Large-diameter rubber butterfly valve for fluid delivery and opening degree fine adjustment method thereof

Abstract

The application discloses a large-diameter rubber-lined butterfly valve for fluid delivery, which comprises a large-diameter rubber-lined butterfly valve body, the large-diameter rubber-lined butterfly valve body comprises a valve body and a valve plate rotatably installed in the valve body, an inner wall of the valve body is provided with a valve body rubber sealing surface, an adjusting plate is arranged on the valve body, the adjusting plate is arranged between the valve body and the valve body rubber sealing surface, a plurality of fine adjustment bolts are threadedly inserted on an outer wall of the valve body, and through the fact that a thrust bearing positioning structure is sleeved on both ends of a shaft part of the valve plate, it is ensured that the valve plate always keeps accurate axial positioning and does not displace and shift when the valve plate bears fluid high-pressure impact or rotates to open and close. Compared with the prior art, the device guarantees the centering consistency of the valve plate and the circumferential sealing surface from the structural root, and provides guarantee for realizing long-term tight sealing and prolonging the service life.

Description

Technical Field

[0001] This invention belongs to the field of valve technology, specifically relating to a large-diameter rubber-lined butterfly valve for fluid transportation and a method for fine-tuning its opening. Background Technology

[0002] In modern industrial fluid transportation fields such as petrochemicals, power systems, and large-scale water conservancy projects, large-diameter rubber-lined butterfly valves are core components for controlling the flow and cut-off of media. Their sealing performance directly affects the operational safety and efficiency of the entire pipeline.

[0003] Existing rubber-lined butterfly valve devices, due to the enormous fluid pressure and frequent opening and closing of large-diameter valves, are prone to axial displacement or offset of the valve plate shaft under long-term fluid impact. This leads to uneven stress on the sealing surface and accelerates local wear of the rubber layer, resulting in a decrease in sealing tightness. Furthermore, the sealing structure is mostly fixed. Once a leak occurs due to minor wear or deformation of the sealing surface, it is usually necessary to shut down the entire valve from the pipeline system and disassemble it for offline maintenance or replacement of the seals. This forces a long-term interruption of fluid transportation operations, significantly reducing the operational continuity and maintenance economy of the fluid transportation system. Summary of the Invention

[0004] The purpose of this invention is to provide a large-diameter rubber-lined butterfly valve for fluid transport, in order to solve the problems mentioned in the background art.

[0005] In a first aspect, the present invention provides a large-diameter rubber-lined butterfly valve for fluid transport, comprising: The large-diameter rubber-lined butterfly valve body includes a valve body and a valve plate rotatably mounted inside the valve body. Thrust bearings are fitted on the upper and lower ends of the valve plate's shaft. The inner wall of the valve body has a valve body rubber sealing surface. An adjusting plate is provided on the valve body, positioned between the valve body and the valve body rubber sealing surface. Multiple fine-tuning bolts are threaded into the outer wall of the valve body, with one end of each bolt passing through the valve body and abutting against the outer wall of the adjusting plate.

[0006] In one possible implementation of the first aspect, the thrust bearing is fixedly mounted in the bearing housing of the valve body.

[0007] In one possible implementation of the first aspect, the adjusting plate has an arc-shaped structure, and the curvature of the adjusting plate is adapted to the circumferential curvature of the inner wall of the valve body.

[0008] In one possible implementation of the first aspect, multiple regulating plates are provided along the inner circumferential direction of the valve body, and the multiple regulating plates are distributed in a ring array.

[0009] In one possible implementation of the first aspect, the outer walls of the adjusting plate abut against at least two fine-tuning bolts, and the fine-tuning bolts are evenly distributed along the length of the adjusting plate.

[0010] In one possible implementation of the first aspect, the valve body has a threaded through hole adapted to the fine-tuning bolt, the head of the fine-tuning bolt is located outside the valve body, and the end of the fine-tuning bolt is planar and contacts the adjusting plate.

