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MAN B&W 12.05
Jacket Cooling Water System
The jacket cooling water system <strong>is</strong> used for cooling
the cylinder liners, cylinder covers and exhaust
valves of the main engine and heating of the
fuel oil drain pipes, see Fig. 12.05.01.
The jacket water pump) draws water from the
jacket water cooler outlet and delivers it to the
engine.
At the inlet to the jacket water cooler there <strong>is</strong> a
thermostatically controlled regulating valve, with
a sensor at the engine cooling water outlet, which
keeps the main engine cooling water outlet at a
temperature of 80 °C.
The engine jacket water must be carefully treated,
maintained and monitored so as to avoid corrosion,
corrosion fatigue, cavitation and scale formation.
It <strong>is</strong> recommended to install a preheater
if preheating <strong>is</strong> not <strong>available</strong> from the auxiliary
engines jacket cooling water system.
Venting pipe or automatic
venting valve to be arranged
in one end of d<strong>is</strong>charge pipe.
(Opposite end of d<strong>is</strong>charge
to pump)
Tracing of fuel oil
drain pipe
M
AF
*) BD AH
K
Drain from bedplate/cleaning
turbocharger to waste tank
L
AE AE
Main
engine
Jacket cooling water
Sea water
Fuel oil
AN
PT 8413 I
Preheater
The letters refer to l<strong>is</strong>t of ‘Counterflanges’, Fig. 5.10.01
Alarm must be given if excess air
<strong>is</strong> separated from the water in the
deaerating tank
PI
LS 8412 AL
Orifice for adjustment of
cooling water pressure
PI
Jacket water pumps,
3 bar head
Water inlet for
cleaning turbocharger
Fresh cooling water drain
Fig. 12.05.01: Jacket cooling water system
Preheater pump
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The venting pipe in the expansion tank should end
just below the lowest water level, and the expansion
tank must be located at least 5 m above the
engine cooling water outlet pipe.
The freshwater generator, if installed, may be connected
to the seawater system if the generator
does not have a separate cooling water pump.
The generator must be coupled in and out slowly
over a period of at least 3 minutes.
For external pipe connections, we prescribe the
following maximum water velocities:
Jacket water ................................................ 3.0 m/s
Seawater ..................................................... 3.0 m/s
Deaerating tank,
see Fig. 12.07.01
MAN B&W MC/MC�C, ME/ME�C/ME�GI/ME-B engines 198 38 94�8.6
MAN Diesel
TI
High level alarm
Expansion tank
Low level alarm
Alarm device box,
see Fig. 12.07.02
TI TI
Jacket water
cooler
From tracing of fuel oil drain pipe *)
Regulating valve
Freshwater
generator
Normally closed valve.
To be opened when the
system <strong>is</strong> filled with
cooling water. (Manually
or automatically)
*) Flange BD and the tracing line are not applicable on MC/MC-C engines type 42 and smaller
178 50 17�2.5