Compression fittings

[tbl100]

Hi,

I'm using Earls -6 AN Male to 3/8″ Tubing Adapter with 3/8" stainless steel fuel line. Can anyone tell me how tight to tighten the compression fitting? Once fitting is snugged by hand how many turns will be needed to compress the brass ring to seal it? I'm afraid of over tightening them.

Thanks for any assistance.
Tim

[OVCobra]

Tim
I am not certain but not sure these fittings will work with stainless steel tubing. Stainless work hardens quickly when compressed and the brass olive/aluminum fitting may not be able to swage onto the tubing and create a seal.
Suggest you verify with Earl's that the fitting will work...fuel leaks are not good!
Dave

[seagull81]

I doubt they will work, but Swagelok stainless steel fittings will. We used them on Hydrogen systems in semiconductor. They have AN adapters if you are looking for those. You might have to put a couple of fitting together, though.
https://www.swagelok.com/en/product/fittings/tube-fittings-tube-adapters

[Straversi]

Breeze sells a similar fitting. It worked well. I used Earl’s for other AN fittings and they are great. To answer your question, pretty dang tight. I always use short wrenches with AN fittings so I didn’t over tighten but get them on there firm and keep those fitting visible when you put power to the fuel pump.
-Steve

[edwardb]

Since it was referenced, these are the Swagelock fittings that Breeze sells: https://www.breezeautomotive.com/shop/fitting-3-8-od-tube-to-06an-male-316-stainless-steel/. I've used them on multiple builds with SS tubing and recommend them often. They have two rings that wedge into the tubing and are rated far in excess of any PSI we'll have see on our builds.

I'm personally not familiar with the Earl's fittings. They appear to use a more conventional compression sleeve, but are recommended for aluminum, steel, copper, copper/nickel, or stainless steel. Can't help with the installation other than I agree probably need to be pretty tight to set the sleeve. But are aluminum (vs. the Swagelocks which are SS) so I wouldn't crank on them too hard.

[tbl100]

Thank you for all the replies. I bought the Earl fittings from Summit and they did say they would work on SS tubing. After seeing the fittings from Breeze they look like a better way to go. Wish I would have checked these out. They are a little pricier but that would have been ok. As mentioned before fuel leaks are not good. I'll use what I have for now and keep a close eye on them. Thanks again.