The Importance of Tubing in your Fluid System
The Importance of Tubing in your Fluid System
At Swagelok Calgary | Vancouver | Red Deer | Medicine Hat | Prince George, we provide high-quality components and the training you need to select and install them correctly. We often find ourselves speaking with customers around the principles of tube fitting installation – the right way is to firmly seat the tube in the bottom of the fitting, mark the nut at the six o’clock position, and then give the nut one and a quarter turns (3/4 of a turn for 1/16 inch to 3/16 inch fittings). However, it would be remiss to not mention tubing in the greater equation – careful selecting, specifying, purchasing and handling of tubing are essential to the successful use of Swagelok tube fittings.
Check the Ratings
Proper selection, handling, and installation of tubing, when combined with proper selection of Swagelok tube fittings, are essential to reliable tubing systems. The following variables should be considered when ordering tubing for use with Swagelok tube fittings:
- Surface finish
- Material
- Hardness
- Wall thickness
In addition, check your wall thicknesses against the suggested minimum and maximum wall thickness limitation charts provided in the Tubing Data Sheet. A wall too thin will collapse under ferrule action and may not resist enough to allow the ferrules to coin out surface defects. And remember, a wall thickness greater than the maximum suggested wall does not increase the allowable working pressure of a system. All of this information, and more, can be found in the Swagelok Tubing Data Sheet.
Let’s Talk About Gas
Gases, such as air, hydrogen, helium, and nitrogen have very small molecules that can escape a closed system through even the smallest leak paths. Some surface defects on the tubing can provide such a leak path, and as the tube outside diameter (OD) increases, so does the potential for a scratch or surface imperfection to interfere with proper sealing.
A heavy-wall tube resists ferrule action more than a thin-wall tube, allowing the ferrules to coin out minor surface imperfections such as scratches. The Swagelok Tubing Data Sheet offers suggested wall thicknesses for gas service to ensure successful, leak-tight installations.
Handle With Care
Good handling practices can greatly reduce the scratches on tubing and protect the good surface finish that reliable tube manufacturers supply. Tubing should never be dragged out of a tubing rack or across a rough surface. When cutting tubing, use the appropriate tools.
By selecting a lower quality tubing on the principle of cost, an installer is essentially sacrificing the integrity of the system and increasing the likelihood of system leakage, or worse a potential accident. Before installing any piece of tubing into a Swagelok fitting, ensure you are working with the correct material and tools for the job. If you have any questions about the quality of the tubing you are using, give us a call. For a more comprehensive review of tubing fitting installation, component selection and safety, sign up for one of our Swagelok Essentials training courses.
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