The vessel started consuming new bunkers after exhausting the older ones. After putting the bunkers in use, the vessel reported heavy sludge formation in the FO Purifiers. The purifiers are not able to run for more than few minutes because of heavy sludge formation. After 30 minutes, both Main and Auxiliary engine fuel oil auto-filters alarmed due to high differential pressure.
- Excessive sludge formation in both purifiers – Ship staff cleaned the purifier bowl every 2 hours.
- Filters getting clogged every 20 minutes – which caused potentially dangerous situation for main propulsion and power generation engines.
- Engine Room – watch keeping mode and the problems persisted during pilotage.
Regular Full- spec analysis did not reveal anything significant and all parameters were well within the limits.
The problem was reported to Viswa Lab and additional tests were proposed on the fuel sample, which caused the problems reported.
Purifier Completely cleaned:
Purifiers – after 2 hours of Operation:
Proposed Additional Tests:
- PFIN – (Problem Fuel Identification Number),
- GCMS – CRA
Below are the findings from the Additional Tests:
- PFIN was 308, which is higher than the level at which piston ring breakages have been reported in 85 to 90% cases. When PFIN value is greater than 130, the fuel carries a high probability of piston ring breakage.
- The asphaltene content is high at 9.43 %. There is no limit for asphaltenes in ISO 8217.
- Reserve stability number result of 12.8 is very high and the stability reserve of the oil is very low. This means that the asphaltenes will easily flocculate, or have already started to flocculate.
- Xylene Equivalent Test result of 100 is very high. According to Diesel United-Sulzer engine Makers technical document, if the Xylene Equivalent result is high, there is a real risk of fuel pump problems.
- Stability test performed on the sample indicated that the sample is UNSTABLE. If the fuel is unstable, problems such as purifier/filter choking have been reported to us.
- GCMS CRA indicated the presence of the below mentioned chemical contaminants in the fuel sample:
- Total phenol content adds up to 540 ppm (normally less than 100 ppm).
- Methyl styrene is at 25 ppm, Indene is at 107 ppm and DCPD & DH-DCPD 41ppm.
Now, do not worry about the above chemicals and their formula. The ultimate point what has to be noted is:
- ISO 8217 does not have any specifications for these chemicals and above abnormalities,
- A Fuel is supposed not to have any of the above abnormalities which is clearly explained as below:
According to para 5.1 of ISO 8217:2005 quoted below;
5.1 The fuels shall be homogeneous blends of hydrocarbons derived from petroleum refining.
This shall not preclude the incorporation of small amounts of additives intended to improve some aspects of performance The fuels shall be free from inorganic acids and from used lubricating oils.
The fuel should not include any added substance or chemical waste which
- jeopardizes the safety of ships or adversely affects the performance of the machinery; or
- is harmful to personnel; or
- contributes overall to additional air pollution.
Viswa Lab tested the fuel sample and offered an immediate solution to overcome the problem.
Over to you!
Report or write to Fuel Problem Support Team ( [email protected] ) if you face any problems with the fuel or machinery. We are here to help you out. At the end of the day – a trouble-free ship means a trouble-free life at shore!
Do not hesitate to write to us if you have any queries.
Source: Viswa Lab – Fuel Problem Support Team.
Disclaimer: Images used in this write-up are for educational purpose only. Neither Viswa Lab nor MFAME are liable in any case as this write-up is to create awareness of the problems being encountered and solutions to overcome it.