[0011] Compared with the prior art, the present invention provides a large-diameter rubber-lined butterfly valve for fluid transportation, which has the following advantages: 1. By installing thrust bearing positioning structures at both ends of the valve plate shaft, the valve plate maintains precise axial positioning without displacement when subjected to high-pressure fluid impact or rotary opening and closing actions. Compared to existing large-diameter butterfly valves, which are prone to uneven pressure on the sealing surface and uneven wear leakage due to axial misalignment, this device ensures the alignment consistency between the valve plate and the circumferential sealing surface from the structural source, providing a guarantee for long-term tight sealing and extended service life. Second, the online compensation mechanism using fine-tuning bolts and arc-shaped adjusting plates utilizes threaded transmission to drive the adjusting plate to generate radial displacement in the centripetal direction, thereby actively adjusting the interference fit between the rubber sealing surface and the valve plate edge. This effectively solves the technical problem that traditional large-diameter valves must be shut down and completely disassembled for repair after sealing failure. The valve can regain its sealing effect without leaving the pipeline, greatly saving manpower and material costs for installation and maintenance, and significantly improving the operational continuity of the fluid transport system.

[0012] Secondly, the present invention provides a method for fine-tuning the opening of a large-diameter rubber-lined butterfly valve for fluid transport, comprising: Collect fluid differential pressure data when the large-diameter rubber-lined butterfly valve body is in the closed state, analyze the leakage of the valve body rubber sealing surface based on the fluid differential pressure data, and calculate the sealing interference adjustment amount required for the large-diameter rubber-lined butterfly valve body to restore a tight sealing state based on the leakage amount. Obtain the pitch parameter of the fine-tuning bolt, establish the proportional relationship between the rotation angle of the fine-tuning bolt and the displacement of the adjusting plate based on the pitch parameter, and combine the proportional relationship and the sealing interference adjustment amount to obtain the target rotation angle displacement of the fine-tuning bolt; Based on the target rotational angular displacement, the tightening execution parameters of the fine-tuning bolt are set. The tightening execution parameters include the symmetrical adjustment sequence and step angle of multiple bolts. With the valve body still installed in the pipeline and not detached, the fine-tuning bolt is rotated based on the tightening execution parameters, driving the adjustment plate to move radially and squeeze the rubber sealing surface of the valve body, so as to change the contact posture between the sealing surface and the edge of the valve plate, thereby realizing the fine-tuning of the opening degree of the sealing accuracy of the large-diameter rubber-lined butterfly valve in the closed state.

[0013] In one possible implementation of the second aspect, the analysis of the leakage of the valve body rubber sealing surface based on the fluid differential pressure data includes: Based on the fluid differential pressure data, the unit squeezing force generated by the fluid inside the valve body at the sealing interface is determined; Find the nominal diameter and total length of the sealing ring corresponding to the body of the large-diameter rubber-lined butterfly valve; By combining the unit extrusion force, the nominal diameter, and the total length of the sealing ring, the instantaneous seepage intensity of the fluid medium bypassing the rubber sealing surface of the valve body is calculated. Based on the instantaneous seepage intensity, determine the equivalent flow channel cross-sectional area at the rubber sealing surface of the valve body; The leakage amount of the valve body rubber sealing surface is determined based on the unit extrusion force, the equivalent flow channel cross-sectional area, and the instantaneous seepage intensity.

[0014] In one possible implementation of the second aspect, calculating the sealing interference adjustment amount required for the large-diameter rubber-lined butterfly valve body to restore a tight seal based on the leakage amount includes: Based on the leakage amount, determine the actual total amount of fluid seepage in the body of the large-diameter rubber-lined butterfly valve over a specific time span; Query the preset zero leakage reference value of the large-diameter rubber-lined butterfly valve body under standard operating conditions; Based on the actual total seepage and the preset zero leakage benchmark value, the required sealing interference adjustment amount for restoring the large-diameter rubber-lined butterfly valve body to a tight seal state is calculated using the following formula: in, This indicates the amount of sealing interference adjustment required to restore the body of a large-diameter rubber-lined butterfly valve to a tight seal. This represents the actual seepage flow rate corresponding to the i-th sample. This represents the preset zero-leakage baseline value, where i represents the sampling sequence number and n represents the total number of samples within the statistical loop. This indicates the conversion ratio term.

[0015] In one possible implementation of the second aspect, obtaining the target rotational angular displacement of the fine-tuning bolt by combining the proportional relationship and the sealing interference adjustment amount includes: Obtain the initial angle information of the fine-tuning bolt at the starting position, and use the proportional relationship to determine the unit angular displacement feed amount of the bolt at the current screw-in depth; Calculate the displacement loss value of the threaded pair under load due to deformation, and combine it with the sealing interference adjustment amount to obtain the actual physical path that the adjusting plate needs to complete. Based on the aforementioned proportional relationship, the actual physical path, and the torque feedback value of the threaded friction surface, the displacement conversion correction rate of the fine-tuning bolt is calculated. The target rotational angular displacement of the fine-tuning bolt is calculated by measuring the shape recovery period of the sealing material after being compressed, combining the proportional relationship, the displacement conversion correction rate, and the actual physical path.

