Hatchetman,
WELCOME TO THE AWS WELDING FORUM!!
First, please refrain from posting in multiple departments. It only confuses trains of discussion by separating the responses.
Now, D15 is Railroad code. I don't think the code is interested nor deals with the Weld Cells that one may use to accomplish the work.
As such I'm not really sure I understand what you are trying to find out. Can you give us more information?
He Is In Control, Have a Great Day, Brent