Breather valve online detection device and use method thereof

Abstract

The invention relates to the technical field of breather valve detection, in particular to a breather valve online detection device and a using method thereof.The breather valve online detection device comprises a first pipeline, the tail end of the first pipeline is connected with the air inlet end of a stop valve, and the air outlet end of the stop valve is connected with the air inlet end of a pressure reducing valve through a second pipeline; the air outlet end of the pressure reducing valve is connected with the air inlet end of a first three-way switching valve through a third pipeline, the first air outlet end of the first three-way switching valve is connected with the first air inlet end of a second three-way switching valve through a fourth pipeline, and the air outlet end of the second three-way switching valve is connected with the first air inlet end of a pressure stabilizing tank through a fifth pipeline. A balance needle valve is arranged at the first air outlet end of the pressure stabilizing tank; the second air outlet end of the first three-way switching valve is connected with the second air inlet end of the second three-way switching valve through a sixth pipeline, and a negative pressure generator is arranged on the sixth pipeline. According to the invention, the breather valve can be detected online, and the efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of breathing valve detection, and in particular to an online breathing valve detection device and a use method thereof. Background Art

[0002] The breathing valve is an important accessory to protect the safety of the storage tank. It is installed on the top of the storage tank and consists of two parts: the pressure valve and the vacuum valve. Under normal circumstances, its function is to maintain the airtightness of the storage tank, maintain the air pressure balance of the storage tank, and reduce the volatilization of the medium. The breathing valve makes full use of the pressure bearing capacity of the storage tank itself to reduce the discharge of the medium. Its principle is to use the weight of the positive and negative pressure valve disc to control the positive pressure of the exhaust and the negative pressure of the suction of the storage tank. Automatic ventilation adjustment balances the pressure inside and outside the storage tank, which can play a role in the safety of the storage tank. According to the standard requirements of SYT 0511.1-2010 "Petroleum Storage Tank Accessories Part 1: Breathing Valve", the breathing valve should be tested at least once a year, and performance tests such as opening pressure and leakage are essential items. The current off-line calibration device for the breathing valve is to disassemble the breathing valve, clamp it on a calibration table, use a calibration medium (such as nitrogen, compressed air, etc.) to drive the positive pressure opening of the breathing valve (i.e., the opening of the positive pressure valve disc in the breathing valve) and drive the negative pressure opening of the breathing valve (i.e., the opening of the negative pressure valve disc in the breathing valve) by vacuuming with a vacuum pump, and confirm the opening pressure value of the breathing valve by observing the micropressure gauge. This offline detection method not only has a long detection cycle, high cost, and high labor intensity, but also affects safety. Summary of the invention

[0003] The purpose of the present invention is to provide a breathing valve online detection device and a use method thereof, which can perform online detection on the breathing valve.

[0004] The present invention adopts the following technical solutions to achieve the above purpose:

[0005] A breathing valve online detection device comprises a first pipeline, wherein the end of the first pipeline is connected to the air inlet end of the stop valve, the air outlet end of the stop valve is connected to the air inlet end of the pressure reducing valve via a second pipeline, the air outlet end of the pressure reducing valve is connected to the air inlet end of a first three-way switching valve via a third pipeline, the first air outlet end of the first three-way switching valve is connected to the first air inlet end of a second three-way switching valve via a fourth pipeline, the air outlet end of the second three-way switching valve is connected to the first air inlet end of a pressure stabilizing tank via a fifth pipeline, and the first air outlet end of the pressure stabilizing tank is provided with a balancing needle valve;

[0006] The second air outlet end of the first three-way switching valve is connected to the second air inlet end of the second three-way switching valve via a sixth pipeline, and a negative pressure generator is provided on the sixth pipeline;

[0007] The fourth gas outlet end of the pressure-stabilizing tank is connected to the breathing valve via a seventh pipeline;

[0008] The first end of the first pipeline is connected to a gas source.

[0009] Preferably, a first pressure gauge is provided on the first pipeline, a second pressure gauge is provided on the third pipeline, and a third pressure gauge is provided at the second gas outlet end of the pressure-stabilizing tank.

[0010] Preferably, a first micro-pressure sensor is provided on the third pipeline; a third three-way switching valve is provided on the third gas outlet end of the pressure-stabilizing tank, and a second micro-pressure sensor and a third micro-pressure sensor are respectively provided on two gas outlet ends of the third three-way switching valve.

