[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR180.213]

[Page 1083-1084]
 
                        TITLE 49--TRANSPORTATION
 
 CHAPTER I--RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION, DEPARTMENT OF 
                             TRANSPORTATION
 
PART 180_CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS--Table of 
Contents
 
        Subpart C_Qualification, Maintenance and Use of Cylinders
 
Sec. 180.213  Requalification markings.

    (a) General. Each cylinder requalified in accordance with this 
subpart with acceptable results must be marked as specified in this 
section. Required specification markings may not be altered or removed.
    (b) Placement of markings. Each cylinder must be plainly and 
permanently marked on the metal of the cylinder as permitted by the 
applicable specification. Unless authorized by the cylinder 
specification, marking on the cylinder sidewall is prohibited.
    (1) Requalification and required specification markings must be 
legible so as to be readily visible at all times. Illegible 
specification markings may be remarked on the cylinder as provided by 
the original specification. Requalification markings may be placed on 
any portion of the upper end of the cylinder excluding the sidewall, as 
provided in this section. Requalification and required specification 
markings that are illegible may be reproduced on a metal plate and 
attached as provided by the original specification.
    (2) Previous requalification markings may not be obliterated, except 
that, when the space originally provided for requalification dates 
becomes filled, additional dates may be added as follows:
    (i) All preceding requalification dates may be removed by peening 
provided that--
    (A) Permission is obtained from the cylinder owner;
    (B) The minimum wall thickness is maintained in accordance with 
manufacturing specifications for the cylinder; and
    (C) The original manufacturing test date is not removed.
    (ii) When the cylinder is fitted with a footring, additional dates 
may be marked on the external surface of the footring.
    (c) Requalification marking method. The depth of requalification 
markings may not be greater than specified in the applicable 
specification. The markings must be made by stamping, engraving, 
scribing or other method that produces a legible, durable mark.
    (1) A cylinder used as a fire extinguisher (Sec. 180.209(j)) may be 
marked by using a pressure sensitive label.
    (2) For a DOT 3HT cylinder, the test date and RIN must be applied by 
low-stress steel stamps to a depth no greater than that prescribed at 
the time of manufacture. Stamping on the sidewall is not authorized.
    (d) Requalification markings. Each cylinder that has successfully 
passed requalification must be marked with the RIN set in a square 
pattern, between the month and year of the requalification date. The 
first character of the RIN must appear in the upper left corner of the 
square pattern; the second in the upper right; the third in the lower 
right, and the fourth in the lower left. Example: A cylinder requalified 
in September 1998, and approved by a person who has been issued RIN 
``A123'', would be marked plainly and permanently

[[Page 1084]]

into the metal of the cylinder in accordance with location requirements 
of the cylinder specification or on a metal plate permanently secured to 
the cylinder in accordance with paragraph (b) of this section. An 
example of the markings prescribed in this paragraph (d) is as follows:
[GRAPHIC] [TIFF OMITTED] TR08AU02.018

Where:

``9'' is the month of requalification,
``A123'' is the RIN,
``98'' is the year of requalification, and
``X'' represents the symbols described in paragraphs (f)(2) through 
(f)(7) of this section.

    (1) Upon a written request, variation from the marking requirement 
may be approved by the Associate Administrator.
    (2) Exception. A cylinder subject to the requirements of Sec. 
173.301(l) of this subchapter may not be marked with a RIN.
    (e) Size of markings. The size of the markings must be at least 6.35 
mm (\1/4\ in.) high, except RIN characters must be at least 3.18 mm (\1/
8\ in.) high.
    (f) Marking illustrations. Examples of required requalification 
markings for DOT specification and exemption cylinders are illustrated 
as follows:
    (1) For designation of the 5-year volumetric expansion test, 10-year 
volumetric expansion test for cylinders conforming to Sec. 180.209(f) 
and (h), or 12-year volumetric expansion test for fire extinguishers 
conforming to Sec. 173.309(b) of this subchapter and cylinders 
conforming to Sec. 180.209(e) and Sec. 180.209(g), the marking is as 
illustrated in paragraph (d) of this section.
    (2) For designation of the 10-year volumetric expansion test for 
cylinders conforming to Sec. 180.209(b), the marking is as illustrated 
in paragraph (d) of this section, except that the ``X'' is replaced with 
a five-point star.
    (3) For designation of special filling limits up to 10% in excess of 
the marked service pressure for cylinders conforming to Sec. 
173.302a(b) of this subchapter, the marking is as illustrated in 
paragraph (d) of this section, except that the ``X'' is replaced with a 
plus sign ``+''.
    (4) For designation of the proof pressure test, the marking is as 
illustrated in paragraph (d) of this section, except that the ``X'' is 
replaced with the letter ``S''.
    (5) For designation of the 5-year external visual inspection for 
cylinders conforming to Sec. 180.209(g), the marking is as illustrated 
in paragraph (d) of this section, except that the ``X'' is replaced with 
the letter ``E''.
    (6) For designation of DOT 8 series cylinder shell requalification 
only, the marking is as illustrated in paragraph (d) of this section, 
except that the ``X'' is replaced with the letter ``S''.
    (7) For designation of DOT 8 series cylinder shell and porous filler 
requalification, the marking is as illustrated in paragraph (d) of this 
section, except that the ``X'' is replaced with the letters ``FS''.