[0016] As can be seen, this invention collects fluid pressure differential data when the large-diameter rubber-lined butterfly valve body is in the closed state, and analyzes the leakage of the valve body's rubber sealing surface based on the fluid pressure differential data. This allows for a quantitative assessment of the weakening degree and void distribution of the sealing surface under pressure load, providing a quantitative basis for the subsequent precise displacement adjustment of the fine-tuning bolt. By obtaining the pitch parameter of the fine-tuning bolt, this invention confirms the proportional relationship between the rotation angle and the displacement of the adjusting plate, and calculates the target rotation angle displacement in conjunction with the sealing interference adjustment amount. This provides a physical feedback correlation between the displacement and rotation angle of the adjusting plate during the sealing adjustment process, providing a quantitative basis for the precise execution of the subsequent sealing pre-tightening action. By combining the target rotation angle displacement and the symmetrical adjustment sequence, this invention sets the order of bolt rotation, thereby obtaining an adjustment rhythm that is balanced with the circumferential stress distribution of the valve body, ensuring that the adjusting plate remains aligned with the axis during the advancement process and avoiding stress tilting of the sealing interface. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a three-dimensional structural diagram of a large-diameter rubber-lined butterfly valve for fluid transport according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the main structure of a large-diameter rubber-lined butterfly valve body according to an embodiment of the present invention; Figure 3 This is a partial cross-sectional schematic diagram of the valve body and sealing adjustment assembly according to an embodiment of the present invention; Figure 4This is a partially enlarged schematic diagram of the contact state between the valve plate edge and the rubber sealing surface according to an embodiment of the present invention; Figure 5 This is a partially enlarged schematic diagram of the mating part between the fine-tuning bolt and the adjusting plate according to an embodiment of the present invention; Figure 6 This is a schematic diagram showing the connection details between the adjusting plate and the rubber sealing surface of the valve body according to an embodiment of the present invention; Figure 7 This is a flowchart of a method for fine-tuning the opening of a large-diameter rubber-lined butterfly valve for fluid transport, according to an embodiment of the present invention. In the diagram: 1. Large-diameter rubber-lined butterfly valve body; 11. Thrust bearing; 12. Valve plate; 13. Valve body; 14. Adjusting plate; 15. Valve body rubber sealing surface; 16. Fine-tuning bolt. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1-6 The valve body includes a large-diameter rubber-lined butterfly valve body 1. The large-diameter rubber-lined butterfly valve body 1 includes a valve body 13 and a valve plate 12 rotatably mounted inside the valve body 13. Thrust bearings 11 are fitted onto the upper and lower ends of the valve plate 12. A valve body rubber sealing surface 15 is provided on the inner wall of the valve body 13. An adjusting plate 14 is provided on the valve body 13, positioned between the valve body 13 and the valve body rubber sealing surface 15. Multiple fine-tuning bolts 16 are threaded into the outer wall of the valve body 13. One end of the adjusting bolt 16 passes through the valve body 13 and abuts against the outer wall of the adjusting plate 14. The tightening pressure of the adjusting bolt 16 acts on the adjusting plate 14, which can directly change the interference between the rubber sealing surface 15 of the valve body and the edge of the valve plate 12. When the valve fails to seal properly after a certain period of use, the operator can drive the adjusting plate 14 to move towards the center of the valve cavity by turning the adjusting bolt 16 inward without disassembling the valve, thereby increasing the interference and achieving the effect of resealing, effectively extending the service life of the valve.

[0020] The thrust bearing 11 is fixedly installed in the bearing seat of the valve body 13. The thrust bearing 11 can provide precise axial positioning for the valve plate 12, ensuring that the valve plate 12 will not move axially during fluid pressure impact or rotation, thus ensuring the alignment of the valve plate 12 with the circumferential sealing surface from the structural basis.

[0021] The adjusting plate 14 has an arc-shaped structure, and the curvature of the adjusting plate 14 is adapted to the circumferential curvature of the inner wall of the valve body 13. Multiple adjusting plates 14 are provided along the inner circumference of the valve body 13, and the multiple adjusting plates 14 are arranged in a ring array. Through the combination of multiple arc-shaped adjusting plates 14, the entire circumferential surface of the valve seat is fully covered.

