An online adjustable flow corrugated butterfly gas extraction check valve

Abstract

This application discloses an online adjustable flow bellows butterfly check valve, relating to the technical field of butterfly check valves. It includes a valve body, a butterfly plate, a valve cover, an actuator, a split valve stem, a lower valve stem assembly, an upper valve stem assembly, an adjusting structure, a bellows, a guide sleeve, and a protrusion. The actuator drives the upper valve stem assembly to rise and fall, while the lower valve stem assembly pushes the protrusion to rotate the butterfly plate, thus opening and closing the valve. The upper valve stem assembly only performs linear motion, avoiding torsional stress on the bellows, and, together with the welded sealed cavity, achieves zero external leakage sealing. By increasing or decreasing the number of thin and thick gaskets in the adjusting structure, the total length of the split valve stem is changed, and the opening angle of the butterfly plate is adjusted online, thereby precisely controlling the medium flow rate. This application offers the advantages of reliable sealing, online adjustable flow rate, no need to disassemble the valve, and adaptability to different operating conditions.

Description

Technical Field

[0001] This application relates to the technical field of butterfly-type air extraction check valves, and in particular to an online adjustable flow bellows butterfly-type air extraction check valve. Background Technology

[0002] Currently, pneumatic vacuum check valves are widely used in the pipelines from the low-pressure cylinder outlet to the low-pressure heater in thermal power systems. These are commonly classified into two main types: swing and butterfly. Their connection method is mostly butt welding, which means that offline maintenance or adjustment is not possible once installed. Existing vacuum check valves often use flexible graphite packing for the valve stem seal. However, with long-term operation in a high-temperature steam environment, the graphite packing is prone to carbonization. Furthermore, with the reciprocating or rotating motion of the valve stem, the contact surface between the packing and the valve stem gradually wears down, leading to media leakage and posing a safety hazard. Additionally, when these valves are opened, the opening height of the butterfly plate or valve disc is determined by a fixed limiting mechanism within the valve body, allowing only fully open or fully closed states. This makes it impossible to adjust the steam flow according to the differentiated needs of thermal power units under different seasons and loads. If flow regulation is required, an additional regulating valve must be added, increasing equipment costs and pipeline complexity. Moreover, in the manufacturing of industrial automatic control systems, actuators integrating measurement and control functions often require valves with online adjustment capabilities, a requirement that traditional vacuum check valves cannot meet.

[0003] Regarding the aforementioned technologies, existing air extraction check valves generally suffer from unreliable packing seals and are prone to leakage during long-term operation. Furthermore, the valves cannot be adjusted online after installation to regulate flow, thus failing to meet the actual needs of thermal power units operating under varying conditions.

[0004] Therefore, there is an urgent need to provide a vacuum check valve with good sealing performance that can adjust the medium flow rate online without disassembling the valve, in order to solve the problems of high-temperature steam leakage risk and unadjustable flow rate. Summary of the Invention

[0005] The purpose of this application is to provide an online adjustable flow bellows butterfly type air extraction check valve to solve the problems in the prior art.

[0006] The online adjustable flow bellows butterfly check valve provided in this application adopts the following technical solution: it includes a valve body, a butterfly plate, a valve cover, and an actuator. The valve body is provided with a rotatable butterfly plate. The upper end of the valve body is locked with a valve cover by a stud. An actuator is connected above the valve cover. A protrusion is fixed to the middle of the side of the butterfly plate. A guide sleeve is built into the upper end of the valve body. It also includes a split valve stem connected to the butterfly plate and connected to the output end of the actuator.

[0007] By adopting the above technical solution, namely by setting a split valve stem structure, the valve stem can be disassembled and adjusted as a whole. Combined with the bellows sealing structure, it can effectively prevent high-temperature steam from leaking out from the valve stem. At the same time, it can adjust the opening angle of the butterfly plate online without disassembling the valve, thereby controlling the medium flow rate. It can also be used as a detection instrument and actuator for steam pipelines in industrial control systems to realize online adjustment of parameters such as temperature, pressure, and flow rate.

[0008] Preferably, the split valve stem includes a lower valve stem assembly and an upper valve stem assembly, the upper valve stem assembly and the lower valve stem assembly are connected by threads, and the upper valve stem assembly is sealed to the valve cover. The lower end of the lower valve stem assembly is rotatably connected to a protrusion, and the lower valve stem assembly is slidably connected to the inside of the guide sleeve. The split valve stem also includes an adjustment structure for adjusting the threaded connection length between the upper valve stem assembly and the lower valve stem assembly.

