anoland....
IMHO, the phrasing of your question, reveals another deeper problem
Somehow, the perception of all US Codes and standards has incorrectly shifted from "a book of approved criteria, materials, methods and recommendations" to one of "a list of things that I can't do".
This prompts angry questions such as "Show me where in the code it says that I can't do X ?????"
This is a fundamental misunderstanding of the nature of the document.....
While ASME B31.3 Piping Code contains some limitations on material usage, pressure ratings and the like, it is primarily a book of approved and time tested methods of design, fabrication, inspection and testing.
Anyone else ?
MJCronin
Sr. Process Engineer