Safety test method for pneumatic valve and safety test device thereof

Abstract

The embodiment of the application provides a safety test method and safety test device of a pneumatic valve, and belongs to the technical field of valve control and test. The safety test method comprises the following steps: controlling the pneumatic actuator through a working gas circuit to control the opening or closing of the pneumatic valve; controlling the pneumatic actuator through a test gas circuit to control the test stroke of the pneumatic valve, that is, the stroke of the partial opening degree change of the pneumatic valve; in the opening state of the pneumatic valve, opening the test gas circuit to make the pneumatic valve execute the test stroke within a preset time, and meanwhile, the pneumatic actuator converts the actual stroke of the pneumatic valve into an electric signal through a feedback module and transmits the electric signal to a control module; when the electric signal received by the control module is equal to the preset electric signal value and the time for the pneumatic valve to complete the test stroke is less than or equal to the preset time, it is judged that the pneumatic valve has completed the test stroke and has no fault. The safety test method is simple, has fast feedback response speed and can be used for efficient test without stopping.

Description

Technical Field

[0001] This invention relates to the technical field of valve control and testing, and in particular to a safety testing method and device for pneumatic valves. Background Technology

[0002] In industrial process control, ensuring the functional safety of key components such as valves and instruments connected to large production equipment, such as large complete sets of equipment, large rotating equipment, and large pipeline transportation systems, is a key focus of industrial process control technology.

[0003] For example, valves on pipelines in industrial production often need to remain open for extended periods. As materials flow through the pipe, deposits and foreign objects accumulate inside the valve, affecting its normal movement. In an emergency requiring system shutdown, these deposits or blockages can prevent the valve from closing properly, leading to serious safety issues such as equipment damage, irreversible process disruptions, and production stoppages, resulting in comprehensive economic losses.

[0004] Therefore, it is necessary to conduct regular functional safety tests on valves while they are in operation, such as when they are open on a pipeline. The main purpose of functional safety testing is to detect whether there is any blockage or damage inside the valve, whether the valve can be fully opened or its opening degree can be adjusted normally, and whether it can be closed normally. If the valve fails to operate within the specified time, cannot be closed, or cannot be opened, it should be included in the list of valves for inspection and maintenance, and repairs should be carried out as appropriate.

[0005] Current technologies for valve functional safety testing typically require complex control systems or complex mechanical linkage devices. This complexity reduces the response speed and efficiency of valve testing and introduces new uncertainties into large industrial systems.

[0006] In view of this, there is a need for a new safety testing method and device for pneumatic valves to solve all or part of the above problems. Summary of the Invention

[0007] To address at least one of the aforementioned problems and deficiencies in the prior art, embodiments of the present invention provide a safety testing method and apparatus for pneumatic valves. By adding an independent test air path and converting the actual valve movement into an electrical signal using a feedback module located on the valve side, the method enables real-time testing of valve functional safety during operation, improving feedback response speed and valve testing efficiency, and ensuring the safe operation of the valve and its connected equipment. The technical solution is as follows:

[0008] According to one aspect of the present invention, a safety testing method for a pneumatic valve is provided, the safety testing method comprising:

[0009] The pneumatic actuator is controlled by the working air circuit to control the opening or closing of the pneumatic valve;

[0010] The test stroke of the pneumatic valve is controlled by the pneumatic actuator through the test air circuit. This test stroke is the stroke of the pneumatic valve during a partial change in opening.

[0011] When the pneumatic valve is open, the test air path is opened so that the pneumatic valve can perform the test stroke within a preset time. At the same time, the pneumatic actuator converts the actual stroke of the pneumatic valve into an electrical signal through the feedback module and transmits it to the control module.

[0012] When the electrical signal received by the control module is equal to its preset electrical signal value and the time for the pneumatic valve to complete the test stroke is less than or equal to the preset time, it is determined that the pneumatic valve has completed the test stroke and the pneumatic valve is fault-free.

[0013] In some embodiments, the safety testing method further includes a step of adjusting test parameters before controlling the pneumatic actuator via the working air path to control the opening or closing of the pneumatic valve. The test parameters are a preset electrical signal and a preset time. The specific steps for adjusting the test parameters are as follows:

[0014] Confirm that the pneumatic valves connected to the working equipment are functioning correctly;

[0015] When the working equipment is in a stopped state, the pneumatic actuator is controlled through the working air circuit to control the pneumatic valve to be fully opened;

[0016] With the pneumatic valve fully open, open the test air circuit and record the action time required for the pneumatic valve to complete the test stroke. Preferably, the preset time is set to 1.1-1.3 times the action time.

[0017] When the pneumatic valve completes the test stroke, the feedback module receives a feedback electrical signal and sets the preset electrical signal to be equal to the feedback electrical signal.

[0018] The preset time and preset electrical signal are recorded in the control program of the control module.

[0019] In some embodiments, the test stroke specifically includes a partial opening stroke from the test start point to the test end point, wherein the test start point is the position when the pneumatic valve is fully open, and the test end point is the position where the pneumatic valve moves from fully open to closed to reach a preset partial opening. Preferably, the range of the preset partial opening is 90%-95% of the opening when the pneumatic valve is fully open.

[0020] In some embodiments, specifically, the feedback module communicates with the control module through a first valve position detector to provide feedback on whether the pneumatic valve has completed the fully opening action; the feedback module communicates with the control module through a second valve position detector to provide feedback on whether the pneumatic valve has completed the fully closing action; and the feedback module communicates with the control module through at least one third valve position detector to provide feedback on whether the pneumatic valve has reached the test end point of the test stroke.

[0021] In some embodiments, alternatively, the first valve position detector, the second valve position detector, and at least one third valve position detector are any one or any combination of mechanical contact switches, electromagnetic proximity contact switches, feedback circuits, and optocoupler feedback circuits.

[0022] In some embodiments, the testing process of the security testing method specifically includes:

[0023] The test air circuit is activated to control the pneumatic actuator to exhaust air at a preset exhaust speed.

[0024] This moves the pneumatic valve from the start of the test stroke to the end of the test stroke.

[0025] The feedback module obtains the feedback electrical signal of the pneumatic valve at the end of the test stroke through at least one third valve position detector, and the control module records the action time of the pneumatic valve.

[0026] When the feedback electrical signal of the pneumatic valve is equal to the preset electrical signal of the control module and the action time of the pneumatic valve is less than or equal to the preset time of the control module, the pneumatic valve is judged to be fault-free, the test air circuit is closed and the pneumatic valve is restored to the fully open state.

