AFMAN24-604 9 October 2020 275
A6.5. Nonliquefied Compressed Gases. Package nonliquefied compressed gases as follows:
A6.5.1. Ship nonliquefied, compressed gases in accordance with the filling, pressure, and DOT
cylinder specification requirements of Table A6.1. If the compressed gas is not specifically
identified in Table A6.1., ship in DOT 3, 3A, 3AA, 3AL, 3B, 3E, 4B, 4BA, or 4BW. Use of
existing cylinders, DOT 3, 3C, 3D, 4, 4A, 4C, 25, 26, 33, and 38 is authorized, but new
construction of these cylinders is not authorized.
A6.5.2. DOT-3HT Cylinders. DOT-3HT cylinders for use in aircraft only, having a maximum
service life of 24 years, are only authorized for nonflammable gases. They must be equipped
with a frangible disc safety relief device, without fusible metal backing, with a rated bursting
pressure not over 90 percent of the minimum required test pressure of the cylinder with which
the device is used. (T-0). Pack cylinders in strong outer packagings.
A6.5.3. DOT 39 Cylinder. Use DOT 39 cylinder for compressed gasses. When used for
flammable gases, the internal volume must not exceed 1.23 L (75 cubic inches). (T-0). Use
aluminum cylinders for oxygen only under the following conditions:
A6.5.3.1. Cylinder threads must be straight threads (except for UN Cylinders). (T-0).
A6.5.3.2. Valves must be made of brass or stainless steel. (T-0).
A6.5.3.3. Each cylinder must be cleaned to comply with the requirements of DLAI 4145.25
or MIL-STD-1411, Inspection and Maintenance of Compressed Gas Cylinders. (T-0).
A6.5.3.4. The pressure in each cylinder must not exceed 20,684 kPa (3000 psig) at 21
degrees C (70 degrees F). (T-0).
A6.5.4. DOT 3AL Cylinder. Ship flammable gases in 3AL cylinders on cargo aircraft only.
When used in oxygen service, the cylinders must comply with 49 CFR Subparagraph
173.302a(a)(5). (T-0).
A6.5.5. DOT 3AX, 3AAX, 3T Cylinders. Use cylinders, DOT 3AX, 3AAX, or 3T for Division
2.1 and 2.2 materials and for carbon monoxide. DOT 3T cylinders are not authorized for
hydrogen. When used in methane service, the methane must be a nonliquefied gas with a
minimum purity of 98.0 percent methane and which is commercially free of corroding
components. (T-0).
A6.5.6. UN Specification cylinders as authorized in 49 CFR Section 173.302b.
A6.5.7. Foreign Cylinders. Foreign cylinders meeting the requirements of A3.3.2.10.
A6.5.8. Compressed Oxygen and Oxidizing Gases. Ship compressed oxygen and oxidizing
gases in DOT specification 3A, 3AA, 3AL, 3E, 3HT, 39 cylinders, 4E (filled to less than 200
psig at 21 °C (70 °F), and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO 9809-3 and
ISO 7866 cylinders. Cylinders must be equipped with a pressure relief device in accordance
with 49 CFR Paragraph 173.301(f) and, DOT specification cylinders or for the UN pressure
receptacles prior to initial use. (T-0). The rated burst pressure of a rupture disc for DOT 3A,
3AA, 3AL, 3E, and 39 cylinders, and UN pressure receptacles ISO 9809-1, ISO 9809-2, ISO
9809-3 and ISO 7866 cylinders must be 100% of the cylinder minimum test pressure with a
tolerance of plus zero to minus 10%. (T-0). The rated burst pressure of a rupture disc for a
DOT 3HT cylinder must be 90% of the cylinder minimum test pressure with a tolerance of
plus zero to minus 10%. (T-0). A cylinder containing compressed oxygen, compressed