art

[0002] Hydrocracking is a major crude oil refining process. Hydrocracking units operate under high temperature and high pressure, using flammable and explosive hydrogen and hydrocarbons as media. These conditions are extremely hazardous, and leaks can lead to explosions, posing a significant safety hazard. This places high demands on valve design and structure. Controlling internal and external leakage is a key indicator of valve quality, and valve manufacturers implement various measures to minimize these. Hydrogen leakage not only pollutes the environment but can also cause fires or explosions. Internal leakage primarily occurs at the valve seat, while external leakage primarily occurs at the stem packing and bonnet gasket. The bonnet gasket is a static seal with virtually no external leakage, while the stem is a dynamic seal, prone to wear and tear, leading to external leakage. Flexible graphite and braided flexible graphite packing are commonly used for stem seals. The top and bottom packing rings are braided flexible graphite rings, while the center ring is a molded graphite ring. Preventing pre-compression during packing is also crucial for ensuring a good seal, especially a long-term seal. Most domestic valves only compact the packing during packing, so their sealing performance deteriorates over time. Some foreign Yanmen products utilize a 28MPa preload during packing and incorporate specialized pre-tightening tools, enabling them to maintain a good seal for extended periods. However, excessive packing preload increases stem wear and increases the valve's opening force. Therefore, continuous improvements should be made to packing selection and stem surface treatment. Using packing primarily composed of flexible graphite rings can reduce stem wear and lower the valve's opening torque.

[0003] Some valves also use a "live load" structure on the packing gland. That is, a disc spring is added to the bolts of the packing gland, so that the packing gland always exerts a greater pressure on the packing, thus avoiding leakage caused by loose gland bolts or packing.

[0004] Currently, most of the shut-off valves on hydrogenation units on the market are ordinary stop valves. Ordinary stop valves use packing as the main seal at the valve stem. No matter which technical solution is adopted, leakage will inevitably occur after the packing is worn.

[0005] Hydrogen is a light gas with high flammability. Once it leaks, it reacts with oxygen in the air, potentially causing fire or explosion. Therefore, the risks of hydrogen leaks in the environment primarily include fire and explosion. Utility Model Content

[0006] Purpose of the utility model: The technical problem to be solved by the utility model is to provide a hydrogen-specific valve that can be leak-tested online, which solves the problem that the existing valves using packing seals are prone to leakage.

[0007] Technical Solution

[0008] In order to solve the above problems, the technical solution provided by the present invention is as follows:

[0009] A hydrogen-specific valve capable of online leak detection comprises a valve body, a valve cover and a bracket, wherein the valve cover is mounted on the valve body, and the bracket is mounted on the valve cover. A valve stem is provided in the valve cover and is inserted into the valve body and passes through the valve cover and the bracket deep inside. A bellows assembly is provided on the valve stem located in the valve cover.

[0010] Furthermore, the bellows assembly consists of a bellows upper seat, a bellows lower seat, and a bellows fixed between the bellows upper seat and the bellows lower seat.

[0011] Furthermore, the bellows lower seat is fixed to the wall on the lower side of the valve cover, and the bellows upper seat is fixed to the shoulder of the valve stem located on the upper side of the valve cover.

[0012] Furthermore, two independent hydrogen flow channels are provided in the valve body, an isolation wall is provided between the two independent hydrogen flow channels, a hydrogen through hole is provided on the isolation wall, and a guide bracket is provided in the hydrogen through hole.

[0013] Furthermore, the guide bracket consists of a guide ring located at the center and three support brackets distributed at 120 degrees.

[0014] Furthermore, one end of the valve stem located in the valve body is connected to a valve flap, the valve flap is arranged corresponding to the hydrogen through hole, and a limiting rod inserted into the guide ring is provided at the bottom of the valve flap.

[0015] Furthermore, a packing space is provided on the upper side of the valve cover, the packing space is filled with packing, and a packing gland is inserted into the packing space.

[0016] Furthermore, a control space is provided in the bracket, a bearing is fixedly provided in the control space, a valve stem nut is rotatably provided in the bearing, the valve stem passes through the valve stem nut, and the valve stem nut is threadably matched with the valve stem.

