Alternate Arrangement portable tank means a UN portable tank that has been approved to alternative technical requirements or testing methods other than those specified for UN portable tanks in part 178 or part 180 of this subchapter.
Approval agency means the designated approval agency authorized to approve the portable tank in accordance with the procedures in subpart E of part 107 of this subchapter.
Design pressure is defined according to the hazardous materials intended to be transported in the portable tank. See §§178.275, 178.276 and 178.277 , as applicable.
Design type means a portable tank or series of portable tanks made of materials of the same material specifications and thicknesses, manufactured by a single manufacturer, using the same fabrication techniques (for example, welding procedures) and made with equivalent structural equipment, closures, and service equipment.
Fine grain steel means steel that has a ferritic grain size of 6 or finer when determined in accordance with ASTM E 112-96 (IBR, see §171.7 of this subchapter).
Fusible element means a non-reclosing pressure relief device that is thermally activated and that provides protection against excessive pressure buildup in the portable tank developed by exposure to heat, such as from a fire (see §178.275(g) ).
Jacket means the outer insulation cover or cladding which may be part of the insulation system.
Leakage test means a test using gas to subject the shell and its service equipment to an internal pressure.
Maximum allowable working pressure (MAWP) is defined according to the hazardous materials intended to be transported in the portable tank. See §§178.275, 178.276 and 178.277 , as applicable.
Maximum permissible gross mass (MPGM) means the sum of the tare mass of the portable tank and the heaviest hazardous material authorized for transportation.
Mild steel means a steel with a guaranteed minimum tensile strength of 360 N/mm2 to 440 N/mm2 and a guaranteed minimum elongation at fracture as specified in paragraph (c)(10) of this section.
Offshore portable tank means a portable tank specially designed for repeated use in the transportation of hazardous materials to, from and between offshore facilities. An offshore portable tank is designed and constructed in accordance with the Guidelines for the Approval of Containers Handled in Open Seas specified in the IMDG Code (IBR, see §171.7 of this subchapter).
Reference steel means a steel with a tensile strength of 370 N/mm2 and an elongation at fracture of 27%.
Service equipment means measuring instruments and filling, discharge, venting, safety, heating, cooling and insulating devices.
Shell means the part of the portable tank which retains the hazardous materials intended for transportation, including openings and closures, but does not include service equipment or external structural equipment.
Structural equipment means the reinforcing, fastening, protective and stabilizing members external to the shell.
Test pressure means the maximum gauge pressure at the top of the shell during the hydraulic pressure test equal to not less than 1.5 times the design pressure for liquids and 1.3 for liquefied compressed gases and refrigerated liquefied gases. In some instances a pneumatic test is authorized as an alternative to the hydraulic test. The minimum test pressures for portable tanks intended for specific liquid and solid hazardous materials are specified in the applicable portable tank T codes (such as T1-T23) assigned to these hazardous materials in the §172.101 Table of this subchapter.
Re = yield strength in N/mm2 , or 0.2% proof strength or, for austenitic steels, 1% proof strength;
Rm = minimum tensile strength in N/mm2 .
Where:
e1 = required equivalent thickness (in mm) of the metal to be used;
e0 = minimum thickness (in mm) of the reference steel specified in the applicable T code or portable tank special provision indicated for each material in the §172.101 Table of this subchapter;
d1 = 1.8m, unless the formula is used to determine the equivalent minimum thickness for a portable tank shell that is required to have a minimum thickness of 8mm or 10mm according to the applicable T code indicated in the §172.101 Table of this subchapter. When reference steel thicknesses of 8mm or 10mm are specified, d1 is equal to the actual diameter of the shell but not less than 1.8m;
Rm1 = guaranteed minimum tensile strength (in N/mm 2 ) of the metal to be used;
A1 = guaranteed minimum elongation at fracture (in %) of the metal to be used according to recognized material standards.
Country of manufacture
U N
Approval Country
Approval Number
Alternative Arrangements (see § 178.274 (a)(2) ) "AA"
Manufacturer's name or mark
Manufacturer's serial number
Approval Agency (Authorized body for the design approval)
Owner's registration number
Year of manufacture
Pressure vessel code to which the shell is designed
Test pressure____bar gauge.
MAWP____bar gauge.
External design pressure (not required for portable tanks used for refrigerated liquefied gases)____bar gauge.
Design temperature range____ °C to____ °C. (For portable tanks used for refrigerated liquefied gases, the minimum design temperature must be marked.)
Water capacity at 20 °C/____liters.
Water capacity of each compartment at 20 °C____liters.
Initial pressure test date and witness identification.
MAWP for heating/cooling system____bar gauge.
Shell material(s) and material standard reference(s).
Equivalent thickness in reference steel____mm.
Lining material (when applicable).
Date and type of most recent periodic test(s).
Month____Year____ Test pressure____bar gauge.
Stamp of approval agency that performed or witnessed the most recent test.
For portable tanks used for refrigerated liquefied gases:
Either "thermally insulated" or "vacuum insulated"____.
Effectiveness of the insulation system (heat influx)____Watts (W).
Reference holding time____days or hours and initial pressure____bar/kPa gauge and degree of filling____in kg for each refrigerated liquefied gas permitted for transportation.
Name of the operator.
Name of hazardous materials being transported and maximum mean bulk temperature (except for refrigerated liquefied gases, the name and temperature are only required when the maximum mean bulk temperature is higher than 50 °C).
Maximum permissible gross mass (MPGM)____kg.
Unladen (tare) mass____kg.
NOTE TO PARAGRAPH ( i )(2): For the identification of the hazardous materials being transported refer to part 172 of this subchapter.
49 C.F.R. §178.274
At 68 FR 57633, Oct. 6, 2003, § 178.274 was amended in paragraph (b)(1); however, the amendment could not be incorporated due to inaccurate amendatory instruction.