Durable diaphragm valve and control method

Abstract

The application provides a durable diaphragm valve and a control method. The diaphragm valve comprises a valve body, a valve cover, a valve rod, a diaphragm assembly, an air pump, a driver and a controller. The valve body comprises a medium inlet channel, a medium outlet channel and a valve seat part. The downstream flow sensor is arranged on the medium outlet channel. The upstream pressure sensor is arranged on the medium inlet channel. The diaphragm assembly comprises an upper diaphragm and a lower diaphragm. The deformation cavity is formed between the upper diaphragm and the lower diaphragm. The air bag is arranged in the deformation cavity. The upper end surface of the middle part of the air bag is connected with the upper diaphragm. The lower end surface of the middle part is connected with the lower diaphragm. The lower diaphragm is close to the upper diaphragm when the air bag is contracted and is away from the upper diaphragm when the air bag is expanded. The air pump is used for inflating or deflating the air bag to maintain the pressure. The air pump is provided with the air bag pressure sensor for monitoring the pressure of the air bag. The service life of the valve cycle opening and closing is significantly improved in the application. The deformation of the diaphragm is reduced by inflating and deflating the air bag, so that the diaphragm fatigue caused by stress concentration is reduced.

Description

Technical Field

[0001] This invention relates to the field of diaphragm valve technology, and more specifically to a durable diaphragm valve and its control method. Background Technology

[0002] A diaphragm valve consists of a flexible diaphragm or a combination of diaphragms housed within the valve body and bonnet. Its closing element is a compression device connected to the diaphragm. The valve seat can be weir-shaped or a straight pipe wall. The advantages of a diaphragm valve are that its operating mechanism is isolated from the media passage, ensuring the purity of the working medium and preventing the possibility of media in the pipeline impacting the operating parts of the operating mechanism. Furthermore, no separate seal of any kind is required at the valve stem, except when used as a safety device in controlling hazardous media. In a diaphragm valve, since the working medium only contacts the diaphragm and valve body, both of which can be made of various materials, the valve can ideally control a variety of working media, especially those containing chemical corrosive substances or suspended particles. Traditional diaphragm valves require significant deformation of the diaphragm through the pushing and pulling of the valve stem during opening and closing, which can easily lead to diaphragm fatigue and shorten the valve's service life. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a durable diaphragm valve and control method.

[0004] The technical solution adopted by this invention is as follows: In a first aspect, this application provides a durable diaphragm valve, including a valve body, a valve cover, a valve stem, a diaphragm assembly, a driver, and a controller. The valve body includes an inlet medium channel, an outlet medium channel, and a valve seat. A downstream flow sensor is disposed on the outlet medium channel, and an upstream pressure sensor is disposed on the inlet medium channel. The diaphragm assembly includes an upper diaphragm and a lower diaphragm, forming a deformation cavity between the upper and lower diaphragms. An air bladder is disposed within the deformation cavity. The upper end face of the middle portion of the air bladder is connected to the upper diaphragm, and its lower end face is connected to the lower diaphragm, such that the lower diaphragm contracts with the air bladder and moves closer to the upper diaphragm. The valve expands and moves away from the upper diaphragm. The upper diaphragm has an air tube connected to the airbag along its axial direction. The valve cover has a connecting tube. One end of the connecting tube is connected to the air tube via a hose, and the other end is connected to an air pump. The air pump is used to inflate or deflate the airbag to maintain pressure. The air pump has an airbag pressure sensor to monitor the airbag pressure. When the valve is closed, the valve stem descends under the drive of the actuator, and the airbag is inflated by the air pump, so that the lower diaphragm and the valve seat come into contact to form a seal. When the valve is opened, the valve stem rises under the drive of the actuator, and the airbag is deflated by the air pump, so that the lower diaphragm and the valve seat separate to form a conduction.

