Valve packing gland sealing compensation device and gate valve

Abstract

The invention discloses a valve packing gland sealing compensation device and a gate valve, and belongs to the technical field of steam-water valves. A valve packing gland sealing compensation device comprises a compensation screw, a supporting compensation sleeve is arranged on the lower portion of the compensation screw, and the compensation screw is sleeved with the supporting compensation sleeve. The compensation screw is further provided with a compensation nut located above the supporting compensation sleeve, and the compensation nut is connected to the compensation screw in a threaded mode and can press the supporting compensation sleeve downwards. When the compensation device is used, the overall length of the compensation device is adjusted in advance, the compensation device is installed on a gate valve, the upper end of the compensation screw rod is fixedly connected in an abutting mode, the lower end of the supporting compensation sleeve is connected with a valve packing in an abutting mode, and then the supporting compensation sleeve is further extruded downwards through the compensation nut so as to achieve compensation extrusion on the valve packing. Therefore, the sealing recovery of the valve packing can be completed in a non-stop state, and the reliability of system operation is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steam valve, in particular to a valve packing gland sealing compensation device and gate valve. BACKGROUND

[0002] As a key fluid control device, the gate valve is widely used in the pipe network system of many industries such as petroleum, chemical industry, power supply, water supply, etc. Its core function is to connect or cut off the medium flow in the pipeline. The sealing performance of the gate valve is a key indicator to measure its working reliability and safety, and the valve stem dynamic sealing is the key part to ensure that the gate valve has no external leakage.

[0003] At present, the valve stem sealing structure commonly used in the industry is to fill the packing in the packing chamber of the valve cover (such as graphite, polytetrafluoroethylene, etc.), and rely on a packing gland to press the packing from the axial direction, so that the packing expands radially, thereby tightly wrapping the valve stem to achieve sealing effect. In order to provide and maintain sufficient compression force, the existing technical solution usually symmetrically sets multiple bolts on the flange of the packing gland. These bolts pass through the flange of the packing gland and are screwed into the threaded holes of the valve cover. By tightening the bolts, the packing gland is driven to move downward to achieve compression of the packing.

[0004] However, this traditional structure has a significant inherent defect (as shown in FIG. 1). Since the gate valve operates in various harsh conditions for many years, the fastening bolts and nuts (or threaded holes) of the valve packing are completely exposed to the environment and are affected by medium corrosion, moisture, chemicals and temperature changes for a long time, which is prone to rust, seizure and other problems, resulting in the packing chamber leaking steam and the packing being unable to be fastened again, or the fastening bolts being broken during the fastening process. Once the fastening bolts and nuts fail, the valve body medium must be depressurized and emptied before they can be replaced. At this time, the only repair method is to completely empty and depressurize the medium in the pipeline where the valve body is located, that is, the entire system must be shut down before the bolts can be drilled, replaced, and the packing can be maintained. Figure 1 This repair process is not only complex, time-consuming and labor-intensive, but more importantly, it requires the entire system to stop running. In a continuous production industrial process, unplanned downtime will result in significant economic losses. Therefore, the contradiction between the repair operation time and the gate valve downtime caused by the existing technology is particularly prominent, making it impossible to perform online maintenance when the valve needs emergency maintenance, which seriously affects the operation reliability and economy of the entire system.

[0005] SUMMARY

[0006] To solve the problem that the repair operation time and the gate valve downtime are difficult to match after the gate valve has a sealing problem, the present application provides a valve packing gland sealing compensation device and gate valve.​

[0007] The present application is realized by the following technical solutions: A valve packing gland sealing compensation device, comprising a compensation screw, the lower part of the compensation screw is provided with a supporting compensation sleeve, the supporting compensation sleeve is sleeved on the compensation screw; the compensation screw is further provided with a compensation nut above the supporting compensation sleeve, the compensation nut is threadedly connected on the compensation screw and can press the supporting compensation sleeve downward.

