PART THREE:EXHAUST SYSTEMS
Figure 9-3.
Expansion slip
joint
stainless pipe of the diameter required to meet
the engine manufacturer’s specifications.
Alternatively, a flexible bellows may be
used instead of the slip joint (Figure 9-4). Note
that the expansion slip joint is not completely
vapor tight. It should be used only in locations
where the ventilation air will clear any possi-
ble fumes. This means high up on the exhaust
stack. Lower down or in the boat hull and
cabin spaces, bellows should be used.
Keeping Water Out
To keep rain and spray out, the open end of
the exhaust outlet is cut off at approxi-
mately 15 degrees past vertical as shown in
Figure 9-1 and equipped with the three drain
slots as shown in Figure 9-5.
Fastening to Accept
Expansion and Contraction
Keep in mind that the exhaust piping’s tem-
perature will vary from as cold as 10° or
20°F (−12° or −6°C ) or less, to as hot as
Figure 9-4. Slip joints or stainless bellows
allow for expansion
Figure 9-5. Drain slots (Courtesy
Caterpillar, Inc.)