WÄRTSILÄ 46F Series, Product Manual

Page: 118 / 208

9.3 External cooling water system
It is recommended to divide the engines into several circuits in multi-engine installations. One
reason is of course redundancy, but it is also easier to tune the individual flows in a smaller
system. Malfunction due to entrained gases, or loss of cooling water in case of large leaks
can also be limited. In some installations it can be desirable to separate the HT circuit from
the LT circuit with a heat exchanger.
The external system shall be designed so that flows, pressures and temperatures are close
to the nominal values in Technical data and the cooling water is properly de-aerated.
Pipes with galvanized inner surfaces are not allowed in the fresh water cooling system. Some
cooling water additives react with zinc, forming harmful sludge. Zinc also becomes nobler
than iron at elevated temperatures, which causes severe corrosion of engine components.
9-6 DAAB605814
Wärtsilä 46F Product Guide 9. Cooling Water System