5 Maintenance and inspection procedures
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC/Circular.851 – Guidelines on Engine-Room Oil Fuel Systems – (Adopted on 1 June 1998) - Annex – Guidelines on Engine-Room Oil Fuel Systems - 5 Maintenance and inspection procedures

5 Maintenance and inspection procedures

  5.1 The ship Safety Management System should contain procedures to identify vibration, fatigue, defects, poor components and poor fitting of the fuel system and ensure that proper attention to protecting hot surfaces is maintained. Check lists should be prepared to ensure that all procedures are followed at major overhauls and that all components, supports, restraints etc., are refitted on completion of such work. The installed system should be routinely inspected for:

  • verifying the adequacy of its supports and the condition of its fittings;
  • evidence of fatigue stresses to welded or brazed pipes and connections;
  • assessing the level of vibration present; and
  • the checking of the lagging or shielding of hot surfaces.

  5.2 Components of the fuel system should be comprehensively examined, particularly threaded connections, at each dismantling.

  5.3 Injection pump restraining bolts should be proved tight by testing with a torque spanner at frequent intervals (interval not to exceed 3 months).

  5.4 The supports and retaining devices of the low pressure fuel system should be checked at regular intervals (interval not to exceed 6 months), to be proved tight and to provide adequate restraint. The lining of such devices should be examined for wear and renewed if they provide insufficient support.

  5.5 Flexible pipes should be closely examined and renewed if signs of material cracking or deterioration are evident. Extra care should be exercised in the tightening of these pipe connections to ensure that they are not twisted when re-installed.

  5.6 Flexible pipes should be pressure tested to their original design pressure at least at five yearly intervals. Alternatively, such pipes should be the subject of a study aimed at determining their finite life and then be automatically renewed before that has been reached. The views of engine and fuel system manufacturers should be sought and considered.

  5.7 All gasket and seal ring materials, and any jointing compounds used, should comply with the requirements of the engine manufacturer.

  5.8 Where already fitted, compression fittings should be carefully examined and if necessary tightened (but not over-tightened) with a torque spanner to the manufacturer's specification. Replacement with flanged connections should be considered.

  5.9 Existing copper and aluminium-brass piping should be heat treated (annealed) and sufficient supports fitted to prevent damage from vibration. Replacement with steel piping should be considered.

  5.10 All component locking devices, such as spring and tab washers, locking wires etc., should be present and in use. (It is recognised that it is impracticable to lock fuel pump vent screws with wire, due to their frequent use. However, wire loops containing a weight attached to each screw would prevent them unscrewing under the influence of vibration if they became slack.)

  5.11 Spray or deflection plates and lagging should be correctly replaced after maintenance to reduce the possibility of fire in the event of fuel leakage.

  5.12 The fuel system on existing ships should be checked for compatibility with the high pressure pulses which are generated by the fuel injection pumps.


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