[0011] Preferably, the pressure reducing valve is a precision pressure reducing valve.

[0012] A method for using a breathing valve online detection device, the method is as follows:

[0013] 1. Forward detection:

[0014] (1) Positive pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline, and then the pressure reducing valve and the balancing needle valve are adjusted to slowly increase the air pressure in the pressure regulating tank until the positive pressure valve disc is opened. When the positive pressure valve disc is opened, the value displayed on the third pressure gauge is the pressure value of the positive pressure opening of the breathing valve;

[0015] (2) Negative pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the second gas outlet of the first three-way switching valve into the sixth pipeline, and then the gas enters the negative pressure generator to generate negative pressure, so that negative pressure is also generated in the pressure regulating tank, and then the negative pressure in the pressure regulating tank is slowly increased by adjusting the pressure reducing valve and the balancing needle valve until the negative pressure valve disc is opened. When the negative pressure valve disc is opened, the value displayed on the third pressure gauge is the pressure value of the negative pressure opening of the breathing valve;

[0016] (3) Leakage detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline. Then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline. Then, the pressure reducing valve and the balancing needle valve are adjusted so that the air pressure in the pressure regulating tank slowly reaches 0.75 times the positive pressure opening pressure of the breathing valve. When this pressure is reached, the second three-way switching valve and the balancing pressure valve are quickly closed. After the pressure in the pressure regulating tank is stable, the timing is started and the initial pressure in the tank is recorded. After the timing is over, the pressure in the tank is recorded again, and the leakage of the breathing valve under test is calculated by the difference between the initial pressure and the pressure in the tank at the end and the timing time.

[0017] 2. Reverse Detection

[0018] (1) Positive pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas enters the sixth pipeline from the second gas outlet of the first three-way switching valve. Then the gas enters the negative pressure generator to generate negative pressure, so that negative pressure is also generated in the pressure regulating tank, and then the negative pressure in the pressure regulating tank is slowly increased by adjusting the pressure reducing valve and the balancing needle valve until the negative pressure valve disc opens. When the positive pressure valve disc opens, the value displayed on the third pressure gauge is: the sum of the pressure value of the positive pressure opening of the breathing valve and the basic pressure value in the storage tank; then the basic pressure value in the storage tank is subtracted from this value to obtain the pressure value of the positive pressure opening of the breathing valve;

[0019] (2) Negative pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline, and then the pressure reducing valve and the balancing needle valve are adjusted to slowly increase the air pressure in the pressure regulating tank until the negative pressure valve disc is opened. When the negative pressure valve disc is opened, the value displayed on the third pressure gauge is: the sum of the pressure value of the negative pressure opening of the breathing valve and the basic pressure value in the storage tank; then the basic pressure value in the storage tank is subtracted from this value to obtain the pressure value of the negative pressure opening of the breathing valve.

[0020] (3) Leakage detection: The gas is introduced into the first pipeline through the nitrogen source, and the stop valve is slowly opened. Then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline. Then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas enters the sixth pipeline from the second gas outlet of the first three-way switching valve. Then the gas enters the negative pressure generator to generate negative pressure, which also generates negative pressure in the pressure regulating tank. Then the pressure reducing valve and the balancing needle valve are adjusted so that the negative air pressure in the pressure regulating tank slowly reaches 0.75 times the positive pressure opening pressure of the breathing valve. When this pressure is reached, the second three-way switching valve and the balancing pressure valve are quickly closed. After the pressure in the pressure regulating tank is stable, the timing is started and the initial pressure in the tank is recorded. After the timing is over, the pressure in the tank is recorded again. The leakage of the breathing valve under test is calculated by combining the difference between the initial pressure and the pressure in the tank at the end with the timing time.

[0021] Preferably, the formula for leakage detection is:

[0022]

[0023] Where: The average density of the gas in the breathing valve cavity;

[0024] P1: The inner cavity pressure when the breathing valve is closed at the beginning of the test;

[0025] P2: The pressure value of the inner cavity of the breathing valve after a period of time;

[0026] V1: volume of surge tank;

[0027] M 2,mol : The molar mass of the gas in the inner cavity of the leaking breathing valve after a period of time;

[0028] RT1: The change in the temperature of the breathing valve cavity after a period of time;

[0029] From this, the leakage amount △V can be calculated.

