Air pressure valve detection device

Abstract

The invention relates to the technical field of valve detection, in particular to an air pressure valve detection device, which comprises a gas-liquid double-detection module, which can be used for firstly carrying out air pressure test and then switching to water pressure test, and can be used for detecting liquid leakage through a liquid level sensor, so that the detection time can be shortened; the multi-air-chamber isolation module can realize multi-air-chamber static isolation to eliminate environmental interference and reduce the leakage error detection rate; the detection module comprises a differential pressure sensor, a float flowmeter and a liquid level sensor, and the two ends of the differential pressure sensor are connected with the reference gas chamber and the detection gas chamber respectively; the automatic control module is used for controlling the propelling assembly to automatically clamp the valve, synchronously triggering a gas-liquid detection process and setting parameters through a touch screen; the overpressure protection module is used for preventing the sensor from being damaged. The problems of low detection efficiency and poor accuracy of air pressure valve detection in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of valve detection, and more specifically, to a pneumatic valve detection device. Background Art

[0002] A steam trap is a device used in steam systems to automatically discharge condensate, air, and other non-condensable gases, while preventing steam leakage. Its core function is to improve the efficiency of the steam system, reduce energy loss, and prevent equipment damage such as water hammer. Its core components include a valve body, an inlet, an outlet, a filter screen, and a valve cover.

[0003] In practical applications, due to reasons such as filter screen blockage, valve disc wear, and gasket aging, there is a risk of air pressure leakage in the valve of the steam trap. The leakage detection of the valve of the steam trap is a key link to ensure the efficient operation and energy conservation of the steam system.

[0004] Existing detection methods include visual inspection (visual, auditory), temperature detection, conductivity detection, and ultrasonic detection. There are problems of missed detection and false detection. For example, in a noisy environment (such as a factory workshop), background noise may mask the leakage signal; temperature detection cannot detect leaks inside concealed or complex structures, etc.

[0005] In view of this, it is necessary to provide a pneumatic valve detection device and its calibration method that can perform gas-liquid double detection, multi-air chamber isolation, and automatic control for high-precision leakage detection of industrial valves to solve the above problems. Summary of the Invention

[0006] In view of this, the present invention proposes a pneumatic valve detection device, aiming to solve the problems of low detection efficiency and poor accuracy in the detection of pneumatic valves in the prior art.

[0007] On the one hand, the present invention proposes a pneumatic valve detection device, including:

[0008] A gas-liquid double detection module, including a water pressure power device and a gas pressure power device. The water pressure power device is connected to the test valve inlet through a water system valve, and the gas pressure power device is connected to the test valve inlet through a regulating valve;

[0009] A multi-air chamber isolation module, including solenoid valve A, solenoid valve B, and solenoid valve C. Solenoid valve A is arranged at the test valve outlet, solenoid valve B is arranged on the reference air chamber pipeline, and solenoid valve C is arranged on the detection air chamber pipeline;

[0010] A detection module, including a differential pressure sensor, a rotameter, and a liquid level sensor. Both ends of the differential pressure sensor are respectively connected to the reference air chamber and the detection air chamber;

[0011] The automatic control module controls the opening and closing of the solenoid valve A, solenoid valve B, and solenoid valve C through a PLC controller; starts and stops the pneumatic power device and the hydraulic power device, and is electrically connected to the detection module;

[0012] The overpressure protection module includes a voltage comparator and a relay. The relay is connected in series to the power supply circuit of the solenoid valve A. The voltage comparator monitors the output of the differential pressure sensor in real time and triggers the relay to disconnect when the limit is exceeded.

[0013] Further, the hydraulic power device includes a reciprocating pump, a water tank, and a pressure stabilizing container. The pneumatic power device includes an air compressor station, a pressure stabilizing tank, and a regulating valve. The water system valve and the regulating valve are connected in parallel to the inlet of the test valve.

[0014] Further, in the multi-chamber isolation module, the volume ratio of the reference chamber to the detection chamber is 1:1 to 1:2, and the two are isolated from the gas source through the solenoid valves B and C.

