This code of practice provides guidelines for the chemical treatment of water used in industrial and commercial cooling systems. It covers methodologies to prevent scaling, corrosion, fouling, and microbiological growth to maintain system efficiency and longevity.
Provides guidelines for the treatment of water used in cooling systems, including cooling towers and chilled water systems, to prevent scaling, corrosion, and biological growth.
Quick Reference Values
typical pH range7.0 to 9.0 for open recirculating systems
cycles of concentration target3.0 to 6.0 (depending on makeup water quality)
LSI target range+0.5 to +1.5 (slightly scaling to protect against corrosion)
total suspended solids limit< 100 mg/l
Key Formulas
Cycles of Concentration (COC) = Concentration of ion in blowdown / Concentration of ion in makeup water
Langelier Saturation Index (LSI) = pH - pHs
Practical Notes
Always balance the Cycles of Concentration (COC) to minimize water consumption while preventing excessive scaling.
Alternating between oxidizing and non-oxidizing biocides prevents microbial resistance, critical for Legionella control.
Corrosion coupons should be installed in a bypass line mimicking system flow to accurately monitor the treatment program's effectiveness.