Gas pipeline flange leakage early warning device and early warning method

Abstract

The invention discloses a gas pipeline flange leakage early warning device and method, and belongs to the technical field of flange leakage detection.The device comprises a first sensor, a second sensor, a data acquisition module, a wireless transmission module and an upper computer, and the first sensor and the second sensor are both connected with the data acquisition module; the first sensor detects gasket deformation of a gasket between flanges, converts the gasket deformation into a voltage signal and outputs the voltage signal to the data acquisition module, the second sensor detects bolt pre-tightening force between the flanges, converts the bolt pre-tightening force into a voltage signal and outputs the voltage signal to the data acquisition module, and the data acquisition module is connected with the wireless transmission module. And the wireless transmission module transmits the data to an upper computer. The differential variable-pressure type displacement sensor is used for detecting the deformation of the gasket between the flanges, the spoke type sensor is used for detecting the pre-tightening force of the bolt between the flanges, and leakage early warning of the gas pipeline flanges is doubly guaranteed; and the real-time leakage rate of the corresponding position can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of flange leakage detection technology, specifically relating to a gas pipeline flange leakage early warning device and early warning method. Background Technology

[0002] High-pressure gas pipelines in cities form the main arteries of urban gas supply. The reliability of flange connection structures is crucial to ensuring the long-term safe operation of pipelines. Urban medium-pressure pipelines are typically laid underground and partially overhead. There are numerous flange connection structures in medium-pressure valve wells and overhead pipe bridges. Due to the thermal expansion and contraction of gas pipelines and insufficient load compensation, these flange connections experience very complex stress conditions in different seasons. Affected by high stress and fatigue, the reduced bolt preload weakens the constraint effect on the flanges, leading to frequent pipeline flange leaks. These areas have poor working environments and are difficult to inspect manually, resulting in long-term safety hazards and indirectly causing energy waste. Summary of the Invention

[0003] In view of the above-mentioned problems in the prior art, the technical problem to be solved by the present invention is to provide a gas pipeline flange leakage early warning device and early warning method to realize online monitoring of pipeline flange leakage.

[0004] Technical Solution: To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A gas pipeline flange leakage early warning device includes a first sensor, a second sensor, a data acquisition module, a wireless transmission module, and a host computer. Both the first and second sensors are connected to the data acquisition module. The first sensor detects the deformation of the gasket between the flanges and converts it into a voltage signal, which is then output to the data acquisition module. The second sensor detects the preload of the bolts between the flanges and converts it into a voltage signal, which is then output to the data acquisition module. The data acquisition module is connected to the wireless transmission module, which transmits the data to the host computer.

[0006] Preferably, the first sensor is a differential transformer displacement sensor, and the second sensor is a spoke sensor.

[0007] Preferably, the host computer includes a display.

[0008] This invention also provides a method for early warning of gas pipeline flange leakage, using the aforementioned gas pipeline flange leakage early warning device, comprising the following steps:

[0009] Step 1: Use a spoke-type sensor to detect the preload of bolts between flanges, and use a differential transformer displacement sensor to detect the deformation of gaskets between flanges.

[0010] Step 2: Using a calibration method, gradually increase the tightening torque to change the tightening torque of the bolts between the flanges, causing the gasket to deform. At the same time, the spoke sensor records the bolt preload, and the differential transformer displacement sensor records the gasket deformation. Obtain the bolt preload and gasket deformation under different tightening torques, and record the maximum gasket deformation. Based on the gasket deformation, obtain the corresponding gasket load.

[0011] Step 3: Repeat the calibration multiple times to obtain the relationship between the shim load and the analog voltage value of the differential transformer displacement sensor and the analog voltage value of the spoke sensor at that location;

[0012] Step 4: Install differential pressure displacement sensors and spoke sensors at each flange of the gas pipeline. Obtain the bolt preload at that location based on the specified gasket load. Calculate the tightening torque required to achieve the specified gasket load based on the relationship between bolt preload and tightening torque.