[0017] Furthermore, a detection space is provided at the top of the valve stem, a hydrogen sensor is provided in the detection space, a hydrogen detection channel is provided in the valve stem, one end of the hydrogen detection channel is opened to the side of the valve stem on the upper side of the shoulder of the valve stem, and the other end of the hydrogen detection channel is opened at the bottom of the detection space.

[0018] Furthermore, a special pressure block that cooperates with the valve stem thread is provided in the detection space, and the special pressure block is located on the upper side of the hydrogen sensor. A sealing gasket is provided between the hydrogen sensor and the bottom surface of the detection space.

[0019] Beneficial effects

[0020] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects:

[0021] This utility model provides a dual-seal design that utilizes a bellows as the primary valve seal and a packing seal as a secondary seal, preventing leakage and improving valve reliability. The bellows welding and packing seal are separate and independent of each other. Even if the bellows is damaged or the welds develop quality issues, the packing seal still provides a strong seal, providing a double layer of security. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model;

[0023] Figure 2 For the utility model embodiment 1 Figure 1 A magnified schematic diagram of point A in the middle;

[0024] Figure 3 For the utility model embodiment 1 Figure 2 A magnified schematic diagram of point B in the middle;

[0025] Figure 4 This is a top view of the valve body of Example 1 of the present utility model. DETAILED DESCRIPTION

[0026] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] Combined with attachment Figure 1-4 A hydrogen-specific valve with online leak detection is used to detect in real time whether the hydrogen in the valve is leaking. It is suitable for working conditions such as hydrogen pipelines with a pressure range of ≤10.0MPa and a temperature of ≤500℃. It includes a valve body 1 and a valve cover 8. The valve cover 8 is installed on the top of the valve body 1. There is a sealing gasket at the connection between the valve cover 8 and the valve body 1, which is fixed and tightened by bolts to achieve a seal between the valve body 1 and the valve cover 8.

[0029] The valve body 8 consists of two independent hydrogen flow channels, one of which occupies the upper half and right half of the valve body 8, and the other independent hydrogen flow channel occupies the lower half and left half of the valve body 8. The left half and right half of the two independent hydrogen flow channels are respectively connected to external hydrogen pipelines or equipment, and the upper half and lower half of the two independent hydrogen flow channels are used for mutual communication and isolation between the two independent hydrogen flow channels.

[0030] An isolation wall 50 is provided between the upper and lower halves of the two independent hydrogen flow channels in the valve body 1 for isolating the upper and lower halves of the two independent hydrogen flow channels. The isolation wall 50 is provided with a hydrogen through-hole 51 for connecting the upper and lower halves of the two independent hydrogen flow channels. A guide bracket 52 is provided in the hydrogen through-hole 51. The guide bracket 52 consists of a guide ring 521 located in the center and three support brackets 522 distributed at 120 degrees. One end of the three support brackets 512 is fixed to the guide ring 511, and the other end is fixed to the inner wall of the hydrogen through-hole 51.

[0031] A valve disc 2 is provided in the valve body 1. The valve disc 2 consists of a valve disc body 201 that can block the hydrogen through-hole 51 and a limiting rod 202 installed at the bottom of the valve disc body 201. The limiting rod 202 is inserted into the guide ring 511 at the center position of the guide bracket 52. The guide ring 511 limits the limiting rod 202, so that the limiting rod 202 can only slide up and down while the guide ring 511 remains vertical, so that the valve disc 2 can only move up and down, so that when the valve 2 descends to block the hydrogen through-hole 51, the two independent hydrogen flow pipes are isolated from each other. The three support brackets 522 are used to support the valve disc body 201, so that the user can quickly move the valve disc 2 to a position where the hydrogen through-hole 51 blocks the two independent hydrogen flow channels, thereby isolating the independent hydrogen flow channels. When the valve disc 2 rises, the hydrogen through-hole 51 connects the two independent hydrogen flow channels, so that hydrogen can flow from one hydrogen flow channel to the other.