[0022] At least two fine-tuning bolts 16 abut against the outer side wall of the adjusting plate 14, and the fine-tuning bolts 16 are evenly distributed along the length of the adjusting plate 14. The arrangement of double or multiple bolts ensures that the thrust acting on the adjusting plate 14 is more uniform and balanced, avoids the adjusting plate 14 from tilting, and thus ensures the uniform deformation of the valve body rubber sealing surface 15 after being compressed.

[0023] The valve body 13 has a threaded through hole that matches the fine-tuning bolt 16. The head of the fine-tuning bolt 16 is located outside the valve body 13, and the end of the fine-tuning bolt 16 is flat and contacts the adjusting plate 14. Without stopping production or removing the valve from the pipeline, the sealing surface can be compensated with simple external tools, which greatly saves the time, manpower and material resources for installation and maintenance.

[0024] The working principle and usage process of the large-diameter rubber-lined butterfly valve for fluid transportation of the present invention are as follows: First, the large-diameter rubber-lined butterfly valve body 1 is installed in the fluid transportation pipeline. The valve plate 12 is precisely axially positioned by the thrust bearings 11 at both ends to ensure that the valve plate 12 is always in the center position of the valve body 13 during the rotation and opening and closing process, so as to avoid uneven pressure on the sealing surface caused by axial movement. During the long-term operation after the valve is put into use, if the rubber sealing surface 15 of the valve body and the valve plate 12 are not sealed properly or leak due to rubber wear or media erosion, the operator can perform online sealing compensation without stopping production or disassembling the valve. The specific adjustment process is as follows: The operator determines the corresponding adjustment area according to the specific location of the leakage, and then rotates the fine adjustment bolt 16 corresponding to the area from the outside of the valve body 13; the fine adjustment bolt 16 is pushed towards the center of the valve body through the thread drive, and its flat end abuts against and drives the arc-shaped adjustment plate 14 to move synchronously. The adjustment plate 14 then squeezes the rubber sealing surface 15 of the valve body, causing it to deform radially towards the valve plate 12, thereby actively increasing the interference between the rubber sealing surface and the edge of the valve plate 12; Through the above adjustment process, the gaps caused by wear are compensated, allowing the valve body to regain a tight seal. Furthermore, because the adjusting plates 14 are arranged in a ring array, precise fine-tuning of the circumferential sealing surface can be achieved. After adjustment, the valve can return to its normal high-pressure sealing operation. The entire process requires no disassembly or installation, greatly improving maintenance efficiency and extending the valve's service life.

[0025] See Figure 7 The diagram shows a flowchart of a method for fine-tuning the opening of a large-diameter rubber-lined butterfly valve for fluid transport, according to an embodiment of the present invention, including: S1. Collect the fluid differential pressure data when the large-diameter rubber-lined butterfly valve body is in the closed state, analyze the leakage of the valve body rubber sealing surface based on the fluid differential pressure data, and calculate the sealing interference adjustment amount required for the large-diameter rubber-lined butterfly valve body to restore a tight sealing state based on the leakage amount.

[0026] This invention collects fluid differential pressure data when the large-diameter rubber-lined butterfly valve body is in the closed state. Based on this fluid differential pressure data, it analyzes the leakage of the valve body's rubber sealing surface. This allows for a quantitative assessment of the weakening degree and void distribution of the sealing surface under pressure load, providing a quantitative basis for subsequent precise displacement adjustment of the fine-tuning bolts. It should be noted that the fluid differential pressure data refers to the pressure difference between the high-pressure and low-pressure sides obtained by pressure sensing elements installed at both ends of the valve body when the valve is closed. The leakage refers to the total volume of medium lost through the sealing gap within a specific statistical time period. Furthermore, the fluid differential pressure data when the large-diameter rubber-lined butterfly valve body is in the closed state can be collected by pressure transmitters installed at preset pressure measuring holes on the pipe walls at both ends of the valve body. The pressure transmitters convert the sensed hydrostatic pressure into an electrical signal and transmit it to the control unit. By comparing the differences in values ​​before and after valve closure, as well as between the inlet and outlet sides, pressure drop characteristics reflecting the sealing tightness are obtained, providing measured raw data for accurately assessing the degree of rubber layer wear or deformation.

