Section 52.05-30 - Minimum requirements for attachment welds (modifies PW-16)(a) The location and minimum size of attachment welds for nozzles and other connections must be as required by PW-16 of Section I of the ASME BPVC (incorporated by reference; see § 52.01-1 ) except as noted otherwise in this section.(b) When nozzles or couplings are attached to boilers, as shown in Figure PW-16 (a) and (c) of Section I of the ASME BPVC, and are welded from one side only, backing strips must be used unless it can be determined visually or by nondestructive test methods that complete penetration has been obtained.(c) When attachments as shown in Figure PW-16 (y) and (z) of Section I of the ASME BPVC are employed they must be limited to 2-inch pipe size for pressure exceeding 150 psig.CGFR 68-82, 33 FR 18815, Dec. 18, 1968, as amended by USCG-2003-16630, 73 FR 65161 , Oct. 31, 2008