In the previous article "Coating of equipment suitable for potentially explosive atmospheres" key technical aspects were analyzed regarding electrostatic risk mitigation and corrosion resistance in harsh environmental conditions.

In this context, the central role of the ISO 12944 standard emerged clearly, particularly ISO 12944-6, which defines both the corrosivity categories of installation environments and the expected durability levels of protective coating systems.

In response to the growing market interest in high-reliability solutions, the Cortem coating system, characterized by the typical RAL 7035 color, was subjected to specific testing to verify its performance in C4-classified environments. The results demonstrated the achievement of high durability class H (High), confirming the effectiveness of the system in highly aggressive industrial settings.

Building on these positive outcomes, testing activities were extended to even more demanding conditions corresponding to corrosivity class C5. The tests showed that:

• on aluminum substrates, the standard coating cycle meets the requirements of C5 High;
• on stainless steel substrates, achieving C5 High requires a multi-layer coating process, optimized to ensure superior long-term performance.

Although ISO 12944 does not cover all types of metals and alloys, it remains a well-established technical reference for evaluating anticorrosion performance, even for materials not explicitly included.These results strengthen Cortem’s positioning as a technological benchmark in the industry, offering coating systems designed to ensure reliability, safety, and durability even in the most extreme industrial environments.