[0027] Specifically, the analysis of the leakage of the valve body rubber sealing surface based on the fluid differential pressure data includes: Based on the fluid differential pressure data, the unit squeezing force generated by the fluid inside the valve body at the sealing interface is determined; Find the nominal diameter and total length of the sealing ring corresponding to the body of the large-diameter rubber-lined butterfly valve; By combining the unit extrusion force, the nominal diameter, and the total length of the sealing ring, the instantaneous seepage intensity of the fluid medium bypassing the rubber sealing surface of the valve body is calculated. Based on the instantaneous seepage intensity, determine the equivalent flow channel cross-sectional area at the rubber sealing surface of the valve body; The leakage amount of the valve body rubber sealing surface is determined based on the unit extrusion force, the equivalent flow channel cross-sectional area, and the instantaneous seepage intensity.

[0028] Wherein, the unit extrusion force is the normal force characteristic value of the fluid acting on the sealing pair, the total length of the sealing ring is the circumferential length when the edge of the valve plate is completely in contact with the rubber sealing surface of the valve body, the instantaneous seepage intensity is the volume flow rate of the fluid penetrating the sealing barrier per unit time, and the equivalent flow channel cross-sectional area is the macroscopic flow orifice diameter after summarizing and converting the micro leaks.

[0029] Furthermore, the pressure difference between the high-pressure and low-pressure sides is obtained through a pressure transmitter, and the nominal diameter information and sealing length are extracted from the nameplate data of the valve body; the instantaneous seepage intensity is calculated through the fluid mechanics correspondence, that is, the instantaneous seepage intensity is equal to the pressure difference multiplied by the reciprocal of the flow resistance and the viscosity of the medium; the gap distribution density of the sealing surface is determined by shape fitting of the equivalent flow channel cross-sectional area; the specific process of generating the leakage amount is as follows: the instantaneous seepage intensity is multiplied by the equivalent flow channel cross-sectional area, and the observation time period is integrated and accumulated to obtain the leakage amount value reflecting the degree of seal failure.

[0030] This invention calculates the required sealing interference adjustment amount for the large-diameter rubber-lined butterfly valve body to restore a tight seal based on the leakage amount. This allows for the determination of the required radial feed amplitude of the adjusting plate, ensuring that the rubber deformation precisely seals the microscopic leakage channels. This achieves a tight seal while effectively preventing fatigue damage to the rubber layer caused by blind tightening. The sealing interference adjustment amount refers to the additional radial deformation value that the adjusting plate needs to generate by pushing the rubber to compensate for the leakage gap.

[0031] Specifically, the calculation of the required sealing interference adjustment amount for restoring the large-diameter rubber-lined butterfly valve body to a tight seal state based on the leakage amount includes: Based on the leakage amount, determine the actual total amount of fluid seepage in the body of the large-diameter rubber-lined butterfly valve over a specific time span; Query the preset zero leakage reference value of the large-diameter rubber-lined butterfly valve body under standard operating conditions; Based on the actual total seepage and the preset zero leakage benchmark value, the required sealing interference adjustment amount for restoring the large-diameter rubber-lined butterfly valve body to a tight seal state is calculated using the following formula: in, This indicates the amount of sealing interference adjustment required to restore the body of a large-diameter rubber-lined butterfly valve to a tight seal. This represents the actual seepage flow rate corresponding to the i-th sample. This represents the preset zero-leakage baseline value, where i represents the sampling sequence number and n represents the total number of samples within the statistical loop. This indicates the conversion ratio term.

[0032] Wherein, the actual total seepage volume is the media loss value obtained by converting the pressure drop rate, the preset zero leakage benchmark value is the industry-permitted trace permeation threshold, the statistical cycle is the time cycle for the pressure transmitter to complete one complete data reading, and the conversion ratio term is the displacement mapping characteristic value determined by the elastic modulus of the rubber, which is calculated by measuring the numerical correlation between the deformation length of the sealing surface rubber under pressure and the change in seepage volume.

[0033] Furthermore, the preset zero-leakage reference value can be obtained by consulting valve design specifications or engineering manuals. For example, for heavy-duty valve components with nominal diameters of 1000 mm, 1500 mm, and 2000 mm, the reference value ranges are 0.015 to 0.045, 0.025 to 0.075, and 0.035 to 0.115 (unit: ml / min), respectively.

[0034] In the above formula, the dimension of the actual total seepage is cubic millimeters, the dimension of the preset zero leakage reference value is cubic millimeters, the number of samplings is a dimensionless pure number, and the dimension of the conversion ratio term is set to the ratio of length to volume. Therefore... The calculated result has a dimension of cubic millimeters. After summing, averaging, and multiplying by the proportional term, the dimension of the sealing interference adjustment remains in millimeters, ensuring the consistency of the calculation logic in terms of physical dimensions and conforming to the conversion logic between fluid pressure and solid deformation.