[0013]

[0014] Where T represents the tightening torque, K represents the torque coefficient, F represents the bolt preload, and D represents the bolt diameter; adjust the bolt at this location to the corresponding tightening torque;

[0015] Step 5: Based on the relationship model between gasket load and leakage rate:

[0016]

[0017] In the formula, L L It is the leakage rate, η is the dynamic viscosity of the medium in the pipeline, and S G This is the actual gasket load, S G0 This is the standard load of the gasket, p is the pressure of the medium in the pipeline, and D is the pressure of the gasket. x D0 is the outer diameter of the gasket, and A is the outer diameter of the reference gasket. L It is the regression coefficient, n l It is the regression coefficient;

[0018] During the monitoring process, the corresponding gasket load is obtained by using the analog voltage value of the differential transformer displacement sensor and the analog voltage value of the spoke sensor at that location. The leakage rate is then calculated based on the gasket load to obtain the real-time leakage rate of the gasket at that location.

[0019] Preferably, the tightening torque in step 2 is in the range of 10 N·m to 80 N·m.

[0020] Preferably, during the monitoring process in step 5, an alarm is issued when the leakage rate exceeds a preset alarm value.

[0021] Preferably, during the monitoring process in step 5, an alarm is issued when the spoke sensor detects that the bolt preload is outside the preset range.

[0022] Preferably, during the monitoring process in step 5, when the differential transformer displacement sensor detects that the maximum gasket deformation exceeds the threshold, an alarm is issued.

[0023] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0024] 1. Two types of sensors are set up: the first sensor is a differential transformer displacement sensor, and the second sensor is a spoke sensor. The differential transformer displacement sensor detects the deformation of the gasket between flanges, while the spoke sensor can detect the preload of the bolts between flanges, providing dual protection for early warning of gas pipeline flange leaks.

[0025] 2. By calibrating the spoke-type sensor and the differential transformer displacement sensor multiple times using the calibration method, the bolt preload and gasket deformation under different tightening torques are obtained. The relationship between the gasket load and the analog voltage values ​​of the differential transformer displacement sensor and the spoke-type sensor is obtained. Based on the relationship between the gasket load and the leakage rate, the real-time leakage rate at the corresponding location can be obtained.

[0026] 3. An alarm can be triggered when the spoke-type sensor detects that the bolt preload is outside the preset range;

[0027] 4. By calibrating multiple times, the bolt preload and shim deformation under different tightening torques are obtained, and the maximum shim deformation is recorded. When the differential transformer displacement sensor detects that the maximum shim deformation exceeds the threshold, an alarm can be triggered.

[0028] 5. After multiple calibration methods, based on the relationship between the shim load and the simulated voltage values ​​of the differential transformer displacement sensor and the spoke sensor, the bolt preload at that location can be obtained. The required tightening torque can be obtained when using a torque wrench at that location, which is convenient for construction personnel. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the early warning device according to an embodiment of the present invention;

[0030] Figure 2 This is a diagram showing the installation structure of the first and second sensors in this embodiment;

[0031] Figure 3 This is a structural diagram of the sample used in the compression-rebound test in the embodiment;

[0032] Figure 4 This is the compression-rebound curve of sample A in the compression-rebound test in the embodiment;

[0033] Figure 5 This is the compression-rebound curve of sample B in the compression-rebound experiment of the embodiment. Detailed Implementation

[0034] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0035] like Figure 1 and Figure 2 As shown, a gas pipeline flange leak early warning device includes a first sensor, a second sensor, a data acquisition module, a wireless transmission module, and a host computer. The first sensor is a differential transformer displacement sensor (e.g., a Shivaka 485 micrometer), and the second sensor is an existing spoke-type sensor. The first sensor is connected to the outer walls of two flanges. One flange has a reference panel, and the other flange has a fixed bracket. The first sensor is connected to the fixed bracket, and its working head rests against the reference panel. When the distance between the two flanges changes, the first sensor can measure the distance moved, i.e., the deformation of the gasket between the two flanges. The second sensor is positioned between a bolt head and one flange. The bolt body passes through the central hole of the spoke-type sensor, and the bolt head presses the spoke-type sensor against the flange, thus allowing the second sensor to detect the bolt preload between the two flanges. Both the first and second sensors are connected to the data acquisition module. The first sensor detects the deformation of the gasket and converts it into a voltage signal, which is then output to the data acquisition module. In this embodiment, a TD-4027 data acquisition module is used. The TD-4027 is a multi-channel analog-to-RS485 converter, capable of simultaneously converting eight channels of analog data. The voltage signal from the first sensor is converted into RS232 / 485 serial data via the serial port data acquisition module. The second sensor detects the bolt preload between the flanges and converts it into a voltage signal, which is then output to the data acquisition module. The voltage signal from the second sensor is also converted into RS232 / 485 serial data via the serial port data acquisition module. The data acquisition module is connected to a wireless transmission module, which can use wireless network technologies such as WIFI and 4G to transmit data to a host computer. For gas pipeline flange leak warning devices, the installation area is usually large, making it difficult to achieve full WIFI signal coverage of the monitored area. Therefore, 4G networks are typically used for data transmission. This embodiment uses a cloud-based wireless transmission module (e.g., DTU 4G).

