TP24-04 Design Guide: Compatibility of Materials of Construction for Cooling Water Systems

Engineering designers often lack the required knowledge and/or water quality information to accurately specify compatible materials of construction in heat exchangers in evaporative cooling water systems. The consequences of this knowledge gap include compromised heat transfer efficiency, corrosion, and premature failure. Climate change, sustainability initiatives and supply chain issues have increased the complexity of successful selection of materials of construction due to the use of poorer-quality make-up waters, recycled sewage effluent (Treated Sewage Effluent (TSE)), and high-stress waterside operating conditions from water conservation initiatives. This paper provides guidance for equipment designers to match the water quality with the compatible materials of construction. Topics include a review of the method to estimate the quality of recirculating water from the chemical analysis of the makeup water, explanations about common parameters for water analyses, specifications for various water sources, materials of construction and the value of off-line passivation for copper and copper alloys to improve the reliability of copper and copper alloy materials that use lower-quality waters.