[0035] Furthermore, the above formula is based on the principle of mass conservation, expressing the degree of weakening of the sealing surface as the deviation between the actual flow rate and the reference flow rate, wherein, It reflects the deviation of the sealing performance from the standard interface during a single pressure fluctuation. By averaging multiple samples, the random deviation caused by pipeline disturbances is eliminated. Finally, by combining the conversion ratio term, the radial adjustment depth required for the valve sealing pair can be obtained.

[0036] S2. Obtain the pitch parameter of the fine-tuning bolt, establish the proportional relationship between the rotation angle of the fine-tuning bolt and the displacement of the adjusting plate based on the pitch parameter, and obtain the target rotational angular displacement of the fine-tuning bolt by combining the proportional relationship and the sealing interference adjustment amount.

[0037] This invention obtains the pitch parameter of the fine-tuning bolt, confirms the proportional relationship between the rotation angle and the displacement of the adjusting plate, and calculates the target rotation angle displacement by combining the sealing interference adjustment amount. This allows us to obtain the physical feedback correlation between the displacement and rotation angle of the adjusting plate during the sealing adjustment process, providing a quantitative basis for the precise execution of subsequent sealing pre-tightening actions.

[0038] The pitch parameter is the relative distance between adjacent thread profiles of the fine-tuning bolt in the axial direction. The proportional relationship is the ratio of the linear lengths that the adjusting plate moves when the fine-tuning bolt rotates by one unit revolution. The sealing interference adjustment is the preset compression depth of the adjusting plate pressing the seal to ensure the sealing effect. The target rotational angular displacement is the total circumferential angle required to drive the bolt to rotate so that the adjusting plate reaches the specified pressing position. Furthermore, the pitch parameter can be obtained by measuring with a thread gauge or by retrieving a standard part specification table. The proportional relationship can be established by setting scale marks on the edge of the adjusting plate and observing the displacement increment after the bolt rotates a number of revolutions. The measurement point is selected as the intersection of the central axis of the adjusting plate and the contact surface of the seal as the calculation basis.

[0039] In detail, the process of obtaining the target rotational angular displacement of the fine-tuning bolt by combining the proportional relationship and the sealing interference adjustment amount includes: Obtain the initial angle information of the fine-tuning bolt at the starting position, and use the proportional relationship to determine the unit angular displacement feed amount of the bolt at the current screw-in depth; Calculate the displacement loss value of the threaded pair under load due to deformation, and combine it with the sealing interference adjustment amount to obtain the actual physical path that the adjusting plate needs to complete. Based on the aforementioned proportional relationship, the actual physical path, and the torque feedback value of the threaded friction surface, the displacement conversion correction rate of the fine-tuning bolt is calculated. The target rotational angular displacement of the fine-tuning bolt is calculated by measuring the shape recovery period of the sealing material after being compressed, combining the proportional relationship, the displacement conversion correction rate, and the actual physical path.

[0040] Wherein, the initial angle information is the initial orientation of the fine-tuning bolt head baseline in the spatial coordinate system; the unit angular displacement feed is the theoretical displacement value corresponding to each degree angle calculated based on the proportional relationship; the displacement loss value is the displacement loss caused by thread clearance and micro-elastic deformation of the material; the actual physical path is the real straight-line distance that the adjusting plate must travel to achieve interference seal; the displacement conversion correction rate is a dimensionless value used to calibrate the deviation between the theoretical proportional relationship and the actual transmission efficiency; and the shape recovery period is the time interval required for the seal to deform under pressure to reach a stable state.

[0041] Furthermore, the pitch is decomposed into an angular displacement mapping table using the aforementioned proportional relationship. The displacement reference under the current thread specification is determined by searching the mapping table. A dial indicator installed on the side of the adjusting plate is used to monitor micro-displacement, and the displacement loss value after the thread pair is subjected to force is calculated using Hooke's law. The sealing interference adjustment amount and the displacement loss value are vector-superimposed to obtain the actual physical path of the adjusting plate. The resistance evolution during the rotation process is obtained through a torque monitor, and the deviation between the actual displacement and the theoretical displacement derived from the proportional relationship is analyzed to obtain the displacement conversion correction rate reflecting the transmission loss. The final target rotational angular displacement calculation process is as follows: First, the actual physical path is divided by the unit angular displacement feed amount using the aforementioned proportional relationship to obtain the initial angle value. Then, the displacement conversion correction rate is used to scale this value. Finally, the creep displacement within the shape recovery period is combined for fine-tuning to obtain the precise scale of the target rotational angular displacement of the fine-tuning bolt.

