Answer
Oct 01, 2025 - 10:27 AM
ChemWorld QK401 would be a very effective closed loop cleaning product that will work at neutral pH and can be done while the closed loop system is on-line. The product should circulate for up to a week and the water will turn a dark green when the cleaning reaction is complete. We also suggest the system be heated (if possible) to 130 F– 180F and circulated for 24-48 hours at elevated temperatures. It can take 3-7 days if not heated (depending on the severity of the iron fouling). The product will solubilize the iron so you will need to bleed the system. A side stream filtration may help with anything that may “break off” but you would want to combine that with a controlled bleed.
If aluminum or galvanized metal is present, we recommend breaking the cleaning into two (2) feedings of 2.5% additions with system flush in between cleanings. Corrosion of galvanized and aluminum will not be problem if the pH of the recirculating water does not drop below 4.5. We recommend lab/field testing the effect that a 2.5% addition will have on the pH of the closed loop before the cleaning is performed to determine if the feedrate must be further reduced.
For this product, the solution will turn a dark, turbid green color, indicating completion of cleaning; pH will be >6.0 (probably 6.5) when cleaning is complete. The product can dissolve up to ~5000 ppm of iron and is non-corrosive to base metal.
If aluminum or galvanized metal is present, we recommend breaking the cleaning into two (2) feedings of 2.5% additions with system flush in between cleanings. Corrosion of galvanized and aluminum will not be problem if the pH of the recirculating water does not drop below 4.5. We recommend lab/field testing the effect that a 2.5% addition will have on the pH of the closed loop before the cleaning is performed to determine if the feedrate must be further reduced.
For this product, the solution will turn a dark, turbid green color, indicating completion of cleaning; pH will be >6.0 (probably 6.5) when cleaning is complete. The product can dissolve up to ~5000 ppm of iron and is non-corrosive to base metal.
