Anyone use aluminum/brass comression fittings on aluminum fuel line ?? I'm talking about aluminum AN compression fittings that use a brass compression sleeve. Are these an acceptable alternative to flaring the tube ends ?? Intended use is aluminum EFI fuel lines.

Used them a long time ago on a low pressure system. It was a Barry Grant 220HR pump with a 1/2" line. Worked well

Not sure how it would go on an EFI system though, I've no experience in that regard.

I probably wouldn't use that type fittings on anything above 10 PSI,
How about PTFE line AN hose, stainless covered or fabric covered like hydraulic or AN high pressure lines

In a word, yes, specifically it is an acceptable alternative to flaring. But as has been said I wouldn't recommend it unless it was on the inlet side of an EFI fuel system with good consideration IRT all aspects of its routing. (Shock and vibration compliance.)

IMO just use a proper flare on the line and dont look back....

Yeah, leaning that way !! Now to find a reasonably priced 37 degree flare tool !!

After you wreck a car because of a compression fitting you kinda shy away from them. I know I did.

You could get away with putting a 45 on soft aluminum tubing, Single flare is all that is needed. The fittings would draw it all together. Much preferable to compression fittings.

Yeah, that thought crossed my mind too. Summit has a 37 degree flare tool for under $40.. Even though I only have to do six flares, that's reasonable enough and I can probably sell it afterwards for $25.

I inserted a socket extension backwards and tapped on the end w/ a hammer to flare out aluminum fuel line against the shape highlighted in the attached image. Doesn't have to be perfect because the soft aluminum will conform to the fitting's surfaces when tightened down.