[0015] Further, the detection module further includes a glass tube container and a blind plate. The glass tube container is arranged at the outlet of the test valve and communicates with the atmosphere. The blind plate seals both ends of the test valve, and the liquid level sensor probe is inserted into the glass tube container.

[0016] Further, the automatic control module includes a touch screen, which is used to set the test pressure, the pressure stabilizing time, and the leakage threshold, and display the qualified / unqualified indicator lights.

[0017] Further, the trigger threshold of the overpressure protection module is 1.5 times the full scale of the differential pressure sensor, and the response time ≤ 10ms.

[0018] Further, a method for detecting air pressure valve leakage includes the following steps:

[0019] Step S1: Clamp the valve, fix the test valve through the vertical / horizontal propulsion assembly, and seal all outlets with plugs;

[0020] Step S2: Start the air detection mode, fill in high-pressure gas, close the solenoid valves B and C, and record the initial pressure difference P1;

[0021] Step S3: Read the pressure difference P2 after the interval time T. If |P2 - P1| > the threshold value, it is determined that the gas leaks;

[0022] Step S4: Switch to the liquid detection mode, fill in high-pressure liquid, and detect the leakage amount through the liquid level sensor;

[0023] Step S5: If both the air and liquid detections are qualified, perform the life test in a loop; otherwise, trigger an alarm and terminate.

[0024] Further, in step S2, the pressure of the high-pressure gas is 0.7 MPa, and the pressure stabilization time is 10 s; the pressure of the high-pressure liquid is 1.5 times the rated pressure of the valve, and the pressure stabilization time is 5 s.

[0025] Further, in step S3, the threshold value is dynamically adjusted according to the valve specification, and the calculation formula is: threshold value = K × P1, where K = 0.05 - 0.1.

[0026] Further, in step S5, when the cumulative number of switchings in the life test reaches the preset value N, steps S2 - S4 are automatically executed after every n tests until leakage occurs or the maximum number of cycles is reached.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] An air pressure valve detection device of the present invention:

[0029] ① Through the air-liquid double detection module, air pressure test can be carried out first, and then switched to water pressure test. The liquid leakage is detected by the liquid level sensor, which can shorten the detection time.

[0030] ② The multi-air chamber isolation module can statically isolate multiple air chambers to eliminate environmental interference, reduce the misdetection rate of leakage, and improve the detection accuracy.

[0031] ③ The overpressure protection module can avoid damage to the sensor and improve the service life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0033] Figure 1 is a schematic block diagram of an air pressure valve detection device provided by an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of a detection method of an air pressure valve detection device provided by an embodiment of the present invention.

[0035] In the figure: 100, water system valve; 200, regulating valve; 300, test valve; 400, solenoid valve B; 500, solenoid valve C; 600, reference air chamber; 700, detection air chamber; 800, relay; 101, reciprocating pump; 102, water tank; 103, pressure stabilizing container; 201, air compressor station; 202, pressure stabilizing tank; 203, regulating valve; 900, solenoid valve A. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0037] In practical applications, due to reasons such as filter screen blockage, valve plate wear, and gasket aging, there is a risk of air pressure leakage in the valves of steam traps. Therefore, the detection of valve leakage in steam traps is a key link to ensure the efficient operation and energy conservation of the steam system. If leakage occurs, it will reduce the efficiency of the steam system, increase energy loss, and cause equipment damage such as water hammer. If the leakage cannot be detected and processed in time, it will not only affect the normal working efficiency of the steam system, but may also lead to serious safety accidents. Most of the existing fault diagnosis methods rely on manual regular inspections and intuitive judgments, which have problems such as low detection efficiency and poor accuracy, and cannot meet the requirements for efficient and accurate leakage judgment of steam traps.

[0038] Therefore, the present invention proposes a pneumatic valve detection device to solve the problems of low detection efficiency and high missed detection rate existing in the pneumatic valve detection device in the prior art.

[0039] Refer to Figure 1 As shown, in some embodiments of the present application, a pneumatic valve detection device includes a gas-liquid double detection module, a multi-air chamber isolation module, a detection module, an automatic control module, and an overpressure protection module.