[0027] If the feedback electrical signal of the pneumatic valve is not equal to the preset electrical signal of the control module and / or the action time of the pneumatic valve is greater than the preset time of the control module, then the pneumatic valve is judged to be faulty.

[0028] According to another aspect of the present invention, a safety testing apparatus for a pneumatic valve is provided. This safety testing apparatus performs safety testing on the pneumatic valve using the safety testing method described above. The safety testing apparatus includes:

[0029] The working air path is connected to the first air port on the pressure regulating side of the pneumatic actuator, and is used to output the air source to drive the pneumatic valve to the pneumatic actuator;

[0030] The test air path is connected to the second air port on the pressure regulating side of the pneumatic actuator, and is used to drive the pneumatic valve to operate according to the test stroke by controlling the exhaust of the pneumatic actuator during safety testing;

[0031] The feedback module, connected to the drive unit of the pneumatic valve, is used to convert the mechanical motion of the pneumatic valve during the test stroke into an electrical signal;

[0032] The control module is connected to the working air circuit, the test air circuit, and the feedback module. It is used to send pneumatic valve action commands to the working air circuit and the test air circuit respectively, and to determine whether the pneumatic valve is faulty during safety testing.

[0033] In some embodiments, preferably, the working air path and the test air path share a single air source. Specifically, the working air path connects the first filter valve, the first solenoid valve, and the first pneumatic control valve in series from the air source to the first air port. The first solenoid valve is communicatively connected to the control module and receives opening or closing commands from the control module to control the opening or closing of the pneumatic valve. The test air path connects the second filter valve, the second solenoid valve, and the second pneumatic control valve in series from the air source to the second air port. The second solenoid valve is communicatively connected to the control module. When the pneumatic valve is in the working state, the control module sends an opening command to the second solenoid valve to put the test air path into a locked state. When the pneumatic valve is in a safety detection state, the control module sends a closing command to the second solenoid valve to put the test air path into an exhaust state.

[0034] In some embodiments, the feedback module specifically includes: a feedback rod connected to the drive unit of the pneumatic valve, which drives the feedback rod to rotate when the drive unit moves; a first valve position detector, a second valve position detector, and at least one third valve position detector are spaced apart on the feedback rod and rotate together with the feedback rod; a first feedback switch, a second feedback switch, and at least one third feedback switch, which are respectively connected to the control module, are provided corresponding to the first valve position detector, the second valve position detector, and at least one third valve position detector.

[0035] In some embodiments, further, when the first feedback part on the first valve position detector rotates to the sensing range of the first feedback switch, a first feedback loop is formed and a first feedback signal is output to the control module, the first feedback signal indicating that the pneumatic valve is fully open; when the second feedback part on the second valve position detector rotates to the sensing range of the second feedback switch, a second feedback loop is formed and a second feedback signal is output to the control module, the second feedback signal indicating that the pneumatic valve is fully closed; when the third feedback part on any one of the at least three third valve position detectors rotates to the sensing range of its corresponding third feedback switch, a third feedback loop is formed and a third feedback signal is output to the control module, the third feedback signal indicating that the pneumatic valve has completed the test stroke and the valve opening is at the test endpoint position.

[0036] In some embodiments, preferably, the pneumatic actuator is a piston-cylinder type pneumatic actuator, including a first cylinder and a second cylinder connected together. The first drive side of the first cylinder is connected to a pneumatic valve for driving the valve to operate, and the second drive side of the second cylinder is connected to the first pressure regulating side of the first cylinder. A limiting partition is provided between the first cylinder and the second cylinder, and the limiting partition has an opening through which the second piston rod of the second cylinder enters the first cylinder. The working air path is connected to the second pressure regulating side of the second cylinder, and the test air path is connected to the first pressure regulating side of the first cylinder.

[0037] In some embodiments, the second piston stroke of the second cylinder is less than the first piston stroke of the first cylinder, and when the pneumatic valve completes the test stroke, there is a preset gap between the end of the second piston rod of the second cylinder away from the second piston plate and the first piston plate of the first cylinder.

[0038] The present invention also provides several embodiments according to the following aspects, as detailed below:

[0039] Aspect 1: A feedback device for detecting valve opening, used to convert the mechanical motion of a pneumatic valve in its working state and during a test stroke into an electrical signal, the feedback device comprising:

[0040] The feedback rod is connected to the drive unit of the pneumatic valve. When the drive unit moves, it drives the feedback rod to rotate.

[0041] The first valve position detector, the second valve position detector, and at least one third valve position detector are spaced apart on the feedback rod and rotate together with the feedback rod;

[0042] A first feedback switch, a second feedback switch, and at least one third feedback switch are respectively provided for the first valve position detector, the second valve position detector, and at least one third valve position detector;

[0043] The control module is communicatively connected to the first feedback switch, the second feedback switch, and at least one third feedback switch.

[0044] Aspect 2: The feedback device according to aspect 1, wherein,

[0045] When the first feedback part on the first valve position detector rotates to the sensing range of the first feedback switch, a first feedback loop is formed and a first feedback signal is output to the control module. The first feedback signal indicates that the pneumatic valve is fully open.

[0046] When the second feedback part on the second valve position detector rotates to the sensing range of the second feedback switch, a second feedback loop is formed and a second feedback signal is output to the control module. The second feedback signal indicates that the pneumatic valve is completely closed.

[0047] When the third feedback part on any one of the at least three valve position detectors rotates to the sensing range of its corresponding third feedback switch, a third feedback loop is formed and a third feedback signal is output to the control module. The third feedback signal indicates that the pneumatic valve has completed the test stroke and the valve opening is at the end of the test.

[0048] Aspect 3: The feedback device according to aspect 2, wherein,

[0049] The first valve position detector, the second valve position detector, and at least one third valve position detector are any one of mechanical contact switches, electromagnetic proximity contact switches, feedback circuits, optocoupler feedback circuits, or any combination thereof.

[0050] Aspect 4: A pneumatic actuator for a pneumatic valve, the pneumatic actuator being a piston-cylinder type pneumatic actuator, the pneumatic actuator comprising a first cylinder and a second cylinder connected together, wherein,

[0051] The first driving side of the first cylinder is connected to the pneumatic valve and is used to drive the pneumatic valve to perform an action. The second driving side of the second cylinder is connected to the first pressure regulating side of the first cylinder.

