What is a common cause of boiler feedwater contamination?

Inadequate water treatment is a common cause of boiler feedwater contamination because it directly affects the chemistry of the water being supplied to the boiler. Proper water treatment involves the removal of impurities, such as dissolved solids, oxygen, and carbon dioxide, which can lead to corrosion, scaling, and other problems that affect the efficiency and longevity of the boiler system. When water treatment is insufficient, it allows contaminants to enter the boiler, resulting in issues such as foaming, carryover, or even failure of the boiler components.

The other factors listed, while they can impact boiler performance, do not directly cause contamination in the same manner as inadequate treatment. Excessive steam pressure, high flow rates, and low temperatures might influence operational efficiency or safety, but they are not primary sources of contaminants entering the system. Inadequate treatment uniquely allows harmful substances to persist in the feedwater, making it the most relevant answer regarding contamination.