Exhaust Valve
The exhaust valve consists of the valve housing
and the valve spindle. The valve housing is made
of cast iron and is arranged for water cooling. The
housing is provided with a water cooled bottom
piece of steel with a flame hardened seat of the
W-seat design.
The exhaust valve spindle is a DuraSpindle, a
spindle made of Nimonic is available as an option.
The housing is provided with a spindle guide in
any case.
The exhaust valve is tightened to the cylinder cov-
er with studs and nuts. It is opened hydraulically
and closed by means of air pressure. The hydrau-
lic system consists of a piston actuator placed on
the roller guide housing, a highpressure pipe, and
a working cylinder on the exhaust valve.
The piston actuator is activated by a cam on the
camshaft, a built-in timing piston and a control
valve enables control of the closing time of the ex-
haust valve.
In operation, the valve spindle slowly rotates, driv-
en by the exhaust gas acting on small vanes fixed
to the spindle.
Sealing of the exhaust valve spindle guide is pro-
vided by means of Controlled Oil Level (COL), an
oil bath in the bottom of the air cylinder, above the
sealing ring. This oil bath lubricates the exhaust
valve spindle guide and sealing ring as well.
Reversing
On reversible engines (with Fixed Pitch Propellers
mainly), reversing of the engine is performed in
the Engine Control System by letting the starting
air distributor supply air to the cylinders in order of
the desired direction of rotation and by timing the
fuel injection accordingly.
The exhaust valve gear is not to be reversed.
Indicator Cock
The engine is fitted with an indicator cock to
which the PMI pressure transducer is connected.
The PMI system, a pressure analyser system, is
described in Section 18.02.
MAN B&W Alpha Cylinder Lubrication
The electronically controlled MAN B&W Alpha
cylinder lubrication system is applied to the ME-B
engines.
The main advantages of the MAN B&W Alpha cyl-
inder lubrication system, compared with the con-
ventional mechanical lubricator, are:
• Improved injection timing
• Increased dosage flexibility
• Constant injection pressure
• Improved oil distribution in the cylinder liner
• Possibility for prelubrication before starting.
More details about the cylinder lubrication system
can be found in Chapter 9.
Manoeuvring System
The engine is provided with a pneumatic/electric
manoeuvring system. The system transmits orders
from the Engine Control System to the engine.
The manoeuvring system makes it possible to
start, stop, reverse the engine and control the en-
gine speed.
The engine is provided with an engine side con-
sole and instrument panel.
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