[0052] A limiting partition is provided between the first cylinder and the second cylinder, and the limiting partition is provided with an opening so that the second piston rod of the second cylinder can enter the first cylinder through the opening;

[0053] The working air circuit is connected to the second pressure regulating side of the second cylinder, and the test air circuit is connected to the first pressure regulating side of the first cylinder;

[0054] The second piston stroke of the second cylinder is less than the first piston stroke of the first cylinder. When the pneumatic valve completes the test stroke, there is a preset gap between the end of the second piston rod of the second cylinder away from the second piston plate and the first piston plate of the first cylinder.

[0055] Aspect 5: A safety testing apparatus for a pneumatic valve using a feedback device according to any one of aspects 1-3 and / or using a pneumatic actuator according to aspect 4, the safety testing apparatus comprising:

[0056] The working air path is connected to the first air port on the pressure regulating side of the pneumatic actuator, and is used to output the air source to drive the pneumatic valve to the pneumatic actuator;

[0057] The test air path is connected to the second air port on the pressure regulating side of the pneumatic actuator, and is used to drive the pneumatic valve to operate according to the test stroke by controlling the exhaust of the pneumatic actuator during safety testing;

[0058] The feedback module, connected to the drive unit of the pneumatic valve, is used to convert the mechanical motion of the pneumatic valve during the test stroke into an electrical signal;

[0059] The control module is connected to the working air circuit, the test air circuit, and the feedback module. It is used to send pneumatic valve action commands to the working air circuit and the test air circuit respectively, and to determine whether the pneumatic valve is faulty during safety testing.

[0060] Aspect 6: A safety testing method for performing safety testing on a pneumatic valve using the safety testing apparatus according to aspect 5, the safety testing method comprising:

[0061] The pneumatic actuator is controlled by the working air circuit to control the opening or closing of the pneumatic valve;

[0062] The test stroke of the pneumatic valve is controlled by the pneumatic actuator through the test air circuit. This test stroke is the stroke of the pneumatic valve during a partial change in opening.

[0063] When the pneumatic valve is open, the test air path is opened so that the pneumatic valve can perform the test stroke within a preset time. At the same time, the pneumatic actuator converts the actual stroke of the pneumatic valve into an electrical signal through the feedback module and transmits it to the control module.

[0064] When the electrical signal received by the control module is equal to its preset electrical signal value and the time for the pneumatic valve to complete the test stroke is less than or equal to the preset time, it is determined that the pneumatic valve has completed the test stroke and the pneumatic valve is fault-free.

[0065] The safety testing method and apparatus for pneumatic valves provided in the embodiments of the present invention have at least one or a portion of the following advantages:

[0066] (1) This safety test method increases the independent test air path and converts the valve movement status into an electrical signal through a feedback module set on the valve side to realize the real-time test of valve functional safety in the valve working state, improves the feedback response speed and valve test efficiency, and ensures the safe operation of the valve and its connected equipment.

[0067] (2) The feedback module of this safety test device drives several valve position detectors to rotate through the feedback rod to realize the switch feedback loop. It has a simple and compact structure, fast feedback response speed, and is suitable for partial stroke testing of common types of valves.

[0068] (3) By setting the test stroke in the range of 90%-95% of the valve fully open, it is ensured that the valve still has a large opening when conducting safety testing, which will not affect the flow of working fluid or cause disturbance;

[0069] (4) The second solenoid valve in the test gas line communicates with the control module. By controlling the exhaust speed of the test gas line, the valve completes the test stroke in a controlled manner, avoiding the valve from closing suddenly due to excessive exhaust speed or uncontrolled exhaust, which would affect the normal operation of the connected equipment.

[0070] (5) The control module judges the functional safety status of the valve by the electrical signal value of the feedback module and the time it takes for the valve to complete the test stroke. The control logic / program is simple and improves the efficiency of stroke testing.

[0071] (6) By connecting an auxiliary second cylinder to the first pressure regulating side of the first cylinder, it is helpful to maintain the working air circuit and test air circuit online or replace the pneumatic control components or functional valves of the working air circuit and test air circuit online.

[0072] (7) By adjusting the length of the second piston rod of the second cylinder to control the second piston stroke, when the pneumatic valve and / or the first cylinder malfunctions and causes exhaust, the second piston rod can press against the first piston plate of the first cylinder to keep the pneumatic valve in a normal open state. Attached Figure Description

[0073] These and / or other aspects and advantages of the present invention will become apparent and readily understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:

[0074] Figure 1 This is a flowchart illustrating the steps of a safety testing method for a pneumatic valve according to an embodiment of the present invention.

[0075] Figure 2 This is a schematic diagram illustrating the process of adjusting test parameters in a safety testing method for a pneumatic valve according to an embodiment of the present invention.

[0076] Figure 3 This is a schematic diagram of the structure of a safety testing device for a pneumatic valve according to Embodiment 1 of the present invention;

[0077] Figure 4 for Figure 3 A schematic diagram of the structure of a feedback module in the safety testing device shown;

[0078] Figure 5 According to Figure 1 The flowchart shown illustrates the safety testing method for pneumatic valves.

[0079] Figure 6 This is a schematic diagram of the pneumatic actuator of the safety testing device according to Embodiment 2 of the present invention;

[0080] Figure 7 for Figure 6 The diagram shows the structure of the pneumatic actuator during the safety testing process of the pneumatic valve. Detailed Implementation

[0081] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. In this specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as a limitation thereof.

[0082] It should also be understood that although the terms "first," "second," "third," etc., may be used in the following embodiments of the present invention to describe a component comprising two or more of the same component, these components should not be limited to these terms, which are only used to distinguish each component from one another. Furthermore, descriptions indicating orientation such as "upper," "lower," "left," and "right" are merely illustrative of the relative positions of components and should not be construed as a limitation of the present invention.

[0083] This invention designs a simple safety testing method for pneumatic valves and, combined with this method, provides a simple and highly reliable safety testing device to achieve functional safety testing of pneumatic valves in operation. Specifically, by adding an independent test air path to the pneumatic actuator or system that controls the movement of the pneumatic valve, and using a simple feedback module located on the side of the pneumatic valve, the actual movement of the pneumatic valve is converted into an electrical signal, enabling real-time functional safety testing in its operating state. This improves the feedback response speed and testing efficiency of the pneumatic valve, ensuring the safe operation of the pneumatic valve and its connected equipment.