[0042] S3. Based on the target rotational angular displacement, set the tightening execution parameters of the fine-tuning bolt. The tightening execution parameters include the symmetrical adjustment sequence and step angle of multiple bolts. While the valve body is installed in the pipeline and does not detach, rotate the fine-tuning bolt based on the tightening execution parameters to drive the adjustment plate to move radially and squeeze the rubber sealing surface of the valve body, thereby changing the contact posture between the sealing surface and the edge of the valve plate, and realizing the fine-tuning of the opening degree of the sealing accuracy of the large-diameter rubber-lined butterfly valve in the closed state.

[0043] This invention combines the target rotational angular displacement and the symmetrical adjustment sequence to set the order of bolt rotation, thereby obtaining an adjustment rhythm that is balanced with the stress distribution around the valve body. This ensures that the adjustment plate remains aligned with the axis during the advancement process, preventing the sealing interface from tilting under stress. The symmetrical adjustment sequence is the directional order of multiple sets of bolts alternately tightened around the valve seat. Furthermore, the overall rotational target is distributed to each set of bolts, and the intervention point of each adjustment node is determined by a cross-reciprocating progressive method, avoiding excessive feed at a single position that could lead to local stress concentration on the rubber surface or distortion of the sealing surface.

[0044] This invention, by setting the step angle, ensures that the extrusion process of the adjusting plate on the rubber sealing surface is smooth and controlled. The step angle is the incremental value of the minute arc covered by each rotation of the tool. Furthermore, based on the hardness grade and resilience characteristics of the rubber material, the target rotational angular displacement is divided into multiple minute angle intervals, ensuring that the sealing surface undergoes slow physical deformation at the microscopic level. Simultaneously, a brief period of stillness is maintained after each rotation, allowing the rubber material to fully fill the gaps, forming a stable physical contact shape, preventing internal tearing of the rubber due to excessively rapid extrusion, and ensuring a tight seal between the sealing surface and the valve plate edge.

[0045] This invention achieves coordinated adjustment of sealing accuracy by controlling the physical displacement of the fine-tuning bolt. Furthermore, the actuator applies a predetermined torque at the initial position, driving the bolt to gradually screw in according to a set step angle. The displacement feedback of the adjusting plate is monitored in real time during each adjustment sequence to ensure uniform pressure distribution. Once the contact position between the sealing surface and the valve plate reaches the predetermined closing accuracy, the bolt position is locked. Through the coordination of these values, the large-diameter rubber-lined butterfly valve experiences balanced force in the closed state, ensuring the accuracy of the sealing fine-tuning results and the long-term effectiveness of the seal.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A large-diameter rubber-lined butterfly valve for fluid transport, comprising a large-diameter rubber-lined butterfly valve body (1), characterized in that: The large-diameter rubber-lined butterfly valve body (1) includes a valve body (13) and a valve plate (12) rotatably installed inside the valve body (13). Thrust bearings (11) are sleeved on the upper and lower ends of the valve plate (12). A valve body rubber sealing surface (15) is provided on the inner wall of the valve body (13). An adjusting plate (14) is provided on the valve body (13). The adjusting plate (14) is located between the valve body (13) and the valve body rubber sealing surface (15). A plurality of fine-tuning bolts (16) are threaded into the outer wall of the valve body (13). One end of the fine-tuning bolt (16) passes through the valve body (13) and abuts against the outer wall of the adjusting plate (14).

2. The large-diameter rubber-lined butterfly valve for fluid transport as described in claim 1, characterized in that, The thrust bearing (11) is fixedly installed in the bearing seat of the valve body (13).

3. The large-diameter rubber-lined butterfly valve for fluid transport as described in claim 1, characterized in that, The adjusting plate (14) has an arc-shaped structure, and the arc of the adjusting plate (14) is adapted to the circumferential arc of the inner wall of the valve body (13).

4. The large-diameter rubber-lined butterfly valve for fluid transport as described in claim 1, characterized in that, Multiple adjustment plates (14) are provided along the inner circumference of the valve body (13), and the multiple adjustment plates (14) are arranged in a ring array.

5. The large-diameter rubber-lined butterfly valve for fluid transport as described in claim 1, characterized in that, The outer side wall of the adjustment plate (14) abuts against at least two fine adjustment bolts (16), and the fine adjustment bolts (16) are evenly distributed along the length direction of the adjustment plate (14).