[0036] The device in this embodiment requires the following components: one main power switch, one Arduino UNO development board (the development board is part of the data acquisition module), one differential transformer displacement sensor, one 4G communication module (wireless transmission module), and one A / D converter module (set on the development board; the A / D converter connects the sensor and the output terminal to realize the digital-to-analog conversion of the signal, and is part of the data acquisition module). The Arduino Uno adopts a low-power design, which consumes less power during operation. In sensor detection scenarios, it has a longer working time compared to other development boards.

[0037] The Arduino UNO development board, with its powerful and flexible application capabilities, is an ideal choice for monitoring systems. Using the Arduino IDE as the development platform for a pipeline safety monitoring system, the Arduino UNO development board will connect to a differential transformer displacement sensor and a spoke sensor. The differential transformer displacement sensor is responsible for monitoring the gasket deformation at the pipe flange connection, enabling timely capture of gasket deformation information under external loads. The spoke sensor is responsible for detecting the bolt preload between flanges.

[0038] Once the gasket deformation data is collected, the differential transformer displacement sensor transmits the data to the Arduino UNO development board. Through the serial communication function on the Arduino UNO, the data is sent to a connected host computer for display. The host computer is a computer, and MATLAB is used as the data analysis and processing tool. MATLAB has powerful mathematical calculation capabilities, enabling precise analysis of the collected voltage values. Based on voltage changes, the load state and trend of the flange can be inferred, and the leakage rate formula can be used to determine the leakage situation. If the leakage rate exceeds the standard, an early warning mechanism will be triggered, issuing an alarm signal through the status indicator light on the computer's display. An alarm will also sound if the gasket deformation exceeds a threshold or the bolt preload exceeds a predetermined range, prompting the operator to inspect or take necessary maintenance measures.

[0039] In this embodiment, an intuitive and easy-to-use graphical user interface was designed on the host computer using the MATLAB app designer. This interface includes not only a configuration area for serial communication settings, but also a gasket load status indicator and a gasket load gauge, allowing operators to clearly observe the current status of the gasket. Furthermore, the real-time updated XY curve provides users with an intuitive way to track the dynamic changes in the gasket load, with the dial pointer refreshing in real time and accurately pointing to the voltage value changes acquired by the corresponding differential transformer displacement sensor.

[0040] This embodiment also provides a gas pipeline flange leakage early warning method, using the above-mentioned gas pipeline flange leakage early warning device, the method includes the following steps:

[0041] Step 1: Use a spoke-type sensor to detect the preload of bolts between flanges, and use a differential transformer displacement sensor to detect the deformation of gaskets between flanges.

[0042] A spoke-type sensor is placed between a bolt and a flange. The head of the bolt presses the spoke-type sensor onto the flange. A differential transformer displacement sensor is connected to the flange. Both the spoke-type sensor and the differential transformer displacement sensor are connected to a data acquisition module via cables. The data acquisition module is connected to a wireless transmission module, which then sends the data to a host computer.

[0043] Step 2: Calibrate the spoke-type sensor and the differential transformer displacement sensor by gradually increasing the tightening torque using a torque wrench. Considering the adjustable range of the torque wrench and the tightening torque required for the maximum load on the gasket, the tightening torque range is 10 N·m to 80 N·m. Change the tightening torque of the bolts between the flanges to deform the gasket. At the same time, the spoke-type sensor records the bolt preload, and the differential transformer displacement sensor records the gasket deformation. Obtain the bolt preload and gasket deformation under different tightening torques, and record the maximum gasket deformation. Obtain the corresponding gasket load based on the gasket deformation.

[0044] In this embodiment, the bolt preload and washer deformation under different tightening torques are shown in Table 1.

[0045] Table 1. Bolt preload, washer deformation, and washer load corresponding to each tightening torque.

