Stiffening rings may be placed on the inside or outside
of a vessel, and except for the configurations permitted
by UG-29, shall be attached to the shell by welding or
brazing. Brazing may be used if the vessel is not to be
later stress relieved. The ring shall be essentially in contact
with the shell and meet the rules in UG-29(b) and (c).
Welding of stiffening rings shall comply with the requirements
of this Division for the type of vessel under construction