Hi All u all,
Can I use copper pipe instead of black pipe for my processor ?.
Have a heap of copper pipe lying around plus brass fittings seems a shame not to use it.

Blacksmith,
from the Biodiesel Handling and Use Guide distributed by the US DOE

"Brass, bronze, copper, lead, tin, and zinc may accelerate the oxidation of diesel and biodiesel fuels and potentially create fuel insolubles (sediments) or gels and salts when reacted with some fuel components. Lead solders and zinc linings should be avoided, as should copper pipes, brass regulators, and copper fittings. The fuel or the fittings will tend to change color and insolubles may plug fuel filters. Affected equipment should be replaced with stainless steel, carbon steel, or aluminum."

On the other hand, during the processing of biodiesel, it will be in contact with the copper or brass for such a short time that it is probably a non-issue. I think that the above relates more to fuel lines in vehicles.

My processor uses brass fittings and I am looking for some soft copper 3/4 tubing to replace a section of fibre reinforced transparent poly hose that is breaking down too quickly.
George

Golden rule: Never use copper bronze or brass anywhere in contact with biodiesel or feedstock if you want it to have some shelf life before use. Trace amounts of copper in particular acts as a catalyst in the oxidation process.

Hi biobmw,

Can you post any technical data to back up your statement about copper being a catalyst? I have read similar comments before but have not seen any testing to prove this one way or another and wondered whether this is just hearsay. I can understand the reasons for not using gal as the caustic goes for the zinc.

I have a mix of brass, gal, black iron and plastic fittings on my processor, as I could not always find the piece I needed in black iron. I have not observed any degradation of the biodiesel, probably because I use it within a few weeks of production. In fact, what does oxidised biodiesel look like?

I could if I could be bothered. Heck if your using it quickly you wont need to worry. You shouldn't drink you should eat lots of fruit and you should exercise regularly but it doesn't mean we do.

2pmm copper will bring the shelf life down from over 12 months to a few weeks. You can put some copper shavings in some bio heat it up and blow air through it if you really want to see what happens to it.

[quote=Blacksmith;15386]Hi All u all,
Can I use copper pipe instead of black pipe for my processor ?.
Have a heap of copper pipe lying around plus brass fittings seems a shame not to use it.[/quot

My apologies for not replying sooner,the doctors were rearranging my pipework(prostate surgery )
Thanks for all your help guess I'll play it safe and buy some blackpipe