Terminology used in this part are: pounds per square inch gauge (p.s.i.g.) or pounds per square inch absolute (p.s.i.a.). 14.7 p.s.i.a. is equal to 0 p.s.i.g. P.s.i.g. is normally used in reference to design or operating requirements.
46 C.F.R. § 151.03-43