WHAT’S WRONG WITH THIS PICTURE
METALLIC EXHAUST
SYSTEM COMPONENTS
The marine wet exhaust
system is a torture chamber
if ever there was one.
Exhaust can be as high as
800°F or more and mixed
with water that is obviously
much cooler, creating a rapid
change in temperature and
contraction of the gasses.
The temperature differential
on the metallic portion of
the exhaust can be several
hundred degrees across just a
few inches, creating incredible
stresses that are cycled hundreds and
thousands of times over the life of
the system components.
A variety of materials have been
used for water-cooled exhaust
systems, from ordinary steel, cast
iron, and stainless steel to more
exotic, corrosion-resistant alloys
such as cupronickel and Inconel.
Different materials offer different
advantages and liabilities. Ordinary
steel is strong, inexpensive, and easily
fabricated, however, it is highly
prone to corrosion, which is only
accelerated by higher temperatures.
Stainless steel is significantly more
corrosion resistant than ordinary
steel, however, it is also more
expensive, requires different welding
skills and equipment (it benefits
from MIG and TIG welding),
and contrary to popular belief, it’s
not immune from corrosion and
failure all together. Cupronickel
is even more corrosion resistant
than stainless steel, and Inconel
goes a step further in its corrosion
resistance—it’s used in nuclear power
and nuclear propulsion plant cooling
systems for ships and submarines.
PRODUCTS & SERVICES
davit.com
If it’s for an inflatable,
you’ll find it here.
All on-line, all the time for your convenience.
or call. . . . .612.724.9361
To view the rest of this PM visit www.wheelhousetech.com/pm. To discuss
how WheelHouse can help you improve the safety, reliability, and value of
your vessel or fleet call 978-562-5211 or email info@wheelhousetech.com
September 2011
passagemaker.com 119
