Pneumatic Fittings: Everything You Need to Know

Pneumatic fittings

by Justin Uhm

Pneumatic fittings are essential to keeping your pneumatic systems running.

In this post, we will cover all the different types of pneumatic fittings and their applications.

Read on to learn more.

Pneumatic Tubes, Hoses, and Pipes

Before we begin, lets us distinguished the type of components that are being connected in a system. This will help you understand the appropriate pneumatic fittings to consider for your application.

There are three different types of components you could be connecting.

Hoses

These are flexible vessels that are made up of many layers of different types of materials. Fittings used for hoses are almost always temporary because hoses have to be replaced fairly often.

Tubes

These vessels are fairly rigid and made of one solid material throughout. Tubes are usually defined by the outside diameter of the tube itself.

Pipes

Completely rigid vessels, like pipes, are always constructed of one solid material. Pipes, unlike tubes, are defined by their interior diameter.

Types of Pneumatic Fittings

Now that you understand the different vessels you’ll be fitting we can move on to the different types of pneumatic fittings and their proper applications.

They are commonly distinguished based on the type of connection they’ll form and the function the connection will serve.

Ball and Sleeve Fittings

These fittings connect an outer sleeve to an inner ball. The sleeve retracts to connect and to disconnect the two different ends. These types of fittings generally function as a push-to-connect.

This makes these particularly useful in applications where there are frequent disconnections and reconnections of the hose systems.

Compression Fittings

Any fitting that uses compression force to connect the vessels together is considered a compression fitting. Many different pneumatics fittings fall into this category and they all have a different application.

Standard Compression Fitting

These fittings make use of metal gaskets, rings, or types of ferrules to form a seal on a vessel from compression. Typically, a nut will be tightened over the fitting to compress the vessel inside. 

Standard compression fittings do not require any special tools for installation so they are a good option if the machine will be out in the field and not accessible to specialty tools.

Mechanical Grip Fittings

These are two-ferrule assembly fittings. The back ferrule is in charge of gripping the vessel while pressing up against the front ferrule. This causes a spring load of the front and creates the seal of the vessel and the fitting.

These are able to be reassembled over and over again without damaging any of the components or the vessel itself. They are particularly good in mechanical applications because they have very good resistance to the vibrations produced by large machinery.

Bite-Type Fittings

These compression fittings feature a sharp ferrule. This “bites” onto the vessel when it’s compressed and causes the seal. Bite-type fittings don’t require any special tools, just like a standard, but the seal is stronger and provides a higher pressure connection.

Flare Fittings

These have a body with one end that is coned or flared. Installation requires special flaring tools to place the vessel inside the flared end of the fitting. This provides a deep and dependable seal.

Flare fittings handle super-high pressures and have a wider range of parameters of what they can handle than standard compression fittings.

Crimp Fittings

These are installed by placing the hose over the tubular end and crimping against it using a sleeve, ring, or crimp socket. You’ll need a crimping tool or a machine to create the connections.

End Fittings

These provide specific surfaces for connecting the vessels in certain kinds of pneumatic systems.

You’ll use either a clamp end which will allow a hose or tube to be clamped over the part itself, or plain ends that are connected through adhesive, welding, or another permanent connection.

Push-To-Connect Fittings

These are designed to accept the tubing or other vessel by simply pushing it into the end of the fitting. Then they can disconnect via a collar retraction. These are great if you’re disconnecting and reconnecting the vessel often. See more in this definition.

Threaded Fittings

Threaded fittings have screw-top heads and can accept vessels with threads that match. The threads can either be straight or tapered depending on the type of seal you’re looking for.

These threads create a dry fit which means they do not require the use of a sealant which runs the risk of contamination or corrosion in certain systems.

If you’re using straight threads you can make the seal better by using seal tape. If you need the fitting to be seal free you’ll need to use tapered threads to provide an airtight seal without sealant.

Finding the Right Fitting for Your Next Project

We hope this has given you a good idea of the different types of pneumatic fittings on the market.

Here at TPC Automation, we keep an inventory of all different types of fittings to handle any of your pneumatics needs.

Check out our store here so we can provide you with the fittings you need for your application.

Contact us today with any questions about your project. We will be happy to help you and get you what you need to get you moving again and back in business.

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