[0032] A valve stem 5 is provided in the valve cover 8, which passes through the valve cover 8 from top to bottom. A connecting space 203 with an upwardly opening groove structure is provided on the top of the valve disc 2. The lower end of the valve stem 5 is inserted into the connecting space 203 of the valve disc 2. A split ring 3 is provided on the valve stem 5. The split ring 3 is arranged at one end of the valve stem 5 inserted into the connecting space 203 of the valve disc 2. An annular groove for mounting the split ring 3 is provided on the lower side of the valve stem 5. The split ring 3 is composed of two semi-circular rings combined in the annular groove to form a complete ring. The inner diameter of the split ring 3 is larger than the outer diameter of the valve stem 5. Therefore, the split ring 3 requires two semi-circular rings to form a complete ring. The valve stem 5 can only be installed on the valve disc 5, and the outer diameter of the split ring 3 is larger than the outer diameter of the valve stem 5. The split ring 3 is located in the connecting space 203 of the valve disc 2 and protrudes from the valve stem 5. The valve disc gland 4 is inserted into the upper side of the connecting space 203, and the valve disc gland 4 is inserted into the diameter gap between the valve stem 5 and the valve disc 2. The bottom end surface of the valve disc gland 4 abuts against the part of the split ring 3 protruding from the valve stem 5. The valve disc gland 4 fixes the valve stem 5 and the valve disc 2 to each other through interference friction fit. The valve disc gland 4 abuts against the split ring 3, and the valve disc 2 and the valve stem 5 are fixed together through the valve disc gland 4.

[0033] A bellows space 85 is provided in the valve cover 8, and the valve stem 5 passes through the bellows space 85. A bellows assembly 7 is sleeved on the valve stem 5 located in the bellows space 85. The bellows assembly 7 has a bellows upper seat 71 located on the upper side, a bellows lower seat 72 located on the lower side, and a bellows 70 connected between the bellows upper seat 71 and the bellows lower seat 72. The bellows lower seat 72 is fixedly welded to the wall of the valve cover 8 at the bottom end wall of the bellows space 85, and the bellows upper seat 71 is fixedly welded to the shoulder on the valve stem 5. The valve stem 5 drives the bellows assembly 7 to move up and down through the bellows upper seat 71 fixed to the valve stem 5, and the bellows lower seat 72 at one end of the bellows assembly 7 connected to the valve cover 8 will not move.

[0034] A packing space is provided on the upper side of the valve cover 8. The packing space is located at the top of the valve cover 8 and the opening is located on the upper surface of the valve cover 8. The valve stem 5 is inserted into the packing space. The packing space is filled with packing 9. A packing gland 10 is provided on the packing space. The packing gland 10 is inserted into the packing space and abuts against the packing. The packing gland 10 is inserted into the gap between the inner surface of the packing space and the outer surface of the valve stem 2. The packing gland 10 is used to continuously apply pressure to the packing 9, so that the packing 9 still has a sealing effect when the valve stem 5 moves up and down.

[0035] The bellows 70 serves as the valve's primary seal, while the packing 9 serves as a secondary seal. This double-layer seal prevents leakage and improves valve reliability. The bellows welding and packing sealing are separate and independent of each other. Even if the bellows is damaged or the welds experience quality issues, the packing still provides a seal. The bellows 70 features an internal pressure-bearing design. When bent, the direction of the corrugations remains unchanged, preserving the original bellows' elasticity and preventing fatigue failure.

[0036] A bracket 12 is provided on the valve cover 8, and a number of double-headed columns 11 are arranged around the bracket 12 and the valve cover 8. The double-headed columns 11 fix the valve cover 8 and the bracket 12 to each other through bolts, and the double-headed columns 11 support the valve cover 8 and the bracket 12 so that a certain distance is maintained between the valve cover 8 and the bracket 12, which is convenient for workers to adjust the packing cover 10.

[0037] Bracket 12 defines a control space within which the valve stem 5 extends. A valve stem nut 14 rotates within the control space. The valve stem nut 14 is mounted within the control space via bearings 13 located on either side. A valve stem nut gland 15 is located at the top of the control space. The gland 15 abuts against the bearings 13 and presses down on the bearings 13, preventing the valve stem nut 14 from moving up or down within the control space. The gland 15 compresses the valve stem nut 14 and is spot welded to the end face of bracket 12 to prevent loosening. The valve stem nut 14 and the valve stem 5 are designed with matching threads, allowing the rotation of the valve stem nut 14 to drive the valve stem 5 up and down.

