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MAN B&W 7.01
Drain of clean fuel oil from HCU, pumps, pipes
The HCU Fuel Oil Pressure Booster has a leakage
drain of clean fuel oil from the umbrella sealing
through ‘AD’ to the fuel oil drain tank.
The flow rate in litres <strong>is</strong> approximately as l<strong>is</strong>ted in
Table 7.01.01.
Engine
Flow rate,
litres/cyl. h.
K98ME/ME-C, S90ME-C
K90ME/ME-C, S/K80ME-C, S70ME-C/
1.25
ME-GI, L70ME-C, S65ME-C/-GI 0.75
S/L60ME-C, S60ME-C-GI 0.60
Table 7.01.01: Approximate flow in HCU leakage drain.
<strong>Th<strong>is</strong></strong> drained clean oil will, of course, influence the
measured SFOC, but the oil <strong>is</strong> not wasted, and the
quantity <strong>is</strong> well within the measuring accuracy of
the flowmeters normally used.
The main purpose of the drain ‘AF’ <strong>is</strong> to collect
pure fuel oil from the fuel pumps as well as the
unintentional leakage from the high pressure
pipes. The drain oil <strong>is</strong> led to a sludge tank and can
be pumped to the Heavy Fuel Oil service tank or
to the settling tank.
The ‘AF’ drain <strong>is</strong> provided with a box for giving
alarm in case of leakage in a high pressure pipe.
The size of the sludge tank <strong>is</strong> determined on the
bas<strong>is</strong> of the draining intervals, the classification
society rules, and on whether it may be vented
directly to the engine room.
Drains ‘AD’ and ‘AF’ are shown in Fig. 7.03.01.
Drain of contaminated fuel etc.
Leakage oil, in shape of fuel and lubricating oil
contaminated with water, dirt etc. and collected
by the HCU Base Plate top plate, <strong>is</strong> drained off
through the bedplate drains ‘AE’.
Drain ‘AE’ <strong>is</strong> shown in Fig. 8.07.02.
MAN B&W K98ME/ME-C, S90ME-C, K90ME/ME-C,
S80ME-C, K80ME-C, S70ME-C/ME-GI, L70ME-C,
S65ME-C/ME-GI, S60ME-C/ME-GI/ME-B, L60ME-C
MAN Diesel
Heating of fuel drain pipes
Page 3 of 3
Owing to the relatively high v<strong>is</strong>cosity of the heavy
fuel oil, it <strong>is</strong> recommended that the drain pipes
and the fuel oil drain tank are heated to min. 50 °C,
but max. 100 °C.
The drain pipes between engine and tanks can
be heated by the jacket water, as shown in Fig.
7.01.01 ‘Fuel pipe heating’ as flange ‘BD’.
Fuel oil flow velocity and v<strong>is</strong>cosity
For external pipe connections, we prescribe the
following maximum flow velocities:
Marine diesel oil .......................................... 1.0 m/s
Heavy fuel oil ............................................... 0.6 m/s
The fuel v<strong>is</strong>cosity <strong>is</strong> influenced by factors such as
emulsification of water into the fuel for reducing
the NO x em<strong>is</strong>sion. <strong>Th<strong>is</strong></strong> <strong>is</strong> further described in Section
7.06.
An emulsification arrangement for the main engine
<strong>is</strong> described in our publication:
Exhaust Gas Em<strong>is</strong>sion Control Today and
Tomorrow
Further information about fuel oil specifications <strong>is</strong>
<strong>available</strong> in our publication:
Guidelines for Fuels and Lubes Purchasing
The publications are <strong>available</strong> at:
www.mandiesel.com under
‘Quicklinks’ → ‘Technical Papers’.
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