An answer of sorts, anyway.
On Fri, 27 Jul 2001 22:53:02 -0500, Dale Scroggins <scrof@swbell.net>
wrote:
>You have the numbers right. I don't have the most current edition of AC
>65 here, but I don't think anything has changed in this area. My AC
>65-9a reads:
>
>"A double flare should be used on 5052-0 and 6061-T aluminum alloy
>tubing for all sizes from 1/8- to 3/8-inch outside diameter. This is
>necessary to prevent cutting off the flare and failure of the tube
>assembly under operating pressures. Double flaring is not necessary on
>steel tubing. <snip> The double flare is smoother and more concentric
>than the single flare and, therefore, seals better. It is also more
>resistant to the shearing effect of torque."
>
This references a book, which I presume is an FAA publication or similar,
and implies that double flares on steel tube using AN fittings isn't a bad
thing and may in fact be an improvement over single flares. Now, with the
snipped portion we don't *quite* know this (may be referring back to
aluminium tube only), but a lead for further investigation if nothing else.
So there you go!
Brian
Brian Evans
Director, Canada
MCI Wholesale Internet Services
|