Stainless Steel Duolok Tube Fitting, 0.25 Inch Tube OD Union

Full interchangeability with Swagelok brand fittings is built into the Duolok design, so you can swap them in without modifying the surrounding hardware. The dimensions and double ferrule system are controlled to match, which is part of why gageability is built in as well. That gaugeability feature also helps confirm you've got enough pull-up on initial installation, so you're not left guessing whether the connection seated right.

Generally, these Duolok tube fittings are rated for pressures equal to the maximum allowable working pressures of the stainless steel tubing recommended for use with them. Keep in mind that some specially designed fittings may have a lower pressure rating than the tubing itself.

Use it when you need a straight union to connect two pieces of 0.25 inch OD tubing in an instrumentation or process tubing line. It uses a double ferrule setup that helps seal up even when tube wall thickness or hardness varies.