Corrosion inhibitors sodium sulfite

Oxygen 0, Severe metallic corrosion Addition of corrosion inhibitors, sodium sulfite Automatic air vents, deaeration... 

Where water softening is provided and there is no reduction in system water TDS, treatments are primarily based on inorganic corrosion inhibitor blends (nitrite, molybdate, etc.). Under these circumstances, there is no benefit in using an expensive organic oxygen scavenger to keep the TDS level low, and a common chemical such as catalyzed sodium sulfite may be used. 

Oxygen 02 Corrosion of water lines, heat exchange equipment, boilers, return lines, etc. Deaeration, sodium sulfite, corrosion inhibitors, hydrazine or suitable substitutes... 

The prevention of iron-oxide-induced corrosion can be accomplished by mechanical filtration of iron oxide, by the use of additives (iron oxide dispersants), and by adding inhibitors for corrosion. Standard procedures for reduction of corrosion in boilers include deaeration of the feedwater and the use of additives such as sodium sulfite. 

A water system naturally contains sulfate-based compounds, but when sulfite is added to a closed water system as an oxygen scavenger and corrosion inhibitor, the sodium sulfite is oxidized to sodium sulfate, as indicated in Equation 18.1 (Yuzwa 1991) ... 

Oxygen scavengers are added to water either alone or with a corrosion inhibitor. Organic corrosion inhibitors alone in aerated brine water will slow general corrosion, but will not always prevent pitting attack. The most common oxygen scavengers used in water at ambient temperature are sodium sulfite and sulfur dioxide. 

For preventing chloride stress corrosion attack on austenitic stainless-steel-tubed steam generators, nitrate and sodium sulfite are effective inhibitors. The combination of the two is superior to either inhibitor alone or to any other inhibitor or combination. These inhibitors are effective in alkaline phosphate boiler water containing up to 500 ppm chloride. 

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