§ 54.20-3 - Design (modifies UW-9, UW-11(a), UW-13, and UW-16).

§ 54.20-3 Design (modifies UW-9, UW-11(a), UW-13, and UW-16).

(a) Fabrication by welding shall must be in accordance with the provisions of this part and with part 57 of this subchapter.

(b) Welding subject to UW-11(a) of section Section VIII of the ASME Boiler and Pressure Vessel Code BPVC (incorporated by reference; see 46 CFR § 54.01-1) shall must be modified as described in § 54.25-8 for radiographic examination.

(c) A butt-welded joint with one plate edge offset, as shown in Figure UW-13.1(k) of section Section VIII of the ASME Boiler and Pressure Vessel CodeBPVC, may only be used for circumferential joints of Class II and Class III pressure vessels.

(d) Attachment welds for nozzles and other connections shall must be in accordance with UW-16 of section Section VIII of the ASME Boiler and Pressure Vessel CodeBPVC. When nozzles or connections are made to pressure vessels, as shown in Figure UW-16.1 (a) and (c) of the ASME CodeBPVC, and are welded from one side only, backing strips shall must be used unless it can be determined visually that a full penetration weld has been achieved.

(e) When fabricating by welding the minimum joint requirements shall must be as specified under the column headed “minimum joint requirements” in table 2 to § 54.01-5(b) for various classes of pressure vessels.

(f) Joints in Class II or III pressure vessel cargo tanks must meet the following:

(1) Category A and B joints must be type (1) or (2).

(2) Category C and D joints must have full penetration welds extending through the entire thickness of the vessel wall or nozzle wall.

[CGFR 68-82, 33 FR 18828, Dec. 18, 1968, as amended by CGD 77-147, 47 FR 21810, May 20, 1982; CGD 85-061, 54 FR 50964, Dec. 11, 1989; USCG-2003-16630, 73 FR 65170, Oct. 31, 2008]