[0030] Beneficial effects of the present invention:

[0031] (1) The present invention provides an embodiment in which the pressure reducing valve and the balancing needle valve can slowly adjust the air pressure in the pressure regulating tank, which is convenient for the subsequent detection of the breathing valve. A negative pressure generator is provided on the sixth pipeline. When the gas enters the negative pressure generator, negative pressure is generated, so that negative pressure is generated in the pressure regulating tank, which is convenient for the negative pressure detection of the breathing valve.

[0032] (2) In one embodiment of the present invention, the first micro-pressure sensor can transmit the detected value to the external system for internal recording, and can detect and record the air pressure in the third pipeline in real time to reduce errors. The second micro-pressure sensor is used to detect positive pressure values, and the third micro-pressure sensor is used to detect negative pressure values. The detected values ​​can be transmitted to the external system for internal recording, and can detect and record the air pressure in the pressure-stabilizing tank in real time to reduce errors.

[0033] The present invention can perform online detection on the breathing valve, thereby improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the present invention.

[0035] In the figure: a first pipeline 1, a stop valve 2, a second pipeline 3, a pressure reducing valve 4, a third pipeline 5, a first three-way switching valve 6, a fourth pipeline 7, a second three-way switching valve 8, a fifth pipeline 9, a pressure regulating tank 10, a balancing needle valve 11, a first pressure gauge 12, a second pressure gauge 13, a third pressure gauge 14, a sixth pipeline 15, a negative pressure generator 16, a seventh pipeline 17, a breathing valve 18, an air source 19, a first micro-pressure sensor 20, a third three-way switching valve 21, a second micro-pressure sensor 22, and a third micro-pressure sensor 23. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings.

[0037] like Figure 1 As shown, an embodiment is provided in the present invention, which provides an online detection device for a breathing valve, including a first pipeline 1, the end of the first pipeline 1 is connected to the air inlet end of the stop valve 2, the air outlet end of the stop valve 2 is connected to the air inlet end of the pressure reducing valve 4 through the second pipeline 3, the air outlet end of the pressure reducing valve 4 is connected to the air inlet end of the first three-way switching valve 6 through the third pipeline 5, the first air outlet end of the first three-way switching valve 6 is connected to the first air inlet end of the second three-way switching valve 8 through the fourth pipeline 7, the air outlet end of the second three-way switching valve 8 is connected to the first air inlet end of the pressure stabilizing tank 10 through the fifth pipeline 9, and the first air outlet end of the pressure stabilizing tank 10 is provided with a balancing needle valve 11. The stop valve 2 is used to open or close the connection between the first pipeline 1 and the second pipeline 3, the first three-way switching valve 6 is used to open or close the connection between the third pipeline 5 and the fourth pipeline 7, and the second three-way switching valve 8 is used to open or close the connection between the fourth pipeline 7 and the fifth pipeline 9, so as to facilitate the subsequent detection of the breathing valve 18. The air pressure in the pressure-stabilizing tank 10 can be slowly adjusted by the pressure reducing valve 4 and the balancing needle valve 11 , so as to facilitate the subsequent detection of the breathing valve 18 .

[0038] The first pipeline 1 is provided with a first pressure gauge 12 for detecting the pressure value in the first pipeline 1, the third pipeline 5 is provided with a second pressure gauge 13 for detecting the pressure value in the third pipeline 5, and the second air outlet end of the pressure stabilizing tank 10 is provided with a third pressure gauge 14 for detecting the pressure value in the pressure stabilizing tank 10.

[0039] The second air outlet end of the first three-way switching valve 6 is connected to the second air inlet end of the second three-way switching valve 8 via the sixth pipeline 15. A negative pressure generator 16 is arranged on the sixth pipeline 15. After the gas enters the negative pressure generator 16, negative pressure will be generated, so that negative pressure is generated in the pressure regulating tank 10, which is convenient for the negative pressure detection of the breathing valve 18.

[0040] The fourth air outlet end of the pressure-stabilizing tank 10 is connected to the breathing valve 18 via the seventh pipe 17. When the pressure-stabilizing tank 10 is tested in the forward direction, the seventh pipe 17 is connected to the air inlet end of the breathing valve 18. When the pressure-stabilizing tank 10 is tested in the reverse direction, the seventh pipe 17 is connected to the air outlet end of the breathing valve 18.

[0041] The first end of the first pipeline 1 is connected to a gas source 19 , and the gas source 19 may be a nitrogen source 19 , but is not limited thereto.

