In ships equipped with demineralizers, what is the water entering the demineralizer from any tank referred to as?

The water entering the demineralizer from any tank is referred to as "raw feedwater." This terminology is used because the water has not yet undergone the demineralization process, which is essential for removing impurities and dissolved solids that could cause corrosion or scaling in the ship's systems. The term "raw" signifies that it is the initial state of the water before treatment.

Reserve feedwater, as mentioned in the incorrect choice, typically refers to water that is stored for future use and may not necessarily be in its raw state or be directed to the demineralizer immediately. Condensate water refers to steam that has been cooled and turned back into liquid form, which may have undergone some degree of purification. Return water might imply water being cycled back into the system after use, but it does not accurately represent the water entering the demineralizer for processing.