Corrosion inhibitors and water treatment

Industrial water systems and water networks in the tertiary sector are subject to corrosion, scaling and biological proliferation. These phenomena generate significant maintenance costs.

The use of corrosion inhibitors helps to reduce these costs by increasing the durability of the equipment in these circuits.

Among the installations treated, the following stand out:

• steam generators and steam distribution and condensate return networks;

• semi-open cooling circuits (with recirculation on a cooling tower) or open circuits (with lost water);

• closed circuits (heating, chilled water, closed cooling) ;

• sanitary hot and cold water networks.

Equipment affected by corrosion includes water or steam distribution pipes, heat exchangers, heating surfaces and storage capacities.

This article will help network designers, thermal engineers and chemists in charge of monitoring these systems, as well as the technicians in charge of operating them, to gain a better understanding of the role and mode of action of corrosion inhibitors, as well as their application in the various water circuits encountered in industry and the tertiary sector, and their possible interaction with the other water treatment products used.

The legislative aspects of these different circuits are also discussed:

• quality limits that treated water must meet depending on its use: sanitary, technical (cooling, heating) or steam production;

• quality standards for inhibitors depending on the destination of the treated water ;

• environmental constraints, including drought decrees.