[0008] In use, the overall length of the compensation device is adjusted in advance and installed on the gate valve, the upper end of the compensation screw forms a fixed abutment, the lower end of the supporting compensation sleeve abuts against the valve packing, and the supporting compensation sleeve is further pressed downward by the compensation nut to realize the compensation and pressing of the valve packing, so that the sealing recovery of the valve packing can be completed without stopping the machine, and the reliability of the system operation is improved.

[0009] Further improvement of the present application is that the top of the compensation screw is provided with an ejection assembly.

[0010] Further improvement of the present application is that the ejection assembly comprises a second fixed nut, which is threadedly connected on the top of the compensation screw. The second fixed nut is threadedly connected on the upper part of the compensation screw and can be used to adjust and adapt to the height of the upper installation space.

[0011] Further improvement of the present application is that the ejection assembly further comprises a first fixed nut below the second fixed nut, which is threadedly connected on the compensation screw and can abut against the second fixed nut. The first fixed nut is added and abuts against the second fixed nut to form a classic double-nut anti-loosening structure. This structure can effectively prevent the second fixed nut at the top from loosening and shifting under the condition of long-term vibration or temperature change of the valve, and ensure the long-term stability of the adjustment position of the ejection assembly, thereby ensuring the long-term working reliability of the sealing compensation device.

[0012] Further improvement of the present application is that a gasket is arranged between the compensation nut and the supporting compensation sleeve, and the gasket is sleeved on the outside of the compensation screw. The gasket can reduce the friction between the compensation nut and the supporting compensation sleeve when adjusting the compensation nut, make the operation of tightening the compensation nut more labor-saving and smooth, increase the contact area and disperse the pressure to avoid the end surface of the compensation nut directly pressing the contact surface of the supporting compensation sleeve, and play a protective role. Different materials of the gasket (such as polytetrafluoroethylene) can be selected to improve the corrosion resistance and wear resistance and prolong the service life of the device.

[0013] Further improvement of the present application has the gasket provided with guiding plates extending downward and capable of cooperating with the side wall of the supporting compensation sleeve; the guiding plates are provided with at least two, when two guiding plates are provided, the two guiding plates are arranged in axial symmetry, and when three or more guiding plates are provided, the guiding plates are arranged uniformly around the compensation screw.

[0014] Further improvement of the present application has the side wall of the compensation sleeve provided with an observation gap, and the height of the observation gap is greater than the axial thickness of the fastening bolt. The height of the whole valve packing gland sealing compensation device is adjusted in advance by rotating the compensation nut, and after being placed on the valve body, the compensation nut is further tightened, the force feedback of the supporting compensation sleeve pressing the valve packing is perceived, and the gap between the fastening nut and the valve packing and the state of the fastening nut are observed through the observation gap, so as to assist in judging the failure degree of the valve body sealing performance and facilitating the development of subsequent preventive maintenance plan.

[0015] A gate valve comprises a valve cover, a valve packing and a valve rod, the valve packing is arranged above the valve cover, and the valve packing is fastened by a fastening bolt, the valve rod penetrates the valve packing, the valve packing gland sealing compensation devices are uniformly arranged on the circumference of the valve rod, the bottom end of the supporting compensation sleeve abuts against the valve packing, and the top of the compensation screw is connected with the valve rod. The sealing compensation devices are arranged around the outer periphery of the valve rod, so as to ensure the sealing effect of the valve packing; when the valve packing sealing fails, maintenance personnel do not need to operate the system to stop pressure relief, but can directly operate the compensation devices to restore the sealing, so as to solve the core contradiction that the maintenance operation and the shutdown time of the gate valve are difficult to match.

[0016] Further improvement of the present application has the compensation screw abutting against the bottom surface of the pressing plate through the ejection assembly. The pressing plate is a convenient component for operating the valve rod and can correspond to the valve packing up and down, so that the top of the compensation screw can bear stress, the transmission path of the stress is optimized, and the stability of the sealing performance is ensured.

