Exhaust system
4
General
Exhaust systems for marine engines can be divided
in two categories :
•
Wet exhaust line
•
Dry exhaust line, insulated
Most of the boats/vessels in Volvo Penta power range
with inboard engines are equipped with wet exhaust
systems. Water is injected into the system to cool the
exhaust gas and the mixture passes out together with
the exhaust.
A wet system has several advantages compared with
a dry system. The water lowers the exhaust tempera-
ture considerably after the point where the water is
fed into the system, enough to permit the use of a
flexible rubber hose. A flexible hose is usually easier
to install than pipes, is not affected by corrosion
or stress and absorbs the vibration from a flexibly
mounted engine. A wet exhaust system does not
need insulation either and radiates less heat.
The importance of using a wet exhaust is to make a
proper design and make sure the coolant cannot en-
ter backwards into the engine.
IMPORTANT! The exhaust system should be
designed and installed in such a way that the
exhaust emissions are taken out of the boat
without any harmful backpressure for the en-
gine and so that there is no risk of overheating
any adjacent parts of the boat. The demand for
silencing must also be met and the system ar-
ranged in such a way as to prevent the gases
from entering the boat. All exhaust systems
must be installed in such a way that water can-
not force its way back into the engine when the
engine has been switched off.
When designing the exhaust system, note that
the backpressure must not exceed the values in
the table in chapter Backpressure.
The dry exhaust system for inboard diesel engines
is mainly used for slower vessels, commercial opera-
tion. A dry system is neccessary in cold climates with
temperatures below 0°C (32°F). The dry system in
general requires less maintenance and has longer
service life. Insulation of the system is usually re-
quired as temperatures are dangerously high and
heat radiation into the engine room is negative for
engine operation.
Volvo Penta does not market complete wet or dry
exhaust systems but provides some of the key
components.
Exhaust system
Wet exhaust system
Dry exhaust system
Summary of Contents for D11 series
Page 1: ...Marine Propulsion Diesel Engines Installation 1 1 D E D5 D16 series ...
Page 2: ......
Page 208: ...206 References to Service Bulletins Group No Date Concerns ...
Page 209: ...207 Notes ...
Page 210: ...208 Notes ...
Page 212: ...7748655 English 11 2007 ...