[0038] The top of the stem nut 14 protrudes from the control space. A handwheel 16 is fixed on the stem nut 14 protruding from the control space. The outer circle of the stem nut 14 and the inner hole of the handwheel 16 are designed with matching square holes. The upper end face of the handwheel is designed with a nut for tightening the handwheel, thereby fixing the handwheel and the stem nut 14 into an integrated structure. The worker drives the stem nut 14 to rotate by turning the handwheel 16. The top of the valve stem 5 passes through and extends out of the handwheel 16. The part of the valve stem 5 located in the control is provided with a thread that matches the stem nut 14. The rotation of the stem nut 14 can drive the valve stem 5 to slide up and down.

[0039] A detection space is provided at the top of the valve stem 5, and a hydrogen detection channel 60 is provided inside the valve stem 5. The aperture of the hydrogen detection channel 60 is preferably 2 mm. One end of the hydrogen detection channel 60 is opened on the side of the valve stem 5 on the upper side of the shoulder of the valve stem 5 in the bellows space 85, and the other end of the hydrogen detection channel 60 is opened at the bottom of the detection space.

[0040] A hydrogen sensor 19 is provided in the detection space. The detection head 191 of the hydrogen sensor 19 is inserted into the hydrogen detection channel 60 through the opening of the hydrogen detection channel 60 at the bottom of the detection space. The detection head 191 of the hydrogen sensor inserted into the hydrogen detection channel 60 is provided with an O-ring 17 for sealing.

[0041] A sealing gasket 18 is provided on the lower side of the hydrogen sensor 19 and is located at the bottom of the detection space. The sealing gasket 18 is made of PTFE. A special pressure block 21 is provided on the upper side of the hydrogen sensor 19. The special pressure block 21 is used to press down the hydrogen sensor 19 so that the detection head 191 of the hydrogen sensor 19 will not withdraw from the hydrogen detection channel 60. A rubber pad 20 is provided between the hydrogen sensor 19 and the special pressure block 21. A wiring harness channel is provided in the special pressure block 21. A signal receiver 24 is provided on the special pressure block 21. An indicator light 25 is provided in the signal receiver 24. A wiring harness connector 23 is provided on the indicator light 25. The data transmission wiring harness 22 of the hydrogen sensor 19 is connected to the wiring harness connector 23 through the wiring harness channel.

[0042] A PTFE sealing gasket 18 is installed between the bottom surface of the hydrogen sensor 19 and the bottom surface of the detection space, surrounding the end surface hydrogen detection channel 60. This prevents failure of the O-ring 17 and leakage of the medium, providing a more reliable double-layer seal. A rubber pad 20 is installed at the top of the hydrogen sensor 19, and a dedicated pressure block 21 is used to compress the hydrogen sensor 19, preventing accidental damage to the hydrogen sensor 19 due to direct pressure.

[0043] The special pressure block 20 is threadedly connected to the valve stem 5. The hydrogen sensor 19 transmits the detected signal to the signal receiver 24. The signal receiver 24 sends an alarm signal and the indicator light 25 lights up red to warn the factory inspection personnel that the valve is leaking and to replace the valve in time.

[0044] The bellows assembly 7 ensures that the medium cannot leak into the bellows space and packing space of the valve cover 8. When the medium leaks into the bellows space in the valve cover 8, the hydrogen detection channel 60 on the valve stem 5 for leak detection will transmit the leaked hydrogen to the detection head 191 of the hydrogen sensor 19, which will be detected by the hydrogen sensor 19. The hydrogen sensor 19 transmits the signal to the signal receiver 24. The signal receiver 24 receives the signal and sends an alarm signal, causing the indicator light 25 to light up red, alerting the factory inspection personnel that the valve is leaking and to replace the valve in time.

[0045] An O-ring 17 seals the insertion point between the sensor's detection head 191 and the hydrogen detection channel 60 to prevent leaked hydrogen from escaping into the air. A PTFE sealing gasket 18, designed between the lower end of the hydrogen sensor 19 and the port of the hydrogen detection channel 60, forms a double seal with the O-ring 17, preventing leaked media from escaping into the air. When the sensor detects a hydrogen leak, it transmits the detected signal to a signal receiver, which then issues an alarm signal, causing the indicator light to illuminate red.

