Boiler feedwater

(mechanical engineering) Water supplied to a steam-generating unit.

Water supplied to a boiler unit for the generation of steam. Feedwater should be virtually free of impurities that are harmful to the boiler and its associated system. Generally, natural waters are unsuitable for direct use as feedwater because of their contamination by contact with the earth, the atmosphere, or other sources of pollution. These contaminants can be removed or altered by chemical treatment and other means to provide satisfactory feedwater. See also Raw water; Water treatment.