[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR180.212]

[Page 1131]
 
                        TITLE 49--TRANSPORTATION
 
   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 
                      DEPARTMENT OF TRANSPORTATION
 
PART 180_CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS--Table 
of Contents
 
        Subpart C_Qualification, Maintenance and Use of Cylinders
 
Sec.  180.212  Repair of seamless DOT 3-series specification cylinders 
and seamless UN pressure receptacles.

    (a) General requirements for repair of DOT 3-series cylinders and UN 
pressure receptacles. (1) No person may repair a DOT 3-series cylinder 
or a seamless UN pressure receptacle unless--
    (i) The repair facility holds an approval issued under the 
provisions in Sec.  107.805 of this chapter; and
    (ii) Except as provided in paragraph (b) of this section, the repair 
and the inspection is performed under the provisions of an approval 
issued under subpart H of Part 107 of this chapter and conform to the 
applicable cylinder specification or ISO standard contained in part 178 
of this chapter.
    (2) The person performing the repair must prepare a report 
containing, at a minimum, the results prescribed in Sec.  180.215.
    (b) Repairs not requiring prior approval. Approval is not required 
for the following specific repairs:
    (1) The removal and replacement of a neck ring or foot ring on a DOT 
3A, 3AA or 3B cylinder or a UN pressure receptacle that does not affect 
a pressure part of the cylinder when the repair is performed by a repair 
facility or a cylinder manufacturer of these types of cylinders. The 
repair may be made by welding or brazing in conformance with the 
original specification. After removal and before replacement, the 
cylinder must be visually inspected and any defective cylinder must be 
rejected. The heat treatment, testing and inspection of the repair must 
be performed under the supervision of an inspector and must be performed 
in accordance with the original specification.
    (2) External re-threading of DOT 3AX, 3AAX or 3T specification 
cylinders or a UN pressure receptacle mounted in a MEGC; or the internal 
re-threading of a DOT-3 series cylinder or a seamless UN pressure 
receptacle when performed by a cylinder manufacturer of these types of 
cylinders. The repair work must be performed under the supervision of an 
independent inspection agency. Upon completion of the re-threading, the 
threads must be gauged in accordance with Federal Standard H-28 or an 
equivalent standard containing the same specification limits. The re-
threaded cylinder must be stamped clearly and legibly with the words 
``RETHREAD'' on the shoulder, top head, or neck. No DOT specification 
cylinder or UN cylinder may be re-threaded more than one time without 
approval of the Associate Administrator.

[71 FR 33895, June 12, 2006, as amended at 71 FR 54398, Sept. 14, 2006; 
72 FR 55697, Oct. 1, 2007]