[0005] In some embodiments, the valve stem is connected to the upper diaphragm via a connecting seat. The edges of the upper and lower diaphragms press against the valve cover and valve body, forming an upper cavity between the upper diaphragm and the valve cover, and a lower cavity between the lower diaphragm and the valve body. The valve seat protrudes from the lower cavity and can form a sealing fit with the lower diaphragm to isolate the inlet medium channel from the outlet medium channel.

[0006] In some embodiments, the airbag gradually narrows from the middle to both ends, and the upper and lower end faces of the airbag are horizontally arranged along the length direction of the valve seat portion, while the upper and lower end faces are arc-shaped along the width direction of the valve seat portion.

[0007] In some embodiments, a sealing protrusion is provided on the lower end face of the lower diaphragm, and the sealing protrusion is provided along the length direction of the valve seat portion.

[0008] In some embodiments, there are multiple airbags arranged in parallel along the length of the valve seat portion, and the air tube is connected to each airbag.

[0009] Secondly, this application provides a control method for the aforementioned durable diaphragm valve, comprising the following steps:

[0010] S1: When closing the valve, the valve stem is lowered to the sealing reference position by the actuator, the air bladder is inflated by the air pump, and the initial pressure value of the inflation advance medium channel is detected by the upstream pressure sensor.

[0011] S2: The flow rate of the medium channel is detected in real time by the downstream flow sensor, and the airbag is inflated until the detection value of the downstream flow sensor is less than the threshold.

[0012] S3: When the detection value of the downstream flow sensor is less than the threshold, the current airbag pressure value is recorded by the airbag pressure sensor. At the same time, based on the measurement and detection of the final pressure value of the medium channel after inflation and sealing by the upstream pressure sensor, a mapping database of initial pressure value, airbag pressure value and final pressure value is constructed.

[0013] S4: When the valve remains closed, the current pressure value of the inlet medium channel is obtained based on the measurement of the upstream pressure sensor, and the corresponding final pressure value is found by comparing it with the database to obtain the corresponding airbag pressure value. Based on the airbag pressure value, the airbag pressure is adjusted in real time by the air pump so that the lower diaphragm and valve seat always maintain an effective seal.

[0014] In some embodiments, when the valve is closed again, the corresponding airbag pressure value is retrieved from the database based on the initial pressure value measured by the upstream pressure sensor, and the airbag is inflated by an air pump according to the airbag pressure value.

[0015] In some embodiments, after the diaphragm valve has been used for a certain period of time, if the detection value of the downstream flow sensor reaches a threshold during the valve closing phase, the airbag is inflated until the detection value of the downstream flow sensor is less than the threshold. Based on the newly obtained airbag pressure value, a mapping database of initial pressure value - new airbag pressure value - final pressure value is constructed. Before the diaphragm assembly is replaced, the new mapping database is used. If the diaphragm assembly is replaced, the original mapping database is switched back.

[0016] In some embodiments, dynamically adjusting the inflation rate during airbag inflation includes:

[0017] Coarse adjustment phase: Inflate the airbag at a rate of V to 90% of the airbag pressure value;

[0018] Fine-tuning phase: Inflate the airbag at a rate of 0.3V-0.5V until the remaining 10% of the airbag pressure value is reached;

[0019] Maintenance phase: The actual airbag pressure value is maintained within ±0.5% of the airbag pressure value using a PID algorithm.

[0020] In some embodiments, when the actual pressure value of the airbag exceeds ±0.5% of the airbag pressure value each time, the airbag is inflated or deflated to adjust the actual pressure value of the airbag back to the airbag pressure value, and this is recorded as an adjustment action. The number of adjustment actions within a time period T is recorded as a complete service cycle of the diaphragm assembly in the diaphragm valve. A service life prediction model is established based on multiple complete service cycle data. In subsequent new diaphragm valve operations, the service life of the diaphragm assembly is predicted based on the service life prediction model.

