Why is sodium sulfite tested for in boiler water?

Sodium sulfite is tested for in boiler water primarily to maintain oxygen scavenger levels. In the context of boiler operations, oxygen is a corrosive agent that can cause significant damage to the internal surfaces of the boiler. Sodium sulfite acts as an oxygen scavenger, chemically reacting with dissolved oxygen to form sodium sulfate, thereby preventing oxidation and corrosion within the boiler system.

By testing for sodium sulfite, operators can ensure that an adequate level of this compound is maintained in the boiler water, which is crucial for protecting the equipment and extending its lifespan. Proper management of sodium sulfite levels helps to mitigate the risks associated with oxygen in water, which is particularly important in steam generation processes where high pressures and temperatures are involved.

Other options, while they may relate to water treatment, do not directly pertain to the primary reason for monitoring sodium sulfite. For instance, monitoring dissolved solids is important for overall water quality, increasing water temperature does not involve sodium sulfite directly, and measuring acidity levels relates more to pH controls rather than the function of sodium sulfite as an oxygen scavenger.