Fuel line question

Our most popular forum is for Citroën problems, discussions and chat.
Specialising in AX, BX, ZX, Xantia,C5, Xsara, Saxo and XM. CX, 2cv & Berlingo, all are welcome.NOT for selling cars/parts!

Moderator: RichardW

alan s
RIP 2010
Posts: 2624
Joined: 26 Jan 2001, 16:53
Location: Australia
My Cars:
x 4

Fuel line question

Postby alan s » 11 Jun 2002, 03:36

I am trying to jolt my memory regarding something I am sure I was told about some time ago and hope that perhaps someone here may know; What are the poblems associated with using copper as fuel lines?
Is it chemical reaction, fire risk or something else.
I can remember being quite astounded at the time & as we had just made some copper device up at great expense (a swirl pot from memory) it was very quickly removed from the car. I had someone mention doing the same thing on another board but for the life of me I can't remember the reason why.
Any help jolting my failing brain greatly appreciated.
Alan S
0 x

NiSk
Posts: 1435
Joined: 24 Jan 2002, 21:11
Location: Sweden
My Cars:

Postby NiSk » 11 Jun 2002, 13:13

The biggest problem with using copper, both for fuel lines and for brake lines, is that it doesn't rust and fall apart sufficently quickly (which is why car manufacturers don't use it!).
No, but seriously, the problem with copper is that it self-hardens when exposed to vibration, to the extent that it can fracture. However, this doen't stop dozens of boat manufacturers from using it in marin applications. And as long as you can ensure that the line won't be exposed to excessive vibration (fasten it properly to the car body) it will last longer than the original steel fuel line.
There is also an alloy of copper and nickel which doesn't suffer from this mallady but is somewhat harder (more difficult to bend).
Since copper is approved internationally for brake lines i don't think you really have a problem.
//NiSk
0 x

Dave Burns
Posts: 1934
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Postby Dave Burns » 12 Jun 2002, 02:03

Copper bearing metals are infact corroded by petrochemical auto fuels including diesel, aviation fuels are also corrosive.
Fuel's have to pass a test called " the copper strip corrosion standard " which is in place to ensure fuels don't uneccassarily damage or corrode part's of fueling system's.
A copper sample with a known surface finnish is immersed in the fuel under specific conditions and for a precise length of time, the amount of tarnishing of the sample is compared with test peices, the darker the sample become's the more corrosive the fuel is.
Here is something I know about copper from using gas welding/brazing equipment.
Copper tube/pipe or fitting should never be used to transport Acetylene gas from the cylinder.
Copper and Acetylene will form Copper Acetylide, a black/brown solid wich is explosive and will explode on impact, does'nt need to be ignited, just walloped.
So check your welding and burning tackle for copper tube, if there is some and it's been there for a long time IT IS DANGEROUS, dont touch it call for help.
The only other really dangerous substance that should be kept away from copper is Hydrogen peroxide (HTP) which is not in itself dangerous, but on contact with copper or metals containig it such as brass, it breaks down and gives off Oxygen and water vapour or steam, when HTP becomes hot gas it expands in volume an amazing 5,000 times.
This would rapidly pressurise an enclosed space to the point where an explosion occurs.
It was the Hydrogen peroxide used in Russian torpedo motors that sank the Kursk two years ago.
Dave
0 x

alan s
RIP 2010
Posts: 2624
Joined: 26 Jan 2001, 16:53
Location: Australia
My Cars:
x 4

Postby alan s » 12 Jun 2002, 04:01

Thanks Dave,
I knew it was a safety concern that threw us into panic mode. Would be obliged if I could pass this answer on to the guy in question on another forum as I feel it is something of a fairly important nature due to the fact that so many people have responded on a couple of forums basically along the lines that they think I also drink my own bath water & that copper is a great idea - For someone with a death wish it probably is <img src=icon_smile_dissapprove.gif border=0 align=middle>
Alan S
0 x

Dave Burns
Posts: 1934
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:

Postby Dave Burns » 13 Jun 2002, 03:01

Hi Alan, the copper strip corrosion test gives a rough measure of the amount of active sulphur present in petrochemical product's, sulphur is corrosive and the crude oil from the Gulf States is naturally high in it.
I personally would be more concerned by the fact that copper tube will work harden and fracture if allowed to vibrate as NiSk has allready pointed out, but then I've never seen a corroded fuel line or it's result, I suppose because it simply isn't used for that purpose.
Any member of the public may read the information contained in this forum, it therefore becomes public information and in my view you can take that information and convey it to other's, any way you like.
Dave
0 x


Return to “Citroën”

Who is online

Users browsing this forum: No registered users and 10 guests