6. The large-diameter rubber-lined butterfly valve for fluid transport as described in claim 1, characterized in that, The valve body (13) has a threaded through hole that matches the fine-tuning bolt (16). The head of the fine-tuning bolt (16) is located outside the valve body (13), and the end of the fine-tuning bolt (16) is flat and contacts the adjusting plate (14).

7. A method for fine-tuning the opening degree of a large-diameter rubber-lined butterfly valve for fluid transport according to any one of claims 1 to 6, characterized in that, The method includes: Collect fluid differential pressure data when the large-diameter rubber-lined butterfly valve body is in the closed state, analyze the leakage of the valve body rubber sealing surface based on the fluid differential pressure data, and calculate the sealing interference adjustment amount required for the large-diameter rubber-lined butterfly valve body to restore a tight sealing state based on the leakage amount. Obtain the pitch parameter of the fine-tuning bolt, establish the proportional relationship between the rotation angle of the fine-tuning bolt and the displacement of the adjusting plate based on the pitch parameter, and combine the proportional relationship and the sealing interference adjustment amount to obtain the target rotation angle displacement of the fine-tuning bolt; Based on the target rotational angular displacement, the tightening execution parameters of the fine-tuning bolt are set. The tightening execution parameters include the symmetrical adjustment sequence and step angle of multiple bolts. With the valve body still installed in the pipeline and not detached, the fine-tuning bolt is rotated based on the tightening execution parameters, driving the adjustment plate to move radially and squeeze the rubber sealing surface of the valve body, so as to change the contact posture between the sealing surface and the edge of the valve plate, thereby realizing the fine-tuning of the opening degree of the sealing accuracy of the large-diameter rubber-lined butterfly valve in the closed state.

8. The method according to claim 7, characterized in that, The analysis of the leakage of the valve body rubber sealing surface based on the fluid differential pressure data includes: Based on the fluid differential pressure data, the unit squeezing force generated by the fluid inside the valve body at the sealing interface is determined; Find the nominal diameter and total length of the sealing ring corresponding to the body of the large-diameter rubber-lined butterfly valve; By combining the unit extrusion force, the nominal diameter, and the total length of the sealing ring, the instantaneous seepage intensity of the fluid medium bypassing the rubber sealing surface of the valve body is calculated. Based on the instantaneous seepage intensity, determine the equivalent flow channel cross-sectional area at the rubber sealing surface of the valve body; The leakage amount of the valve body rubber sealing surface is determined based on the unit extrusion force, the equivalent flow channel cross-sectional area, and the instantaneous seepage intensity.

9. The method according to claim 7, characterized in that, The calculation of the sealing interference adjustment amount required for the large-diameter rubber-lined butterfly valve body to restore a tight seal based on the leakage amount includes: Based on the leakage amount, determine the actual total amount of fluid seepage in the body of the large-diameter rubber-lined butterfly valve over a specific time span; Query the preset zero leakage reference value of the large-diameter rubber-lined butterfly valve body under standard operating conditions; Based on the actual total seepage and the preset zero leakage benchmark value, the required sealing interference adjustment amount for restoring the large-diameter rubber-lined butterfly valve body to a tight seal state is calculated using the following formula: ； in, This indicates the amount of sealing interference adjustment required to restore the body of a large-diameter rubber-lined butterfly valve to a tight seal. This represents the actual seepage flow rate corresponding to the i-th sample. This represents the preset zero-leakage baseline value, where i represents the sampling sequence number and n represents the total number of samples within the statistical loop. This indicates the conversion ratio term.

10. The method according to claim 7, characterized in that, The process of obtaining the target rotational angular displacement of the fine-tuning bolt by combining the proportional relationship and the sealing interference adjustment amount includes: Obtain the initial angle information of the fine-tuning bolt at the starting position, and use the proportional relationship to determine the unit angular displacement feed amount of the bolt at the current screw-in depth; Calculate the displacement loss value of the threaded pair under load due to deformation, and combine it with the sealing interference adjustment amount to obtain the actual physical path required to be completed by the adjusting plate. Based on the aforementioned proportional relationship, the actual physical path, and the torque feedback value of the threaded friction surface, the displacement conversion correction rate of the fine-tuning bolt is calculated. The target rotational angular displacement of the fine-tuning bolt is calculated by measuring the shape recovery period of the sealing material after being compressed, combining the proportional relationship, the displacement conversion correction rate, and the actual physical path.

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