RDG603A73 - Issue 3
Page 33 of 96
Work Boat with Water Injected Exhaust:
If the engine is installed low down in the boat, below the outside water level, a system such
as a Lift Silencer with a siphon break system, must be used to prevent sea water from flowing
back down the exhaust and into the engine. Standard marine house must be used. The
exhaust outlet size is 50mm Ø.
NOTE: Engines fitted with an optional PRM 280 gearbox
will have 60mm Ø exhaust outlet.
•
Lift Silencer
The correct installation of the lift silencer is vital to safety, and to avoid back flooding of
shows how to install the lift silencer correctly (Note: Halyard (M&I)
Limited have given Barrus permission to use the diagram).
Figure 16: Correct Installation of the Lift Silencer
1. The
swan neck must reach at least 450mm (18”) above the waterline, when
installed on hull centreline.
2. The top
of the silencer should be at least 300mm (12”) below the water injection
point.
3. The silencer must be installed as near as possible to the centreline of the hull,
particularly where severe angles of heel are expected. The swan neck must be
450mm above heeled water line.
4. Remember that 15% of the volume of the exhaust hose may be water. The size
of the silencer selected must be such that water draining into it will fit it by no
more than one third.
5. A siphon break must be used.
The silencer may only be used in a Water Injected marine exhaust system. The