[0042] In one embodiment of the present invention, this embodiment is based on the previous embodiment, and this embodiment provides a method for using an online detection device for a breathing valve. In this embodiment, two detection methods are provided, namely forward detection and reverse detection. When forward detection is used online, it is necessary to close the stop valve on the connecting pipe between the storage tank and the breathing valve 18. Due to the high cost of the stop valve, generally, there is no stop valve on the connecting pipe between the storage tank and the breathing valve 18. Therefore, forward detection is suitable for the case where there is a stop valve on the connecting pipe between the storage tank and the breathing valve 18, while reverse detection is suitable for the case where there is no stop valve on the connecting pipe between the storage tank and the breathing valve 18. There are positive pressure valve discs and negative pressure valve discs in the breathing valve 18. The positive pressure detection is used to detect the opening pressure of the positive pressure valve disc, and the negative pressure detection is used to detect the opening pressure of the negative pressure valve disc.

[0043] Here’s how:

[0044] 1. Forward detection:

[0045] (1) Positive pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline, and then the pressure reducing valve and the balancing needle valve are adjusted to slowly increase the air pressure in the pressure regulating tank until the positive pressure valve disc is opened. When the positive pressure valve disc is opened, the value displayed on the third pressure gauge is the pressure value of the positive pressure opening of the breathing valve;

[0046] (2) Negative pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the second gas outlet of the first three-way switching valve into the sixth pipeline, and then the gas enters the negative pressure generator to generate negative pressure, so that negative pressure is also generated in the pressure regulating tank, and then the negative pressure in the pressure regulating tank is slowly increased by adjusting the pressure reducing valve and the balancing needle valve until the negative pressure valve disc is opened. When the negative pressure valve disc is opened, the value displayed on the third pressure gauge is the pressure value of the negative pressure opening of the breathing valve;

[0047] (3) Leakage detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline. Then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline. Then, the pressure reducing valve and the balancing needle valve are adjusted so that the air pressure in the pressure regulating tank slowly reaches 0.75 times the positive pressure opening pressure of the breathing valve. When this pressure is reached, the second three-way switching valve and the balancing pressure valve are quickly closed. After the pressure in the pressure regulating tank is stable, the timing is started and the initial pressure in the tank is recorded. After the timing is over, the pressure in the tank is recorded again, and the leakage of the breathing valve under test is calculated by the difference between the initial pressure and the pressure in the tank at the end and the timing time.

[0048] 2. Reverse Detection

[0049] (1) Positive pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas enters the sixth pipeline from the second gas outlet of the first three-way switching valve. Then the gas enters the negative pressure generator to generate negative pressure, so that negative pressure is also generated in the pressure regulating tank, and then the negative pressure in the pressure regulating tank is slowly increased by adjusting the pressure reducing valve and the balancing needle valve until the negative pressure valve disc opens. When the positive pressure valve disc opens, the value displayed on the third pressure gauge is: the sum of the pressure value of the positive pressure opening of the breathing valve and the basic pressure value in the storage tank; then the basic pressure value in the storage tank is subtracted from this value to obtain the pressure value of the positive pressure opening of the breathing valve;

[0050] (2) Negative pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline, and then the pressure reducing valve and the balancing needle valve are adjusted to slowly increase the air pressure in the pressure regulating tank until the negative pressure valve disc is opened. When the negative pressure valve disc is opened, the value displayed on the third pressure gauge is: the sum of the pressure value of the negative pressure opening of the breathing valve and the basic pressure value in the storage tank; then the basic pressure value in the storage tank is subtracted from this value to obtain the pressure value of the negative pressure opening of the breathing valve.

[0051] (3) Leakage detection: The gas is introduced into the first pipeline through the nitrogen source, and the stop valve is slowly opened. Then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline. Then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas enters the sixth pipeline from the second gas outlet of the first three-way switching valve. Then the gas enters the negative pressure generator to generate negative pressure, which also generates negative pressure in the pressure regulating tank. Then the pressure reducing valve and the balancing needle valve are adjusted so that the negative air pressure in the pressure regulating tank slowly reaches 0.75 times the positive pressure opening pressure of the breathing valve. When this pressure is reached, the second three-way switching valve and the balancing pressure valve are quickly closed. After the pressure in the pressure regulating tank is stable, the timing is started and the initial pressure in the tank is recorded. After the timing is over, the pressure in the tank is recorded again. The leakage of the breathing valve under test is calculated by combining the difference between the initial pressure and the pressure in the tank at the end with the timing time.

