On 9 Jan 2005 18:43:47 GMT, Dave Hinz wrote:

On Fri, 07 Jan 2005 20:05:54 -0500, wrote:

Yet copper is now not only approved, but is the line of choice for
connecting natural gas appliances.

Sure, but that's very low pressure, _and_ low to zero vibration.
Not at all like an automotive application.

I would NEVER use copper in an automotive or aircraft application, due
to both the work-hardening/fatique issues and the "greenies".My 1928
Chevy had copper lines. So did my 35 Chevy and 37 Terraplane.
My old 2 stroke lawnmower built in 1957 HAD copper fuel lines.
All of the above had "greenie" problems, and the lawnmower line
cracked. (still have the lawnmower).

Aeroplanes use aluminum fuel lines, which also suffer from work
hardening and fatigue - but the lines MUST be well supported, and
isolated from vibration with rubber flex lines.