Only a few years ago, it was considered foolhardy in the United States to operate high-pressure
electric utility drum boilers with free caustic in the boiler water. It was assumed that free caustic in the
boiler would lead to caustic gouging of boiler tube metal. It became evident that many electric utility
boilers in other countries were operating successfully on caustic treatment programs.
Many U.S. electric utilities have converted their drum boilers to caustic treatment and eliminated
problems such as phosphate hideout. This paper will discuss the basics of caustic treatment and present
some case histories of successful operation in a caustic boiler water treatment regimen.
Keywords: caustic treatment, electric utility boiler, cycle chemistry, phosphate chemistry, boiler
corrosion control