[0017] Further improvement of the present application has the fastening bolts uniformly arranged on the circumference of the valve rod, the lower part of the fastening bolt is mounted on the valve cover, the upper part of the fastening bolt penetrates the valve packing and is connected with the fastening nut through threads, the fastening nut presses the top surface of the valve packing, and the fastening nut is arranged in the supporting compensation sleeve.

[0018] From the above technical scheme can be seen, the beneficial effects of the present application are: when using the compensation device is pre-adjusted to the overall length and installed on the gate valve, the upper end of the compensation screw is formed to fixedly abut, the lower end of the supporting compensation sleeve abuts the valve packing, and the compensation nut is further used to extrude the supporting compensation sleeve downward to realize the compensation extrusion of the valve packing, so that the sealing recovery of the valve packing can be completed without stopping the machine, and the reliability of the system operation is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present application, the drawings needed to be used in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 It is a local structure schematic diagram of the existing gate valve.

[0021] Figure 2 It is a structure schematic diagram of the valve packing gland sealing compensation device of the specific embodiment of the present application.

[0022] Figure 3 It is a structure schematic diagram of the gate valve of the specific embodiment of the present application.

[0023] In the drawings: 10, valve cover; 20, valve stem; 21, pressing plate; 30, valve packing; 31, packing filler; 40, fastening bolt; 41, fastening nut; 50, supporting compensation sleeve; 501, observation gap; 60, compensation screw; 61, compensation nut; 62, ejection assembly; 621, fixed nut one; 622, fixed nut two; 70, gasket; 71, guide plate. DETAILED DESCRIPTION

[0024] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the specific embodiment. Obviously, the following described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present patent, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present patent.

[0025] As Figures 2-3As shown, the application discloses a valve packing gland sealing compensation device, which comprises a compensation screw 60, a supporting compensation sleeve 50 arranged on the lower part of the compensation screw 60, and a compensation nut 61 arranged above the supporting compensation sleeve 50 and threadedly connected to the compensation screw 60 and capable of pressing the supporting compensation sleeve 50 downward.

[0026] In use, the compensation device is pre-adjusted in overall length and installed on the gate valve, the upper end of the compensation screw 60 is fixedly abutted, the lower end of the supporting compensation sleeve 50 is abutted against the valve packing 30, and the supporting compensation sleeve 50 is further pressed downward by the compensation nut 61, so as to realize the compensation and pressing of the valve packing 30, thereby realizing the recovery of the sealing of the valve packing 30 without stopping the system, and improving the reliability of the system operation.

[0027] The top of the compensation screw 60 is provided with an ejection assembly 62.

[0028] The ejection assembly 62 comprises a second fixed nut 622 threadedly connected to the top of the compensation screw 60, and the second fixed nut 622 is threadedly connected to the upper part of the compensation screw 60 and can be used for adjusting and adapting to the height of the upper installation space.

[0029] The ejection assembly 62 further comprises a first fixed nut 621 arranged below the second fixed nut 622 and threadedly connected to the compensation screw 60 and capable of abutting against the second fixed nut 622. The first fixed nut 621 is arranged and abutted against the second fixed nut 622, thereby forming a classic double-nut anti-loosening structure. This structure can effectively prevent the loosening and displacement of the second fixed nut 622 at the top under the long-term vibration or temperature change of the valve, thereby ensuring the long-term stability of the adjusting position of the ejection assembly 62 and the long-term working reliability of the sealing compensation device.

[0030] A gate valve comprises a valve cover 10, a valve packing 30 and a valve rod 20, the valve packing 30 is arranged above the valve cover 10 and is pressed on the valve cover 10 by a fastening bolt 40, the valve rod 20 penetrates through the valve packing 30, the valve packing gland sealing compensation devices are evenly distributed on the circumference of the valve rod 20, the bottom end of the supporting compensation sleeve 50 abuts against the valve packing 30, and the top of the compensation screw 60 is connected with the valve rod 20. The sealing compensation devices are arranged in multiple and surround the outer periphery of the valve rod 20, thereby ensuring the sealing effect of the valve packing 30, when the valve packing 30 is sealed invalidly, the maintenance personnel can directly operate the compensation devices to recover the sealing without stopping the system for pressure relief, thereby solving the core contradiction between the maintenance operation and the stopping time of the gate valve.

