Flaring of SS tubing

[Sherin Achenkunju]

I hope somebody can help me to find out what is the best flaring tool to flare SS tubes. There are two sorts of tubes. one is 3/8" O.D with a thickness of 2.11mm thick and 1/4" OD X 1.65mm thick. Is that possible to flare these tubes to 37 degrees to mate it with parker triple-lok fittings. I need help to find out the best flaring tool for this application. Please.......

 

[EdStainless]

These are very thick walls, is this annealed tube or is cold worked high pressure tube?


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P.E. Metallurgy, consulting work welcomed

 

[Sherin Achenkunju]

These are solution annealed tubes at a temperature of minimum 1040 degree celcius and quenched

 

[Sherin Achenkunju]

Manufacturers states flaring test found ok

 

[EdStainless]

You need to look up the tube spec and see what kind of flare that is.
What angle and how much expansion.
I would expect annealed tube to flare easily.
In heavy tube like this you have to be careful, if you flare very gradually you may get a lot of cold work.
You also may need to lubricate because of how heavy it is. The lube must be Cl free (no soaps).

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P.E. Metallurgy, consulting work welcomed

 

[TugboatEng]

How many of these are you doing? Compression fittings outperform flared fittings. The higher fitting cost can be offset by lower tooling costs and higher reliability (fewer quality checks required and less rework). Swagelok is the gold standard but there are many clones now and they also perform well. See Parker A-Lok for an example.

 

[Sherin Achenkunju]

The designer had instructed to use triple-lok fittings instead of compression fittings as this is going to deal with hydrogen gas.

 

[TugboatEng]

Then you should be using compression fittings as they perform better than flared fittings.

Search the Swagelok system. It will answer all of your questions.

 

[EdStainless]

Unless these flares use a shouldered nut, shaped backing gland, and a crush seal you will have real trouble getting them to pass He leak tests.
Double ferrule systems are generally much better in this service.

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P.E. Metallurgy, consulting work welcomed

 

[TugboatEng]

The Parker Triple-Lok 2 system is available with an o-ring groove on the male seat. I still despise flared stainless tubing, though.