[0021] The beneficial effects of this invention are as follows: When the valve is closed, the valve stem is mechanically pressed down to provide basic positioning, and the air bladder inflates to achieve flexible pressure sealing. When the valve is open, the valve stem actively lifts to cooperate with the air bladder to release pressure, preventing the lower diaphragm from sticking to the valve seat and significantly improving the valve's lifespan during cyclic opening and closing. Secondly, traditional diaphragm valves require the valve stem to push and pull the diaphragm to generate significant deformation for opening and closing, while this invention uses the air bladder to reduce diaphragm deformation, thereby reducing diaphragm fatigue caused by stress concentration. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0023] Figure 1 This is a schematic diagram of the durable diaphragm valve in this invention;

[0024] Figure 2 This is a cross-sectional view of the durable diaphragm valve of the present invention;

[0025] Figure 3 This is a cross-sectional view of the diaphragm assembly in this invention;

[0026] Figure 4 This is a cross-sectional view of the airbag in this invention;

[0027] Figure 5 This is a flowchart of the control method for the durable diaphragm valve in this invention. Detailed Implementation

[0028] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but rather to the widest scope consistent with the claims.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "longitudinal", "lateral", "radial", "length", "width", "thickness", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element or component to have a specific orientation, or to be constructed and operated in a specific orientation.

[0030] It should be noted that the terms "first," "second," and similar words do not indicate any order, quantity, or importance, but are only used to distinguish different components and should not be construed as limiting the embodiments of this application.

[0031] It should be noted that the terms "installation," "setup," "equipped with," "connection," and "connected" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral structures; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two devices, components, or parts.

[0032] It should be noted that the terms "in some embodiments," "exemplarily," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "in some embodiments," "exemplarily," or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "in some embodiments," "exemplarily," and "for example" is intended to present related concepts in a specific manner, meaning that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the above terms in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0033] Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] Regarding the accompanying drawings of this application, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not necessarily drawn to scale.

[0035] like Figures 1 to 4 As shown in the figure, this specification provides a durable diaphragm valve, including a valve body 1, a valve cover 2, a valve stem 3, a connecting seat 4, a diaphragm assembly 5, an actuator, and a controller. The valve body 1 includes an inlet medium channel 100, an outlet medium channel 101, and a valve seat 6. The valve stem 3 is connected to the diaphragm assembly 5 via the connecting seat 4. The edge of the diaphragm assembly 5 abuts against the valve cover 2 and the valve body 1, forming an upper cavity 7 between the diaphragm assembly 5 and the valve cover 2, and a lower cavity 8 between the diaphragm assembly 5 and the valve body 1. The valve seat 6 protrudes into the lower cavity 8 and can form a sealing fit with the diaphragm assembly 5 to isolate the inlet medium channel 100 from the outlet medium channel 101. The valve seat 6 has a straight shoulder located between the inlet medium channel 100 and the outlet medium channel 101.

[0036] The diaphragm assembly 5 includes an upper diaphragm 50 and a lower diaphragm 51. The upper diaphragm 50 is connected to the connecting seat 4. The edges of the upper diaphragm 50 and the lower diaphragm 51 press against the valve cover 2 and the valve body 1, forming a deformation cavity 52 between them. At least one airbag 9 is disposed in the deformation cavity 52. ​​The upper end face of the middle part of the airbag 9 is connected to the upper diaphragm 50, and the lower end face of the middle part is connected to the lower diaphragm 51, so that the lower diaphragm 51 moves closer to the upper diaphragm 50 as the airbag 9 contracts and moves away from the upper diaphragm 50 as it expands. The airbag 9 gradually shrinks from the middle to both ends. The upper and lower end faces of the airbag 9 are horizontally arranged along the length direction of the valve seat 6, and the upper and lower end faces are arc-shaped along the width direction of the valve seat 6. With this arrangement, the airbag 9 maintains a uniform pressure distribution when inflating and deflating.

