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Comprehensive Water Treatment

for Closed Loops

A Program Designed Specifically for Your Equipment

Closed loops are widely variable, and this applies both to construction materials and modes of operation. Our water treatment programs have been developed specifically to meet the requirements of these systems and effectively control corrosion, fouling and harmful microbial activity. These issues, typical of closed loops, can quickly lead to equipment failure and costly maintenance needs. We work with you to develop the most suitable preventive program to protect your equipment.



Closed loops such as heating and cooling networks have unique conditions that make them susceptible to corrosion. This results not only in premature wear of components but also in fouling: a buildup of residue that affects water circulation. In the case of indoor air quality control, this will mean loss of efficacy and/or comfort.


Closed loops are generally comprised of diverse types of metal, which can result in galvanic corrosion in components. Some metals, such as aluminum, are instantly impacted by the properties of water.


Several other corrosion processes are likely to occur in closed loops, but corrosion induced by microorganisms is certainly one of the most difficult to correct.


Deposits can be caused by corrosion residues that clog piping, thus restricting water flow. Debris from deposits can also chip off and travel through the system, eventually lodging in areas of low flow.


Corrosion is the first factor of fouling. It explains why steel changes shape and increases in volume, thereby reducing the space available for water circulation.


Even though scaling is unusual, it cannot be completely ruled out in high temperature systems, especially if there are high make-up volumes. Hardness salts may precipitate out of the water and accumulate on heating surfaces, resulting in loss of efficiency and risk of breakage by the metal overheating.



Microbial growth can be critical in closed loop systems operating at warm to moderately hot temperatures. Microorganisms typically attach to surfaces forming a biofilm that interferes with heat exchange and the ability to properly protect the metallic surfaces from corrosion. This biofilm is also highly likely to harbor certain aggressive bacteria directly responsible for severe corrosion.


Anaerobic conditions (absence of oxygen) in closed loops are favorable to the growth of certain microorganisms, such as sulfate-reducing bacteria that can accelerate corrosion. Major signs of this problem include a blackish mass, low pH, sulfur odors and metal loss.


Closed loop systems can host many other microorganisms, which can use the chemical treatment as a nutrient. In these situations, corrosion can become difficult to control.

Questions about water treatment solutions?

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