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MAN B&W 7.05
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 spaces
(UMS). Centrifuges must be self�cleaning, either
with total d<strong>is</strong>charge or with partial d<strong>is</strong>charge.
D<strong>is</strong>tinction must be made between installations for:
• Specific gravities < 0.99 (corresponding to ISO
82 7 and Brit<strong>is</strong>h Standard 6843 from RMA to
RMH, and CIMAC from A to H�grades
• Specific gravities > 0.99 and (corresponding to
CIMAC K�grades).
For the latter specific gravities, the manufacturers
have developed special types of centrifuges, e.g.:
Alfa Laval ........................................................Alcap
Westfalia ....................................................... Unitrol
Mitsub<strong>is</strong>hi .............................................. E�Hidens II
The centrifuge should be able to treat approximately
the following quantity of oil:
0.23 litres/kWh = 0.17 litres/BHPh
<strong>Th<strong>is</strong></strong> figure 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 condition
• Purifier service for cleaning and maintenance.
The size of the centrifuge has to be chosen according
to the supplier’s table valid for the selected
v<strong>is</strong>cosity 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.
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A centrifuge for Marine Diesel Oil (MDO) <strong>is</strong> not a
must, but if it <strong>is</strong> decided to install one on board,
the capacity should be based on the above recommendation,
or it should be a centrifuge of the
same size as that for lubricating oil.
The Nominal MCR <strong>is</strong> used to determine the total
installed capacity. Any derating can be taken
into consideration in border�line cases where the
centrifuge that <strong>is</strong> one step smaller <strong>is</strong> able to cover
Specified MCR.
Fuel oil supply pump
<strong>Th<strong>is</strong></strong> <strong>is</strong> to be of the screw or gear wheel type.
Fuel oil v<strong>is</strong>cosity, specified .... up to 700 cSt at 50 °C
Fuel oil v<strong>is</strong>cosity maximum ....................... 000 cSt
Pump head ......................................................4 bar
Fuel oil flow .........................see ‘L<strong>is</strong>t of capacities’
Delivery pressure ............................................4 bar
Working temperature ................................... 00 °C
Minimum temperature .................................... 50 °C
The capacity stated in ‘L<strong>is</strong>t of capacities’ <strong>is</strong> to be fulfilled
with a tolerance of: ÷0% to + 5% and shall also
be able to cover the back�flushing, see ‘Fuel oil filter’.
Fuel oil circulating pump
<strong>Th<strong>is</strong></strong> <strong>is</strong> to be of the screw or gear wheel type.
Fuel oil v<strong>is</strong>cosity, specified .... up to 700 cSt at 50 °C
Fuel oil v<strong>is</strong>cosity normal ................................20 cSt
Fuel oil v<strong>is</strong>cosity maximum ....................... 000 cSt
Fuel oil flow .........................see ‘L<strong>is</strong>t of capacities’
Pump head ......................................................6 bar
Delivery pressure .......................................... 0 bar
Working temperature ................................... 50 °C
The capacity stated in ‘L<strong>is</strong>t of capacities’ <strong>is</strong> to be fulfilled
with a tolerance of: ÷0% to + 5% and shall also
be able to cover the back�flushing, see ‘Fuel oil filter’.
Pump head <strong>is</strong> based on a total pressure drop in
filter and preheater of maximum .5 bar.
MAN B&W MC/MC-C, ME/ME-B/ME�C/ME�GI engines 198 39 51�2.3
MAN Diesel