Edmonton Valve & Fitting Blog

Weekly posts for northern and central Alberta engineers, plant operators, and buyers.

Expertise in Your Hands with Swagelok's Tube Fitter's Manual

by Katie Dennis, on Wed, Mar 12, 2014 @ 16:03 PM

Check the Tube Fitter's Manual when you haven't got all the answers to your questions

  TFM Cover 
 

The Swagelok Tube Fitter's
Manual has been used to
answer tube fitting questions
since 1963. To download a 
copy, click here. 

Eventually everyone has "one of those days." For those who work on fluid systems, it might be tubing that won't fit in the fitting, or a leak that suddenly appears after routine maintenance. Where do these problems come from, and how can you quickly fix them?

Very likely you'll find the answer in the Swagelok Tube Fitter's Manual. It has more than 250 pages on how to get the best performance out of your fittings and tubing. There's a whole chapter on trouble shooting for those times when the parts seem like they don't want to cooperate.

Insight and answers

Say, for instance, that a fitting can't be pulled up the proper amount of turns. The manual lists a half-dozen likely reasons, such as dirt on the threads or a mixture of parts from more than one manufacturer. For each possible cause, the manual offers a basic solution. (For the problem of incompatible parts from different manufacturers, the solution is extremely simple: Don't interchange parts.)

For leakage at the pipe thread, the manual has several suggestions for getting a tight fit. PTFE tape/dope is a must, as pipe threads make poor seals by themselves. It's also important to inspect the threads first. You may have some poor quality pipe to begin with, or the threads could have been damaged along the way.

Leaks can form after the initial installation, after system installation, or after reconnection following maintenance. For each of those circumstances, the manual gives a list you can run through to spot the cause. Much of the time the problem stems from using parts in a way they aren't meant to be used. If the tubing is bent too far out of round through improper bending, the tubing won't fit into the fitting if the bend is near the end of the tubing. 

Good intentions

Dan Constantin, our warehouse manager, understands how some of these problems crop up.

"One of the factors is lack of training," he says. Some people jump in and do whatever they think is best to put a system together, without following instructions. Some people are unintended victims of bad instructions. They've learned how to assemble tubing from someone who learned it from someone else, who learned it from someone else. Along the way, things got garbled or left out. Or the instructions might be right for someone else's parts, but not for Swagelok's. Someone may never have learned that Swagelok makes a gap gauge that helps ensure the proper tightening of a fitting.

Intermixing of parts from different manufacturers may come from a misguided attempt to save time and money.

"Perhaps there is already a fitting in the system and they don't want to remove it," Constantin says. "It might be a matter of cost, where they can get a fitting cheaper somewhere else. For tubing, maybe it's old tubing in the system that they don't want to change out, so they may have issues of scratching, kinking or rust on the outside of the tubing."

Whatever the good intentions, the results can be costly.

"The cost of a steam leakage over a year is actually huge money," Constantin says. "There could be an even bigger cost of having somebody injured by the system fluid if it is toxic or hot. A leak could cause damage to the environment, not to mention your reputation if it gets in the news." A lot of those problems can be avoided by doing it right the first time. Swagelok's Tube Fitter's Manual is an excellent roadmap to follow. Best of all, you can get it for free right here.

Topics:TubingFittings

More... (blog home page)

More...

Join us!

Each week our local team posts original articles featuring tips on fluid system maintenance and design, profiles of team members, and free resources you can download here at our website. Join us!