Filter modifications reduce the risk of engine damage
The forthcoming IMO 2020 regulations will require ships to use low-sulphur fuels more frequently or continuously. Some of these fuels will be 0.5 S% or 0.1 S% residual fuels. As result of their production processes, a considerable level of catalytic fines, also known as cat fines, remain in the fuel, even with the latest ISO 8217 marine fuel standard specifying levels of up to 60ppm concentration. Cat fines are highly abrasive small particles that are a consequence of the refining process known as catalytic cracking. They can cause severe wear in engine components, but the risks can be mitigated with fine filters.
Main and auxiliary engine manufacturers have recommended the maximum acceptable level of cat fines entering the engines at 15ppm for short periods. A 10-micron filter before the engine inlet is recommended by the major engine manufacturers. Studies have shown that a six micron filtration removed the majority of cat fines found in the fuels.
Filter modification is necessary
Fuel handling systems such as HFO and MDO feeder/booster units are usually equipped with auto-back-flushing filters, located typically after the feeder pump (also known as a supply pump).
To provide adequate engine protection, we recommend to explore whether the current system arrangement allows the replacement of existing filters with fine filters. Another possibility is to add a second (fine) filter in front of the engine. The choice depends on the system’s current arrangement on board. Auramarine’s fine filters are available from six microns.