[0046] In order to reduce the impact force of the medium flowing in the valve body 1 on the valve disc 2 and the valve stem 5, which may cause the valve disc 2 to shift in position, this valve adopts a multi-level guide design. In order to ensure that the center of the valve stem 5, the center of the valve disc 2 and the center of the valve body 1 coincide with each other, the guide bracket 52 at the bottom of the valve body 1 is cast as one piece. When the valve is processed, the guide bracket 52, the valve seat sealing surface at the hydrogen through hole (that is, the sealing surface of the valve disc) and the valve body flange stop countersunk hole (that is, the sealing surface of the valve body and the valve cover) are clamped and processed at one time, eliminating the error accumulation caused by multiple clamping; the inner hole of the valve cover and the stepped outer circle that matches the valve body are clamped and processed at one time; the valve stem is clamped with one clamp and one top, and the clamping is completed in one time; the valve disc is clamped with one clamp and one top, and the outer circle, sealing surface, valve stem hole and guide rod are clamped and processed at one time; the assembly datum is guaranteed to be unified, the assembly error accumulation is eliminated, the valve disc and the valve stem center are guaranteed to remain concentric during the lifting process, the wear of the bellows and the packing is reduced, the fit of the sealing surface is improved, the valve life is guaranteed to be long, and the valve is safe and reliable.

[0047] The above-described embodiments merely represent several implementation methods of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A hydrogen-specific valve capable of online leak detection, characterized in that: It includes a valve body, a valve cover and a bracket, the valve cover is installed on the valve body, the bracket is installed on the valve cover, the valve cover is provided with a valve stem inserted into the valve body and passing through the valve cover and the bracket deep inside, and the valve stem located in the valve cover is provided with a bellows assembly.

2. A hydrogen-specific valve capable of online leak detection according to claim 1, characterized in that: The bellows assembly consists of a bellows upper seat, a bellows lower seat, and a bellows fixed between the bellows upper seat and the bellows lower seat.

3. A hydrogen-specific valve capable of online leak detection according to claim 2, characterized in that: The wall of the bellows lower seat valve cover is fixed, and the bellows upper seat is fixed to the shoulder of the valve stem located on the upper side of the valve cover.

4. The hydrogen-specific valve capable of online leak detection according to claim 1, characterized in that: Two independent hydrogen flow channels are provided in the valve body, an isolation wall is provided between the two independent hydrogen flow channels, a hydrogen through hole is provided on the isolation wall, and a guide bracket is provided in the hydrogen through hole.

5. The hydrogen-specific valve capable of online leak detection according to claim 4, characterized in that: The guide bracket consists of a guide ring located at the center and three supporting brackets distributed at 120 degrees.

6. The hydrogen-specific valve capable of online leak detection according to claim 5, characterized in that: One end of the valve stem located in the valve body is connected to a valve flap, the valve flap is arranged corresponding to the hydrogen through hole, and a limiting rod inserted into the guide ring is provided at the bottom of the valve flap.

7. The hydrogen-specific valve capable of online leak detection according to claim 1, characterized in that: A packing space is provided on the upper side of the valve cover. The packing space is filled with packing, and a packing gland is inserted into the packing space.

8. The hydrogen-specific valve capable of online leak detection according to claim 1, characterized in that: A control space is provided in the bracket, a bearing is fixedly provided in the control space, a valve stem nut is rotatably provided in the bearing, the valve stem passes through the valve stem nut, and the valve stem nut is threadably matched with the valve stem.

9. The hydrogen-specific valve capable of online leak detection according to claim 3, characterized in that: A detection space is provided at the top of the valve stem, a hydrogen sensor is provided in the detection space, a hydrogen detection channel is provided in the valve stem, one end of the hydrogen detection channel is opened to the side of the valve stem above the shoulder of the valve stem, and the other end of the hydrogen detection channel is opened at the bottom of the detection space.

10. The hydrogen-specific valve capable of online leak detection according to claim 9, characterized in that: A special pressure block that cooperates with the valve stem thread is also provided in the detection space. The special pressure block is located on the upper side of the hydrogen sensor. A sealing gasket is provided between the hydrogen sensor and the bottom surface of the detection space.

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