The engine room of a ship includes generators, boilers and various other units.
Especially Boiler Feed Water Filter Tank pulling sea water and feeding cooling water to a boiler consists of a filter separating and removing impurities from sea water, an oil detector keeping it from sea oil inflow or a back flow of oil, and a salinometer measuring salinity of incoming sea water.

Steam injector is installed inside tank to keep the temperature of the tank between 60 and 80 degrees Celsius. In addition, outside of the tank outside is kept warm. Similar volume of Pump units, such as Feed Water Pump, Circulation Pump, Economize F.W. Pump, are united all together based on required capacity.