Pneumatic Actuators: A Comparison of the AT and GT Series

Pneumatic actuators are essential components in industrial automation control. They are widely used in valve control, fluid regulation, and mechanical movement. There are various types of pneumatic actuators based on their working principles and control needs. The AT series and GT series are two of the most common types on the market. This article will discuss the design principles, advantages, disadvantages, applications, and setup methods of the AT and GT series pneumatic actuators. This will help users select the right actuator based on their specific needs.

AT Series Pneumatic Actuators

The AT series pneumatic actuator is a widely used pneumatic drive device in industrial automation, especially in valve control, fluid regulation, and mechanical movement. Its design is simple and reliable, making it suitable for various standard operating conditions.

1. Design and Operating Principle

The AT series pneumatic actuator uses a double-piston rack-and-gear rotary mechanism. It is commonly applied in many industrial automation fields. The series includes single-acting and double-acting models. In the single-acting version, a spring is used for return. In the double-acting version, air pressure drives pistons on both ends to open and close the valve. The AT series is popular due to its simple structure, compact size, and light weight.

2. Key Features and Advantages

Cost-effective: The AT pneumatic actuator is relatively inexpensive, making it ideal for applications with budget constraints. Its simple design and low manufacturing cost make it widely used for standard pneumatic control needs.

Easy Operation: The actuator requires only a gas source to operate. It is easy to use, with straightforward controls. The actuator is also easy to maintain, making it suitable for a wide range of operating conditions.

Strong Stability: The AT actuator is built to withstand high working pressures in various environments. It is reliable and stable for long-term operation.

3. Major Disadvantages

Lower Control Precision: The AT pneumatic actuator has relatively low control precision, especially for applications requiring fine adjustments. It does not have advanced micro-adjustment capabilities and is better suited for simpler control tasks.

Poor Air Loss Recovery: In the double-acting AT actuator, if the air source is cut off, the actuator cannot automatically return to its preset position. This could affect the system's reliability and safety. The single-acting version returns to its preset position using spring force, but it may have limitations in speed and accuracy.

4. AT Pneumatic Actuator: Setup and Applications

The AT pneumatic actuator has two interfaces: A and B. When air is connected to interface A, the actuator opens the valve. When air is connected to interface B, the actuator closes the valve. The actuator's motion can be adjusted as needed. The setup steps are as follows:

Opening Setup: Loosen the nuts at both ends of the cylinder. Adjust the bolts until the cylinder fully opens to the preset angle. Then, tighten the nuts.

Closing Setup: Loosen the nuts at both ends of the cylinder. Adjust the bolts until the cylinder fully closes to the preset angle. Then, tighten the nuts.

GT Series Pneumatic Actuators

The GT series pneumatic actuator is designed primarily for applications that require 90° rotary movement, such as ball valves and butterfly valves. The actuator uses a gas source to drive the rotary mechanism inside, allowing precise rotation in valves and mechanical equipment. The GT series is especially designed for fixed 90° rotation, which makes it ideal for valve control systems.

1. Design and Operating Principle

The GT series pneumatic actuator is an important pneumatic device used for 90° rotary movements, such as in ball and butterfly valves. Its operating principle is similar to the AT series. The actuator uses a rotary design, where a gas source drives an output shaft to perform rotary motion. The GT actuator can be used with accessories like solenoid valves, feedback sensors, and air pressure regulators. This allows the actuator to perform both switching and regulating actions.

2. Key Features and Advantages

Compact and Efficient: The GT pneumatic actuator is small and light, making it suitable for installations in limited spaces. Its rotary design allows for quick and stable motion control. It is especially effective for valves that need 90° rotation, such as ball and butterfly valves.

Versatile Adaptability: The GT actuator can be used for standard on/off control. With additional accessories, it can also meet automatic regulation control needs, offering good flexibility for various applications.

Easy Maintenance: The simple design of the GT actuator makes it easy to maintain and replace. This helps reduce maintenance costs and downtime during operation.

3. Major Disadvantages

Lower Adjustment Precision: The GT pneumatic actuator is designed to perform on/off actions and cannot make fine adjustments. It is suitable for simpler control applications. If precise control is required, the GT actuator may not be adequate.

Limited Control Flexibility: Unlike the AT series, the GT actuator cannot simultaneously adjust both opening and closing actions. This limits its flexibility in some applications.

4. GT Pneumatic Actuator: Setup and Applications

The setup method for the GT pneumatic actuator is similar to the AT series. However, due to its design, it only allows for the adjustment of the open and closed positions. The setup steps are:

Opening Setup: Loosen the nuts at both ends of the cylinder. Adjust the bolts until the cylinder fully opens to the preset angle. Then, tighten the nuts.

Closing Setup: Loosen the nuts at both ends of the cylinder. Adjust the bolts until the cylinder fully closes to the preset angle. Then, tighten the nuts.

Conclusion

Both the AT and GT series pneumatic actuators have distinct applications, advantages, and limitations. The AT series is popular due to its cost-effectiveness, flexibility, and broad applicability. It is the preferred choice for most industrial automation control systems. The GT series, on the other hand, is better suited for applications that require 90° rotation but do not need precise control. When selecting a pneumatic actuator, users should consider factors such as operational conditions, control precision, and budget to choose the most appropriate actuator. This will ensure the efficient and stable operation of the equipment in the long term.