[0040] Specifically, the gas-liquid double detection module includes a water pressure power device and a gas pressure power device. The water pressure power device is connected to the inlet of the test valve 300 through the water system valve 100, and the gas pressure power device is connected to the inlet of the test valve 300 through the regulating valve 200. The multi-gas chamber isolation module includes solenoid valve A900, solenoid valve B400, and solenoid valve C500. The solenoid valve A900 is arranged at the outlet of the test valve 300, the solenoid valve B400 is arranged on the pipeline of the reference gas chamber 600, and the solenoid valve C500 is arranged on the pipeline of the detection gas chamber 700. The detection module includes a differential pressure sensor, a rotameter, and a liquid level sensor. The two ends of the differential pressure sensor are respectively connected to the reference gas chamber 600 and the detection gas chamber 700. The automatic control module controls the opening and closing of the solenoid valve A900, solenoid valve B400, and solenoid valve C500 through a PLC controller. The PLC controller controls the start and stop of the gas pressure power device and the water pressure power device, and is electrically connected to the detection module. The overpressure protection module includes a voltage comparator and a relay 800. The relay 800 is connected in series to the power supply circuit of the solenoid valve A900. The voltage comparator monitors the output of the differential pressure sensor in real time and triggers the relay 800 to disconnect when the limit is exceeded.

[0041] It can be understood that the core component of this device is the gas-liquid double detection module, which is composed of a water pressure power device (reciprocating pump 101, water tank 102, pressure stabilizing container 103) and a gas pressure power device (air compressor station 201, pressure stabilizing tank 202, regulating valve 200). Among them, the water pressure power device is connected to the inlet of the test valve 300 through the water system valve 100. The gas pressure power device is connected in parallel with the water pipeline to the inlet of the test valve 300.

[0042] The multi-gas chamber isolation module includes a reference gas chamber 600 and a detection gas chamber 700. Among them, the reference gas chamber 600 is preferably a sealed cavity with a volume of 5L and is isolated from the gas source through the solenoid valve B400. The detection gas chamber 700 is preferably a cavity with a volume of 10L and is communicated with the outlet of the test valve 300 through the solenoid valve C500. The isolation control of the multi-gas chamber isolation module is realized by different opening and closing states of the solenoid valves A900, B, and C. In the default state, the solenoid valves B400 and C are normally closed, and the solenoid valve A900 is normally open. The solenoid valve A900 is arranged at the outlet of the test valve 300 and is used to switch the gas-liquid detection mode.

[0043] The detection module includes a differential pressure sensor (the two ends are respectively connected to the reference gas chamber 600 and the detection gas chamber 700), a liquid level sensor (inserted into the glass tube container for detecting the water leakage amount), and a rotameter (arranged at the blind plate of the valve outlet for detecting the gas leakage rate).

[0044] The core component of the automatic control module is the PLC controller, which includes a touch screen. Test parameters (such as pressure 0.7 MPa, voltage stabilization time 10 s, etc.) can be preset through the touch screen. The propulsion component includes a vertical cylinder and a horizontal cylinder for automatically clamping the valve, and the clamping force is controlled by a pressure feedback closed loop. In one preferred embodiment of the overpressure protection module, the trigger threshold of the voltage comparator is set to 3 V, and a high level is output when the limit is exceeded. The relay 800 is connected in series to the power supply circuit of the solenoid valve A900, with a response time ≤ 10 ms. When overpressure occurs, the solenoid valve A900 is disconnected to release the pressure.

[0045] Specifically, the water pressure power device includes a reciprocating pump 101, a water tank 102 and a pressure stabilizing container 103. The air pressure power device includes an air compressor station 201, a pressure stabilizing tank 202 and a regulating valve 200. The water system valve 100 and the regulating valve 200 are connected in parallel to the inlet of the test valve 300.

