How to Assemble Tube Fittings (1 inch and Under)
Tube fittings are a critical component of fluid systems, providing reliable, leak-tight connections between tubing and system components across a wide range of industrial applications. The Swagelok® tube fitting design uses a two-ferrule mechanical grip to help maintain seal integrity, resist vibration, and support consistent performance when installed correctly. Proper tube preparation and installation are essential to achieving optimal fitting performance and longevity. In this video, you will learn the three-step process for manually assembling tube fittings that are 1 in. and smaller. To complete this task, you will need two open-end wrenches (or one open-end wrench and a vise), a Swagelok gap inspection gauge, a tube cutter or hacksaw, a deburring tool, and a marker. For additional installation guidance, troubleshooting information, and best practices, refer to the Swagelok Tube Fitter's Manual. You can also explore tube fittings and adapters and learn more about tube fitting technologies and applications.
Video Transcript
Welcome to this Swagelok How‑To Video. Here’s what you’ll need to perform the procedure shown in this brief video: two open‑end wrenches (or one open‑end wrench and a vise), a Swagelok gap inspection gauge, a tube cutter or hacksaw, a file or Swagelok deburring tool, and a marker.
The Swagelok tube fitting is designed to provide a leak‑tight seal for pressures up to the suggested allowable pressure rating of the tubing. It is a two‑ferrule, mechanical‑grip, hinging‑colleting type connection consisting of a fitting body, a nut, a front ferrule, and a back ferrule.
Proper tubing preparation is important when installing tube fittings. Two common tools are used to cut tubing: a tube cutter or a hacksaw. Once the tube is cut, burrs created during the cutting process must be removed using a Swagelok deburring tool or a file.
This video focuses on manual assembly of the one‑inch‑and‑under Swagelok tube fitting end connection. Swagelok tube fittings come completely assembled, finger‑tight, and ready for immediate use. They should not be disassembled prior to installation, as disassembly can introduce dirt or foreign material that interferes with sealing.
The typical assembly is a three‑step procedure. These instructions apply to both traditional fittings and fittings with advanced back‑ferrule geometry.
First, fully insert the tubing into the fitting and against the shoulder, then rotate the nut finger‑tight. Next, mark the nut at the six‑o’clock position. This ensures clarity on the starting and ending positions.
Finally, while holding the fitting body steady, tighten the nut one‑and‑one‑quarter turns to the nine‑o’clock position. For 1/16‑, 1/8‑, and 3/16‑inch fittings, and 2, 3, and 4 mm fittings, tighten only three‑quarters of a turn to the three‑o’clock position.
Swagelok tube fittings are recognized for their gaugeability. On initial installation, the Swagelok gap inspection gauge assures the installer or inspector that the fitting has been sufficiently tightened. Position the gauge next to the gap between the nut and the body. If the gauge will not enter the gap, the fitting is sufficiently tightened. If it enters, additional tightening is required.
A key benefit of Swagelok tube fittings is their ability to be disassembled and reassembled many times while retaining a leak‑tight seal. Always depressurize the system before disassembling a fitting.
Before disassembly, mark the tube at the back of the nut and mark a line along the nut and fitting‑body flats. These marks ensure that the nut is returned to the previously pulled‑up position.
Insert the tube with preswaged ferrules into the fitting until the front ferrule seats against the fitting body. While holding the body steady, rotate the nut with a wrench to the previously pulled‑up position, as indicated by the marks. You will feel a significant increase in resistance. Tighten the nut slightly. Do not use the gap inspection gauge with reassembled fittings.
Also, do not mix or interchange parts with those of other manufacturers.
Visit Swagelok.com for additional product information. Thank you for watching. We will continue to develop videos like this to help you get the job done. Get more information by watching our other videos or contacting your authorized sales and service center.
