Marine Installation Manual
2021-08
4-74
4 Ancillary Systems
4.6 Fuel oil system
X72DF
Duplex filter
The second filter in Arrangement ‘A’ is a duplex filter of recommended max
-
imum 25
m abs. A coarser filter is also acceptable. The duplex filter is of manual
cleaning type and is installed in the booster system close to engine inlet. This
filter type is sufficient as most particles are already removed by the 10
m filter as
outlined in
and
.
Table 4
-
13 Specification of duplex filter in booster system
Working viscosity
10-20cSt required for HFO (13-17cSt recommended)
Flow rate
. The capacities cover the needs of the
engine only. If a filter of automatic back-flushing type is in
-
stalled, the feed and booster pump capacities must be in-
creased by the quantity needed for back-flushing of the filter.
Service pressure
Max. 12bar at filter inlet
Test pressure
Specified by classification society
Permitted differential press.
at 17 and 20cSt
— clean filter: max. 0.2bar
— dirty filter: max. 0.6bar
— alarm setting: max. 0.8bar
Note: Real operational settings could be less according to
filter maker’s recommendation.
Minimum bursting press.
of filter insert
Max. 3bar differential across filter
Mesh size
Max. 25
m abs.
Filter insert material
Stainless steel mesh (CrNiMo)
Working temperature
Up to 150°C