[Code of Federal Regulations]
[Title 46, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR54.01-35]

[Page 145]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 54_PRESSURE VESSELS--Table of Contents
 
                   Subpart 54.01_General Requirements
 
Sec. 54.01-35  Corrosion (modifies UG- 25).

    (a) Vessels or portions of vessels subject to corrosion shall be as 
required by UG-25 of the ASME Code except as noted otherwise in this 
section.
    (b) The pressure portions of pressure vessels shall:
    (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 Code for calculating thickness.
    (c) Telltale holes shall 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 is 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.

    Note: No applied linings except as provided in Part UCL of the ASME 
Code shall be acceptable.

[CGFR 68-82, 33 FR 18828, Dec. 18, 1968, as amended by CGFR 72-59R, 37 
FR 6189, Mar. 25, 1972]

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