[0046] It can be understood that the reciprocating pump 101 is a three-cylinder plunger reciprocating pump 101, and its inlet is connected to the water tank 102 through a pipeline. In one preferred embodiment, the water tank 102 is made of stainless steel, with a volume of 500 L, equipped with a liquid level sensor and an automatic water replenishing valve. A buffer partition is provided inside the pressure stabilizing container 103, and a safety valve is installed on the top. The water system valve 100 is an electric ball valve (DN50, response time ≤ 1 s), and is connected in parallel with the air pressure pipeline to the inlet of the test valve 300. The specific connection method is to flow through the water tank 102, the reciprocating pump 101, the pressure stabilizing container 103, and the water system in sequence, and finally flow into the inlet of the test valve 300. And an electric contact pressure gauge is installed at the outlet of the pressure stabilizing container 103 to monitor the water pressure in real time and feedback it to the controller to control the start and stop of the reciprocating pump 101.

[0047] When the device is working specifically, the working process is that the controller sends an instruction to open the water system valve 100 and close the air pressure regulating valve 200. Start the reciprocating pump 101 to pump the water in the water tank 102 into the pressure stabilizing container 103 until the pressure rises to the set value. After the pressure stabilizing container 103 smooths the pressure fluctuation, the water flows through the water system valve 100 into the test valve 300. The liquid level sensor is inserted into the glass tube container to monitor the water level change within 10 minutes. If the rise is > 1 mm, it is determined that there is liquid leakage.

[0048] It can be seen from this that the water system valve 100 and the regulating valve 200 are connected in parallel through a tee fitting, and a check valve is provided at the inlet end to prevent the medium from flowing back. When switching the detection mode, the controller synchronously controls the opening and closing of the valves: when the air detection mode is working, the water system valve 100 is closed and the regulating valve 200 is opened. When the liquid detection mode is working, the regulating valve 200 is closed and the water system valve 100 is opened. And the outlet of the test valve 300 is connected to the evacuation main pipe. After the detection is completed, the residual gas in the air detection is discharged to the muffler through the solenoid valve. The residual water in the liquid detection flows back to the water tank 102 through the hydraulic relief valve. Before switching the mode, the controller automatically executes a 3-second evacuation program to ensure that there is no residual medium in the pipeline.

[0049] In this application, through the optimization of the structural design of the water pressure / air pressure power device, the parallel pipeline switching and the automatic control, the efficient and accurate switching of the air-liquid double detection mode is realized, which can ensure the safety and reliability of the system.

[0050] Specifically, in the multi-air chamber isolation module, the volume ratio of the reference air chamber 600 to the detection air chamber 700 is 1:1 to 1:2, and the two are isolated from the air source through the solenoid valves B400 and C.

[0051] It can be understood that in one of the preferred embodiments, the specific structure of the reference air chamber 600 is a stainless steel cylindrical container with a volume set to 1L. The detection air chamber 700 has a volume designed to be 1.2L, made of the same material as the reference air chamber 600, and a connection interface is reserved at the bottom to connect to the outlet of the valve to be tested. The solenoid valve B400 is a normally closed two-way two-way solenoid valve and is installed on the inlet pipeline of the reference air chamber 600. The solenoid valve C500 is also a normally closed two-way two-way solenoid valve and is installed on the inlet pipeline of the detection air chamber 700. The air source connection path is that the main air path is divided into two paths through a tee and is respectively connected to the inlets of the solenoid valves B400 and C.

[0052] When the device is working, during the detection stage, the solenoid valves B400 and C are closed, and the reference air chamber 600 and the detection air chamber 700 are completely isolated from the air source. The outlets of the two air chambers converge through a tee and are connected to both ends of the differential pressure sensor. In another preferred embodiment of the present application, a buffer tank is installed at the air chamber inlet to reduce the influence of the air source pressure fluctuation and increase the anti-interference performance.

[0053] As can be seen from the above, in this application, by precisely controlling the air chamber volume ratio, solenoid valves and differential pressure sensors, and cooperating with the automatic process of the controller, the efficient isolation and accurate detection of multiple air chambers are realized.

[0054] Specifically, the detection module further includes a glass tube container and a blind plate. The glass tube container is arranged at the outlet of the test valve 300 and communicates with the atmosphere. The blind plate seals both ends of the test valve 300, and the liquid level sensor probe is inserted into the glass tube container.

