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I. Introduction to Pneumatic Valves: 1. A pneumatic valve is an actuator that uses compressed air to operate the valve; it can open and close relatively quickly. It is often used for rapid two-position cutting, and it can also be used to regulate flow rates. Since it operates relying on an air supply, it is highly practical in flammable and explosive environments, and can be used to control gases, liquids, oils, and various corrosive substances. 2. This attachment varies in pneumatic valves, featuring different attachments that make it possible to implement various control methods; users can make the appropriate configurations based on the operational requirements of the specific valves. 3. The main products of pneumatic valves include: pneumatic control valves, pneumatic ball valves, pneumatic gate valves, pneumatic butterfly valves, etc. II. Introduction to the pneumatic valve trio: 1. The pneumatic trio is the most common accessory for pneumatic valves, and its functions can be briefly summarized as filtering + pressure reduction + oil mist supply. Among these, the pressure regulator is an essential component; regardless of the function of the pneumatic valve, its role is to provide the valve with a standard power source pressure, which is typically between 0.4 and 0.7 MPa. 2. A pressure relief valve is a valve that reduces the inlet pressure to a certain outlet pressure, and relies on the energy of the medium itself to automatically maintain a stable outlet pressure. Functions of the two couplings (filter, pressure regulator): to perform filtering and pressure reduction of compressed air ； Three-component unit (filter, pressure regulator, oil mist): It performs the functions of filtering and reducing pressure of compressed air, as well as lubricating the air. III. Introduction to Pneumatic Solenoid Valves: 1. Pneumatic solenoid valves, also known as directional control valves, are suitable only for on/off two-position valves. They represent a necessary component, as they enable the control of the opening and closing of pneumatic valves through magnetization/de-magnetization. 2. Solenoid valves are commonly used to control valves, operating the on/off of the gas circuit powered by a voltage signal in order to regulate the opening and closing of the valve. Definition: Valves operated by electromagnets are usually opened and closed by controlling the movement of a pneumatic actuator. IV. Introduction to pneumatic valve limit switches: 1. Pneumatic limits, also known as travel switches or feedback devices. It is a field instrument used in control systems to detect the status of valves; it outputs the valve’s open or closed position as a digital signal (contact), which is received by a programmer or accessed by a computer for sampling, and upon confirmation, the next procedure is executed. 2. This product can also be used for interlock protection of important valves within the system, as well as for remote alarm indication. To determine the valve position of a two-position valve, a valve limit switch is an effective solution; it is an electrical switch used to indicate and provide feedback on the extreme positions of movement of mechanical equipment. V. Pneumatic valve positioners: Pneumatic positioners are an essential component of pneumatic control valves. They enable the control of the valve at any desired opening position. The valve positioner uses the signal representing the displacement of the valve stem as an input feedback signal, while using the signal output by the controller as the setpoint signal. By comparing these two signals, any discrepancy is detected, and the output signal sent to the actuator is adjusted accordingly, thereby causing the actuator to move. This establishes a one-to-one relationship between the displacement of the valve stem and the output signal from the controller. Another common accessory for pneumatic valves is the hold-down valve, a device used to maintain the valve’s position in the event of a loss of air supply. VI. Precautions for selecting pneumatic valves: 1. If it is a control valve regulated by safety conditions, an electromagnetic valve must also be installed to force the valve to remain in a safe position in case of an emergency. 2. For cylinder valves with large capacity, in order to increase the speed of valve operation, pilot valves are also necessary. The function of a pilot valve is to use a small-volume air signal to operate it, thereby switching the large-volume pipelines and allowing the cylinder valve to have a faster air inlet/outlet process. There are various types of pilot valves, and the choice depends on the specific requirements of the pneumatic valve. 3. If the valve whose position needs to be controlled is a control valve, then a valve position transmitter must be installed; it can provide feedback on the opening degree of the valve at any given position. Due to the requirements of the equipment’s manufacturing process, valves may need to open slowly and then close normally, or open normally and then close slowly. In such cases, pneumatic dampers are required; these dampers control the amount of air flowing through, thereby adjusting the valve’s operating speed to meet the desired levels.