[0009] By adopting the above technical solution, namely the threaded connection and adjustment structure between the upper valve stem assembly and the lower valve stem assembly, the overall length of the split valve stem can be changed, thereby controlling the stroke of the lower valve stem assembly pushing the protrusion, realizing precise adjustment of the butterfly plate opening angle, and meeting the flow requirements under different working conditions.

[0010] Preferably, the lower valve stem assembly includes a lower valve stem body and a threaded connector disposed on its top, the threaded connector being threadedly connected to the lower end of the upper valve stem assembly, and the threaded connector having a U-shaped groove on its exterior.

[0011] By adopting the above technical solution, namely by setting a threaded joint, a detachable and adjustable mechanical connection structure is formed between the lower valve stem assembly and the upper valve stem assembly, which facilitates the adjustment of the total length of the valve stem according to the flow requirements, and also facilitates assembly and maintenance.

[0012] Preferably, the upper valve stem assembly includes an upper valve stem body, a bellows support sleeve, a bellows, a threaded hole, and a cylindrical pin hole. The lower end of the upper valve stem body has a threaded hole, and the threaded hole is threadedly connected to a threaded joint. The upper valve stem body is fitted with a bellows support sleeve and a bellows, respectively, and the bellows is located inside the bellows support sleeve. The upper end of the bellows support sleeve is sealed to the inside of the valve cover. The lower part of the upper valve stem body has a cylindrical pin hole.

[0013] By adopting the above technical solution, namely the sealing structure of the bellows and the bellows support sleeve, the contact between the high-temperature medium and the packing can be effectively isolated, avoiding external leakage caused by high-temperature carbonization and wear of the packing. At the same time, the cylindrical pin hole cooperates with the U-shaped groove in the lower valve stem assembly, which facilitates fixing the adjusted position.

[0014] Preferably, the adjusting structure includes a locking nut, a thin washer, a thick washer, a second cylindrical pin, and a retaining ring for the hole. The thin washer and the thick washer are sleeved on the outside of the threaded joint and are locked by the locking nut, which is locked to the outer end of the threaded joint. The second cylindrical pin is inserted into the lower end of the upper valve stem assembly and extends into the U-shaped groove. A retaining ring for the hole is connected to the side of the second cylindrical pin to limit the axial movement of the second cylindrical pin.

[0015] By adopting the above technical solution, namely by combining the number of thin and thick shims and locking the locking nut, the total length of the split valve stem can be precisely adjusted in a step manner. Furthermore, the anti-rotation and positioning are achieved through the cooperation of the second cylindrical pin and the U-shaped groove, ensuring that the adjusted valve stem length is stable and reliable.

[0016] Preferably, the U-shaped grooves are distributed at 90°, and the second cylindrical pin passes through the U-shaped grooves and engages with the cylindrical pin hole on the upper valve stem body.

[0017] By adopting the above technical solution, namely the cooperation between the 90° distributed U-shaped grooves and the second cylindrical pin, the lower valve stem assembly can be rotated 90° relative to the upper valve stem assembly for alignment when adjusting the number of shims, which facilitates assembly and fixation, while ensuring the accuracy of the adjusted angle.

[0018] Preferably, the locking nuts are symmetrically arranged on the upper and lower sides of the threaded joint, and the thickness of the thin washer between the upper and lower locking nuts is 1 / 4 of the thread pitch of the threaded joint.

[0019] By adopting the above technical solution, that is, by designing the thickness of the thin gasket to be 1 / 4 of the pitch, each addition or removal of a thin gasket causes the lower valve stem assembly to rotate 90° relative to the upper valve stem assembly, matching the 90° distribution of the U-shaped groove, thereby achieving fine adjustment of the butterfly plate opening angle to adapt to different flow requirements.

[0020] Preferably, the number of thin gaskets and thick gaskets is set to be increaseable or decreaseable.

[0021] By adopting the above technical solution, that is, by increasing or decreasing the number of thin gaskets and thick gaskets, the total length of the split valve stem can be flexibly adjusted, thereby changing the maximum opening angle of the butterfly plate and realizing online adjustment of the flow range without having to remove the valve from the pipeline as a whole.

