Man B&W L35MC6-TII, Project Manual

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MAN B&W 1.06
Page 5 of 7
MAN Diesel
198 74 728.0 MAN B&W S50MC/MC-C-TII, S46MC-C-TII, S42MC-TII,
S35MC-TII, L35MC-TII, S26MC-TII
Governor
The engine is to be provided with a governor of
a make approved by MAN Diesel, controlling the
fuel pump through an actuator. The governor must
meet the ISO 3046 standard, part IV, 1997.
The speed setting of the actuator is determined by
an electronic signal from the electronic governor
based on the position of the main engine regulat-
ing handle. The actuator is connected to the fuel
regulating shaft by means of a mechanical linkage.
Alternatively for engines without PTO, a mechani-
cal/hydraulic Woodward governor for pneumatic
speed setting could be provided.
Fuel Oil Pump and
Fuel Oil High Pressure Pipes
The engine is provided with one fuel pump for
each cylinder. The fuel pump consists of a pump
housing of nodular cast iron, a centrally placed
pump barrel, and a plunger of nitrated steel. In
order to prevent fuel oil from mixing with the lu-
bricating oil, the pump actuator is provided with a
sealing arrangement.
The pump is placed on the roller guide hous-
ing and activated by the fuel cam. The volume
injected is controlled by turning the plunger by
means of a toothed rack connected to the regulat-
ing shaft.
On S50MC and S50MC-C, the fuel pumps incor-
porate Variable Injection Timing (VIT) for optimal
combination of NOx and SFOC. The VIT uses the
governor fuel setting as the controlling parameter.
(VIT is not applicable on engines type 46 and
smaller).
The fuel oil pump is provided with a puncture
valve, which prevents high pressure from building
up during normal stopping and shut down.
As an option on engines type 50, the roller guide
housing is provided with a semi-automatic lifting
device which, during rotation of the engine, can
lift the roller guide free of the cam. On engines
type 46 and smaller, a separate tool is used to lift
the roller guide.
The fuel oil highpressure pipes are either double-
walled or of the hose type.
Further information is given in Section 7.01.
Fuel Valves and Starting Air Valve
Each cylinder cover is equipped with two or three
fuel valves, starting air valve (SAV), and indicator
valve.
The opening of the fuel valves is controlled by the
high fuel oil pressure created by the fuel oil pump,
and the valves are closed by a spring. The fuel
valves are cooled by the fuel.
An automatic vent slide allows circulation of fuel
oil through the valve and high pressure pipes
when the engine is stopped. The vent slide also
prevents the compression chamber from being
filled up with fuel oil in the event that the valve
spindle sticks. Oil from the vent slide and other
drains is led away in a closed system.
The starting air valve is opened by control air
from the starting air distributor and is closed by a
spring. The control air supply is regulated so that
the starting valves deliver starting air to the cylin-
ders in the correct firing order.
Starting Air System
The starting air system comprises a main starting
valve, a starting air distributor and a non-return
valve, a bursting disc for the branch pipe and a
starting valve on each cylinder. The main starting
valve is connected with the manoeuvring system,
which controls the start of the engine.
A slow turning valve can be ordered as an option.
The slowturning function is actuated manually
from the manoeuvring console.
The starting air system is described in detail in
Section 13.01.