Westerbeke WPDS-20 Technical Manual page 103

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SERVICE BULLETIN #69
Subject: Exhaust system failures
Models: All marine generators and marine engines
~Jhen engine sea water is fed into an exhaust system so that the full
stream strikes a surface, erosion may cause premature failures.
Proper design of either a water jacketed or a "later injected ("wet")
exhaust system to prevent this problem requires that the sea water
inlet be positioned so that the entering stream of sea water does not
strike a surface directly. Also, the velocity of the entering sea
water stream should be as low as possible which is achieved by having
inlet fittings as big in diameter as possible.
In addition to the above design considerations, it is usually advan-
tageous to divide the sea water flow at the point of entry to the
exhaust system so that only a portion of it enters the exhaust system.
The remainder is normally piped directly over the side. The proper
proportion of the sea water flow to pass through the exhaust system
can only be determined by trial and error. The goal is to prevent
excessive exhaust temperatures with the least amount of sea water.
PN
19149
May
6, 1974
-,\'ESTE~3EKE CORp· AVON INDL.:STRIAL PARK· AVON. MASS 02322 USA
TELEPHONE 6:75887700· TELEX 92·4444· CA8LE WESTCORP