[0022] Preferably, the upper valve stem body, the bellows support sleeve, and the bellows are fixed together by welding, and a sealed cavity is formed between the upper valve stem body, the bellows support sleeve, and the bellows.

[0023] By adopting the above technical solution, namely the integrated sealed cavity formed by welding, the high-temperature medium is completely isolated outside the bellows, eliminating the path of medium leakage upward along the valve stem, and solving the problem of traditional packing seals being prone to carbonization and leakage after wear at high temperatures.

[0024] Preferably, connecting plates are fixed on both sides of the butterfly plate, and a rotating rod is connected between the two connecting plates. The outside of the rotating rod is locked to the inside of the connecting plate by a first cylindrical pin, and the two sides of the rotating rod are connected to the end cover. The end cover is installed at the side opening of the valve body. A pressure plate is fixed to the top of the valve cover by fasteners. The middle part of the pressure plate is connected to the outside of the upper valve stem assembly. A connecting block is provided at the upper end of the pressure plate, and the connecting block is located between the output end of the actuator and the upper end of the upper valve stem assembly. The upper end of the valve cover is filled with filler.

[0025] By adopting the above technical solution, the butterfly plate can be stably rotated through the cooperation of the rotating rod and the connecting plate, and the end cover is easy to disassemble and maintain; the pressure plate and the connecting block transmit the linear motion of the actuator to the upper valve stem assembly, and the packing acts as an auxiliary seal to further improve the overall sealing reliability.

[0026] Preferably, the lower valve stem assembly moves up and down with the upper valve stem assembly and pushes the protrusion to rotate and open the butterfly plate, and the lower valve stem assembly and the upper valve stem assembly do not rotate synchronously.

[0027] By adopting the above technical solution, since the lower valve stem assembly and the upper valve stem assembly do not rotate synchronously, the upper valve stem assembly only moves up and down under the drive of the actuator, which avoids the bellows from being subjected to torsional stress, thereby extending the service life of the bellows, while ensuring that the opening action of the butterfly plate is smooth and reliable.

[0028] In summary, this application includes the following beneficial technical effects: 1. This application, by setting a split valve stem, means that the upper valve stem assembly only moves up and down under the drive of the actuator without any torsional movement, thereby completely avoiding the bellows from bearing torsional loads and effectively extending the service life of the bellows. At the same time, the upper valve stem assembly and the valve cover are welded together by the bellows and the bellows support sleeve to form an integrated sealed cavity, completely isolating the high-temperature medium outside the valve stem, achieving zero external leakage sealing at the valve stem, solving the technical problem of external leakage that inevitably occurs in traditional air extraction check valves due to long-term high-temperature carbonization and wear of graphite packing, and significantly improving the operational safety and maintenance cycle of valves in high-temperature conditions such as thermal power plants.

[0029] 2. This application utilizes an adjustment structure consisting of a locking nut, thin gasket, thick gasket, second cylindrical pin, retaining ring for the bore, and U-groove. By increasing or decreasing the number of thin and thick gaskets online, the overall length of the split valve stem can be flexibly changed without disassembling the valve or cutting the pipeline. This precisely adjusts the stroke of the lower valve stem assembly pushing the protrusion, causing a quantitative change in the maximum opening angle of the butterfly plate. This achieves precise online control of the medium flow rate. Compared to indirectly adjusting the opening by controlling the gas source pressure, this mechanical adjustment method offers higher adjustment accuracy, better stability, and resistance to steam pressure fluctuations. This allows the valve to simultaneously function as both a switching valve and a regulating valve. In industrial control systems and testing instruments requiring precise measurement and control of steam flow in industrial manufacturing scenarios, it can serve as an actuator to directly participate in the closed-loop regulation of variables such as temperature, pressure, and flow rate.

[0030] 3. This application establishes a sealed cavity formed by welding the upper valve stem body, bellows support sleeve, and bellows, completely isolating the high-temperature steam medium within the sealed space outside the bellows. This prevents the medium from leaking upwards along the valve stem. Even if the auxiliary packing at the upper end of the valve cover carbonizes or wears under long-term high-temperature conditions, the valve can still guarantee zero external leakage at the valve stem because the main seal of the bellows remains effective. Therefore, this solves the problem of traditional air extraction check valves relying on a single packing seal experiencing rapid performance degradation at high temperatures and requiring frequent shutdowns to replace the packing.

