Curious because I saw one of the biodiesel (SVO/WVO) sites boast that they had aluminum lines & no brass valves. Is diesel (or vegetable oil) aggressive to copper or brass?

 

I dunno how true it is, but I have been told not mix diesel with copper lines.

 

Our installation engineering standards for our large industrial diesels do not allow yellow metal or zinc (galvanized pipe) in the diesel fuel system.

Rusty

 

Come to think of it, I bet it's the zinc. I know diesel will eat the zinc out of galvanization. Brass has at least 30% zinc in it, so that's why brass would be a no-no. Copper pipe probably has some residual zinc in it (as an impurity), unless a high pirity copper is specified ($$$).

 

Strange, isn't heating oil close to the same as diesel?

 

You would think. Why - do they have copper lines & brass valves?

 

All of my home heating oil plumbing is either brass or copper, and it`s over 30 years old.

 

and we use copper sealing washers on our injectors and banjo fittings

 

If pure copper is used, I would not expect problems. When it has alot of zinc in it (like galvanized parts and brass do) I could foresee problems.

 

ahh, roger that, and for sealing, obviously it'll be dead soft/somewhat pure

 

I know that Galvanized is a big No-no with diesel. I just have heard somewhere before that copper wasn't recomended but I wasn't too sure on how true it was. Brass I always thought was ok because its used in valves on fuel storage tanks and in pump internals.

 

It's the zinc
My understanding has always been that fittings and piping materials are of very little concern. Where the problem comes up is galvanized storage tanks where much more surface area is exposed to diesel.