[0055] It can be understood that the glass tube container is vertically fixed at the outlet flange of the test valve 300. The bottom is connected to the valve outlet through a flange, and the top is open to the atmosphere. A stainless steel bracket is used as a support to fix the glass tube, and a buffer gasket is provided at the bottom to prevent stress concentration. A flange gasket is used to seal the bottom of the glass tube and the valve outlet. An overflow groove is provided at the top of the glass tube to prevent the liquid level from overflowing. The overflow liquid flows back to the water tank 102 through a conduit.

[0056] A rubber gasket is clamped between the blind plate and the valve flange, and the bolt holes are aligned with the valve flange holes. When the equipment is working, the installation steps are as follows: First, clean the sealing surface of the valve flange to remove oil stains and impurities; place the rubber gasket between the blind plate and the valve flange; gradually tighten the bolts in a diagonal order to the standard torque to ensure uniform pressure distribution; fill in 0.5 MPa air pressure and keep the pressure for 5 minutes. If the pressure drop is ≤ 0.01 MPa, it is qualified.

[0057] The sensor probe is vertically inserted from the top of the glass tube. There is a small gap between the end of the probe and the bottom to avoid contacting the bottom sediment. It is fixed on the top flange cover of the glass tube through a threaded locking device to ensure that the probe does not shake. During the detection operation process, a liquid tightness detection needs to be carried out. The specific operation steps are as follows: First, inject water and pressurize. Start the water pressure power device and inject clear water into the valve through the reciprocating pump 101. Pressurize to the set pressure and keep the pressure for 5 minutes. The liquid level sensor monitors the liquid level change in the glass tube in real time and observes the stable pressure. If the liquid level rises ≤ 1 mm within 10 minutes, the liquid tightness detection is qualified; when the liquid level exceeds the limit, in one of the preferred embodiments, the controller triggers an audible and visual alarm and records the leakage curve. At the same time, open the hydraulic relief valve to drain the pressure and discharge the liquid in the valve and pipeline back to the water tank 102, remove the blind plate and the glass tube container, clean the sealing surface and file the detection data.

[0058] As can be seen from the above, in this application, through the combination of a high-precision glass tube container, a strictly sealed blind plate and an intelligent liquid level sensor, the accurate detection of the liquid tightness of the valve is realized.

[0059] Specifically, the automatic control module includes a touch screen, which is used to set the test pressure, the stable pressure time and the leakage threshold, and display the qualified / unqualified indicator lights.

[0060] The present invention also provides a method for detecting the leakage of a pneumatic valve based on this device, including the following steps:

[0061] Step S1: Clamp the valve, fix the test valve 300 through the vertical / horizontal propulsion component, and plug to seal all outlets; Step S2: Start the air detection mode, fill with high-pressure gas, close solenoid valves B400 and C, and record the initial pressure difference P1; Step S3: Read the pressure difference P2 after an interval time T. If |P2 - P1| > the threshold value, it is determined that there is a gas leak; Step S4: Switch to the liquid detection mode, fill with high-pressure liquid, and detect the leakage amount through the liquid level sensor; Step S5: If both the air and liquid detections are qualified, the test ends; otherwise, trigger an alarm and terminate.

[0062] Specifically, in Step S2, the pressure of the high-pressure gas is 0.7 MPa, and the pressure stabilization time is 10 s; the pressure of the high-pressure liquid is 1.5 times the rated pressure of the valve, and the pressure stabilization time is 5 s. In Step S3, the threshold value is dynamically adjusted according to the valve specifications, and the calculation formula is: threshold value = K × P1, where K = 0.05 - 0.1. In Step S5, when the cumulative number of switch operations in the life test reaches the preset value N, Steps S2 - S4 are automatically executed every n tests until leakage occurs or the maximum number of cycles is reached.

