Working purifiers onboard


Published: 23 January 2023

Credit to: donvictorio /

Purifiers are one of the most important pieces of auxiliary machinery and its main purpose is to separate water and other contaminants in the oil mixture using the principle of density difference. Heavier particles will be forced outward, and lighter particles will remain near to the centre.

Good maintenance of purifiers is important for smooth and accurate operation of the units. Some factors that influence a good working purifier are temperature, feed rate, the type of gravity disc and oil density.

To maintain optimal efficiency of the equipment, filters and heaters should be regularly cleaned and opened as per the vessel's planned maintenance system or manufactures' recommendations.

Frequent cleaning should be carried out if the fuel quality is poor, and fuel tanks should be cleaned as per scheduled intervals, in order to avoid high concentration of sediments and cat fines. The vessel should also have adequate spare parts onboard for maintenance of the purifiers.

We have seen cases where the parameters regarding for example water and aluminium plus silicon are near the maximum limit. By having good working purifiers and good fuel handling management and treatment onboard, the values will reduce to acceptable levels.

It is important not to by-pass the fuel filtering equipment as it could result in damaging the main and auxiliary engines. It is recommended, if possible, to run in the purifiers in parallel with a minimum feed rate and to maintain the correct fuel oil inlet temperature at an optimal level. It is important to ensure that the correct gravity disc is used and to have regular fuel system checks, and for fuel samples to be sent to accredited fuel laboratories.