Standard test for Ash: ISO 6345
Maximum Ash content : 0.2%

High ash content may point to residual lubricants or derivates from such a diluent. The dispersant content of lubricants may render the seperation of water by the treatment systems ineffective.

Standard test for Al / Si: ISO 10478
Maximum Al + Si content: 80 mg / kg (ISO 2005) or 60 mg / kg (ISO 2010)

All fuels with Al / Si (Aluminium / Silicon) concentrations above limits are deemed unusable. Even borderline cases should be treated with extreme caution. It is recommended that operators take the below steps;

Standard test for Vanadium: ISO 14597
Maximum V content: 600 mg / kg

Armoured valves and valve seats coupled with improved cooling of these components helps to counter fuels with a high Vanadium content. V, Na, Ca salts burn to ash under engine conditions. Due to their high corrosivity they will over time damage the hot areas they tend to melt on and stick to, such as valves, their seats, heat exchanger pipes and turbo charger blades. Upon resolidifying, they form solid, brittle crusts and may constrict heat transfer or channel heat thereby potentially damaging exhaust valves.

Steps to take against high particle content / increased engine wear:

1. Increase the temperatures in the settling tank (to optimise the settling process) and allow time to settle. 
2. Remove biggest particles with draining the deepest sections frequently.
3. Run two seperators in parallel as purifiers at reduced throughput. Increasing engine output naturally agitates the fuel, increasing the internal movement and circulation of the fuel, thereby increasing dispersion. 
4. Clean the separators more frequently than usual to avoid untreated fuel passing into the service tank.

5. Cat fines are hydrophilic (tend to migrate towards water droplets), hence removal of the Water may help to reduce the cat fines levels to within limits.

Things to bear in mind:

  • There is no viable way try to remove Ca or liquid and oil soluble metal salts (Na, V, Fe, Ni, Cr) from fuels.
  • Rough seas may agitate the sedimentation in the bottoms.
  • Particles exacerbate engine wear and have a critical abrasive action.