MAN B&W 7.05
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MAN Diesel
MAN B&W MC/MC-C, ME/ME-B/MEC/MEGI engines 198 39 512.3
Components for fuel oil system
Fuel oil centrifuges
The manual cleaning type of centrifuges are not to
be recommended, neither for attended machinery
spaces (AMS) nor for unattended machinery spac-
es (UMS). Centrifuges must be selfcleaning, either
with total discharge or with partial discharge.
Distinction must be made between installations for:
• Specic gravities < 0.99 (corresponding to ISO
827 and British Standard 6843 from RMA to
RMH, and CIMAC from A to Hgrades
• Specic gravities > 0.99 and (corresponding to
CIMAC Kgrades).
For the latter specic gravities, the manufacturers
have developed special types of centrifuges, e.g.:
Alfa Laval ........................................................Alcap
Westfalia ....................................................... Unitrol
Mitsubishi .............................................. EHidens II
The centrifuge should be able to treat approxi-
mately the following quantity of oil:
0.23 litres/kWh = 0.17 litres/BHPh
This gure includes a margin for:
• Water content in fuel oil
• Possible sludge, ash and other impurities in the
fuel oil
• Increased fuel oil consumption, in connection
with other conditions than ISO standard condi-
tion
• Purier service for cleaning and maintenance.
The size of the centrifuge has to be chosen ac-
cording to the supplier’s table valid for the select-
ed viscosity of the Heavy Fuel Oil. Normally, two
centrifuges are installed for Heavy Fuel Oil (HFO),
each with adequate capacity to comply with the
above recommendation.
A centrifuge for Marine Diesel Oil (MDO) is not a
must, but if it is decided to install one on board,
the capacity should be based on the above rec-
ommendation, or it should be a centrifuge of the
same size as that for lubricating oil.
The Nominal MCR is used to determine the to-
tal installed capacity. Any derating can be taken
into consideration in borderline cases where the
centrifuge that is one step smaller is able to cover
Specied MCR.
Fuel oil supply pump
This is to be of the screw or gear wheel type.
Fuel oil viscosity, specied .... up to 700 cSt at 50 °C
Fuel oil viscosity maximum .......................000 cSt
Pump head ......................................................4 bar
Fuel oil ow .........................see ‘List of capacities’
Delivery pressure ............................................4 bar
Working temperature ................................... 00 °C
Minimum temperature .................................... 50 °C
The capacity stated in ‘List of capacities’ is to be ful-
lled with a tolerance of: ÷0% to +5% and shall also
be able to cover the backushing, see ‘Fuel oil lter’.
Fuel oil circulating pump
This is to be of the screw or gear wheel type.
Fuel oil viscosity, specied .... up to 700 cSt at 50 °C
Fuel oil viscosity normal ................................20 cSt
Fuel oil viscosity maximum .......................000 cSt
Fuel oil ow .........................see ‘List of capacities’
Pump head ......................................................6 bar
Delivery pressure .......................................... 0 bar
Working temperature ................................... 50 °C
The capacity stated in ‘List of capacities’ is to be ful-
lled with a tolerance of: ÷0% to +5% and shall also
be able to cover the backushing, see ‘Fuel oil lter’.
Pump head is based on a total pressure drop in
lter and preheater of maximum .5 bar.
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