---
kind: "section"
citation: "46 C.F.R. § 54.20-3"
title: "46"
number: "54.20-3"
heading: "Design (modifies UW-9, UW-11(a), UW-13, and UW-16)."
url: "https://uscodex.org/cfr/46/54.20-3"
---

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

- (a) Fabrication by welding must be in accordance with the provisions of this part and with [part 57](/cfr/46/part57.md) of this subchapter.
- (b) Welding subject to UW-11(a) of Section VIII of the ASME BPVC (incorporated by reference; see [§ 54.01-1](/cfr/46/54.01-1.md)) must be modified as described in [§ 54.25-8](/cfr/46/54.25-8.md) for radiographic examination.
- (c) A butt-welded joint with one plate edge offset, as shown in Figure UW-13.1(k) of Section VIII of the ASME BPVC, may only be used for circumferential joints of Class II and Class III pressure vessels.
- (d) Attachment welds for nozzles and other connections must be in accordance with UW-16 of Section VIII of the ASME BPVC. When nozzles or connections are made to pressure vessels, as shown in Figure UW-16.1 (a) and (c) of the ASME BPVC, and are welded from one side only, backing strips 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 must be as specified under the column headed “minimum joint requirements” in table 2 to [§ 54.01-5](/cfr/46/54.01-5.md) 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.

## Notes

### Amendments

[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]

### Authority

Authority: 33 U.S.C. 1509; 43 U.S.C. 1333; 46 U.S.C. 3306, 3703; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 00170.1, Revision No. 01.3.

### Source

Source: CGFR 68-82, 33 FR 18828, Dec. 18, 1968, as amended by USCG-2020-0634, 89 FR 50104, June 12, 2024, unless otherwise noted.

### Amendments

[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]