---
kind: "section"
citation: "46 C.F.R. § 54.01-35"
title: "46"
number: "54.01-35"
heading: "Corrosion (modifies UG-25)."
url: "https://uscodex.org/cfr/46/54.01-35"
---

# §54.01-35. Corrosion (modifies UG-25).

- (a) Vessels or portions of vessels subject to corrosion must be as required by UG-25 of Section VIII of the ASME BPVC (incorporated by reference; see [§ 54.01-1](/cfr/46/54.01-1.md)) except as noted otherwise in this section.
- (b) **The pressure portions of pressure vessels must—**
  - (1) Normally have a corrosion allowance of one-sixth of the calculated thickness, or one-sixteenth inch, whichever is smaller, added to the calculated thickness as determined by the applicable design formula.
  - (2) Be specifically evaluated in cases where unusually corrosive cargoes will be involved, for the possible increase of this corrosion allowance.
  - (3) **Have no additional thickness required when acceptable corrosion resistant materials are used.**
  - (4) Not normally need additional thickness allowance when the effective stress (either S or SE depending on the design formula used) is 80 percent or less of the allowable stress listed in Section VIII of the ASME BPVC for calculating thickness.
- (c) Telltale holes must not be permitted in pressure vessels containing dangerous fluids, such as acid, poison, corrosives, etc.
- (d) Exemption from these corrosion allowance requirements will be granted by the Commandant in those cases where:
  - (1) The contents of the pressure vessel are judged to be sufficiently noncorrosive; and,
  - (2) Where the external surface is also protected from corrosion. A suitable vapor barrier is adequate protection, while paint or other thin coatings exposed to weather or mechanical damage are not acceptable.
- (e) **No applied linings except as provided in part UCL of Section VIII of the ASME BPVC are acceptable.**

## Notes

### Amendments

[CGFR 68-82, 33 FR 18828, Dec. 18, 1968, as amended by CGFR 72-59R, 37 FR 6189, Mar. 25, 1972; USCG-2003-16630, 73 FR 65167, 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 CGFR 72-59R, 37 FR 6189, Mar. 25, 1972; USCG-2003-16630, 73 FR 65167, Oct. 31, 2008]