[0037] The upper diaphragm 50 is provided with an air tube 10 communicating with the airbag 9 along its axial direction. The valve cover 2 is provided with a connecting tube 11. One end of the connecting tube 11 is connected to the air tube 10 via a flexible tube 12, and the other end is connected to an air pump. The air pump is used to inflate or deflate the airbag 9 to maintain pressure. The air pump has an airbag pressure sensor for monitoring the pressure of the airbag 9. It can be understood that the airbag pressure sensor can be integrated into the air pump or an external pressure sensor can be connected. In this way, inflating or deflating the airbag 9 from the middle is not only highly efficient, but also more reliable in forming a seal, and ensures that the airbag 9 maintains a uniform pressure distribution when deformed.

[0038] It should be understood that the air pump can use the same pipeline for both inflation and deflation, which can be switched using a solenoid valve. Alternatively, it can be separated into two independent pipelines. Furthermore, the control valves required for different pipeline configurations, such as check valves and solenoid valves, should be known to those skilled in the art.

[0039] When the valve is closed, the valve stem 3 descends under the drive of the actuator, and at the same time, the air pump inflates the air bag 9, causing the lower diaphragm 51 and the valve seat 6 to come into contact and form a seal. When the valve is opened, the valve stem 3 rises under the drive of the actuator, and at the same time, the air pump deflates the air bag 9, causing the lower diaphragm 51 and the valve seat 6 to separate and form a conduction.

[0040] With this configuration, when the valve is closed, the valve stem 3 is mechanically pressed down to provide basic positioning, and the air bladder 9 is inflated to achieve flexible pressure sealing. When the valve is opened, the valve stem 3 actively lifts to cooperate with the air bladder 9 to release pressure, avoiding adhesion between the lower diaphragm 51 and the valve seat 6, and significantly improving the lifespan of the valve during cyclic opening and closing.

[0041] Secondly, the opening and closing of a traditional diaphragm valve requires the valve stem 3 to push and pull the diaphragm to produce a large deformation. However, in this application, the airbag 9 can reduce the deformation of the diaphragm by inflating and deflating, thereby reducing diaphragm fatigue caused by stress concentration.

[0042] For example, when a conventional diaphragm valve is closed, if the diaphragm needs to be depressed and deformed by 30mm, since the conventional diaphragm in this application is divided into an upper diaphragm 50 and a lower diaphragm 51, the upper diaphragm 50 only needs to be depressed by the valve stem 3 for a deformation distance of less than 30mm, for example, only 15mm. The remaining gap between the lower diaphragm 51 and the valve seat 6 can be filled by inflating the air bag 9, so that the lower diaphragm 51 deforms relative to the upper diaphragm 50 to fill the remaining gap and form a seal. In this way, the large deformation of one diaphragm is divided into the small deformation of two diaphragms, which greatly reduces the maximum deformation of the diaphragm and extends the service life of the diaphragm.

[0043] Furthermore, a sealing protrusion 510 is provided on the lower end face of the lower diaphragm 51. The sealing protrusion 510 is arranged along the length direction of the valve seat portion 6, which can form a more reliable seal with the valve seat portion 6.

[0044] For example, there are multiple airbags 9, which are arranged in parallel along the length of the valve seat 6. The air tube 10 is connected to each airbag 9. The multi-airbag 9 array structure is adopted. The deformation of the lower diaphragm 51 is dynamically adjusted by inflation and deflation to achieve uniform force on the contact sealing surface.

[0045] A downstream flow sensor is installed on the outlet medium channel 101 to monitor the flow rate of the outlet medium channel 101, and an upstream pressure sensor is installed on the inlet medium channel 100 to monitor the pressure of the inlet medium channel 100. The driver, air pump, upstream pressure sensor, and downstream flow sensor are all connected to the controller.

