Smart engineering make Swagelok fittings the right choice

Strong grip with no torque produces a seal that stands up to hard use

Swagelok introduced the two-ferrule fitting back in 1947, and the classic design has proved a stellar performer ever since. Let's take a look at some of the details of Swagelok’s gaugeable tube fittings and adapter fittings, and why they work so well.

By using two ferrules, the Swagelok design separates the sealing and tube-gripping functions. The front ferrule creates a seal against the fitting body and on the outside of the tubing. As the nut is turned, the back ferrule advances along the axis of the tubing and radially applies an effective tube grip. It accomplishes all this without transmitting any torque to the tubing during installation.

The two-ferrule design compensates for changes in temperature such as thermal cycling or during system start up or shut down. This helps eliminate leakage related to rapid thermal expansion or contraction.

Some components may look like Swagelok parts at first glance

Good design is at the heart of a leak-tight seal, but it is also important to have precision parts that were meant to work together. It's important to avoid mixing Swagelok components such as the ferrules, nuts and fitting bodies with those of other manufacturers. While some may look like Swagelok parts at first glance, they can't be made to meet Swagelok's engineering standards, and they can't take advantage of the more than three dozen design and manufacturing patents that Swagelok has obtained since 1989.

Fit in a tube fitting safety seminar

It's also vital to install the components properly. That's where Swagelok Northern California can be a key asset. We offer tube fitting safety seminar that will help you master the skills required for making safe, leak-tight connections, and we offer a variety of tools and accessories designed for use with Swagelok components.

For instance, our hydraulic swaging units preswage the ferrules onto tubing prior to assembly. They place no initial strain on the nut, the fitting body or the body seal surfaces. If you have a lot of fittings to assemble, this saves installation time and cuts down on operator error. We also have a variety of special wrenches, plus gauges to make sure the fitting has been adequately tightened.

Preventing lost time and money -- and headaches

Leaks cost time and money. The best way to deal with them is to prevent them from appearing in the first place. The combination of Swagelok components, tools and customer support will prevent a lot of headaches.

The best testimony to the value of the two-ferrule design comes from customers. On a pair of 12,000-ton oil rigs, one Swagelok customer reported installing over 10,000 fittings without a single leak.

Additional resources

Related articles

• Smart engineering make Swagelok fittings the right choice
• Skill: Tube fitting assembly, one inch and under
• Skill: Applying PTFE tape to tapered pipe threads

Downloads

• Download an information sheet on the tube fitting safety seminar
• Download a customer example
• Download the catalog on tube fittings and adapter fittings