Iron levels cut from 455–838 mg/L to 60–127 mg/L in a 200 m³ system

Yuntianhua Group's pentaerythritol plant ran a 200 m³ ethylene glycol cooling system serving a process at −10 °C. The manufacturer reports that within two years of commissioning the system had corroded severely enough to threaten production continuity, that annual maintenance removed more than one tonne of rust sludge, and that iron ion concentration in the glycol had reached 455–838 mg/L.

The plant replaced the ethylene glycol charge with LM-4 Glacier Coolant, a conversion the manufacturer describes as including system flushing, removal of the spent corrosion inhibitor and filling at the specified concentration. After seventeen months of continuous operation, the manufacturer reports iron ion levels stable at 60–127 mg/L, with annual cost savings exceeding RMB 87,600.

Ethylene glycol degrades into acidic by-products that attack steel, and the iron those acids liberate then circulates and settles as sludge — which is why iron ion concentration is the measurement the manufacturer reports. The manufacturer's comparison figures apply to the concentrations shown.