[0052] In this embodiment, the formula for leakage detection is:

[0053]

[0054] Where: The average density of the gas in the breathing valve cavity;

[0055] P1: The inner cavity pressure when the breathing valve is closed at the beginning of the test;

[0056] P2: The pressure value of the inner cavity of the breathing valve after a period of time;

[0057] V1: volume of surge tank;

[0058] M 2,mol : The molar mass of the gas in the inner cavity of the leaking breathing valve after a period of time;

[0059] RT1: The change in the temperature of the breathing valve cavity after a period of time;

[0060] From this, the leakage amount △V can be calculated.

[0061] In one embodiment of the present invention, this embodiment is based on the previous embodiment, and a first micro-pressure sensor 20 is provided on the third pipeline 5. The first micro-pressure sensor 20 can transmit the detected value to an external system for internal recording, and can detect and record the air pressure in the third pipeline 5 in real time to reduce errors.

[0062] The third air outlet end of the pressure-stabilizing tank 10 is provided with a third three-way switching valve 21, and the second micro-pressure sensor 22 and the third micro-pressure sensor 23 are respectively provided on the two air outlet ends of the third three-way switching valve 21. The second micro-pressure sensor 22 is used to detect the positive pressure value, and the third micro-pressure sensor 23 is used to detect the negative pressure value. The detected value can be transmitted to the external system for recording, and the air pressure in the pressure-stabilizing tank 10 can be detected and recorded in real time to reduce errors.

[0063] When the positive pressure is detected in the forward direction and the negative pressure is detected in the reverse direction, the third three-way switching valve 21 switches to the second micro-pressure sensor 22, so that the second micro-pressure sensor 22 detects the pressure in the pressure-stabilizing tank 10; when the negative pressure is detected in the forward direction and the positive pressure is detected in the reverse direction, the third three-way switching valve 21 switches to the third micro-pressure sensor 23, so that the third micro-pressure sensor 23 detects the pressure in the pressure-stabilizing tank 10.

[0064] In one embodiment of the present invention, which is based on any one of the above embodiments, the pressure reducing valve 4 is a precision pressure reducing valve 4 that can precisely regulate the gas pressure in the pressure stabilizing tank 10 .

[0065] The stop valve, three-way switching valve, balanced needle valve, pressure gauge, negative pressure generator, micro-pressure sensor, and precision pressure reducing valve in the present invention are all prior arts, which are clearly understood by those skilled in the art and will not be described in detail here.

[0066] The above description is only a preferred embodiment of the present invention and should not be construed as limiting the present application. All equivalent changes and modifications made within the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A breathing valve online detection device, characterized in that: The invention comprises a first pipeline, wherein the end of the first pipeline is connected to the air inlet end of the stop valve, the air outlet end of the stop valve is connected to the air inlet end of the pressure reducing valve via a second pipeline, the air outlet end of the pressure reducing valve is connected to the air inlet end of the first three-way switching valve via a third pipeline, the first air outlet end of the first three-way switching valve is connected to the first air inlet end of the second three-way switching valve via a fourth pipeline, the air outlet end of the second three-way switching valve is connected to the first air inlet end of the pressure stabilizing tank via a fifth pipeline, and the first air outlet end of the pressure stabilizing tank is provided with a balancing needle valve; The second air outlet end of the first three-way switching valve is connected to the second air inlet end of the second three-way switching valve via a sixth pipeline, and a negative pressure generator is provided on the sixth pipeline; The fourth gas outlet end of the pressure-stabilizing tank is connected to the breathing valve via a seventh pipeline; The first end of the first pipeline is connected to a gas source.

2. The breathing valve online detection device according to claim 1 is characterized in that: The first pipeline is provided with a first pressure gauge, the third pipeline is provided with a second pressure gauge, and the second gas outlet end of the pressure-surge tank is provided with a third pressure gauge.

3. The breathing valve online detection device according to claim 1 is characterized in that: The third pipeline is provided with a first micro-pressure sensor; the third gas outlet end of the pressure-stabilizing tank is provided with a third three-way switching valve, and the two gas outlet ends of the third three-way switching valve are respectively provided with a second micro-pressure sensor and a third micro-pressure sensor.

4. The breathing valve online detection device according to claim 1 is characterized in that: The pressure reducing valve is a precision pressure reducing valve.