[0031] 4. This application utilizes the cooperation between the lower valve stem assembly and the protrusion. When the system needs to prevent backflow of the medium, the actuator cuts off the air supply and pushes the output end to descend rapidly. This causes the upper valve stem assembly to drive the lower valve stem assembly downward, and the lower valve stem assembly quickly pushes the protrusion to rotate the butterfly plate to the closed position. At the same time, if the medium in the pipeline flows in reverse, the reverse medium pressure will also help push the butterfly plate to tightly fit the valve body sealing surface, forming a dual closing effect of spring driving force and medium pressure, ensuring that the butterfly plate closes quickly and the seal is reliable. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the internal structure of this application; Figure 2 This is a schematic diagram of the left-side view structure of this application; Figure 3 This is a schematic diagram of the split valve stem structure of this application; Figure 4 This is a schematic diagram of the internal structure of the valve stem assembly and regulating structure under this application; Figure 5 This is a front view of the internal structure of the valve stem assembly in this application; Figure 6 This is a schematic diagram of the tension structure of the valve stem assembly in this application.

[0033] Explanation of reference numerals in the attached drawings: 1. Valve body; 2. Butterfly plate; 3. Connecting plate; 4. Rotating rod; 5. First cylindrical pin; 6. End cap; 7. Protrusion; 8. Lower valve stem assembly; 81. Lower valve stem body; 82. Threaded joint; 83. U-groove; 84. Thin gasket; 85. Thick gasket; 86. Lock nut; 87. Second cylindrical pin; 88. Hole retaining ring; 9. Upper valve stem assembly; 91. Upper valve stem body; 92. Bellows support sleeve; 93. Bellows; 94. Threaded hole; 95. Cylindrical pin hole; 10. Valve cover; 11. Pressure plate; 12. Connecting block; 13. Actuator; 14. Guide sleeve; 15. Packing. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1 - Appendix Figure 6 This application will be described in further detail below.

[0035] An online adjustable flow bellows butterfly type air extraction check valve, refer to Figures 1-2 The valve comprises a valve body 1, a butterfly plate 2, a valve cover 10, and an actuator 13. The valve body 1 contains a rotatable butterfly plate 2. The upper end of the valve body 1 is locked with a valve cover 10 by a stud. The actuator 13 is connected above the valve cover 10. A protrusion 7 is fixed to the middle of the side of the butterfly plate 2. A guide sleeve 14 is built into the upper end of the valve body 1. The valve also includes a split valve stem connected to the butterfly plate 2 and connected to the output end of the actuator 13. The valve of this application is suitable for industrial control systems, detection instruments, actuators, and supporting equipment manufacturing in industrial manufacturing scenarios for measuring and controlling variables such as temperature, pressure, flow, and level, or for regulating parameters such as the position, tilt, and rotation of objects. It can be used as an online adjustable actuator for steam pipelines of thermal power units.

[0036] Specifically, by setting a split valve stem structure, the valve stem can be disassembled and adjusted as a whole. Combined with the bellows sealing structure, it can effectively prevent high-temperature steam from leaking out from the valve stem. At the same time, it can adjust the opening angle of the butterfly plate 2 online without disassembling the valve, thereby controlling the medium flow.

[0037] In this design, connecting plates 3 are fixed on both sides of the butterfly plate 2, and rotating rods 4 are connected between the two connecting plates 3. The outside of the rotating rods 4 is locked to the inside of the connecting plates 3 by the first cylindrical pin 5, and the two sides of the rotating rods 4 are connected to the end caps 6. The end caps 6 are installed at the side opening of the valve body 1. The top of the valve cover 10 is fixed with a pressure plate 11 by fasteners. The middle part of the pressure plate 11 is connected to the outside of the upper valve stem assembly 9. The upper end of the pressure plate 11 is provided with a connecting block 12, and the connecting block 12 is located between the output end of the actuator 13 and the upper end of the upper valve stem assembly 9. The upper end of the valve cover 10 is filled with packing 15, and the packing 15 is only used as an auxiliary seal or a backup seal, not a main seal. Even if the packing 15 degrades in performance under long-term high temperature, the valve can still ensure zero external leakage due to the main sealing effect of the bellows 93. This greatly improves the operational reliability of the valve under high temperature conditions such as thermal power.

