What Are Pneumatic Actuators and Why Do We Use Them?
If you don't know anything about what pneumatics are and how a pneumatic system works, be sure to check out the "Introduction to Pneumatics" post here, as we'll take a deep dive into one of the main components that make up the pneumatics machine in this article - Pneumatics Actuator.
Everyone encounters an actuator at least once a day at home, at work, or out and about.
In fact, actuators provide motion within the system as linear or rotary motion. They can be driven hydraulically (water pressure), handwheel, electronically, or pneumatically (air pressure).
At UG Controls, we want to make sure you get the right product for your needs, whether it's in an industrial or domestic setting.
What is the Main Function of a Pneumatic Actuator?
Unlike other ways of powering actuators, pneumatic actuators are primarily used to power valves within a system. They convert pressurized air into energy to keep systems running smoothly. This can be used for gas, load, or water movement.
Pneumatic actuators are usually located in cylinders or electric motors and are used to open or close something. Pneumatic actuators are commonly used in industrial valves due to their strength and durability.
Three Types of Pneumatic Actuators Will be Used in Different Situations;
Single Acting Cylinder Pressurized
Air will enter and exit from a single port on the cap end and the piston end will be equipped with a spring. This works best for lifting heavy objects or moving something in one direction.
Double Acting Cylinder
This type of actuator allows pressurized air to enter and exit through two end ports; the cap and the piston. One is activated to open the valve and the other will be activated to close the valve. So it's your best option when you need to move something back into place.
Pneumatic Rotary Device
A motor with an average speed of about 10,000 rpm. Pneumatic actuators are limited to low to moderate torque due to the compressed air that operates the motor. These are mostly used on sites that are under construction; for consistent motion such as mixing or oscillating.
Why Do We Use Pneumatic Actuators?
There are many benefits to using pneumatic actuators due to their energy supply. Because they use air to operate the system, they are simple in design and have a very high level of safety compared to their counterparts; hydraulic and electronic.
Pneumatic actuators can be manually triggered by changes in pressure or temperature; for example, when a machine overheats, it heats the air in the compression chamber and causes air particles to expand, which activates the actuator and causes the valve to move. In this way, the actuator is automatic, which is useful in industrial places where temperature control is required.
Due to the Wide Variety, Here Are the Main Benefits of Using Pneumatic Actuators:
Electric actuators consume a lot of energy, which is either lost as excess heat or needed for the transmission. Pneumatic actuators, on the other hand, act directly on the closing device. The piston and actuator shaft are sufficient to convert linear compressed air force into rotary motion. Pneumatic solutions are more economical than electric actuators because they only require power for compressed air generation and open-loop control. The actual movement is produced by compressed air.
Durable and Low Maintenance
Over the years, pneumatic actuators have proven to be vibration resistant and durable, and because they are made from a small number of components, they are less likely to fail. In addition, they can withstand continuous loads and remain maintenance-free throughout their service life. No oil changes or additional lubrication is required.
Because pneumatic actuators have overload protection and higher actuation forces can be achieved very simply by increasing the pressure, smaller sizes and lighter weights are often available. The pneumatic system is capable of delivering forces up to 50,000N and torques up to 10,000Nm.
Pneumatic actuators are safe as there are no environmental hazards from fluid leaks or sparks. Compressed air can also be used during power outages. In addition to the compressors for power generation and processing purposes, there is also an air tank ready for emergencies. Additionally, overload and explosion-proof means they can also be used in fail-safe, extreme environments, and critical applications without compromising performance and safety.
In addition to the above advantages, pneumatic actuators also have other advantages:
- They can withstand high temperatures
- They have no magnetic interference
- They are very light because there is no liquid
- They provide high precision control positioning and linear motion accuracy
- They are quieter than other actuators such as hydraulic
Therefore, using a pneumatic system instead of an electric or hydraulic system has proven to be a more economical, hassle-free and safe choice for all applications. They are also reliable over a long period of time.
What Are the Limitations of Using Pneumatic Systems?
Pneumatic systems are not suitable for all applications. In some industries and fields, electric or safer hydraulic actuators offer greater advantages due to speed.
For a pneumatic actuator to be most effective, it must be sized and mounted for the job. This means that there may be more costs involved.
Often, specific jobs require high-speed valve or object movement, rather than a slower pace. In these cases, hydraulic presses are the preferred energy source. This is because leaks and losses of compressed air also occur, causing the actuator to have lower pressure and slower force.
Not only that but the compressed air mixes with other compartments of the cylinder, such as lube or oil, causing the compression function to run at a slower speed.
So, even though pneumatic pressure has many advantages, make sure the actuator is right for your needs.
Which Industries Are Likely to Use Pneumatic Actuators?
As a result, there are many industries across the globe that use pneumatic actuators to power their everyday necessities.
Water Treatment Plant
For example, 30% of the valves in a water treatment plant are controlled by pneumatic systems. They are also used in instruments, sensors, valves, and filter membranes. Due to the large footprint of water treatment plants, the monitoring system may reduce bandwidth, so the use of compressed air modules that can be monitored locally is of great benefit to the overall system.
Chemical and Process Industries
The chemical and process industries only use pneumatic actuators in valves to control the flow of chemicals. Since these industries often perform hazardous tasks, such as handling hazardous or even toxic chemicals, pneumatic actuators are often used for safety and reliability. As mentioned above, their benefits include the ability to withstand high temperatures and durability. That's why these are a common choice for gas, steam and thermal power plants.
Although it is an extensive process, there is almost always room for pneumatic actuators in manufacturing. They are used in manufacturing because of their durability and low maintenance requirements. Because the manufacturing plant is so large, the owner needed moving parts that could last a long time without the refilling or maintenance required by hydraulic and electrical systems.
Food Processing Industry
With hydraulic oil or electricity, the chances of leaking and contaminating food are much higher than with compressed gas leaking and slowing down manufacturing. For food, it may be necessary to have a durable actuator, which could contaminate the food or cause sparks. This is why many food processing industries will use pneumatic systems.
Handling, assembling, and testing small parts are at the heart of the electronics industry. The production and assembly of electronic components such as semiconductors are fast-paced and require high precision. Thanks to the pneumatic system, it is able to position accurately at high speed despite the high moving mass. As product cycles in the electronics industry become shorter, pneumatics also offers a more economical solution than hydraulics in the long run.
But, there's more. Pneumatic actuators are a part of most industries you experience. Here are some other examples where you'll find pneumatic systems at work:
- Amusement park machines
- Coal mining equipment
- Textile industry
- Bicycle pump at home
From cost and safety aspects to ease of operation, pneumatic actuators offer clear advantages in a wide range of applications across many industries. However, it's also important to note that it's not a size fits.
The above introduces some basic information on pneumatic actuators. If you want to order pneumatic actuators, please contact us.
UG Controls is a custom valve actuators and accessories manufacturer. Its main business is the import and export of various automation equipment and technologies. UG Controls is a proprietary business solution integrating chemical engineering, water, oil and gas, power plants, manufacturing, food and beverage, and more.