• Dissolved chemicals in water can destroy a boiler system.Boilers, ladders and pipes at a power plant, image by Andrei Merkulov from Fotolia.com
  
  A boiler system is rugged and dependable, providing you use only pure water. Unfortunately, most water has dissolved gases, minerals and pollutants. All of these corrode and deteriorate the inside of a boiler system, leading to malfunction and costly internal repairs. To avoid this, treatments are available, and the United States Army Corps of Engineers conducted research and issued recommendations on what treatments to use for boiler water.
  
  

Treatment for Dissolved Oxygen

• According to the Corps, dissolved oxygen in water leads to internal rusting and corrosion. The recommended treatments to remove oxygen include the following: Pre-boil the water to release oxygen by using a de-aerator; Use sodium sulfite to scavenge out the oxygen, but do not expose the sodium sulfite to air prior to releasing it into the water; Use both methods to pre-treat water before allowing contaminated water to enter the boiler system.
  
  

Treatment for Dissolved Carbon Dioxide

• Carbon Dioxide forms carbonic acid, which is corrosive to internal components. According to the Corps, the treatments are as follows: Recycle internal water, since this has lower levels of carbon dioxide. Use amine treatments to increase the pH of the water to between 7.5 and 8.5. For water runs of 800 feet or less, use morpholine. For runs of up to one mile use diethylaminoethanol, and for runs of over one mile use cyclohexylamine.
  
  

Treatment for Dissolved Minerals

• Dissolved minerals accumulate on internal components, forming a scale that destroys and renders these components ineffective. The Corps recommends adding orthophosphate or various polyphosphates to the water to sufact the minerals. Feed orthophosphate directly into the boiler since feeding it upstream from the boiler can cause precipitation if calcium is present in the water.
  
  

Use Blowdown Effectively

• Blowdown taking small amounts of water from the boiler, either from the top to remove gases or from the bottom to remove sludge. You can perform this process continuously or only when contaminant levels reach an excessive level. The Corps recommends not over or under doing it since you must treat new water introduced as well. Close monitoring of the water is recommended instead, and only perform blowdown when necessary.