[0038] Specifically, the butterfly plate 2 is stably rotated by the cooperation of the rotating rod 4 and the connecting plate 3, and the end cover 6 is easy to disassemble and maintain; the pressure plate 11 and the connecting block 12 transmit the linear motion of the actuator 13 to the upper valve stem assembly 9, and the packing 15 serves as an auxiliary seal to further improve the overall sealing reliability.

[0039] The lower valve stem assembly 8 moves up and down with the upper valve stem assembly 9 and pushes the protrusion 7 to make the butterfly plate 2 rotate and open. The lower valve stem assembly 8 and the upper valve stem assembly 9 do not rotate synchronously.

[0040] Specifically, since the lower valve stem assembly 8 and the upper valve stem assembly 9 do not rotate synchronously, the upper valve stem assembly 9 only moves up and down under the drive of the actuator 13, which avoids the bellows 93 from being subjected to torsional stress, thereby extending the service life of the bellows 93, while ensuring that the opening action of the butterfly plate 2 is smooth and reliable.

[0041] Reference Figure 3 The split valve stem includes a lower valve stem assembly 8 and an upper valve stem assembly 9. The upper valve stem assembly 9 and the lower valve stem assembly 8 are connected by threads, and the upper valve stem assembly 9 is sealed to the valve cover 10. The lower end of the lower valve stem assembly 8 is rotatably connected to the protrusion 7, and the lower valve stem assembly 8 is slidably connected to the guide sleeve 14.

[0042] Specifically, through the threaded connection and adjustment structure between the upper valve stem assembly 9 and the lower valve stem assembly 8, the overall length of the split valve stem can be changed without disassembling the valve or cutting the pipeline. This allows for precise control of the stroke of the lower valve stem assembly 8 pushing the protrusion 7, enabling online precise adjustment of the opening angle of the butterfly plate 2. Consequently, it breaks the limitation of traditional air extraction check valves being used only as on / off valves, giving them the function of regulating valves. This allows them to meet the differentiated flow requirements of thermal power units under different seasons and loads, while saving additional regulating valve equipment and pipeline space.

[0043] Reference Figure 4The lower valve stem assembly 8 includes a lower valve stem body 81 and a threaded connector 82 disposed on its top. The threaded connector 82 is threadedly connected to the lower end of the upper valve stem assembly 9, and a U-shaped groove 83 is provided on the outside of the threaded connector 82.

[0044] Specifically, by setting the threaded joint 82, a detachable and adjustable mechanical connection structure is formed between the lower valve stem assembly 8 and the upper valve stem assembly 9, which facilitates the adjustment of the total length of the valve stem according to the flow requirements, and also facilitates assembly and maintenance.

[0045] The split valve stem also includes an adjustment structure for adjusting the threaded connection length between the upper valve stem assembly 9 and the lower valve stem assembly 8. The adjustment structure includes a locking nut 86, a thin washer 84, a thick washer 85, a second cylindrical pin 87, and a retaining ring 88. The thin washer 84 and the thick washer 85 are sleeved on the outside of the threaded joint 82 and are locked by the locking nut 86. The locking nut 86 is locked to the outer end of the threaded joint 82. The second cylindrical pin 87 is inserted into the lower end of the upper valve stem assembly 9 and extends into the U-shaped groove 83. The retaining ring 88 is connected to the side of the second cylindrical pin 87 to limit the axial movement of the second cylindrical pin 87.

[0046] Specifically, the regulating structure, through the combination of thin shims 84 and thick shims 85 and the locking of the locking nut 86, can achieve precise step-wise adjustment of the total length of the split valve stem. The anti-rotation and positioning are achieved through the cooperation of the second cylindrical pin 87 and the U-shaped groove 83, ensuring that the adjusted valve stem length is stable and reliable. Compared with the method of adjusting the opening by controlling the gas source pressure, this mechanical combination regulation method has higher precision, stability and anti-interference ability, and is not affected by steam pressure fluctuations.

[0047] The U-shaped grooves 83 are distributed at 90°, and the second cylindrical pin 87 passes through the U-shaped grooves 83 and engages with the cylindrical pin hole 95 on the upper valve stem body 91.

[0048] Specifically, the U-shaped grooves 83 distributed at 90° cooperate with the second cylindrical pin 87, so that when adjusting the number of shims, the lower valve stem assembly 8 can rotate 90° relative to the upper valve stem assembly 9 for alignment, which facilitates assembly and fixation, while ensuring the accuracy of the adjusted angle.

