Pipe Fill Help

[don_resqcapt19]

Found it. I always forget about this one, never applied it myself.

310.15(2) Selection of Ampacity. Where more than one ampacity
applies for a given circuit length, the lowest value shall be
used.
Exception: Where two different ampacities apply to adjacent
portions of a circuit, the higher ampacity shall be permitted to
be used beyond the point of transition, a distance equal to 3.0
m (10 ft) or 10 percent of the circuit length figured at the
higher ampacity, whichever is less.

Yes, that is exactly the code section I had in mind.