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Description of typical air circuit diagram of anti-surge regulating valve: The function of the entire gas circuit realizes precise valve position control under normal circumstances, fast opening and slow closing ； Quickly open the valve to protect the fan in case of emergency (gas loss, power loss). Under normal circumstances, the two solenoid valves are powered. For the three-way solenoid valve, 1 and 2-way ； Two-way solenoid valve, 1 and 2 are disconnected. At this time, the filtered and decompressed air is divided into three paths, one goes through the one-way valve to the four-way, and then to the F port of 2625, air storage tank, and 377 ； After passing through the three-way solenoid valve, it reaches the SUP port of 377. The air pressure of the SUP port compresses the internal spring of 377. In this way, in the internal air path of 377, port A and port B are connected, and port D and port E are connected. ； The other line goes to the SUP port of DVC6020 as the air source of DVC. When the control signal (the 4-20MA signal output by the control system DCS/PLC to the DVC6020) increases, the output of the positioner port A increases and the output of port B decreases. ； The increased air pressure at port A acts on the upper chamber of the cylinder (1061 actuator) through port 377AB and the quick exhaust valve. ； The air pressure at port B is used as the input signal of the air circuit amplifier 2625 through 377DE to control the pressure output by 2625 to the lower chamber of the cylinder (1061 actuator) ； At this time, the pressure on the upper part of the cylinder piston > the pressure on the lower part + the force of the pipeline wind pressure acting on the disc plate, the piston moves downward. It can be seen from the ACTION: PDTC on the nameplate that the valve opening decreases. On the contrary, when the control signal decreases, the output of port A of the positioner decreases and the output of port B increases. At this time, due to the action of the quick exhaust valve and the air amplifier 2625, the piston moves upward quickly and the valve opens quickly. When the solenoid valve loses power, the three-way solenoid valve, barrel 1 and 3, the two-way solenoid valve 1 and 2 ； At this time, the pressure at the 377SUP port is released through port 3 of the three-way solenoid valve, and the air path of the 377 is switched under the action of the internal spring. Port B and port C are connected. E port and F port are connected ； The air in the air storage tank plus the air from the air source passes through port 377FE as the control signal of the air circuit amplifier 2625, because the air pressure in the air storage tank is very high at this time (equal to the outlet pressure of the pressure reducing valve). When 2625 is fully opened, the gas in the gas storage tank and the gas source enters the lower chamber of the cylinder through 2625 at maximum flow. The gas in the upper chamber is quickly discharged to the atmosphere through the quick exhaust valve and the two-way solenoid valve, and the valve opens quickly. When the air is lost, the compressed air in the air storage tank will not flow back due to the existence of the one-way valve. The whole principle is the same as losing power, except that the only thing that makes the valve open quickly is the compressed air in the air tank. The hydraulic protection module uses a hydraulic locking method to control the inlet and outlet oil circuits and load oil circuits of the electro-hydraulic servo valve (see the hydraulic schematic diagram of the hydraulic protection module for details). This module mainly has the following three functions:: 1. Locking function: When the system is in a normal state, the hydraulic lock is in a conductive state, and the electro-hydraulic servo control system adjusts the vane angle or valve opening in time according to the regulator signal and load conditions. When the stator vane angle or valve opening deviates greatly from the set value due to extraordinary reasons (failure of a control element in the servo control system, or other interference factors) or is completely out of control, the solenoid valve Y1 is energized, causing the hydraulic lock to be in a closed state, cutting off the power supply, servo valve inlet and outlet oil lines and load oil lines, and instantly locking the stator vane or valve in place. At this time, the position of the controlled object will be locked at the position when the fault occurred, allowing the user to judge and handle the fault. 2. When the automatic control loop of the inching function is in a locked state, if the position deviation between the vane angle and the required valve opening is large, the electromagnetic adjustment system can be started to correct the vane angle or valve opening in a jogging manner. Even if the two electromagnets of solenoid valve Y2 are energized, the servo cylinder is controlled to move slowly left and right to reach the specified position (note: At this time, the stator vane or valve is not controlled by the servo system), so that the stator vane or valve will not be completely out of control and the system can continue to work. The electro-hydraulic servo control oil circuit and the electromagnetic adjustment oil circuit are used in parallel. Through the switching of the hydraulic lock, the two working states will not interfere with each other. 3. Online replacement of other equipment in the system. When certain equipment in the electro-hydraulic servo control system (such as servo valves, etc.) fails, it can be replaced online without stopping the pump, thus ensuring normal production.