Dry Systems - Perkins M65 Installation Manual

TPD 1399E

Dry Systems

Dry exhaust systems are most commonly used with
engines which are keel cooled. This arrangement
is particularly useful for commercial or leisure craft
operating in heavily polluted water.
Dry exhaust systems for marine installations need
careful design to minimise the disadvantages of
enclosing components that are at a high temperature
in confined spaces. A typical system is shown in (A).
The first part of a dry system should include flexible
connections (A1) to permit movement between the
engine and the fixed part of the exhaust. Connections
of the stainless steel bellows type are suitable, but care
must be taken to ensure that they are only required to
accommodate movements that do not involve twisting
the ends of the bellows relative to each other.
The remainder of the exhaust system should be well
insulated (A2) to avoid fire risk.
If there is a long exhaust run which gains height as it
leaves the exhaust manifold, it may be necessary to
incorporate a trap to collect condensate and allow it
to be drained.
The minimum bore of the exhaust pipe should be
40mm (1.6 inches) for the M65 and 63.5mm (2.5
inches) for the M85T.
Note: Bellows should be in an unstrained condition
when installed, so that the full bellows movement
is available to absorb expansion and engine
movement.
The weight of the exhaust system should be supported
by brackets and not carried by the bellows.
Chapter 3
Page 9