[0049] Among them, the locking nuts 86 are symmetrically arranged on the upper and lower sides of the threaded joint 82, and the thickness of the thin washer 84 between the upper and lower locking nuts 86 is 1 / 4 of the thread pitch of the threaded joint 82.

[0050] Specifically, by designing the thickness of the thin gasket 84 to be 1 / 4 of the pitch, each addition or removal of a thin gasket 84 causes the lower valve stem assembly 8 to rotate 90° relative to the upper valve stem assembly 9. This precisely matches the 90° distribution of the U-shaped groove 83. By adding or removing the number of gaskets and rotating the corresponding angle, the opening angle of the butterfly plate 2 can be quantitatively and precisely adjusted, thereby finely controlling the flow rate and adapting to different working conditions.

[0051] The number of thin gaskets 84 and thick gaskets 85 is set to be increaseable or decreaseable.

[0052] Specifically, by increasing or decreasing the number of thin gaskets 84 and thick gaskets 85, the total length of the split valve stem can be flexibly adjusted, thereby changing the maximum opening angle of the butterfly plate 2 and realizing online adjustment of the flow range without having to remove the valve from the pipeline as a whole.

[0053] Reference Figures 5-6 The upper valve stem assembly 9 includes an upper valve stem body 91, a bellows support sleeve 92, a bellows 93, a threaded hole 94, and a cylindrical pin hole 95. The lower end of the upper valve stem body 91 is provided with a threaded hole 94, and the inside of the threaded hole 94 is threadedly connected to the threaded connector 82. The bellows support sleeve 92 and the bellows 93 are respectively sleeved on the outside of the upper valve stem body 91, and the bellows 93 is located inside the bellows support sleeve 92. The upper end of the bellows support sleeve 92 is sealed to the inside of the valve cover 10. The lower part of the upper valve stem body 91 is provided with a cylindrical pin hole 95.

[0054] Specifically, the sealing structure of the bellows 93 and the bellows support sleeve 92 can effectively isolate the high-temperature medium from the packing 15, preventing external leakage caused by high-temperature carbonization and wear of the packing 15. At the same time, the cylindrical pin hole 95 cooperates with the U-shaped groove 83 in the lower valve stem assembly 8 to facilitate fixing the adjusted position.

[0055] The upper valve stem body 91, the bellows support sleeve 92, and the bellows 93 are fixed together by welding, and a sealed cavity is formed between the upper valve stem body 91, the bellows support sleeve 92, and the bellows 93.

[0056] Specifically, the integrated sealed cavity formed by welding completely isolates the high-temperature medium outside the bellows 93, eliminating the path of medium leakage upward along the valve stem and solving the problem of traditional packing seals being prone to carbonization and leakage after wear at high temperatures.

