High-Tenperature Fittings 2

[Eltron]

Hello, All.

I've been looking all over the place for some high-temperature fittings and so far have been unsuccessful. I am designing a small system that will contain hydrogen and carbon monoxide at 1000psig and 430°C. The system is small (I'm only using 1/4" stainless steel or inconel tubing). I'll need to remove my reactor periodically, so welding it in place isn't an option. Any suggestions will help.

Thanks,

 

[Cockroach]

Yeah, to to the top shelf and ask for the best.

You should call your local Parker-Hannifin representative and get their design manual on fittings.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[moltenmetal]

1000 psig at 430 C isn't all that bad. You might even get away with ordinary compression fittings (Swagelok, Parker etc.) depending on how often you want to thermally cycle this device. You can certainly use Autoclave Engineers Speedbite or cone and thread fittings if you're after a little more robustness. Required wall thickness for the tubing is a relatively easy calculation.

 

[metalonis]

Check out

http://www.highpressure.com

 

[Eltron]

Thanks for the information, everybody. Sorry about the misspelling of "temperature" in the thread title. That aggravates me. Both highpressure.com and the Autoclave Engineers' webpage have what I am looking for. Swagelok and Parker are useless when temperature fluctuations are involved. Thanks, again.

 

[ely94]

Swagelok thats how I would do it

 

[moltenmetal]

Beg to differ Eltron. Swagelok and Parker are NOT useless when temperature fluctuations occur, but they ARE more vulnerable to failure from repeated severe thermal cycling than are either Speedbite or cone and thread fittings. Speedbite and cone and thread fittings, in turn, have their OWN sets of unpleasantness associated with them.

Whether or not external compression fittings are adequate for a particular service is obviously a matter for good engineering design and judgment. I've used Swagelok fittings quite successfully to temperatures much higher than what you're talking about, on devices with repeated thermal cycling- with design to mitigate these effects. I've also used Swagelok stuff very successfully at pressures and pressure/temperature combinations far higher than what you're talking about.

Cone and thread fittings are far more robust against absolute pressure and against thermal cycling, and are strongly recommended if you don't fully understand the design and service life implications of using Swagelok-type fittings in such a service. However, you'll find that the installation labour for C&T type fittings is at least five times as much as for simple Swagelok stuff, requires special tooling etc.

Good luck with your particular service.