Thanks gentlemen. I did call for a positive restraint as it is definitely the right thing to do.
I would have appealed to B31.3 as a reference if nothing else. But, with that direct reference in B31.1, I now have a directly applicable citation in case the vendor wants to challenge.
The moral of the story - don't try to slip a u-bolt support past me w/o a lug!
_________________________
Edward L. Klein
Pipe Stress Engineer
All the world is a Spring