[Code of Federal Regulations]
[Title 46, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR64.5]

[Page 318]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 64_MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS--Table of Contents
 
                            Subpart A_General
 
Sec. 64.5  Definitions.

    As used in this part:
    (a) Marine portable tank or MPT means a liquid-carrying tank that--
    (1) Has a capacity of 110 gallons or more;
    (2) Is designed to be carried on a vessel;
    (3) Can be lifted full or empty onto and off a vessel, and can be 
filled and discharged while on a vessel;
    (4) Is not permanently attached to the vessel; and
    (5) Was inspected and stamped by the Coast Guard on or before 
September 30, 1992.
    (b) Tank means the pressure vessel and the associated fittings of an 
MPT that come in contact with the product being carried.
    (c) Total containment pressure means the minimum pressure for total 
product containment under normal operating conditions at a gauge 
pressure consisting of the absolute vapor pressure of the product at 122 
[deg]F added to the dynamic pressure, based on the tank dimensions and 
the location of the relief devices, of not less than 5 pounds per square 
inch gauge (psig) at the top of the tank in the operating position.
    (d) Maximum allowable working pressure means the maximum gauge 
pressure at the top of the tank in the operating position at 122 [deg]F, 
equal to or greater than the total containment pressure as defined in 
paragraph (c) of this section. The maximum allowable working pressure is 
used in the calculation of the minimum thickness of each element of the 
tank, excluding the allowance for corrosion and the thickness for 
loadings other than pressure, as provided for in the ASME Code.
    (e) Test pressure means a hydrostatic pressure of at least one and 
one-half times the maximum allowable working pressure.
    (f) Dynamic loading conditions means the following:
    (1) A loading in the vertical down direction equal to 2 times the 
weight of the tank and the heaviest product carried.
    (2) A loading in the transverse direction equal to the weight of the 
tank and the heaviest product carried.
    (3) A loading in the longitudinal direction equal to the weight of 
the tank and the heaviest product carried.
    (g) Owner means the person, corporation, company, partnership, or 
organization in which is vested the ownership, dominion, or title of a 
portable tank.

[CGD 73-172, 39 FR 22950, June 25, 1974, as amended by CGD 84-043, 55 FR 
37409, Sept. 11, 1990]

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