[0046] like Figure 5 As shown, this specification also provides a control method based on the above-mentioned diaphragm valve, including the following steps:

[0047] S1: When closing the valve, the valve stem 3 is lowered to the sealing reference position by the actuator, and the air bladder 9 is inflated by the air pump. The initial pressure value of the inflation advance medium channel 100 is detected by the upstream pressure sensor. The sealing reference position is mainly set according to the deformation of the air bladder 9 to ensure that when the valve stem 3 is lowered to the sealing reference position, the remaining gap can be sealed by the inflation deformation of the air bladder 9 alone, avoiding damage to the valve seat 6 by the mechanical hard seal.

[0048] S2: The flow rate of the medium channel 101 is detected in real time by the downstream flow sensor, and the airbag 9 is inflated until the detected value of the downstream flow sensor is less than the threshold. Theoretically, the threshold is zero, but considering the actual working conditions, it may not be possible to reach the theoretical value. Therefore, a smaller value is generally set as the threshold.

[0049] S3: When the downstream flow sensor detects a value less than the threshold, it generally takes a certain period of time before the current airbag pressure value is recorded by the airbag pressure sensor. At the same time, based on the final pressure value of the inlet medium channel 100 after inflation and sealing, a mapping database of initial pressure value, airbag pressure value and final pressure value is constructed.

[0050] S4: When the valve remains closed, the current pressure value of the inlet medium channel 100 is obtained based on the measurement of the upstream pressure sensor. If the change in the current pressure value exceeds a certain range, such as the change value exceeding 0.5%-2% of the current pressure value, the corresponding final pressure value is searched from the database to obtain the corresponding airbag pressure value. Based on the airbag pressure value, the pressure of the airbag 9 is adjusted in real time by the air pump, so that the lower diaphragm 51 and the valve seat 6 always maintain an effective seal.

[0051] It should be noted that, due to the inertia of the fluid, the upstream pressure will rise sharply at the moment the valve is closed, forming a water hammer pressure wave. The measured value at this time is inaccurate. Therefore, the current pressure value is obtained when the medium pressure in the medium channel 100 reaches a new equilibrium state after the valve is closed.

[0052] When the valve is closed again, based on the initial pressure value measured by the upstream pressure sensor, the corresponding airbag pressure value is retrieved from the database. The airbag 9 is then inflated using an air pump according to this pressure value. If no matching record is found in the database, the closest initial pressure value is selected. This improves the efficiency of valve closure, eliminating the need to search for a suitable airbag pressure value every time the valve is closed. Of course, after inflating the airbag 9 according to the retrieved pressure value, it needs to be verified by the downstream flow sensor. If the verification fails, the process returns to step S2.

[0053] After the diaphragm valve has been used for a certain period of time, if the downstream flow sensor's detection value reaches a threshold during the valve closing phase, the air bladder 9 is inflated until the downstream flow sensor's detection value is less than the threshold. Based on the newly obtained air bladder pressure value, a mapping database of initial pressure value, new air bladder pressure value, and final pressure value is constructed. Before replacing the diaphragm assembly 5, the new mapping database is used. If the diaphragm assembly 5 is replaced, the database is switched back to the original mapping database. Because the performance of the diaphragm assembly 5 and air bladder 9 deteriorates after prolonged use, more gas needs to be inflated to achieve a seal. If multiple new mapping databases are constructed, the latest one is used; the database is only switched back to the original mapping database after replacing the diaphragm assembly 5.

[0054] Dynamically adjusting the inflation rate during airbag 9 inflation includes:

[0055] Coarse adjustment phase: Inflate airbag 9 at a rate of V to 90% of the airbag pressure value;

[0056] Fine-tuning phase: Inflate the airbag at a rate of 0.3V-0.5V until the remaining 10% of the airbag pressure value is reached;

[0057] Maintenance Phase: A PID algorithm is used to maintain the actual pressure value of airbag 9 within ±0.5% of the airbag pressure value. Each time it exceeds this range, airbag 9 is inflated or deflated to adjust the actual pressure value back to the airbag pressure value, and this is recorded as an adjustment action. This phased inflation improves inflation efficiency.

