DESIGN AND CONSTRUCTION OF LIQUEFIED GAS CARRIERS

This article describes the design of four basic types of liquified gas carriers, fully pressurized ships in which cargo is carried in two to six uninsulated cylindrical pressure vessels with the working pressure equivalent to the vapor pressure of the cargo at maximum anticipated ambient temperature; semipressurized ships in which the reduced wall thickness of the pressure vessels is partly offset by a requirement to fit a refrigerating plant which utilizes the cargo as the refrigerating medium to maintain the vapor pressure of the cargo; semipressurized/fully refrigerated ships to carry the full range of LPG and similar chemical cargoes in cylindrical or spherical tanks which are constructed of low temperature carbon or low nickel alloy steel, and designed for minimum service temperature of about -45C (-50 F) and pressures in the order of 5 to 8 kg/sq cm (70 to 113 psig); and fully refrigerated ships at atmospheric pressure. The tanks which are usually designed for a minimum service temperature of about -50 C(-58 F) and a maximum working pressure of about 0.28 kg/sq cm (4 psig) are insulated, usually self-supporting and prismatic in form. The tank material which must be ductile at low temperature may be either a fine grain, heat treated carbon steel or a low alloy nickel steel (less than 2 percent nickel). The cargo handling system is also described.

  • Authors:
    • Gray, R C
    • Johnson, L
  • Publication Date: 1971-2

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  • Accession Number: 00028592
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Apr 10 2001 12:00AM