[0046]

[0047] Record the bolt preload and washer deformation, and record the maximum washer deformation of 0.936 mm. The relationship between washer deformation and washer load, i.e., the load-deformation relationship, is fixed. The washer load can be obtained from the washer deformation. The load-deformation relationship of washers of different materials can be obtained through compression-rebound tests. An example of a compression-rebound test is as follows:

[0048] Experimental specimens

[0049] The experimental specimens used were metal spiral wound gaskets with an inner ring and a locating ring (a combination of an inner ring, a locating ring (outer ring), and a sealing ring, suitable for both flat and raised flange sealing surfaces), a nominal size of DN80, and a nominal pressure of PN40. The specimen structure is as follows: Figure 3As shown. The filler materials for the two types of spiral wound gaskets are flexible graphite and PTFE (polytetrafluoroethylene), respectively, with the remainder being 304 stainless steel. The spiral wound gasket with flexible graphite filler is designated as Specimen A; the spiral wound gasket with PTFE filler is designated as Specimen B. The gasket conforms to the standard HG / T20610-09. The dimensional parameters of the spiral wound gasket specimens for pipe flanges according to GB / T 4622.1-2022 are shown in Table 2.

[0050] Table 2 Sample size parameters

[0051]

[0052] Experimental equipment

[0053] The compression resilience of metal spiral wound gaskets was tested on the WAW-600B microcomputer-controlled electro-hydraulic servo universal testing machine manufactured by Jinan Tianchen Experimental Machine Manufacturing Co., Ltd. The WAW-600B microcomputer-controlled electro-hydraulic servo universal testing machine consists of an electronic control system, an information acquisition module, a hydraulic power unit, a speed control system, and flange clamps.

[0054] This testing machine fully meets the requirements for experimental apparatus in the experimental design reference standard GB / T12622-2008 "Test Method for Compression and Resilience of Gaskets for Pipe Flanges—Test Method B". Following the designed experimental steps, the electronic control system controls the flange clamps to load and unload the gasket. The information acquisition module collects real-time data on displacement and load changes, and all data is then processed to plot the curve of the tested gasket sample's compression and resilience performance, thus reflecting the changes in load and deformation during loading and unloading.

[0055] Experimental protocol

[0056] The experimental method was formulated according to GB / T 12622-2008 "Test Method for Compression Ratio and Resilience of Gaskets for Pipe Flanges". The initial load was set to 5% of the total load, and the loading and unloading speeds were 0.5 MPa / s. The formulated method is shown in Table 3. Each sample was tested three times.

[0057] Table 3 Experimental Methods

[0058]

[0059] In laboratory experiments, the applied force is measured in kN. Therefore, it is necessary to convert the unit of the total stress load on the gasket before the experiment. Because errors may occur in the inner ring diameter, sealing element inner diameter, sealing element outer diameter, and outer ring outer diameter of the metal spiral wound gasket during actual manufacturing, the actual dimensions of the sample must be measured with vernier calipers before performing the unit conversion. The area of ​​the sealing element is calculated by averaging the dimensions of three samples.

[0060] Experimental Results and Analysis

[0061] After recording the experimental data according to the above steps, the data were processed using Origin software, and compression-rebound curves of specimen A and specimen B under loads of 30 MPa, 50 MPa, and 70 MPa were plotted. The compression-rebound curve of specimen A is shown below. Figure 4 As shown, the compression-rebound curve of sample B is as follows: Figure 5 As shown. By Figure 4 and Figure 5 It can be seen that the compression-rebound curves of the two types of spiral wound gaskets share many similarities. Regardless of whether the filler material is flexible graphite or PTFE, the maximum compression increases with the load. During the compression stage, although the maximum loads on the same type of spiral wound gasket differ, their load-deformation relationship changes at approximately the same rate, and their compression curves largely overlap. As the load increases further, the compression curves extend along the curves of the lower load until the maximum load is reached. This is because during the compression stage, both types of gaskets are in an elastic compression state. The voids within the filler material, from a microscopic perspective, gradually close under the load. Therefore, the load-deformation relationship changes linearly, like spring compression, and its slope is determined by the elastic modulus of the material. Although in the rebound stage, their load-deformation relationship also changes at approximately the same rate, and the rebound curves in this stage are roughly parallel. This is because during the springback stage, the load is gradually released, and both the filler material and the metal strip recover from elastic deformation. Plastic deformation accounts for a small proportion of the total deformation. Therefore, the rate of change of the load-deformation relationship in the springback curves under different loads is similar and is determined by the springback modulus of the material.