[0084] According to one aspect of the present invention, a safety testing method for pneumatic valves is first proposed. See also Figure 1 The procedure for a safety test of a pneumatic valve is shown, specifically including:

[0085] Step S100: Control the pneumatic actuator through the working air circuit to control the opening or closing of the pneumatic valve;

[0086] Step S200: Control the pneumatic actuator through the test air circuit to control the test stroke of the pneumatic valve, which is the stroke of the pneumatic valve with a partial change in opening degree;

[0087] Step S300: With the pneumatic valve open, the test air path is opened so that the pneumatic valve performs the test stroke within a preset time. At the same time, the pneumatic actuator converts the actual stroke of the pneumatic valve into an electrical signal through the feedback module and transmits it to the control module.

[0088] Step S400: When the electrical signal received by the control module is equal to its preset electrical signal value and the time for the pneumatic valve to complete the test stroke is less than or equal to the preset time, it is determined that the pneumatic valve has completed the test stroke and the pneumatic valve is fault-free.

[0089] In one example, before performing functional safety testing on the pneumatic valve using the safety testing method of steps S100-S400, the test parameters for the safety test need to be adjusted according to the actual situation of the pneumatic valve to be tested and the production equipment or system connected thereto to obtain an accurate basis for judging whether the pneumatic valve is faulty.

[0090] For example, differences in the specifications, models, specific structures, and working principles of pneumatic valves, as well as the structure and application of production equipment or systems, and the differences in the structure, materials, and layout of material transmission pipeline systems connected to pneumatic valves, will all affect the specific values ​​set for the test parameters. In other words, the test parameters need to be matched, adjusted, and debugged according to the actual production situation to obtain accurate judgments for that specific production situation.

[0091] In one example, see Figure 2 Preferably, before step S100, which controls the pneumatic actuator via the working air path to control the opening or closing of the pneumatic valve, a step of debugging and testing parameters is included, wherein the test parameters are specifically a preset electrical signal and a preset time. Figure 2 As shown, the specific steps for debugging and testing these parameters are as follows:

[0092] (1) Determine that the pneumatic valve 200 connected to the working equipment is fault-free. Here, fault-free means that the pneumatic valve 200 can operate at its normal speed that has passed the factory test under the drive of the pneumatic actuator (such as the safety test device 100 in the embodiment of the present invention). Its operation includes, but is not limited to, completely closed, completely open, partially open, etc.

[0093] (2) When the working equipment is in a stopped state, the pneumatic actuator is controlled through the working air circuit to control the pneumatic valve 200 to be fully opened;

[0094] (3) With the pneumatic valve 200 fully open, open the test air circuit and record the action time required for the pneumatic valve to complete the test stroke. Preferably, considering the allowable error, the preset time is set to be 1.1-1.3 times the action time;

[0095] (4) When the pneumatic valve 200 completes the test stroke, the feedback module (e.g., the feedback module 40 of the safety test device 100) receives the feedback electrical signal and sets the preset electrical signal to be equal to the feedback electrical signal.

[0096] (5) Record the preset time and preset electrical signal in the control program of the control module (e.g., the control module 60 of the safety test device 100).

[0097] In one example, preferably, the test stroke includes a partial opening stroke from test start point A to test end point B, where test start point A is the position when the pneumatic valve 200 is fully open, and test end point B is the position where the pneumatic valve 200 moves from fully open to closed to reach a preset partial opening. Preferably, the range of the preset partial opening is 90%-95% of the opening when the pneumatic valve 200 is fully open.

[0098] Those skilled in the art will understand that the specific opening range of the pneumatic valve 200 during safety testing can be further set according to the actual production process, the needs of the production equipment, and the specific requirements of functional safety testing. For example, angular stroke valves widely used in material conveying pipelines in chemical production systems can have their angular stroke controlled between 85° and 90° by a pneumatic actuator during safety testing. That is, during safety testing, the valve is briefly closed at a small angle to quickly test whether the moving parts inside the valve can operate normally, thus allowing the valve to open and close normally. Therefore, the above-mentioned specific numerical setting of the valve opening is only an illustrative example and should not be construed as a limitation of the present invention.

[0099] In one example, specifically, combining Figure 4 An embodiment of the feedback module 40 is shown. The feedback module 40 communicates with the control module 60 through a first valve position detector 421 to provide feedback on whether the pneumatic valve 200 has completed the fully opening action; communicates with the control module 60 through a second valve position detector 422 to provide feedback on whether the pneumatic valve 200 has completed the fully closing action; and communicates with the control module 60 through at least one third valve position detector 423 to provide feedback on whether the pneumatic valve 200 has reached the test end position of the test stroke.

[0100] In order to achieve efficient and reliable functional safety testing of pneumatic valves using the safety testing method for pneumatic valves described above, another aspect of the present invention provides a safety testing apparatus for pneumatic valves.

[0101] See Figure 3 The diagram illustrates the overall structure of a safety testing apparatus 100 according to one embodiment. The safety testing apparatus 100 comprises six main parts: a working air path 10, a test air path 20, a pneumatic actuator 30, a feedback module 40, an air source 50, and a control module 60.

[0102] Specifically, the working air passage 10 is connected to the first air port 31 of the pressure regulating side 30a of the pneumatic actuator 30, and is used to output gas from the air source 50 to the pneumatic actuator 30 to drive the pneumatic valve 200.

[0103] The test air path 20 is connected to the second air port 32 of the pressure regulating side 30a of the pneumatic actuator 30, and is used to drive the pneumatic valve 200 to operate according to the test stroke by controlling the exhaust of the pneumatic actuator 30 during safety testing.

[0104] The feedback module 40 is connected to the drive unit (not shown) of the pneumatic valve 200 and is used to convert the mechanical motion of the pneumatic valve 200 during the test stroke into an electrical signal.

[0105] The control module 60 is communicatively connected to the working air circuit 10, the test air circuit 20 and the feedback module 40, respectively. It is used to send the action command of the pneumatic valve 200 to the working air circuit 10 and the test air circuit 20, respectively, and to determine whether the pneumatic valve 200 is faulty based on the electrical signal of the feedback module 40 during safety detection.

[0106] Example 1

[0107] like Figure 3 As shown, the pneumatic actuator 30 used in Embodiment 1 is a piston-cylinder type pneumatic actuator with only one cylinder. The advantages of a single cylinder are simple structure, fewer maintenance parts, and reduced manufacturing and maintenance costs. The pneumatic actuator 30 divides the cylinder into a pressure regulating side 30a and a driving side 30b through an internal piston structure. Figure 3 The right side is the part where the working air passage 10 and the test air passage 20 connect to the pressure regulating side 30a of the pneumatic actuator 30. Figure 3 The left side is the part where the pneumatic valve 200 and feedback module 40 are connected to the drive side 30b of the pneumatic actuator 30.

