Section 52.01-100 - Openings and compensation (modifies PG-32 through PG-39, PG-42 through PG-55)(a) The rules for openings and compensation must be as indicated in PG-32 through PG-55 of Section I of the ASME BPVC (incorporated by reference; see § 52.01-1 ) except as noted otherwise in this section.(b) (Modifies PG-39.) Pipe and nozzle necks must be attached to vessel walls as indicated in PG-39 of Section I of the ASME BPVC except that threaded connections must not be used under any of the following conditions:(c) (Modifies PG-42.) Butt-welding flanges and fittings must be used when full radiography is required by § 56.95-10 of this subchapter. The revisions read as follows:CGD 81-79, 50 FR 9432, Mar. 8, 1985, as amended by USCG-2003-16630, 73 FR 65161 , Oct. 31, 2008