[0031] The valve packing 30 is filled with packing filler 31 around and in contact with the valve stem 20 between the valve cover 10, and the valve cover 10 is provided with a step capable of placing the packing filler 31.

[0032] The compensation screw 60 abuts against the bottom surface of the pressing plate 21 through the ejection assembly 62. The pressing plate 21 is a component for facilitating the operation of the valve stem 20 and can correspond to the valve packing 30 up and down, so that the support force of the top of the compensation screw 60 is realized, the transmission path of the force is optimized, and the stability of the sealing is guaranteed.

[0033] The compensation nut 61 and the supporting compensation sleeve 50 are provided with a gasket 70, which is sleeved outside the compensation screw 60. The gasket 70 can reduce the friction between the compensation nut 61 and the supporting compensation sleeve 50 during adjustment, make the operation of tightening the compensation nut 61 more labor-saving and smooth, increase the contact area and disperse the pressure, avoid the end surface of the compensation nut 61 directly pressing the contact surface of the supporting compensation sleeve 50, and play a protective role, and improve the corrosion resistance and wear resistance by selecting gaskets 70 of different materials (such as polytetrafluoroethylene), thereby prolonging the service life of the device.

[0034] The gasket 70 is provided with a guide plate 71 extending downward and capable of cooperating with the side wall of the supporting compensation sleeve 50; the guide plate 71 is provided with at least two, and when two guide plates 71 are provided, the two guide plates 71 are arranged in axial symmetry, and when three or more guide plates 71 are provided, they are uniformly arranged around the compensation screw 60. The guide plate 71 is arranged on the gasket 70 and cooperates with the side wall of the supporting compensation sleeve 50 to form an assembly guide.

[0035] The valve stem 20 is uniformly distributed with fastening bolts 40 around the circumference, the lower part of the fastening bolt 40 is mounted on the valve cover 10, and the upper part of the fastening bolt 40 penetrates the valve packing 30 and is connected by a threaded nut 41 to press the top surface of the valve packing 30; the threaded nut 41 is in the supporting compensation sleeve 50.

[0036] The side wall bottom of the supporting compensation sleeve 50 is provided with an observation gap 501, and the height of the observation gap 501 is greater than the height of the fastening bolt 40. The height of the whole valve packing gland sealing compensation device is adjusted in advance by rotating the compensation nut 61, and after being placed on the valve body, the compensation nut 61 is further tightened, the force feedback of the supporting compensation sleeve 50 pressing the valve packing 30 is perceived, and the gap between the threaded nut 41 and the valve packing 30 and the state of the threaded nut 41 are observed through the observation gap 501, which assists in judging the failure degree of the valve body sealing, and facilitates the subsequent development of preventive maintenance plan.

[0037] In summary, the working principle of the device is as follows: the device realizes online compensation of the sealing force of the packing 31 without relying on the original fastening bolt 40. The device takes the pressing plate 21 above the valve stem 20 as a fixed fulcrum, and takes the compensation screw 60 as a force transmission member. When the compensation nut 61 is tightened, the downward pressure generated by the compensation nut 61 is transmitted to the support compensation sleeve 50 through the gasket 70, and the force is vertically and uniformly applied to the valve packing 30 through the support compensation sleeve 50, so as to compress the packing 31 along the axial direction of the valve stem 20, promote the radial expansion of the packing 31, and re-tightly wrap the valve stem 20, thereby eliminating the gap caused by the wear of the packing 31 or the wear of the original fastening nut 41 and fastening bolt 40, and restoring the sealing performance. The entire force transmission path is independent of the original fastening bolt 40 which is prone to rust, and the recoverability of the sealing function is realized.