[0108] In one example, preferably, the working air path 10 and the test air path 20 share the same air source 50. That is, one end of the working air path 10 and the test air path 20 are respectively connected to the first air port 31 and the second air port 32 of the pneumatic actuator 30 on the pressure regulating side 30a, while the other end of the working air path 10 and the test air path 20 are both connected to the same air source 50. The working air path 10 uses the gas stored in the air source 50 to drive the pneumatic actuator 30 to move, thereby driving the pneumatic valve 200 to open or close. The test air path 20 uses the gas stored in the air source 50 to lock or replenish gas. The air pressure of the air source 50 remains basically unchanged after initial debugging, providing a stable air pressure for the pneumatic valve 200 to maintain the required opening degree.

[0109] In one example, specifically, the working air path 10 connects the first filter valve 11, the first solenoid valve 12, and the first pneumatic control valve 13 in series from the air source 50 to the first air port 31. The first solenoid valve 12 in the working air path 10 is mainly communicatively connected to the control module 60 and receives the action command of opening or closing the pneumatic valve 200 sent by the control module 60 to control the gas delivery parameters (such as gas pressure, gas flow rate, etc.) in the working air path 10 and send the gas into the pneumatic actuator 30 to drive the piston structure in the pneumatic actuator 30 to move, thereby driving the pneumatic valve 200 to open or close.

[0110] In one example, specifically, the test air path 20 connects the second filter valve 21, the second solenoid valve 22, and the second pneumatic control valve 23 in series from the air source 50 to the second air port 32. The second solenoid valve 22 in the test air path 20 is mainly connected to the control module 60 for communication. When the pneumatic valve 200 is in the working state, the control module 60 sends an opening command to the second solenoid valve 22 to put the test air path 20 into a locked state; when the pneumatic valve 200 is in the safety detection state, the control module 60 sends a closing command to the second solenoid valve 22. After the second solenoid valve 22 closes, the pneumatic actuator 30 exhausts gas into the test air path 20, and at the same time, the pneumatic valve 200 performs a test stroke from the fully open state at a certain speed, that is, closes a small opening.

[0111] When the pneumatic valve 200 is closed, both the first solenoid valve 12 and the second solenoid valve 22 are de-energized, and both the first pneumatic control valve 13 and the second pneumatic control valve 23 exhaust gas.

[0112] When the pneumatic valve 200 needs to be opened, the control module 60 sends a command to energize both the first solenoid valve 12 and the second solenoid valve 22. At this time, the first pneumatic control valve 13 takes in air, the second pneumatic control valve 23 locks in air, and drives the pneumatic actuator 30 to pneumatically open the pneumatic valve 200.

[0113] When the pneumatic valve 200 enters the test stroke with its open state, the control module 60 issues a command to de-energize the second solenoid valve 22, while the first solenoid valve 12 remains energized. At this time, the pneumatic actuator 30 exhausts gas through the second pneumatic control valve 23. Preferably, the flow coefficient (CV value) of the second pneumatic control valve 23 can be set to a relatively small value; for example, setting its CV value to less than 1 will result in a slower exhaust speed. Thus, as the pneumatic actuator 300 gradually depressurizes, the spring in the valve body of the pneumatic valve 200 will gradually and slowly recover, and the pneumatic valve will slowly move towards the closing direction.

[0114] After the test stroke is completed, the pneumatic valve 200 needs to be restored to the fully open state. At this time, the control module 60 sends a command to restore the second solenoid valve 22 to power. After the pneumatic actuator 30 restores the pneumatic pressure balance, it drives the pneumatic valve 200 back to the fully open position.

[0115] In one example, when the pneumatic valve 200 performs the test stroke, in order to allow the pneumatic actuator 30 to further release pressure slowly and in a controlled manner, alternatively, a flow limiting valve (not shown) can be installed at the exhaust end of the second pneumatic control valve 23. The flow limiting valve can further control and reduce the speed of pressure release, so as to avoid the sudden closure of the pneumatic valve 200 that may be caused by excessively fast pressure release, thereby improving the safety of the test process.

[0116] In one example, alternatively, the first filter valve 11 on the working air path 10 and the second filter valve 21 on the test air path 20 can be filter pressure reducing valves. Independently setting filter pressure reducing valves on each air path allows for independent maintenance or replacement of functional valves during repairs. Especially for the test air path 20, since the stroke test is performed within a preset test cycle, the stroke test in the test air path 20 will be repeated repeatedly within a certain cycle. This means that the opening and closing of the functional valves on the test air path 20 is relatively frequent, which can easily lead to component fatigue or even damage. With independently connected filter pressure reducing valves, maintenance, repair, and component replacement can be performed independently without affecting the normal operation of the pneumatic actuator 30.

[0117] Those skilled in the art will understand that the functional valves connected in the pneumatic circuit, such as solenoid valves, pneumatic control valves, and filter valves, can be specifically selected and matched according to actual production and safety testing requirements. For example, the solenoid valve can be a direct-acting solenoid valve, a step-by-step direct-acting solenoid valve, or a pilot-operated solenoid valve; the pneumatic control valve can be a mechanical pneumatic control valve, an electromagnetic pneumatic control valve, or a pressure control valve or a flow control valve; and the filter valve can be a Y-type filter valve, a T-type filter valve, or a precision filter valve. These are merely illustrative examples and should not be construed as limiting the invention.

[0118] See Figure 4 The diagram illustrates the specific structure and working principle of the feedback module 40. The feedback module 40 consists of three main parts: a feedback rod 41, a valve position detector 42, and a feedback switch 43. The feedback module 40 is communicatively connected to the control module 60, and outputs electrical signals to the control module 60.

[0119] The feedback rod 41 is connected to the drive unit (not shown) of the pneumatic valve 200, and when the drive unit moves, it drives the feedback rod 41 to rotate.

[0120] The valve position detector 42 includes two sets of valve position detectors. One set converts the fully open and fully closed states of the pneumatic valve 200 into corresponding electrical signals and feeds them back to the control module 60. If the control module 60 receives an electrical signal, it indicates that the pneumatic valve 200 has completed the fully open or fully closed action. The other set converts the action state of the pneumatic valve 200 during the test stroke into corresponding electrical signals and feeds them back to the control module 60. If the control module 60 receives an electrical signal, it indicates that the pneumatic valve 200 has completed the test stroke and its opening position has reached the end point of the test.

