The most important measurement point in the water/steam cycle for chlorides and sulfates is at the turbine inlet. This ensures that only acceptable levels of chlorides and sulfates enter with the steam into the turbine, the most expensive capital equipment in the power plant. Another important measurement point is after the condensate polisher to monitor for sulfonated resin breakdown. It is also essential to employ a chloride and sulfate analyzer to monitor these ions before the boiler, to ensure the boiler is not damaged. It also provides an opportunity to remove chlorides and sulfates from the water/steam cycle via boiler blowdown if high levels of the ions are detected at the boiler inlet.
Low chloride and sulfate levels are ensured in makeup water by monitoring them after all treatment stages, before the water is sent to the storage tank that feeds the water/steam cycle.