Round 2: FAQs from Edmonton Valve's Customer Service Desk

As previously mentioned in our last FAQ blog, here is the next round of Frequently Asked Questions from our customer service desk. 

1. What is the pressure rating of a Swagelok tube fitting?

The pressure rating of a Swagelok tube fitting is dependent on the lowest pressure rating of the system, which will almost always be the rating of the tubing itself. The pressure rating of tubing varies depending on the size and wall thickness of the tubing. Swagelok provides a selection of charts of the approved pressure ratings for each size and wall thickness we offer, which are available in the eDTR, online, and in the Swagelok Tube Fitting Pocket Guide. 

2. Which valves are the green handled valves?

Our Swagelok Plug Valves come standard with a green handle. Swagelok plug valves offer low-torque, quarter turn operation in a simple, compact design that provides positive shutoff of forward flow with up to 3000 psig pressure. They feature a straight-through flow path and forward-flow throttling in a simple design. They are also available with a variety of end connections and sizes, from 1/8 inch to ½ inch.

3. What’s the procedure for a properly installed first time Swagelok fitting, using a wrench for installation?

The installation procedure of a Swagelok tube fitting depends on the size of the fitting.

From 1/16 to 3/16 inch:
Fully insert the tube into the fitting and against the shoulder; rotate the nut finger tight.
Mark the nut at the 6 o’clock position.
While holding the fitting body steady, tighten the nut three-quarters turn to the 3 o’clock position.

From 1/4 to 1 inch:
Fully insert the tube into the fitting and against the shoulder; rotate the nut finger tight.
Mark the nut at the 6 o’clock position.
While holding the fitting body steady, tighten the nut one and one-quarter turns to the 9 o’clock position.

Over 1 inch:
Preswage the ferrules onto the tube using a Swagelok multihead hydraulic Swagelok unit.
Apply the lubricant packaged with the fitting lightly to the body threads and the rear surface of the back ferrule.
Insert the tube with preswaged ferrules into the fitting until the front ferrule seats against the fitting body; rotate the nut finger-tight.
Mark the nut at the 6 o’clock position.
While holding the fitting body stead, tighten the nut one-half turn to the 12 o’clock position.

Always check your fittings using the appropriate Swagelok gap inspection gauge.

For information on high pressure applications, installation using hydraulic swaging units, or for a more detailed description of tube fitting installation, please see the Tube Fitter’s Pocket Guide. If you'd prefer hands-on installation training, see the Swagelok Total Support Seminar.

4. What is a Swagelok Gap Inspection Gauge?

The Swagelok gap inspection gauge assures an installer or inspector that a Swagelok tube fitting has been sufficiently pulled up on initial installation. To use, position the gap inspection gauge next to the gap between the nut and body. If the gauge will not enter the gap, the fitting is sufficiently tightened. If the gauge will enter the gap, additional tightening is required.

The gap inspection gauges are available in a multitude of sizes and styles, depending on the installation process used (by hand with a wrench or by using a hydraulic swaging unit), so be sure to always use the correct gap inspection gauge. 

Always depressurize a system before adjusting the tightness of a tube fitting connection.

5. What is the reassembly procedure for a Swagelok tube fitting?

All sizes:

	Prior to disassembly, mark the tube at the back of the nut; mark a line along the nut and fitting body flats.
	Insert the tube with preswaged ferrules into the fitting until the front ferrule seats against the fitting body. (Over 1 inch: If needed, reapply lubricant lightly to the body threads and the rear surface of the back ferrule.)
	While holding the fitting body steady, rotate the nut with the wrench to the previously pulled-up position, as indicated by the marks on the tube and flats. At this point, you will feel a significant increase in resistance. Tighten the nut slightly.

Do not use the Swagelok gap inspection gauge with reassembled fittings.

For a copy of the Swagelok Tube Fitter’s Pocket Guide, see your authorized Swagelok Sales and Service Centre, or ask us.