[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR173.24b]
[Page 455-456]
TITLE 49--TRANSPORTATION
CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION,
DEPARTMENT OF TRANSPORTATION
PART 173_SHIPPERS_GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS--
Subpart B_Preparation of Hazardous Materials for Transportation
Sec. 173.24b Additional general requirements for bulk packagings.
(a) Outage and filling limits. (1) Except as otherwise provided in
this subchapter, liquids and liquefied gases must be so loaded that the
outage is at least five percent for materials poisonous by inhalation,
or at least one percent for all other materials, of the total capacity
of a cargo tank, portable tank, tank car (including dome capacity),
multi-unit tank car tank, or any compartment thereof, at the following
reference temperatures--
(i) 46 [deg]C (115 [deg]F) for a noninsulated tank;
(ii) 43 [deg]C (110 [deg]F) for a tank car having a thermal
protection system, incorporating a metal jacket that provides an overall
thermal conductance at 15.5 [deg]C (60 [deg]F) of no more than 10.22
kilojoules per hour per square meter per degree Celsius (0.5 Btu per
hour/per square foot/ per degree F) temperature differential; or
(iii) 41 [deg]C (105 [deg]F) for an insulated tank.
(2) Hazardous materials may not be loaded into the dome of a tank
car. If the dome of the tank car does not provide sufficient outage,
vacant space must be left in the shell to provide the required outage.
(b) Equivalent steel. For the purposes of this section, the
reference stainless steel is stainless steel with a guaranteed minimum
tensile strength of 51.7 deka newtons per square millimeter (75,000 psi)
and a guaranteed elongation of 40 percent or greater. Where the
regulations permit steel other than stainless steel to be used in place
of a specified stainless steel (for example, as in Sec. 172.102 of this
subchapter, special provision B30), the minimum thickness for the steel
must be obtained from one of the following formulas, as appropriate:
Formula for metric units
e1 = (12.74e0) / (Rm1 A1)\1/
3\
Formula for non-metric units
e1 = (144.2e0) / (Rm1 A1)\1/
3\
where:
e0 = Required thickness of the reference stainless steel in
mm or inches respectively;
e1 = Equivalent thickness of the steel used in mm or inches
respectively;
Rm1 = Specified minimum tensile strength of the steel used in
deka-newtons per square millimeter or pounds per square inch
respectively; and
A1 = Specified minimum percentage elongation of the steel
used multiplied by 100 (for example, 20 percent times 100 equals 20).
Elongation values used must be determined from a 50 mm or 2 inch test
specimen.
(c) Air pressure in excess of ambient atmospheric pressure may not
be used to load or unload any lading which may create an air-enriched
mixture within the flammability range of the lading in the vapor space
of the tank.
(d) A bulk packaging may not be loaded with a hazardous material
that:
(1) Is at a temperature outside of the packaging's design
temperature range; or
(2) Except as otherwise provided in this subchapter, exceeds the
maximum weight of lading marked on the specification plate.
(e) UN portable tanks. (1) A UN portable tank manufactured in the
United States must conform in all details to the applicable requirements
in parts 172, 173, 178 and 180 of this subchapter.
(2) UN portable tanks manufactured outside the United States. A UN
portable tank manufactured outside the United States, in accordance with
national or international regulations based on the UN Recommendations
(IBR, see Sec. 171.7 of this subchapter), which is an authorized
packaging under Sec. 173.24 of this subchapter, may be filled, offered
and transported in the United States, if the Sec. 172.101 Table of this
subchapter authorizes the hazardous material for transportation in the
UN portable tank and it conforms to the applicable T codes, and tank
provision codes, or other special provisions assigned to the hazardous
material in Column (7) of the Table when manufactured in a country other
than the United States. In addition, the portable tank must--
(i) Conform to applicable provisions in the UN Recommendations (IBR,
see Sec. 171.7 of this subchapter) and the requirements of this
subpart;
(ii) Be capable of passing the prescribed tests and inspections in
part 180 of this subchapter applicable to the UN portable tank
specification;
[[Page 456]]
(iii) Be designed and manufactured according to the ASME Code (IBR,
see Sec. 171.7 of this subchapter) or a pressure vessel design code
approved by the Associate Administrator;
(iv) Be approved by the Associate Administrator when the portable
tank is designed and constructed under the provisions of an alternative
arrangement (see Sec. 178.274(a)(2) of this subchapter); and
(v) The competent authority of the country of manufacture must
provide reciprocal treatment for UN portable tanks manufactured in the
United States.
[Amdt. 173-224, 55 FR 52612, Dec. 21, 1990, as amended at 56 FR 66266,
Dec. 20, 1991; Amdt. 173-234, 58 FR 51532, Oct. 1, 1993; Amdt. 173-243,
60 FR 40038, Aug. 4, 1995; Amdt. 173-252, 61 FR 28676, June 5, 1996;
Amdt. 173-255, 61 FR 50624, Sept. 26, 1996; 66 FR 33426, June 21, 2001;
67 15743, Apr. 3, 2002; 68 FR 75742, Dec. 31, 2003]