Pneumatic actuatorPneumatic actuator or pneumatic actuator is the actuator of opening and closing or regulating valve driven by pneumatic force, but it is commonly called pneumatic head. The actuating mechanism and regulating mechanism of pneumatic actuator are unified as a whole. The actuating mechanism of pneumatic actuator includes film type, piston type, fork type and gear rack type.

　　The piston stroke is long and suitable for situations requiring greater thrust, while the membrane stroke is small and can only drive the valve stem directly. Pneumatic fork actuator has the characteristics of large torque, small space, torque curve more in line with the torque curve of the valve, but it is not very beautiful; it is commonly used in large torque valves. The rack-and-pinion pneumatic actuator has the advantages of simple structure, stable and reliable operation, and safety and explosion-proof. It has been widely used in power plants, chemical industry, oil refining and other production processes with high safety requirements.

　　Working Principle of Pneumatic Actuator

　　1.Working Principle Diagram of Double-acting Pneumatic Actuator

　　When the air source pressure enters the middle cavity between the two pistons of the cylinder from the air port (2), the two pistons are separated and moved towards the two ends of the cylinder. The air in the air cavity at both ends is discharged through the air port (4), and the racks of the two pistons drive the output shaft synchronously. (gear) rotated counterclockwise. On the contrary, when the air source pressure enters the air chambers at both ends of the cylinder from the air port (4), the two pistons move towards the middle direction of the cylinder, and the air in the middle of the air chamber is discharged through the air port (2), while the racks of the two pistons synchronously drive the output shaft (gear) to rotate clockwise. (If the piston is installed in the opposite direction, the output shaft will rotate in the opposite direction.)

　　2.Working Principle Diagram of Single-acting Pneumatic Actuator

　　When the air source pressure enters the middle cavity between the two pistons of the cylinder from the air port (2), the two pistons are separated and moved toward the two ends of the cylinder, forcing the springs at both ends to compress. The air in the air cavity at both ends is discharged through the air port (4), and simultaneously the racks of the two pistons synchronously drive the output shaft (gear) to rotate counterclockwise. After the air source pressure is reversed by the solenoid valve, the two pistons of the cylinder move towards the middle direction under the spring elastic force, and the air in the middle cavity is discharged from the air port (2). At the same time, the racks of the two pistons synchronously drive the output shaft (gear) to rotate clockwise. If the piston is installed in the opposite direction, the output shaft will turn into reverse rotation when the spring is reset.

　　Zhejiang Oudelong Auto-control Valve Co., Ltd. is located in the "Township of Pump and Valve in China" - Wuxing Avenue, Dongou Industrial Zone, Oubei Town. It is a technical company integrating the engineering, manufacturing, marketing and service of industrial automation control system. It specializes in R&D and production of pneumatic, hydraulic and electric drive devices and matching products of auto-control valves. This is the case. On the basis of introducing advanced technology and equipment at home and abroad, the company has designed and manufactured a series of products with contemporary leading level, which are widely used in the fields of petroleum, chemical industry, light industry, power station, metallurgy, HVAC, medicine, fire protection, water treatment and other pipeline installations. It has successively provided high-quality products and good services for national key projects such as power plant sets, petrochemical industry, nuclear power, military industry, oil field development, etc. And exported to Europe, America, the Middle East and Southeast Asia market, well received by users.