Cleaning & Corrosionprotection for glycol systems

Technical Insight – Glycol Systems Under Pressure

Closed-loop glycol systems, commonly used for HVAC and industrial cooling, face two critical challenges: fouling and corrosion. Over time, glycol degrades into organic acids, lowering pH and accelerating metal attack. Simultaneously, biofilm and particulate accumulation impair heat transfer, leading to performance drift and energy inefficiency. Without proactive chemical cleaning and corrosion protection, these systems become costly liabilities—both in terms of maintenance and asset longevity.

As water treatment professionals, it is our responsibility to ensure long-term system integrity through rigorous monitoring, targeted cleaning procedures, and tailored corrosion inhibitor programs.

Client Case – Major North American Wastewater Facility

System

BOILER HOUSE : 5 boilers, one of which is always down for maintenance.

• Process Heating (Heating up sludges)
• Estimated System Volume: 80’000 gal
• Contains: City Water + Glycol
• Equipment: 1 Filter Housing

Solution

Treatment Strategy:
The corrosion control program implemented relied on a formulation fully compatible with glycols. The dual-action mechanism includes:

• Filming amines to create a protective molecular layer on metallic surfaces.
• Alkalizinf amines to stabilize pH and buffer glycol degradation byproducts.

This approach rapidly became a standard treatment model for glycol-based systems in North-America.

Implementation Notes:

• Progressive injection was initiated to promote controlled cleaning and avoid mobilizing excessive deposits too quickly.
• Weekly filter replacements were scheduled to capture suspended solids and corrosion products released during the initial film formation phase.

Technical Outcome:
The strategy enabled both system cleaning and long-term corrosion protection without shutdown, while maintaining stable pH and minimal turbidity—a robust operational benchmark for similar facilities.

After 4 weeks of treatment, the filters showed no visible fouling—indicating successful deposit removal and stabilization of the system. Dissolved iron levels were consistently under control, confirming the effectiveness of the corrosion inhibition and cleaning program.

At this stage, Boiler #3—which had remained offline—was brought back into operation. This reactivation triggered a new cleaning phase lasting several weeks, during which similar monitoring protocols (filter changes, iron tracking) were maintained to ensure uniform protection and system-wide cleanliness