[Code of Federal Regulations]

[Title 49, Volume 2]

[Revised as of October 1, 2005]

From the U.S. Government Printing Office via GPO Access

[CITE: 49CFR173.24b]



[Page 442-443]

 

                        TITLE 49--TRANSPORTATION

 

   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 

                      DEPARTMENT OF TRANSPORTATION

 

PART 173_SHIPPERS_GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS

--Table of Contents

 

     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:



[[Page 443]]



                        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;

    (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]