[0063] It can be seen that in Step S1: Clamp the valve, fix the test valve 300 through the vertical / horizontal propulsion component, and plug to seal all outlets. The specific operation process is as follows: Place the valve to be tested at the center of the working platform, and initially position it through the fixture centering mechanism; for the vertical propulsion component, start the vertical cylinder, drive the upper pressure plate to press down to the top flange of the valve, and the clamping force is real-time fed back through the pressure sensor to ensure that the set value is reached. Among them, for the horizontal propulsion component, synchronously start the horizontal cylinder, push the side plug to seal the bypass port of the valve, and the surface of the plug is coated with an elastic sealing layer. When verifying the sealing performance, fill with 0.3 MPa low-pressure gas, maintain the pressure for 10 seconds, and the pressure drop ≤ 0.01 MPa is qualified. Through pressure closed-loop control, overpressure damage to the valve or insufficient sealing is avoided, high-precision clamping is achieved, and at the same time, without manual intervention, the elastic plug adapts to different valve diameters, and the sealing reliability is high.

[0064] Step S2: Start the air detection mode, fill with high-pressure gas, close solenoid valves B400 and C, and record the initial pressure difference P1. The operation process is air path switching. The controller closes the water system valve 100, opens the pneumatic pressure regulating valve 200, starts the air compressor, and after the gas is buffered by the pressure stabilizing tank 202 (volume 300 L), it is filled into the valve at a pressure of 0.7 MPa, and the pressure curve is monitored in real time. After reaching the target pressure, close solenoid valve B400 (isolation valve of the reference air chamber 600) and C (isolation valve of the detection air chamber 700) to isolate the gas source. The differential pressure sensor reads the initial pressure difference. Among them, the design of the pressure stabilizing tank 202 reduces the pressure fluctuation, and the inflation time ≤ 10 seconds. After isolating the gas source, external interference is eliminated, and the detection accuracy is high. The differential pressure data is automatically uploaded to the controller to avoid manual recording errors, and the data is synchronized in real time.

[0065] Step S3: Read the differential pressure P2 after the interval time T. If |P2 - P1| > the threshold value, it is determined that there is a gas leak. The specific operation process is as follows: Keep the air chamber in an isolated state, stand still, and eliminate the influence of temperature fluctuations. The differential pressure sensor reads, calculates the leakage value |P2 - P1|, and performs secondary differential pressure acquisition. If |P2 - P1| ≤ 0.1 kPa, it is determined that the airtightness is qualified, and the touch screen displays a green indicator light. If |P2 - P1| > 0.1 kPa, it is determined that there is a leak, triggering a red alarm light and a buzzer to complete the leak determination. Among them, the resolution of the differential pressure sensor is 0.001 kPa, which can identify tiny leaks and complete highly sensitive detection. At the same time, the threshold value can be dynamically adjusted according to the valve specifications to adapt to the threshold value. And the determination result can be fed back in real time for a quick response.

[0066] In summary, the gas-liquid double detection module of the present application includes a water pressure power device and an air pressure power device. The opening and closing of the solenoid valve A900, solenoid valve B400, and solenoid valve C500 are controlled by a controller; the controller controls the start and stop of the air pressure power device and the water pressure power device and is electrically connected to the detection module. This greatly shortens the single detection time. And the entire process of clamping, pressurizing, detecting, and determining does not require manual intervention, and the automated process is completed, reducing the labor operation cost. The switching time between the air detection and liquid detection modes is small, and the mode can be quickly switched.

[0067] The detection module includes a differential pressure sensor, a rotameter, and a liquid level sensor. The two ends of the differential pressure sensor are respectively connected to the reference air chamber 600 and the detection air chamber 700. Among them, the differential pressure sensor has a high resolution, can identify tiny leaks, and has a high precision in airtight detection. The liquid level sensor has a high accuracy, a small error in quantifying the leakage amount, and a high accuracy in liquid level detection. The leakage threshold value is dynamically adjusted to avoid misjudgment.

[0068] The overpressure protection module includes a voltage comparator and a relay 800. The relay 800 is connected in series to the power supply circuit of the solenoid valve A900. The voltage comparator monitors the output of the differential pressure sensor in real time and triggers the relay 800 to disconnect when over the limit. It has high safety and overpressure protection: it can avoid damage to the sensor due to overload. When the detection is completed or a fault occurs, the controller uses a pressure relief valve to empty the residual pressure to prevent accidental opening.