[0057] The working principle of this application is as follows: When the actuator 13 is not ventilated or is in a de-ventilated state, the actuator 13 pushes its output end downward, which drives the upper valve stem assembly 9 to descend through the connecting block 12. The upper valve stem assembly 9 drives the lower valve stem assembly 8 to descend synchronously. The lower end of the lower valve stem assembly 8 pushes the protrusion 7, causing the butterfly plate 2 to rotate around the rotating rod 4 to a position that is in contact with the sealing surface of the valve body 1. The valve is in the closed state. At this time, the medium cannot pass through the valve, thus realizing the check valve function. When the actuator 13 is connected to the air source, its output end is lifted upward, driving the upper valve stem assembly 9 to rise through the connecting block 12. Since the upper valve stem assembly 9 and the lower valve stem assembly 8 are connected by threads, and the lower end of the lower valve stem assembly 8 is rotatably connected to the protrusion 7, the upper valve stem assembly 9 will drive the lower valve stem assembly 8 to slide upward along the guide sleeve 14 when it rises. After the lower valve stem assembly 8 rises, the pushing constraint on the protrusion 7 is released, and the butterfly plate 2 rotates around the rotating rod 4 under the push of the medium pressure, and the medium begins to flow. During this process, the upper valve stem assembly 9 only makes linear lifting and lowering movements and does not generate torsion, thereby effectively avoiding the bellows 93 from bearing torsional load and extending its service life. The upper valve stem body 91, bellows support sleeve 92, and bellows 93 in the upper valve stem assembly 9 are fixed together by welding to form a sealed cavity. When the valve is installed in the pipeline, the high-temperature steam medium is completely isolated outside the sealed cavity and cannot leak upward along the valve stem. At the same time, the packing 15 filled inside the upper end of the valve cover 10 is only used as an auxiliary seal or a backup seal. Even if the packing 15 carbonizes or wears under long-term high-temperature environment, the main sealing function of the bellows 93 is still effective, and the valve can still ensure zero external leakage at the valve stem, which completely solves the problem of external leakage caused by packing wear in traditional air extraction check valves. When a thermal power unit needs to change the steam flow through the valve under different circumstances, there is no need to cut or remove the valve from the pipeline or replace any parts. Operators only need to follow these steps for online adjustment: First, remove the pressure plate 11 and connecting block 12 to expose the connection between the upper valve stem assembly 9 and the lower valve stem assembly 8. Next, loosen the locking nut 86 and calculate the number of thin shims 84 and thick shims 85 that need to be added or removed based on the required flow rate change. The thickness of the thin shim 84 is designed to be 1 / 4 of the thread pitch of the threaded connector 82. For each addition or removal of a thin shim 84, the lower valve stem assembly 8 rotates 90° relative to the upper valve stem assembly 9, which matches the 90° distribution of the U-shaped groove 83. Then, after adjusting the number of thin shims 84 and thick shims 85, tighten the locking nut 86 to lock the adjusted length, and pass the second cylindrical pin 87 through the U-shaped groove 83 to engage with the cylindrical pin hole 95. Finally, insert the hole retaining ring 88 to prevent the cylindrical pin from moving axially. After adjustment, reinstall the connecting block 12 and the pressure plate 11. At this time, the total length of the split valve stem has changed. When the actuator 13 opens the valve again, the stroke limit point of the lower valve stem assembly 8 on the protrusion 7 changes, and the maximum opening angle of the butterfly plate 2 changes accordingly, thereby realizing the online precise adjustment of the medium flow rate and meeting the flow requirements under different operating conditions. When the system needs to prevent backflow of the medium, the actuator 13 cuts off the air source and pushes the output end down rapidly, which drives the upper valve stem assembly 9 and the lower valve stem assembly 8 to move downward. The lower valve stem assembly 8 quickly pushes the protrusion 7, causing the butterfly plate 2 to rotate quickly to the closed position. At the same time, if the medium in the pipeline flows in reverse, the medium pressure will also help push the butterfly plate 2 to tightly fit the sealing surface of the valve body 1, forming a double closing effect to ensure a reliable check flow effect.

[0058] This application provides an online adjustable flow bellows butterfly check valve, comprising a valve body 1, a butterfly plate 2, a valve cover 10, an actuator 13, a split valve stem, a lower valve stem assembly 8, an upper valve stem assembly 9, an adjusting structure, a bellows 93, a guide sleeve 14, and a protrusion 7. The actuator 13 drives the upper valve stem assembly 9 to rise and fall, while the lower valve stem assembly 8 pushes the protrusion 7 to rotate the butterfly plate 2, thus opening and closing the valve. The upper valve stem assembly 9 only performs linear motion, avoiding torsional stress on the bellows 93, and, together with the welded sealed cavity, achieves zero external leakage sealing. By increasing or decreasing the number of thin gaskets 84 and thick gaskets 85 in the adjusting structure, the total length of the split valve stem is changed, and the opening angle of the butterfly plate 2 is adjusted online, thereby precisely controlling the medium flow rate. This application features reliable sealing, online adjustable flow, no need to disassemble the valve, and adaptability to different operating conditions.

[0059] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. An online adjustable flow bellows butterfly type air pumping check valve, comprising a valve body (1), a butterfly plate (2), a valve cover (10) and an actuator (13), wherein a rotatable butterfly plate (2) is provided inside the valve body (1), the valve cover (10) is locked to the upper end of the valve body (1) by a stud, the actuator (13) is connected above the valve cover (10), a protrusion (7) is fixed to the middle of the side of the butterfly plate (2), and a guide sleeve (14) is built into the upper end of the valve body (1); characterized in that It also includes a split valve stem connected to the butterfly plate (2) and connected to the output end of the actuator (13). The split valve stem includes a lower valve stem assembly (8) and an upper valve stem assembly (9). The upper valve stem assembly (9) and the lower valve stem assembly (8) are connected by threads, and the upper valve stem assembly (9) is sealed to the valve cover (10). The lower end of the lower valve stem assembly (8) is rotatably connected to the protrusion (7), and the lower valve stem assembly (8) is slidably connected to the guide sleeve (14). The split valve stem also includes an adjustment structure for adjusting the threaded connection length between the upper valve stem assembly (9) and the lower valve stem assembly (8).