[0058] Furthermore, the number of adjustment actions within time T is recorded as a complete service life cycle of the diaphragm assembly 5 in the diaphragm valve. A service life prediction model is established based on data from multiple complete service life cycles. Common methods for constructing service life prediction models include regression models (such as linear regression and support vector regression), time series models (such as ARIMA and LSTM), survival analysis models (such as Cox proportional hazards models), or machine learning models (such as random forests and gradient boosting trees). In subsequent operation of new diaphragm valves, the service life of the diaphragm assembly 5 is predicted based on the service life prediction model. For example, T is 1 hour. Multiple complete service life cycles are statistically analyzed. The product's service life reaches its limit after situations such as more than 10 consecutive adjustment actions per hour, or multiple instances of more than 10 adjustment actions per hour within 24 hours. Combining this with analysis of the time between more than 8 consecutive adjustment actions per hour and more than 10 consecutive adjustment actions per hour (e.g., 1000 hours), when the current valve experiences more than 8 consecutive adjustment actions per hour, it can be predicted that the valve has 1000 hours of remaining service life, facilitating timely replacement of the diaphragm assembly 5. This introduction of adjustment action reduces the difficulty of building a lifespan prediction model.

[0059] In some embodiments, when the valve is opened in a non-emergency situation, the airbag is deflated by an air pump, initially releasing 0.5%-2% of the airbag pressure value. The flow rate of the medium channel 101 is then obtained by a downstream flow sensor and compared with a threshold. If the flow rate is less than the threshold, the corresponding airbag pressure value in the database is replaced with the original airbag pressure value. This configuration allows for the correction of the inflation amount, forming a seal with minimal inflation, preventing over-inflation of the airbag 9, and eliminating the need for correction during valve closure, thus preventing leakage when the valve is closed.

[0060] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that the requirements of this application encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this application and are within the spirit and scope of the exemplary embodiments of this application.

[0061] Furthermore, it should be understood that in the foregoing description of the embodiments of this application, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this application. That is, the embodiments in this application can also be understood as an integration of multiple sub-embodiments. It is also valid when each sub-embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0062] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments of this application. Other modified embodiments are also within the scope of this application. Therefore, the embodiments disclosed herein are merely examples and not limitations. Those skilled in the art can adopt alternative configurations to implement the applications in this application based on the embodiments in this application. Therefore, the embodiments of this application are not limited to the embodiments precisely described in the application.

Claims

1. A durable diaphragm valve, comprising a valve body, a valve cover, a valve stem, a diaphragm assembly, an actuator, and a controller, wherein the valve body includes an inlet medium passage, an outlet medium passage, and a valve seat, characterized in that, An upstream pressure sensor is installed on the inlet medium channel, and a downstream flow sensor is installed on the outlet medium channel. The diaphragm assembly includes an upper diaphragm and a lower diaphragm, forming a deformation cavity between them. An air bladder is installed within the deformation cavity. The upper end face of the middle portion of the air bladder is connected to the upper diaphragm, and its lower end face is connected to the lower diaphragm, allowing the lower diaphragm to move closer to the upper diaphragm as the air bladder contracts and to move away from the upper diaphragm as it expands. An air tube communicating with the air bladder is provided along the axial direction of the upper diaphragm. The valve cover is provided with... The device has a connecting tube, one end of which is connected to a hose and an air tube, and the other end is connected to an air pump. The air pump is used to inflate or deflate the airbag to maintain pressure. The air pump has an airbag pressure sensor to monitor the airbag pressure. When the valve is closed, the valve stem descends under the drive of the actuator, and the air pump inflates the airbag, causing the lower diaphragm and the valve seat to come into contact and form a seal. When the valve is opened, the valve stem rises under the drive of the actuator, and the air pump deflates the airbag, causing the lower diaphragm and the valve seat to separate and form a conduction.