[0062] contrast Figure 4 and Figure 5 It can be observed that the rate of change of load-deformation during the compression stage of the compression-rebound curve of sample A is less than that of sample B during the rebound stage. This indicates that the elastic modulus of flexible graphite is less than that of PTFE. Conversely, the rate of change of load-deformation during the rebound stage of sample A is greater than that of sample B, indicating that the springback modulus of flexible graphite is greater than that of PTFE.

[0063] Step 3: Repeat the calibration multiple times to obtain the relationship between the shim load and the analog voltage value of the differential transformer displacement sensor and the analog voltage value of the spoke sensor at that location;

[0064] Since the analog voltage values ​​output by the differential transformer displacement sensor differ under different shim deformation amounts, and the analog voltage values ​​output by the spoke sensor also differ under different bolt preloads, the relationship between the shim load and the analog voltage values ​​output by the differential transformer displacement sensor and the analog voltage values ​​output by the spoke sensor can be obtained under different shim deformation amounts. In this embodiment, they are all positively correlated, that is, the larger the shim load, the larger the analog voltage value output by both the differential transformer displacement sensor and the spoke sensor. The shim load at that location can be obtained based on the analog voltage values ​​output by the differential transformer displacement sensor or the spoke sensor.

[0065] Step 4: Install differential pressure displacement sensors and spoke sensors at each flange gasket location on the gas pipeline. Obtain the bolt preload at that location based on the specified gasket load. Calculate the tightening torque required to achieve the specified gasket load based on the relationship between bolt preload and tightening torque.

[0066]

[0067] Where T represents the tightening torque, K represents the torque coefficient, F represents the bolt preload, and D represents the bolt diameter; the bolt at this location is adjusted to the corresponding tightening torque using a torque wrench;

[0068] Differential pressure displacement sensors and spoke sensors are installed on each of the multiple flanges of the gas pipeline to monitor each flange. Before tightening the bolts, the gasket load required for the flange at that location is a specified value. The bolts need to be tightened with a torque wrench to bring the gasket load at that location to the specified value. Step 4 allows the torque wrench to be used at that location to obtain the required tightening torque, which is convenient for personnel to carry out the work.

[0069] Step 5: Based on the relationship model between gasket load and leakage rate:

[0070]

[0071] In the formula, It's the leakage rate. It is the dynamic viscosity of the medium in the pipeline, S G It is the gasket compression stress (actual gasket load), S G0 This refers to the gasket preload (gasket standard load), where p is the pressure of the medium in the pipeline. D0 is the outer diameter of the gasket, and A is the outer diameter of the reference gasket. L It is the regression coefficient. It is the regression coefficient;

[0072] Typical leakage models include flat plate models, parallel circular plate models, circular pipe models, triangular groove models, and porous media models. Among these numerous leakage models, the porous media leakage model is commonly used for the metal spiral wound gaskets in this embodiment, as shown below:

[0073]

[0074] In the formula, L L Indicates the leakage rate. Indicates the dynamic viscosity of the medium. P represents residual preload stress. l P1 represents the pressure at the inner end of the capillary tube, P2 represents the pressure at the outer end of the capillary tube, and P... m The average pressure across the capillary tube is represented by M, the molecular weight of the gas is represented by T, and the absolute temperature of the gas is represented by A. L n represents the regression coefficient; l Represents the regression coefficient; A M denoted by ; nM represents the regression coefficient; b represents the regression coefficient. Since laminar flow leakage is predominant in this embodiment, leakage caused by molecular flow can be ignored, thus simplifying the model as follows:

[0075]

[0076] This refers to the dynamic viscosity of the medium in the pipeline. Different transported media have different dynamic viscosities, S. G This is the actual shim load, which can be obtained from the shim deformation based on the load-deformation relationship. A differential transformer displacement sensor can be used to obtain the shim deformation, S. G0 This is the standard load for the gasket at that location; it is the standard value. Different gaskets have different regression coefficients. The regression coefficient A for different gaskets... L and n l The results were obtained through existing gasket leakage rate tests, with the test method referring to GB / T 12385-2008 "Test Method for Sealing Performance of Gaskets for Pipe Flanges".

