Comparison of several common model types of pneumatic actuators

The common types of  pneumatic actuators  are compared with the actuator that uses air pressure to drive the opening and closing or adjust the valve, also known as the Pneumatic Actuator or pneumatic device, but it is generally called the Pneumatic Actuator. There are many types of pneumatic actuators, There are many types of pneumatic actuators. Taking the commonly used pneumatic actuator THEOBORN as an example, there are three common models: AT, GT, and AW pneumatic actuators. This article provides a brief comparison of these three types of pneumatic actuators:

1. AT type Pneumatic Actuator is a double-piston rack and gear rotation structure design, which is divided into two ways: double-acting and single-acting, and is suitable for all kinds of indoor or outdoor non-corrosive working environments. Valves with small and medium sizes and small torques, such as the AT type Pneumatic Actuator from THEOBORN, comply with the latest international standards: ISO5211, DIN3337 and VDI/VDE3845, NAMUR standards. Extruded high-strength aluminum cylinder block, the inner surface is finely ground and hard anodized, which has a long service life, low friction coefficient and fast action. Beautiful, compact, modern styling, and a wide range of pneumatic actuators make the selection more economical. 　　　　　

2. GT type pneumatic actuator is a more commonly used pneumatic actuator relative to AW pneumatic actuator, in the actuator market, pneumatic actuator share is expected to be greater than 80%, GT pneumatic actuator is characterized by low price, small size, light weight, flexible action. As long as the air source can be summarized to realize the opening and closing of the valve, it is very safe and reliable.

Referring to the definition of THEOBORN, GT series pneumatic actuator is a pneumatic actuator that uses compressed air as the power, through the mechanical transmission of piston rack and pinion and gear, and outputs torque at the quarter stroke. It is a new type of pneumatic actuator product at present. It is divided into double-acting and single-acting (spring return). It is suitable for the opening and closing of quarter-turn Control Valves (ball valves, butterfly valves, etc.). It can also be used in other occasions where rotation is required.
3. The torque output of AW type pneumatic actuator is relatively larger than that of AT actuator, using a fork transmission mechanism, the output torque can change with the change of angle, and the torque value is the largest in the position of opening or closing the valve, which is consistent with the law of the valve; Moreover, the fork and fork arm are highly overlapped, which greatly saves the installation space and meets the needs of various large rotary valves. It has the advantages of safety and explosion-proof, and is widely used in industries with high safety requirements such as chemical industry and energy industry.
Taking the commonly used American Weidun VTON as an example, the AW type pneumatic actuator has the following characteristics
1. AW pneumatic actuators are divided into double-acting type and single-acting type (spring return), two split cylinders, which are easy to manufacture large-size cylinders. Meet the needs of a wide range of large rotary valves.
2. The output torque is large, and the action is flexible and stable; The cylinder inner wall and piston shaft are plated with hard chrome, which has good wear resistance; All sliding parts are equipped with oil-free lubrication shafts and guide rings to reduce the coefficient of friction and prolong the service life, and the U-shaped curve characteristic output torque of AW  pneumatic actuator  is more suitable for large-diameter ball valves and butterfly valves.
3. Rotation angle: double-acting = 90°, single-acting = 90° adjustable angle from both ends ± 5°
4. Working environment temperature: -20~90°C.
5. Air source: filtered, dried or lubricated clean air, the minimum air pressure is 0.4MPa, and the maximum air pressure is 1.0MPa.
6. Basic design: pneumatic double-cylinder double-piston fork transmission mechanism.
　 Model AWxx = double acting;　
　 Model AWxxS = Single-acting (spring return).
7. Powerful accessory function: it can be equipped with single (double) electronically controlled Solenoid Valve, limit switch feedback device, electric potentiometer, air source treatment triplet and manual operation mechanism, which can fully realize  automatic  or manual control.