2. The durable diaphragm valve according to claim 1, characterized in that, The valve stem is connected to the upper diaphragm via a connecting seat. The edges of the upper and lower diaphragms press against the valve cover and valve body, forming an upper cavity between the upper diaphragm and the valve cover, and a lower cavity between the lower diaphragm and the valve body. The valve seat protrudes from the lower cavity and can form a sealing fit with the lower diaphragm to isolate the inlet medium channel from the outlet medium channel.

3. The durable diaphragm valve according to claim 1, characterized in that, The airbag gradually narrows from both ends in the middle. The upper and lower end faces of the airbag are horizontally arranged along the length of the valve seat and arc-shaped along the width of the valve seat.

4. The durable diaphragm valve according to claim 1, characterized in that, The lower end face of the lower diaphragm is provided with a sealing protrusion, which is arranged along the length direction of the valve seat.

5. The durable diaphragm valve according to claim 1, characterized in that, There are multiple airbags, which are arranged in parallel along the length of the valve seat, and the air tube is connected to each airbag.

6. A control method applied to the durable diaphragm valve according to any one of claims 1 to 5, characterized in that, The steps include the following: S1: When closing the valve, the valve stem is lowered to the sealing reference position by the actuator, the air bladder is inflated by the air pump, and the initial pressure value of the inflation advance medium channel is detected by the upstream pressure sensor. S2: The flow rate of the medium channel is detected in real time by the downstream flow sensor, and the airbag is inflated until the detection value of the downstream flow sensor is less than the threshold. S3: When the detection value of the downstream flow sensor is less than the threshold, the current airbag pressure value is recorded by the airbag pressure sensor. At the same time, based on the measurement and detection of the final pressure value of the medium channel after inflation and sealing by the upstream pressure sensor, a mapping database of initial pressure value, airbag pressure value and final pressure value is constructed. S4: When the valve remains closed, the current pressure value of the inlet medium channel is obtained based on the measurement of the upstream pressure sensor, and the corresponding final pressure value is found by comparing it with the database to obtain the corresponding airbag pressure value. Based on the airbag pressure value, the airbag pressure is adjusted in real time by the air pump so that the lower diaphragm and valve seat always maintain an effective seal.

7. The control method for the durable diaphragm valve according to claim 6, characterized in that, When the valve is closed again, the corresponding airbag pressure value is retrieved from the database based on the initial pressure value measured by the upstream pressure sensor, and the airbag is inflated by the air pump according to the airbag pressure value.

8. The control method for the durable diaphragm valve according to claim 6, characterized in that, After the diaphragm valve has been used for a certain period of time, if the downstream flow sensor detects a value that reaches a threshold during the valve closing phase, the air bladder is inflated until the downstream flow sensor detects a value that is less than the threshold. Based on the newly obtained air bladder pressure value, a mapping database of initial pressure value, new air bladder pressure value, and final pressure value is constructed. Before the diaphragm assembly is replaced, the new mapping database is used. If the diaphragm assembly is replaced, the original mapping database is switched back.

9. The control method for the durable diaphragm valve according to claim 6, characterized in that, Dynamically adjusting the inflation rate during airbag inflation includes: Coarse adjustment phase: Inflate the airbag at a rate of V to 90% of the airbag pressure value; Fine-tuning phase: Inflate the airbag at a rate of 0.3V-0.5V until the remaining 10% of the airbag pressure value is reached; Maintenance phase: The actual airbag pressure value is maintained within ±0.5% of the airbag pressure value using a PID algorithm.

10. The control method for the durable diaphragm valve according to claim 9, characterized in that, Each time the actual pressure value of the airbag exceeds ±0.5% of the airbag pressure value range, the airbag is inflated or deflated to adjust the actual pressure value back to the airbag pressure value, and this is recorded as an adjustment action. The number of adjustment actions within a time period T is recorded as a complete service cycle of the diaphragm assembly in the diaphragm valve. Based on the data from multiple complete service cycles, a service life prediction model is established. In subsequent new diaphragm valve operations, the service life of the diaphragm assembly is predicted based on the service life prediction model.

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