[0069] Finally, it should be noted that: The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0070] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent for the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention shall be subject to the appended claims.

Claims

1. A pneumatic valve detection device, characterized in that, Including: A gas-liquid dual detection module, including a water pressure power device and a gas pressure power device. The water pressure power device is connected to the test valve inlet through a water system valve, and the gas pressure power device is connected to the test valve inlet through a regulating valve; A multi-gas chamber isolation module, including solenoid valve A, solenoid valve B, and solenoid valve C. Solenoid valve A is arranged at the test valve outlet, solenoid valve B is arranged on the reference gas chamber pipeline, and solenoid valve C is arranged on the detection gas chamber pipeline; A detection module, including a differential pressure sensor, a rotameter, and a liquid level sensor. The two ends of the differential pressure sensor are respectively connected to the reference gas chamber and the detection gas chamber; An automatic control module, which controls the opening and closing of solenoid valve A, solenoid valve B, and solenoid valve C through a PLC controller; the PLC controller controls the start and stop of the gas pressure power device and the water pressure power device, and is electrically connected to the detection module; An overpressure protection module, including a voltage comparator and a relay. The relay is connected in series in the power supply circuit of solenoid valve A. The voltage comparator monitors the output of the differential pressure sensor in real time, and triggers the relay to disconnect when the limit is exceeded.

2. The pneumatic valve detection device according to claim 1, characterized in that, The water pressure power device includes a reciprocating pump, a water tank, and a pressure stabilizing container. The gas pressure power device includes an air compressor station, a pressure stabilizing tank, and a regulating valve. The water system valve and the regulating valve are connected in parallel to the test valve inlet.

3. The air pressure valve detection device according to claim 1, characterized in that, In the multi-gas chamber isolation module, the volume ratio of the reference gas chamber to the detection gas chamber is 1:1 to 1:2, and the two are isolated from the gas source through solenoid valves B and C.

4. An air pressure valve detection device according to claim 1, characterized in that, The detection module also includes a glass tube container and a blind plate. The glass tube container is arranged at the test valve outlet and communicates with the atmosphere. The blind plate seals both ends of the test valve, and the liquid level sensor probe is inserted into the glass tube container.

5. The air pressure valve detection device according to claim 1, characterized in that, The automatic control module includes a touch screen, which is used to set the test pressure, the pressure stabilizing time, and the leakage threshold, and display the qualified / unqualified indicator lights.

6. The air pressure valve detection device according to claim 1, characterized in that, The trigger threshold of the overpressure protection module is 1.5 times the full scale of the differential pressure sensor, and the response time ≤ 10 ms.

7. A method for detecting air pressure valve leakage, based on the device according to any one of claims 1-6, characterized in that, Including the following steps: Step S1: Clamp the valve, fix the test valve through a vertical / horizontal propulsion component, and seal all outlets with a plug; Step S2: Start the gas detection mode, fill in high-pressure gas, close solenoid valves B and C, and record the initial pressure difference P1; Step S3: Read the pressure difference P2 after an interval time T. If |P2 - P1| > the threshold, it is determined that there is a gas leak; Step S4: Switch to the liquid detection mode, fill in high-pressure liquid, and detect the leakage amount through the liquid level sensor; Step S5: If both the gas and liquid detections are qualified, the test ends; otherwise, trigger an alarm and terminate.

8. A method for detecting air pressure valve leakage according to claim 7, characterized in that, In step S2, the high-pressure gas pressure is 0.7 MPa, and the pressure stabilizing time is 10 s; the high-pressure liquid pressure is 1.5 times the rated pressure of the valve, and the pressure stabilizing time is 5 s.

9. A method for detecting air pressure valve leakage according to claim 7, characterized in that, In step S3, the threshold is dynamically adjusted according to the valve specifications, and the calculation formula is: threshold = K × P1, where K = 0.05 - 0.

1.

10. A method for detecting air pressure valve leakage according to claim 7, characterized in that, In step S5, when the cumulative number of switch operations in the life test reaches the preset value N, steps S2 - S4 are automatically executed every n tests until leakage occurs or the maximum number of cycles is reached.

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