4.5
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Specifications and Manuals - Inert Gas Systems - 4 Operation of Inert Gas Plant - 4.5

4.5

 Possible failures of the inert gas system and actions to be taken include:

  • .1 High oxygen content which may be caused or indicated by the following conditions:

    • .1.1 poor combustion control at the boiler, especially under low load conditions;

    • .1.2 drawing air down the uptake when boiler gas output is less than the inert gas blower demand, especially under low load conditions;

    • .1.3 air leaks between the inert gas blower and the boiler uptake;

    • .1.4 faulty operation or calibration of the oxygen analyser;

    • .1.5 inert gas plant operating in the recirculation mode; or

    • .1.6 entry of air into the inert gas main through the pressure vacuum valves, mast risers etc. due to maloperation.

  • .2 If the inert gas plant is delivering inert gas with an oxygen content of more than 5%, the fault should be traced and repaired. Regulation 62.19.5 requires, however, that all cargo tank operations shall be suspended if the oxygen content exceeds 8% unless the quality of the gas is improved.

  • .3 Inability to maintain positive pressure during cargo discharge or deballasting operations which may be caused by:

    • .3.1 inadvertent closure of the inert gas valves;

    • .3.2 faulty operation of the automatic pressure control system;

    • .3.3 inadequate blower pressure; or

    • .3.4 a cargo discharge rate in excess of the blower output.

  • .4 The cargo discharge or deballasting should be stopped or reduced depending on whether or not the positive pressure in the tanks can be maintained while the fault is rectified.

Parent topic: 4 Operation of Inert Gas Plant
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