[0077] During monitoring, the corresponding gasket load is obtained by using the simulated voltage values ​​of the differential transformer displacement sensor and the spoke sensor. The leakage rate is then calculated using a model relating gasket load and leakage rate, yielding the real-time leakage rate of the gasket at that location. An alarm is triggered by the host computer when the leakage rate exceeds a preset alarm value. Similarly, an alarm is triggered when the differential transformer displacement sensor detects that the maximum gasket deformation exceeds a threshold, such as exceeding 0.936 mm under a tightening torque of 80 N·m. Finally, an alarm is triggered when the spoke sensor detects that the bolt preload is outside a preset range (e.g., 10 kN-28 kN). This indicates either excessive or insufficient bolt preload, both of which are abnormal, and the host computer will issue an alarm.

[0078] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A gas pipeline flange leakage early warning device, characterized in that, The system includes a first sensor, a second sensor, a data acquisition module, a wireless transmission module, and a host computer. Both the first and second sensors are connected to the data acquisition module. The first sensor detects the deformation of the gasket between the flanges and converts it into a voltage signal, which is then output to the data acquisition module. The second sensor detects the preload of the bolts between the flanges and converts it into a voltage signal, which is then output to the data acquisition module. The data acquisition module is connected to the wireless transmission module, which transmits the data to the host computer.

2. The gas pipeline flange leakage early warning device according to claim 1, characterized in that, The first sensor is a differential transformer displacement sensor, and the second sensor is a spoke-type sensor.

3. The gas pipeline flange leakage early warning device according to claim 1, characterized in that, The host computer includes a display.

4. A method for early warning of gas pipeline flange leakage, using the gas pipeline flange leakage early warning device according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Use a spoke-type sensor to detect the preload of bolts between flanges, and use a differential transformer displacement sensor to detect the deformation of gaskets between flanges. Step 2: Using a calibration method, gradually increase the tightening torque to change the tightening torque of the bolts between the flanges, causing the gasket to deform. At the same time, the spoke sensor records the bolt preload, and the differential transformer displacement sensor records the gasket deformation. Obtain the bolt preload and gasket deformation under different tightening torques, and record the maximum gasket deformation. Based on the gasket deformation, obtain the corresponding gasket load. Step 3: Repeat the calibration multiple times to obtain the relationship between the shim load and the analog voltage value of the differential transformer displacement sensor and the analog voltage value of the spoke sensor at that location; Step 4: Install differential pressure displacement sensors and spoke sensors at each flange of the gas pipeline. Obtain the bolt preload at that location based on the specified gasket load. Calculate the tightening torque required to achieve the specified gasket load based on the relationship between bolt preload and tightening torque. ； Where T represents the tightening torque, K represents the torque coefficient, F represents the bolt preload, and D represents the bolt diameter; adjust the bolt at this location to the corresponding tightening torque; Step 5: Based on the relationship model between gasket load and leakage rate: ； In the formula, L L It is the leakage rate, η is the dynamic viscosity of the medium in the pipeline, and S G This is the actual gasket load, S G0 This is the standard load of the gasket, p is the pressure of the medium in the pipeline, and D is the pressure of the gasket. x D0 is the outer diameter of the gasket, and A is the outer diameter of the reference gasket. L It is the regression coefficient, n l It is the regression coefficient; During the monitoring process, the corresponding gasket load is obtained by using the analog voltage value of the differential transformer displacement sensor and the analog voltage value of the spoke sensor at that location. The leakage rate is then calculated based on the gasket load to obtain the real-time leakage rate of the gasket at that location.

5. The gas pipeline flange leakage early warning method according to claim 4, characterized in that, The tightening torque range in step 2 is 10 N·m to 80 N·m.

6. The gas pipeline flange leakage early warning method according to claim 4, characterized in that, During the monitoring process in step 5, an alarm is issued when the leakage rate exceeds the preset alarm value.

7. The gas pipeline flange leakage early warning method according to claim 4, characterized in that, During the monitoring process in step 5, when the spoke sensor detects that the bolt preload is outside the preset range, an alarm is issued.

8. The gas pipeline flange leakage early warning method according to claim 4, characterized in that, During the monitoring process in step 5, when the differential transformer displacement sensor detects that the maximum gasket deformation exceeds the threshold, an alarm is issued.

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