[0121] Preferably, the valve position detector 42 includes a first valve position detector 421, a second valve position detector 422 and at least one third valve position detector 423, and each valve position detector 42 is spaced apart on the feedback rod 41 and rotates with the feedback rod 41.

[0122] Furthermore, a corresponding number of feedback switches 43 that are communicatively connected to the control module 60 are provided for the valve position detector 42. Preferably, a first feedback switch 431 is provided for the first valve position detector 421, a second feedback switch 432 is provided for the second valve position detector 422, and the same number of third feedback switches 433 are provided for at least one third valve position detector 423.

[0123] In one example, specifically, the feedback module 40 communicates with the control module 60 via a first valve position detector 421 to provide feedback on whether the pneumatic valve 200 has completed a fully open action; via a second valve position detector 422 to provide feedback on whether the pneumatic valve 200 has completed a fully closed action; and via at least one third valve position detector 423 to provide feedback on whether the pneumatic valve 200 has reached the end point of the test stroke (e.g., ...). Figure 2 The location of the test endpoint (B) is shown.

[0124] Those skilled in the art will understand that the specific number of third valve position detectors 423 can be set according to the actual safety testing requirements of the pneumatic valve 200. For example, one, two, three, or more third valve position detectors 423 can be set. Preferably, in various embodiments of the present invention, in order to ensure that the feedback module 40 can accurately feedback the actual action of the pneumatic valve 200 during the execution of the test stroke, two third valve position detectors 423a and 423b are set on the feedback rod 41. When one of them fails, the other can continue to complete the detection and transmission of the feedback signal. This is only an illustrative example and should not be construed as a limitation of the present invention.

[0125] Furthermore, in its initial state, the feedback module 40 needs to fix the installation position of each valve position detector 42 according to the actual test stroke of the pneumatic valve 200. For example... Figure 4 As shown, an exemplary embodiment of the specific structure of the feedback module 40 and the installation position of its valve position detector 42 is provided.

[0126] To reduce interference or crosstalk between electrical signals, preferably, the first valve position detector 421 is fixed at the upper end of the feedback rod 41, the second valve position detector 422 is fixed at the lower end of the feedback rod 41, and the third valve position detector 423a and the third valve position detector 423b are fixed in the middle of the feedback rod 41.

[0127] In one example, specifically, taking the first valve position detector 421 as a reference, the pneumatic valve 200 is initially in a fully open state. At this time, the first feedback unit 4211 of the first valve position detector 421 should be within the sensing range of its corresponding first feedback switch 431. Once the test endpoint of the test stroke of the pneumatic valve 200 is determined (e.g., the position of an angle valve closing from 100% to 95% opening, refer to...),... Figure 2 From A to B in the diagram, the installation position of the third valve position detector 423 in the initial state can be obtained by reverse deduction, especially the offset angle of the third valve position detector 423 relative to the first valve position detector 421. Similarly, the offset angle of the second valve position detector 422 relative to the first valve position detector 421 can be obtained.

[0128] In one example, after the feedback module 40 is connected to the drive end of the pneumatic valve 200, when the first feedback part 4211 on its first valve position detector 421 rotates to the sensing range of the first feedback switch 431, a first feedback loop is formed and a first feedback signal V1 is output to the control module 60. The first feedback signal V1 indicates that the pneumatic valve 200 is fully open.

[0129] Similarly, when the second feedback part 4221 on the second valve position detector 422 rotates to the sensing range of the second feedback switch 432, a second feedback loop is formed and a second feedback signal V2 is output to the control module 60. The second feedback signal V2 indicates that the pneumatic valve 200 is completely closed.

[0130] Similarly, with Figure 4Taking the third valve position detectors 423a and 423b as examples, when the third feedback part 4231a of the third valve position detector 423a rotates to the sensing range of its corresponding third feedback switch 433a and / or when the third feedback part 4231b of the third valve position detector 423b rotates to the sensing range of its corresponding third feedback switch 433b, a third feedback loop is formed and the corresponding third feedback signal V3-a and / or third feedback signal V3-b is output to the control module 60. The third feedback signal V3-a and / or third feedback signal V3-b indicate that the pneumatic valve 200 has completed the test stroke and the valve opening is at the end of the test.

[0131] In one example, optionally, the first valve position detector 421, the second valve position detector 422, and at least one third valve position detector 423 are any one of mechanical contact switches, electromagnetic proximity contact switches, feedback circuits, optocoupler feedback circuits, or any combination thereof. That is, the first valve position detector 421, the second valve position detector 422, and at least one third valve position detector 423 can all be one of, but not limited to, the valve position detectors listed above. Two or more valve position detectors can also be used in the same feedback module 40. For example, the first valve position detector 421 and the second valve position detector 422 can use mechanical contact switches, and the third valve position detector 423 can use an electromagnetic proximity contact switch. Furthermore, when there are two or more third valve position detectors 423, the same type of valve position detector or different types of valve position detectors can be used. This is merely an illustrative example and should not be construed as a limitation of the invention by those skilled in the art.

[0132] In one example, alternatively, control module 60 may use a distributed control system (DCS) and its distributed control test program. A number of feedback switches 43 in feedback module 40 may be directly connected to the control circuitry of the DCS system via cables or connected via cables to the isolation (DI) safety barrier of the DCS system, which in turn connects to the DI card channel.

[0133] See Figure 5 This illustrates a test procedure for performing functional safety testing on a pneumatic valve 200 while the production equipment is in operation. In conjunction with the safety testing methods and safety testing apparatus 100 described in the above embodiments, this test procedure specifically includes:

[0134] P1: The control module 60 issues a command to open the first solenoid valve 12 of the working air circuit 10 and the second solenoid valve 22 of the test air circuit 20. At this time, the first solenoid valve 12 and the second solenoid valve 22 are energized and opened, and the working air circuit 20 sends air to the pneumatic actuator 30 to drive the pneumatic valve 200 to gradually open completely.

[0135] P2: Waiting time t1, which is the time required for the pneumatic valve 200 to be fully opened from the moment the first solenoid valve 12 and the second solenoid valve 22 are energized, as predetermined based on the actual pneumatic valve 200.

[0136] P3: If the first feedback switch 431 of the feedback module 40 receives a feedback electrical signal, the pneumatic valve 200 has been fully opened and a safety test can be performed according to the safety test cycle.

