All machinery just starting up in the Engine Room (E/R) naturally emit heat. To absorb the emitted heat, fresh water circulates surroundings of those machinery in the E/R. As the fresh water temperature goes up, sea water takes the role of cooling down its temperature.
This cooling unit with pipes, valves and other accessories is called Central Fresh Water Cooler Unit. To prevent cooler from corrosion by the highly corrosive sea water, titanium plate (general thickness is 0.5 mm), which has an excellent corrosion resistance feature, is normally used for Central Fresh Water Cooler. A Central Fresh Water Cooler Unit generally consists of 2 or 3 sets of cooler.