2. An online adjustable flow bellows globe suction check valve according to claim 1, wherein: The lower valve stem assembly (8) includes a lower valve stem body (81) and a threaded connector (82) disposed on its top. The threaded connector (82) is threadedly connected to the lower end of the upper valve stem assembly (9). A U-shaped groove (83) is provided on the outside of the threaded connector (82).

3. An online adjustable flow bellows globe suction check valve according to claim 2, wherein: The upper valve stem assembly (9) includes an upper valve stem body (91), a bellows support sleeve (92), a bellows (93), a threaded hole (94), and a cylindrical pin hole (95). The lower end of the upper valve stem body (91) is provided with a threaded hole (94), and the inside of the threaded hole (94) is threadedly connected to the threaded connector (82). The upper valve stem body (91) is respectively fitted with a bellows support sleeve (92) and a bellows (93), and the bellows (93) is located inside the bellows support sleeve (92). The upper end of the bellows support sleeve (92) is sealed to the inside of the valve cover (10). The lower part of the upper valve stem body (91) is provided with a cylindrical pin hole (95).

4. An online adjustable flow bellows globe steam trap valve according to claim 3, wherein: The adjustment structure includes a locking nut (86), a thin washer (84), a thick washer (85), a second cylindrical pin (87), and a retaining ring (88) for holes. The thin washer (84) and the thick washer (85) are fitted onto the outside of the threaded joint (82) and locked by the locking nut (86). The locking nut (86) is locked to the outer end of the threaded joint (82). The second cylindrical pin (87) is inserted into the lower end of the upper valve stem assembly (9) and extends into the U-shaped groove (83). A retaining ring (88) for holes is connected to the side of the second cylindrical pin (87) to limit the axial movement of the second cylindrical pin (87).

5. An online adjustable flow bellows globe suction check valve according to claim 4, wherein: The U-shaped groove (83) is distributed at 90°, and the second cylindrical pin (87) passes through the U-shaped groove (83) and engages with the cylindrical pin hole (95) on the upper valve stem body (91).

6. The online adjustable flow bellows butterfly type air extraction check valve according to claim 4, characterized in that: The locking nuts (86) are symmetrically arranged on the upper and lower sides of the threaded joint (82), and the thickness of the thin washer (84) between the upper and lower locking nuts (86) is 1 / 4 of the thread pitch of the threaded joint (82).

7. The online adjustable flow bellows butterfly type air extraction check valve according to claim 4, characterized in that: The number of thin pads (84) and thick pads (85) is set to be increaseable or decreaseable.

8. The online adjustable flow bellows butterfly type air extraction check valve according to claim 3, characterized in that: The upper valve stem body (91), the bellows support sleeve (92) and the bellows (93) are fixed together by welding, and a sealed cavity is formed between the upper valve stem body (91), the bellows support sleeve (92) and the bellows (93).

9. The online adjustable flow bellows butterfly type air extraction check valve according to claim 1, characterized in that: The butterfly plate (2) is fixed with connecting plates (3) on both sides, and a rotating rod (4) is connected between the connecting plates (3) on both sides. The outside of the rotating rod (4) is locked to the inside of the connecting plate (3) by the first cylindrical pin (5), and the two sides of the rotating rod (4) are connected to the end cover (6). The end cover (6) is installed at the side opening of the valve body (1). The top of the valve cover (10) is fixed with a pressure plate (11) by fasteners. The middle part of the pressure plate (11) is connected to the outside of the upper valve stem assembly (9). The upper end of the pressure plate (11) is provided with a connecting block (12), and the connecting block (12) is located between the output end of the actuator (13) and the upper end of the upper valve stem assembly (9). The upper end of the valve cover (10) is filled with filler (15).

10. The online adjustable flow bellows butterfly type air extraction check valve according to claim 1, characterized in that: The lower valve stem assembly (8) moves up and down with the upper valve stem assembly (9) and pushes the protrusion (7) to make the butterfly plate (2) rotate open and close. The lower valve stem assembly (8) and the upper valve stem assembly (9) do not rotate synchronously.

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