[0137] If the first feedback switch 431 does not receive a feedback signal at this time, it means that the pneumatic valve 200 is not fully open (e.g., it is still in the closed state, or it is only partially open). In this case, it is determined that the pneumatic valve 200 has malfunctioned and needs to be repaired.

[0138] P4: If, after step P3, it is determined that the pneumatic valve 200 can open normally, then the control module 60 can perform a safety test as needed according to the safety test cycle. When the safety test program is started, the control module 60 issues a command to close the second solenoid valve 22 of the test air circuit 20. At this time, the second solenoid valve 22 is de-energized and closes, entering the safety test program. The test air circuit 20 controls the pneumatic actuator 30 to exhaust air at a preset exhaust speed, and the pneumatic valve 200 executes the test stroke from the test start point to the test end point.

[0139] P5: Waiting time T1, which is the preset time pre-entered in the control module 60 and its control program, that is, 1.1-1.3 times the actual action time required to complete the test stroke when the pneumatic valve 200 is fault-free.

[0140] P6: If the feedback signal of the first feedback switch 431 of the feedback module 40 disappears and the third feedback switch 433 receives the feedback signal, it means that the pneumatic valve 200 has completed the test stroke and its opening has reached the end position of the test stroke.

[0141] If the third feedback switch 433 does not receive a feedback signal at this time, it means that the pneumatic valve 200 has not completed the test stroke, and it is determined that the pneumatic valve 200 has malfunctioned and needs to be repaired.

[0142] If the third feedback switch 433 receives a feedback signal only after a period of time following the end of the waiting time T1, it indicates that although the pneumatic valve 200 has completed the test stroke, its actual operating time exceeds the normal operating time. In other words, the pneumatic valve 200 cannot perform part of the stroke at its normal operating speed, and it is determined that the pneumatic valve 200 has malfunctioned and needs to be repaired.

[0143] P7: If the pneumatic valve 200 is determined to be fault-free after the above P6 steps, the control module 60 sends an opening command to the second solenoid valve 22 of the test air circuit 20, and the second solenoid valve 22 is energized and reopened.

[0144] P8: Waiting time t2, which is the time required for the actual pneumatic valve 200 to recover from the opening at the end of the test stroke to full opening, as predetermined in advance.

[0145] P9: If the first feedback switch 431 of the feedback module 40 receives a feedback electrical signal, the pneumatic valve 200 has been restored to the fully open state, this safety test is over, the pneumatic valve 200 is fault-free, and it awaits the next safety test;

[0146] If the first feedback switch 431 does not receive a feedback signal at this time, it means that the pneumatic valve 200 has not returned to the fully open state (for example, it is still in a certain opening position in the test stroke, suddenly closed, or in other opening positions outside the test stroke, etc.), then it is determined that the pneumatic valve 200 has malfunctioned and needs to be repaired.

[0147] Example 2

[0148] Example 2 provides another embodiment of the safety testing device 100', which has the same main structure and working principle as the safety testing device 100 in Example 1. The difference is that the pneumatic actuator 30' used in Example 2 is a piston-cylinder type pneumatic actuator 30' with two cylinders connected together. One cylinder serves as an auxiliary cylinder for the other cylinder, used to replenish air to the pneumatic actuator and prevent the pneumatic valve 200 from suddenly closing and affecting the normal operation of the production equipment. For example, when the solenoid valve in the working air circuit 10 or the test air circuit 20 malfunctions, the sealing structure inside the cylinder ages and leaks, or the pipeline or wiring ages, the pneumatic valve 200 may suddenly close uncontrollably, thus posing a safety hazard to the operation of the production equipment.

[0149] See Figure 6 The diagram shows the specific structure of the pneumatic actuator 30' of the safety testing device 100'. The pneumatic actuator 30' includes three main parts: a first cylinder 301, a second cylinder 302, and a limiting partition 303.

[0150] The first cylinder 301 includes a first driving side 301a and a first pressure regulating side 301b. The first driving side 301a is provided with a first piston plate 3011 and a first piston rod 3012. The first driving side 301a is connected to the pneumatic valve 200 and is used to directly drive the pneumatic valve 200 to open or close.

[0151] The second cylinder 302 includes a second driving side 302a and a second pressure regulating side 302b. A second piston plate 3021 and a second piston rod 3022 are provided in the second driving side 302a. The second driving side 302a is connected to the first pressure regulating side 301b of the first cylinder 301 and serves as an auxiliary cylinder for the first cylinder 301.

[0152] A limiting partition 303 is disposed between the first cylinder 301 and the second cylinder 302, and the limiting partition 303 has an opening 3031 so that the second piston rod 3022 of the second cylinder 302 can enter the space of the first pressure regulating side 301b of the first cylinder 301 through the opening 3031. Alternatively, a sealing ring structure is also provided between the first cylinder 301 and the second cylinder 302 for isolation to prevent air leakage.

[0153] Preferably, the working air passage 10 of the safety testing device 100' is connected to the first pressure regulating side 301b of the first cylinder 301, and the test air passage 20 is connected to the second pressure regulating side 302b of the second cylinder 302.

[0154] Within the space of the first drive side 301a of the first cylinder 301, the first piston plate 3011 and the first piston rod 3012 reciprocate to form the first piston stroke through the gas drive of the working air passage 10. Similarly, in the second drive side 302a of the second cylinder 302, the second piston plate 3021 and the second piston rod 3022 reciprocate to form the second piston stroke.

[0155] Preferably, the length of the second piston rod 3022 within the second cylinder 302 can be specifically designed according to the actual requirements of the pneumatic actuator 30' controlling the pneumatic valve 200. For example, when the pneumatic actuator 30' is used in the safety testing device 100', the length of the second piston rod 3022 needs to be shortened to match the test stroke of the pneumatic valve 200.

[0156] See Figure 7 The internal structure of the cylinder of the pneumatic actuator 30' of the safety testing device 100' in the safety testing state is shown.

[0157] In one example, preferably, the second piston stroke of the second cylinder 302 is less than the first piston stroke of the first cylinder 301. When the pneumatic valve 200 completes the test stroke, there is a preset gap D between the end of the second piston rod 3022 of the second cylinder 302 away from the second piston plate 3021 and the first piston plate 3011 of the first cylinder 301.

