[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR180.203]

[Page 1073-1074]
 
                        TITLE 49--TRANSPORTATION
 
 CHAPTER I--RESEARCH AND SPECIAL PROGRAMS ADMINISTRATION, DEPARTMENT OF 
                             TRANSPORTATION
 
PART 180_CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS--Table of 
Contents
 
        Subpart C_Qualification, Maintenance and Use of Cylinders
 
Sec. 180.203  Definitions.

    In addition to the definitions contained in Sec. 171.8 of this 
subchapter, the following definitions apply to this subpart:
    Commercially free of corrosive components means a hazardous material 
having a dew point at or below minus 46.7 [deg]C (minus 52 [deg]F) at 
101kPa (1 atmosphere) and free of components that will adversely react 
with the cylinder (e.g. chemical stress corrosion).
    Condemn means a determination that a cylinder is unserviceable for 
the continued transportation of hazardous materials in commerce and that 
the cylinder may not be restored by repair, rebuilding, requalification, 
or any other procedure.
    Defect means an imperfection requiring removal of a cylinder from 
service.
    Elastic expansion means a temporary increase in a cylinder's volume, 
due to application of pressure, that is lost when pressure is released 
(elastic expansion = total expansion minus permanent expansion).
    Filled or charged means an introduction or presence of a hazardous 
material in a cylinder.
    Non-corrosive service means a hazardous material that, in the 
presence of moisture, is not corrosive to the materials of construction 
of a cylinder (including valve, pressure relief device, etc.).
    Over-heated means a condition in which the temperature of any 
portion of an aluminum cylinder has reached 176 [deg]C (350 [deg]F) or 
higher, or in which the temperature of any portion of a steel or nickel 
cylinder has reached 343 [deg]C (650 [deg]F) or higher.

[[Page 1074]]

    Permanent expansion means a permanent increase in a cylinder's 
volume after the test pressure is released.
    Proof pressure test means a pressure test by interior pressurization 
without the determination of a cylinder's expansion.
    Rebuild means the replacement of a pressure part (e.g. a wall, head, 
or pressure fitting) by welding.
    Rejected cylinder means a cylinder that cannot be used for the 
transportation of a hazardous material in commerce without repair, 
rebuilding, and requalification.
    Repair means a procedure for correction of a rejected cylinder that 
may involve welding.
    Requalification means the completion of a visual inspection and/or 
the test(s) required to be performed on a cylinder to determine its 
suitability for continued service.
    Requalification identification number or RIN means a code assigned 
by DOT to uniquely identify a cylinder requalification, repair, or 
rebuilding facility.
    Test pressure means the pressure used for the requalification of a 
cylinder.
    Total expansion means the total increase in a cylinder's volume due 
to application of the test pressure.
    Visual inspection means an internal or external visual examination, 
or both, performed as part of the cylinder requalification process.
    Volumetric expansion test means a pressure test to determine the 
total and permanent expansion of a cylinder at a given pressure. The 
volumetric expansion test is conducted using the water jacket or direct 
expansion methods:
    (1) Water jacket method means a volumetric expansion test to 
determine a cylinder's total and permanent expansion by measuring the 
difference between the volume of water the cylinder externally displaces 
at test pressure and the volume of water the cylinder externally 
displaces at ambient pressure.
    (2) Direct expansion method means a volumetric expansion test to 
calculate a cylinder's total and permanent expansion by measuring the 
amount of water forced into a cylinder at test pressure, adjusted for 
the compressibility of water, as a means of determining the expansion.