Fuel System Check

Fuel System Check

Catalytic fines (also known as catfines) are aluminium and silicon oxides used during refinery catalytic cracking. Catfines are extremely hard and abrasive particles which can cause excessive wear to vital components in the combustion chamber such as the piston grooves, piston rings, cylinder liners and fuel injection equipment.

Since ISO8217:2010, the catfines limit for RME 180 fuels was reduced to 50 mg/kg and 60 mg/kg for RMG and RMK fuel grades.

Engine builders recommend that after the onboard treatment, fuels entering the engine should have a catfines concentration of less than 10-15 ppm.

Operators should be more concerned with the level of catfines in the fuel entering the engine than the level of catfines in the fuel from the bunkering sample, as accumulated catfines in the fuel oil system is usually unknown without testing.

When the vessel receives fuels with a catfines concentration of more than 30 ppm, a Fuel System Efficiency Check should be carried out to ensure that the separation efficiency is up to standard. This will help the engineers in ascertaining that the fuel treatment systems onboard are capable of reducing the catfines content to a safe level

Catalytic fines are hydrophilic. Therefore, regular draining of the service and settling tanks will reduce the volume of catfines, which are drained with the water.

Using 10-micron final hot filters instead of 50micron filters will also help to reduce the amount of catfines reaching the engine.

The vessel crew should check the fuel separation and treatment systems by periodically sending onboard samples, which are to be obtained from the following locations, for testing:

  • A. Vessel manifold
  • B. Bunker Tank
  • C. Settling Tank
  • D. Before Centrifuge/Purifier
  • E. After Centrifuge/Purifier
  • F. Service Tank
  • G. After final hot filter before the engines

Limiting the catfines concentration entering the engine will increase mean time between overhauls and improve the service life of engine components

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