[0158] like Figure 7As shown, during safety testing, the first air port 31' connected to the working air circuit 10 continues to be in the intake state until the second piston plate 3021 of the second cylinder 302 abuts against the limiting partition 303, while the second air port 32' connected to the test air circuit 20 exhausts air in a controlled manner at a certain speed. Due to the existence of the preset gap D, when either the pneumatic valve 200 or the first cylinder 301 malfunctions, the first piston plate 3011 in the first cylinder 301 will only retract to the end of the second piston rod 3022 away from its second piston plate 3021, which can prevent the first piston plate 3011 from suddenly retracting to the end of its first pressure regulating side 301b, thereby preventing the pneumatic valve 200 from suddenly closing in this situation and providing working time for subsequent safety handling.

[0159] Similarly, after the safety test is completed, the pneumatic valve 200 returns to its normal open state. Due to the setting of the second cylinder 302 and its preset second piston stroke (second piston rod 3022), it can be ensured that if the pneumatic valve 200 and / or the first cylinder 301 malfunctions and exhaust occurs, the first piston plate 3011 will not suddenly retract to the end of its first pressure regulating side 301b, thereby avoiding the sudden closure of the pneumatic valve 200 and providing working time for subsequent safety handling.

[0160] The other structures of the safety testing device 100' in Example 2 and the process of using the safety testing method of the present invention to perform safety testing on the pneumatic valve 200 are the same as in Example 1, and will not be repeated here.

[0161] The safety testing method and apparatus for pneumatic valves provided in the embodiments of the present invention have at least one or a portion of the following advantages:

[0162] (1) This safety test method increases the independent test air path and converts the valve movement status into an electrical signal through a feedback module set on the valve side to realize the real-time test of valve functional safety in the valve working state, improves the feedback response speed and valve test efficiency, and ensures the safe operation of the valve and its connected equipment.

[0163] (2) The feedback module of this safety test device drives several valve position detectors to rotate through the feedback rod to realize the switch feedback loop. It has a simple and compact structure, fast feedback response speed, and is suitable for partial stroke testing of common types of valves.

[0164] (3) By setting the test stroke in the range of 90%-95% of the valve fully open, it is ensured that the valve still has a large opening when conducting safety testing, which will not affect the flow of working fluid or cause disturbance;

[0165] (4) The second solenoid valve in the test gas line communicates with the control module. By controlling the exhaust speed of the test gas line, the valve completes the test stroke in a controlled manner, avoiding the valve from closing suddenly due to excessive exhaust speed or uncontrolled exhaust, which would affect the normal operation of the connected equipment.

[0166] (5) The control module judges the functional safety status of the valve by the electrical signal value of the feedback module and the time it takes for the valve to complete the test stroke. The control logic / program is simple and improves the efficiency of stroke testing.

[0167] (6) By connecting an auxiliary second cylinder to the first pressure regulating side of the first cylinder, it is helpful to maintain the working air circuit and test air circuit online or replace the pneumatic control components or functional valves of the working air circuit and test air circuit online.

[0168] (7) By adjusting the length of the second piston rod of the second cylinder to control the second piston stroke, when the pneumatic valve and / or the first cylinder malfunctions and causes exhaust, the second piston rod can press against the first piston plate of the first cylinder to keep the pneumatic valve in a normal open state.

[0169] While some embodiments of the present general inventive concept have been shown and described, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined by the claims and their equivalents.

Claims

1. A safety testing method for a pneumatic valve, characterized in that, The security testing method includes: The pneumatic actuator is controlled by the working air circuit to control the opening or closing of the pneumatic valve; The pneumatic actuator is controlled by a test air circuit to control the test stroke of the pneumatic valve. The test stroke is the stroke of the pneumatic valve during a partial opening change. The test stroke includes the partial opening from the test start point to the test end point. The test start point is the position when the pneumatic valve is fully open, and the test end point is the position where the pneumatic valve moves from fully open to closed to reach a preset partial opening. The range of the preset partial opening is 90%-95% of the opening when the pneumatic valve is fully open. With the pneumatic valve open, the test air path is opened, causing the pneumatic valve to execute the test stroke within a preset time. Simultaneously, the pneumatic actuator converts the actual stroke of the pneumatic valve into an electrical signal through the feedback module and transmits it to the control module. The feedback module communicates with the control module through a first valve position detector to provide feedback on whether the pneumatic valve has completed the fully open action, through a second valve position detector to provide feedback on whether the pneumatic valve has completed the fully closed action, and through at least one third valve position detector to provide feedback on whether the pneumatic valve has reached the end point of the test stroke. When the electrical signal received by the control module is equal to its preset electrical signal value and the time for the pneumatic valve to complete the test stroke is less than or equal to the preset time, it is determined that the pneumatic valve has completed the test stroke and the pneumatic valve is fault-free. The testing process of the security testing method includes: The test air path is opened to control the pneumatic actuator to exhaust air at a preset exhaust speed; The pneumatic valve is moved from the starting point of the test stroke to the end point of the test stroke. The control module obtains the feedback electrical signal of the pneumatic valve's stroke at the test endpoint through at least one third valve position detector of the feedback module, and records the action time of the pneumatic valve. When the feedback electrical signal of the pneumatic valve is equal to the preset electrical signal of the control module and the action time of the pneumatic valve is less than or equal to the preset time of the control module, the pneumatic valve is determined to be fault-free, the test air circuit is closed, and the pneumatic valve is restored to the fully open state. If the feedback electrical signal of the pneumatic valve is not equal to the preset electrical signal of the control module and / or the action time of the pneumatic valve is greater than the preset time of the control module, then the pneumatic valve is determined to be faulty.

2. The security testing method according to claim 1, characterized in that, The safety testing method further includes a step of adjusting test parameters before controlling the pneumatic actuator through the working air circuit to control the opening or closing of the pneumatic valve. The test parameters are a preset electrical signal and a preset time. The specific steps for debugging the test parameters are as follows: Confirm that the pneumatic valves connected to the working equipment are functioning correctly; When the working equipment is in a stopped state, the pneumatic actuator is controlled through the working air circuit to control the pneumatic valve to be fully opened; With the pneumatic valve fully open, the test air circuit is opened and the action time required for the pneumatic valve to complete the test stroke is recorded. The preset time is set to be 1.1-1.3 times the action time. When the pneumatic valve completes the test stroke, the feedback module receives a feedback electrical signal and sets the preset electrical signal to be equal to the feedback electrical signal. The preset time and the preset electrical signal are recorded in the control program of the control module.

3. The safety testing method according to any one of claims 1-2, characterized in that, The first valve position detector, the second valve position detector, and the at least one third valve position detector are any one of mechanical contact switches, electromagnetic proximity contact switches, feedback circuits, optocoupler feedback circuits, or any combination thereof.

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