§173.303. Charging of cylinders with compressed gas in solution (acetylene). — Inbound Citations

(3) Filled, marked, and inspected in accordance with 49 CFR 173.301 through 173.308; and

(11) CGA C-12 (CGA C-12), Qualification Procedure for Acetylene Cylinder Design, 1994; into §§ 173.301; 173.303; 178.59; 178.60.

(2) Filling limits for compressed gases and cryogenic liquids are specified in §§ 173.301 through 173.306 for cylinders and §§ 173.314 through 173.319 for bulk packagings.

(i) Except as provided in subpart C of part 171 of this subchapter, packages prepared under § 173.167 of this part, or packages prepared under Packing Instruction Y963 of the ICAO Technical Instructions, packages offered or intended for transportation by aircraft must conform to the general requirements for transportation by aircraft in § 173.27.

(a) Unless otherwise stated, as used in this section, the term “cylinder” includes a UN pressure receptacle. As used in this subpart, filled or charged means an introduction or presence of a hazardous material in a cylinder. A cylinder filled with a Class 2 hazardous material (gas) and offered for transportation must meet the requirements in this section and §§ 173.301a through 173.305, as applicable.

(1) Compressed gases must be in UN pressure receptacles built in accordance with the UN standards or in metal cylinders and containers built in accordance with the DOT and ICC specifications and part 178 of this subchapter in effect at the time of manufacture or CRC, BTC, CTC or TC specification, and requalified and marked as prescribed in subpart C in part 180 of this subchapter, if applicable. The DOT, ICC, CRC, BTC, CTC and TC specifications authorized for use are as follows:

(2) A cylinder must be filled in accordance with this part, except that a “TC” cylinder must be filled in accordance with the Transport Canada TDG Regulations (IBR; see § 171.7 of this subchapter). Before each filling of a cylinder, the person filling the cylinder must visually inspect the outside of the cylinder. A cylinder that has a crack or leak, is bulged, has a defective valve or a leaking or defective pressure relief device, or bears evidence of physical abuse, fire or heat damage, or detrimental rusting or corrosion, may not be filled and offered for transportation. A cylinder may be repaired and requalified only as prescribed in subpart C of part 180 of this subchapter.

(3) Pressure relief devices must be tested for leaks before a filled cylinder is shipped from the cylinder filling plant. It is expressly forbidden to repair a leaking fusible plug device where the leak is through the fusible metal or between the fusible metal and the opening in the plug body, except by removal and replacement of the pressure relief device.

(4) A cylinder that previously contained a Class 8 material must be requalified in accordance with § 180.205(e) of this subchapter.

(5) When a cylinder with a marked pressure limit is prescribed, another cylinder made under the same specification but with a higher marked pressure limit is authorized. For example, a cylinder marked “DOT-4B500” may be used when “DOT-4B300” is specified.

(6) No person may fill a cylinder overdue for periodic requalification with a hazardous material and then offer it for transportation. The prohibition against offering a cylinder for transportation that is overdue for periodic requalification does not apply to a cylinder filled prior to the requalification due date.

(7) A cylinder with an authorized service life may not be offered for transportation in commerce after its authorized service life has expired. However, a cylinder in transportation or a cylinder filled prior to the expiration of its authorized service life may be transported for reprocessing or disposal of the cylinder's contents. After emptying, the cylinder must be condemned in accordance with § 180.205 of this subchapter.

(8) The pressure of the hazardous material at 55 °C (131 °F) may not exceed 5/4 of the service pressure of the cylinder. Sufficient outage must be provided so the cylinder will not be liquid full at 55 °C (131 °F).

(9) Specification 2P, 2Q, 3E, 3HT, spherical 4BA, 4D, 4DA, 4DS, and 39 cylinders must be packed in strong non-bulk outer packagings. The outside of the combination packaging must be marked with an indication that the inner packagings conform to the prescribed specifications.

(10) Any person who installs a valve into an aluminum cylinder in oxygen service must verify the valve and the cylinder have the same thread type.

(11) Cylinder valves manufactured on or after November 7, 2019, used on cylinders to transport compressed gases must conform to the applicable requirements in CGA V-9 (IBR; see § 171.7 of this subchapter). A valve for a UN pressure receptacle must conform to the requirements of § 173.301b(c)(1). Cylinder valves used on cylinders in liquefied petroleum gas (LPG) service are permitted to comply with the requirements of NFPA 58 (IBR; see § 171.7 of this subchapter).

(12) Cylinder valve protection caps manufactured on or after November 7, 2019, must conform to the requirements of CGA V-9.