5. A method for using the breathing valve online detection device according to claim 1, characterized in that: Here’s how:

1. Forward detection: (1) Positive pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline, and then the pressure reducing valve and the balancing needle valve are adjusted to slowly increase the air pressure in the pressure regulating tank until the positive pressure valve disc is opened. When the positive pressure valve disc is opened, the value displayed on the third pressure gauge is the pressure value of the positive pressure opening of the breathing valve; (2) Negative pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the second gas outlet of the first three-way switching valve into the sixth pipeline, and then the gas enters the negative pressure generator to generate negative pressure, so that negative pressure is also generated in the pressure regulating tank, and then the negative pressure in the pressure regulating tank is slowly increased by adjusting the pressure reducing valve and the balancing needle valve until the negative pressure valve disc is opened. When the negative pressure valve disc is opened, the value displayed on the third pressure gauge is the pressure value of the negative pressure opening of the breathing valve; (3) Leakage detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline. Then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline. Then, the pressure reducing valve and the balancing needle valve are adjusted so that the air pressure in the pressure regulating tank slowly reaches 0.75 times the positive pressure opening pressure of the breathing valve. When this pressure is reached, the second three-way switching valve and the balancing pressure valve are quickly closed. After the pressure in the pressure regulating tank is stable, the timing is started and the initial pressure in the tank is recorded. After the timing is over, the pressure in the tank is recorded again, and the leakage of the breathing valve under test is calculated by the difference between the initial pressure and the pressure in the tank at the end and the timing time.

2. Reverse Detection (1) Positive pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas enters the sixth pipeline from the second gas outlet of the first three-way switching valve. Then the gas enters the negative pressure generator to generate negative pressure, so that negative pressure is also generated in the pressure regulating tank, and then the negative pressure in the pressure regulating tank is slowly increased by adjusting the pressure reducing valve and the balancing needle valve until the negative pressure valve disc opens. When the positive pressure valve disc opens, the value displayed on the third pressure gauge is: the sum of the pressure value of the positive pressure opening of the breathing valve and the basic pressure value in the storage tank; then the basic pressure value in the storage tank is subtracted from this value to obtain the pressure value of the positive pressure opening of the breathing valve; (2) Negative pressure detection: The gas is introduced into the first pipeline through the nitrogen source, the stop valve is slowly opened, and then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline, and then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas passes through the first outlet end of the first three-way switching valve and the first inlet end of the second three-way switching valve, and finally enters the pressure regulating tank through the fifth pipeline, and then the pressure reducing valve and the balancing needle valve are adjusted to slowly increase the air pressure in the pressure regulating tank until the negative pressure valve disc is opened. When the negative pressure valve disc is opened, the value displayed on the third pressure gauge is: the sum of the pressure value of the negative pressure opening of the breathing valve and the basic pressure value in the storage tank; then the basic pressure value in the storage tank is subtracted from this value to obtain the pressure value of the negative pressure opening of the breathing valve. (3) Leakage detection: The gas is introduced into the first pipeline through the nitrogen source, and the stop valve is slowly opened. Then the pressure reducing valve is slowly adjusted so that the gas in the first pipeline is introduced into the third pipeline. Then the first three-way switching valve and the second three-way switching valve are adjusted so that the gas enters the sixth pipeline from the second gas outlet of the first three-way switching valve. Then the gas enters the negative pressure generator to generate negative pressure, which also generates negative pressure in the pressure regulating tank. Then the pressure reducing valve and the balancing needle valve are adjusted so that the negative air pressure in the pressure regulating tank slowly reaches 0.75 times the positive pressure opening pressure of the breathing valve. When this pressure is reached, the second three-way switching valve and the balancing pressure valve are quickly closed. After the pressure in the pressure regulating tank is stable, the timing is started and the initial pressure in the tank is recorded. After the timing is over, the pressure in the tank is recorded again. The leakage of the breathing valve under test is calculated by combining the difference between the initial pressure and the pressure in the tank at the end with the timing time.

6. The method for using the breathing valve online detection device according to claim 5, characterized in that: The formula for leakage detection is: Where: The average density of the gas in the breathing valve cavity; P1: The inner cavity pressure when the breathing valve is closed at the beginning of the test; P2: The pressure value of the inner cavity of the breathing valve after a period of time; V1: volume of surge tank; M 2,mol : The molar mass of the gas in the inner cavity of the leaking breathing valve after a period of time; RT1: The change in the temperature of the breathing valve cavity after a period of time; From this, the leakage amount △V can be calculated.

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