Acetylene and copper

Jewelry Discussion
1

I read somewhere that you should never use acetylene with
copper. Why is that?

Marshall T. Jones

Yes you are quite right Marshall, copper pipe and fittings should
never be used for acetylene service. The reason is that over time
they can react, forming a coating of copper acetylide on the
inside. The good news is that this means you have lost some
wall thickness, and restricted the flow a bit. The bad, and really
important news is that copper acetylide is a dangerously
sensitive explosive. I don’t know about Codes around the world,
certainly the combination is not allowed here. Fittings bought
from a reputable manufacturer intended for acetylene are all
OK in this respect. The danger comes when someone tries to
adapt equipment, or decides that it will be safer to keep the
cylinders outside the shop or lab, and pipe the gases in using
copper, same as they used for propane say. Normal tubing for
fixed acetylene installations here is stainless.

Hope this will not get anybody deliberately trying to make the
stuff for fun…it really IS dangerous.

Kevin Eva, Northern England, UK
k.eva@msmail.trctho.simis.com

2

On 19-Nov-96, Eva, Mr. K. ORTRS/2 wrote aboutRe: Acetylene and copper:

I read somewhere that you should never use acetylene with
copper. Why is that?
Marshall T. Jones

I don’t know about Codes around the world, certainly the
combination is not allowed here. Fittings bought from a reputable
manufacturer intended for acetylene are all OK in this respect. Normal
tubing for fixed acetylene installations here is stainless.
EMKO> Kevin Eva, Northern England, UK

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G’day; If copper/acetylene combination is so dangerous, how is it that I’ve
never heard of stainless welding torches, acetylene gauges, etc? Brass
torches and gauges have been used for yonks and brass has a high copper
content, but one never hears of a torch/gauge exploding other than due to
flash-back.
Johnb. johnb@ts.co.nz