[0038] The operation and use method of the device is divided into two stages of initial installation and online compensation. During installation, the device is first placed around the valve stem 20, the bottom end of the support compensation sleeve 50 is in contact with the valve packing 30, then the fixed nut two 622 at the top of the compensation screw 60 is adjusted to tightly abut the pressing plate 21 above, and then the fixed nut one 621 is locked to complete the initial positioning. When online compensation is needed, the system does not need to be stopped, and the compensation nuts 61 on each compensation device are directly tightened symmetrically and sequentially using tools. During the operation process, the state of the internal traditional fastening nut 41 and the gap change can be monitored in real time through the observation gap 501 on the support compensation sleeve 50 to assist in judging the compensation effect. Through this process, the sealing can be safely and quickly recovered online, and the problem of shutdown maintenance is solved.

[0039] The valve packing pressing cover sealing compensation device and the gate valve disclosed by the application are used to pre-adjust the overall length of the compensation device and install the compensation device on the gate valve, the upper end of the compensation screw is formed to be fixedly abutted, the lower end of the support compensation sleeve is abutted against the valve packing, and the support compensation sleeve is further pressed downward by the compensation nut, so as to realize compensation and pressing of the valve packing, thereby realizing recovery of the sealing performance of the valve packing without stopping the device, and improving the reliability of system operation.

[0040] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A valve packing gland sealing compensation device, comprising a compensation screw (60), characterized in that, The lower part of the compensation screw (60) is provided with a support compensation sleeve (50), which is sleeved on the compensation screw (60); the compensation screw (60) is also provided with a compensation nut (61) located above the support compensation sleeve (50), which is threaded on the compensation screw (60) and can press the support compensation sleeve (50) downward.

2. The valve packing gland sealing compensation device according to claim 1, characterized in that, The top of the compensating screw (60) is provided with an ejector assembly (62).

3. The valve packing gland sealing compensation device according to claim 2, characterized in that, The ejection assembly (62) includes a second fixing nut (622) which is threaded onto the top of the compensating screw (60).

4. The valve packing gland sealing compensation device according to claim 3, characterized in that, The ejection assembly (62) also includes a first fixing nut (621) located below the second fixing nut (622), the first fixing nut (621) being threaded onto the compensating screw (60) and capable of abutting against the second fixing nut (622).

5. The valve packing gland sealing compensation device according to claim 1, characterized in that, A washer (70) is provided between the compensation nut (61) and the support compensation sleeve (50), and the washer (70) is sleeved on the outside of the compensation screw (60).

6. A valve packing gland sealing compensation device according to claim 5, characterized in that, The gasket (70) is provided with a guide plate (71) that extends downward and can cooperate with the side wall of the support compensation sleeve (50).

7. The valve packing gland sealing compensation device according to claim 1, characterized in that, The support compensation sleeve (50) has an observation notch (501) at the bottom of its side wall.

8. A gate valve, comprising a valve cover (10), a valve packing (30), and a valve stem (20), wherein the valve packing (30) is disposed above the valve cover (10) and is pressed onto the valve cover (10) by fastening bolts (40), and the valve stem (20) passes through the valve packing (30), characterized in that, The valve stem (20) is evenly distributed with valve packing gland sealing compensation devices as described in any one of claims 1 to 7 in the circumferential direction, the bottom end of the support compensation sleeve (50) abuts against the valve packing (30), and the top of the compensation screw (60) is connected to the valve stem (20).

9. A gate valve according to claim 8, characterized in that, The valve stem (20) is provided with a pressure plate (21) at its top, and the compensating screw (60) abuts against the bottom surface of the pressure plate (21) through the ejector assembly (62).

10. A gate valve according to claim 8, characterized in that, The valve stem (20) is evenly distributed with fastening bolts (40) in the circumferential direction. The lower part of the fastening bolts (40) is installed on the valve cover (10), and the upper part of the fastening bolts (40) penetrates the valve packing (30) and is pressed against the top surface of the valve packing (30) by fastening nuts (41) threaded to the fastening bolts (40). The fastening nuts (41) are located inside the support compensation sleeve (50).

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