Iveco Marine Diesel Engines, Installation Handbook

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9.4 SILENCERS
It is possible to fit the engine with commercially available or special models. In either case, the instal-
lation and manufacturing features must meet the requirements to avoid the return of water to the
engine under any navigation conditions. The total counterpressure, including pipes pressure, must be
within permitted limits.
9.5 COUNTERPRESSURE
In the case of any of the discharge systems previously described, it is necessary to check that the dis-
charge counterpressure value is within the limits mentioned in the engines specific technical chart.
Overlooking limits causes:
■
Reduced performance
■
Fuel consumption increase
■
Fumes
■
Engine overheating
The dockyard personnel must assess installation on the basis of their knowledge and expertise and on
the equipment assembly layout on the vessel. IVECO provides estimates for exhaust gases volume and
temperature for their own engines, in case they are needed.
The diagram in fig. 3 merely illustrates a procedure to measure the diameter of an exhaust pipe system
for gas
not mixed with water.
To size the pipes for gas mixed with water increase the diameter by 10% taking as a reference value
the dry discharge pipe diameter.
In engines equipped with IVECO standard mixers, the pipe diameter shall never be smaller than the
mixer outlet diameter. In each case, it is advisable to check the counterpressure originated by the dis-
charge pipe and the silencer, if present.
The measuring must be taken near the exhaust manifold outlet clamp or the turbine in a straight sec-
tion, if possible. This should be done during navigation, with the engine at maximum speed; IVECO
engines are fitted with a screwed intake to insert the pressure gauge.
MARCH 2004 DISCHARGE
9.96
MARINE ENGINES INSTALLATION