Types of Air Fittings - 2013. 2. 21

Types of Air Fittings
Air fittings are an important part of any compressed air system. They help to redirect the pipes or hoses through which the air is flowing, as well as deliver the air to users if need be. When designing, repairing, or overhauling an air system, you have many options when it comes to air fittings. Looking at each of these types of air fittings and seeing what their potential uses are is an excellent place to begin.
1. Fitting Sizes
The most obvious difference between different types of air fittings is their size. The National Pipe Taper (NPT) is a standard that governs the sizes and configurations of air fittings. NPT sizes come in inches, but the NPT size usually does not match the actual size of the fitting. Fittings will also be designed to fit into different port sizes as well as different tube sizes.
2. Straight Air Fittings
Straight air fittings are the most basic type of air fitting. They accept an air line at one end, and the other end is a male or female thread that connects to a boss, that is, the device into which you are fitting the air supply, which could be a tool, a valve, an air cylinder or any other type of air compressor component.
3. Elbow Air Fittings
Elbow air fittings allow the air line to connect to its fitting at an angle. Most elbow air fittings come with a swivel feature, so that once the fitting is attached the air line connection can be turned so that it is coming from the most convenient direction. This device, however, cannot swivel continuously, but can only be adjusted once and then kept in that position while the tool is being used.
4. Rotary Union Air Fittings
A rotary union overcomes the limitation of an elbow fitting, and allows the air fitting to be moved continuously while in use. It is essentially an elbow fitting that can swivel without wearing out. This constant swiveling effect is accomplished by using ball bearings.
5. One Touch Air Fittings
One touch air fittings are a type of air fitting that provide positive sealing without reducing airflow. They come in a wide variety of thread types and shapes, and are named mostly for the technology used in creating their connecting mechanisms.
6. Special Air Fittings
Special air fittings are designed for use in particularly demanding environments. For instance, one type of special fitting is designed specifically for use with nylon, soft nylon and polyurethane tubing. Another is especially designed for copper-free applications. Another is meant to be used high speed operations using a vacuum or high pressure.