Pneumatic systems regulate the flow and pressure of air and gases as a method for generating mechanical energy. That energy is harnessed and used in a plethora of applications.

One of the advantages to using pneumatics is their versatility. They're simple in design, which allows them to be put to use in factories, laboratories and a host of other demanding environments.

Below, we'll cover several questions that are often asked about pneumatic control systems. The following is not intended to explain the step-by-step installation or application of the instruments. Rather, it is intended to provide an overview of their basic design, uses and operation.

How Do Pneumatic Control Systems Work?

Tools and processes that rely on pneumatics require kinetic energy. That energy is generated by compressing air. When the compressed air is released - i.e. it is allowed to escape - it is used to exert force against a resisting object. That force causes the object to move in some fashion.

The air (or gas) needed to create the kinetic energy is typically compressed to many thousands of pounds per square inch (PSI). A regulator ensures the degree of pressure stays within an appropriate range given the application. When the air is released, it is directed through one or more hoses and valves to an actuator. The actuator is the component of a pneumatic system that applies the physical force generated by the energy contained in the compressed air.

What Are The Different Types Of Pneumatic Valves?

Pneumatic systems use an assortment of valves based on the target application. For example, directional control valves compose a broad category of configurations. That category includes two-way, three-way and four-way valves (the use of multiple paths is explained in more detail in the following section). It also includes needle valves, flow control valves, circuit control valves and quick exhaust valves.

Needle valves are precision components that control flow in two directions. By contrast, the typical air control valve regulates flow in a single direction.

Circuit control valves also compose a category of devices, including shuttle valves, needle valves and quick exhaust valves. The latter tool is often used for applications that require the actuator to return quickly to its default position without allowing air to flow back through the system.


Why Do Directional Control Valves Have Different Flow Paths?

Directional valves are used in both hydraulic and pneumatic systems. In the latter, they regulate the direction and flow of compressed air and gases. In doing so, they influence the speed of the target application.

One of the ways in which these type of valves are categorized is by the number of flow paths they offer. Some offer two paths; others offer three paths; and still others have four paths.

A two-way valve is the simplest configuration. It has two ports connected by an artery through which air can travel in both directions. A three-way valve has three ports, each of which has a different purpose. Connected to each other by multiple arteries, the ports influence flow based on whether they are open or closed. A four-way valve has four ports and four distinct flow paths.

The number of flow paths offered by a directional control valve reflects the complexity of the application. Simple processes may need only a two-way configuration while complicated processes may require the versatility of a four-way configuration.

What Are The Advantages Of Using Pneumatics?

Pneumatic systems are relatively simple compared to hydraulic systems. They use standard components, which makes it easier to purchase replacements when necessary. They also tend to be less costly than hydraulic systems and available in ultra-small sizes.

Another advantage of a pneumatic system is its ability to generate power with little energy. That trait stems from the fact that it runs on compressed air rather than oil. Air is much more "agile."

Pneumatic control systems are also dependable. They rarely break down, which saves the plant or process manager both time and money.

Again, there are many pneumatic system designs. Selecting the right one for your application may present a challenge. The trained engineers and support staff at Applied Engineering can assist you in choosing the most suitable solution given your needs.  See Pneumatic control by fairchild