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Material, corrosivity, pressure classes

Materials, corrosivity, and pressure classes are critical factors in industrial ventilation systems due to their direct impact on durability, safety, and performance. 


The selection of materials for ventilation components must consider the specific industrial environment. Durable and appropriate materials ensure the system can withstand the physical and chemical conditions it will encounter, thereby extending its lifespan and reducing maintenance costs. For example, stainless steel might be used in environments where chemical resistance is essential, while galvanized steel may be suitable for less corrosive conditions.

The system is available in several material such as:
  • Galvanized Z275
  • Recycled galvanized steel GR2 (min. 75% recycled steel)
  • Stainless steel EN 1.4301 (AISI 304)
  • Stainless steel EN 1.4404 (AISI 316L)
  • Aluminium 1050 A
  • Zink-Magnesium ZM 310
  • and powder coated polyester epoxy.
You can read about the corrosivity of the different materals in our General information and theory.


Industrial environments often contain corrosive substances such as chemicals, fumes, and moisture, which can deteriorate ventilation components over time. Understanding the corrosivity of the environment allows for the selection of materials and protective coatings that resist corrosion, ensuring the reliability and longevity of the ventilation system. This is crucial for maintaining air quality and preventing system failures that could lead to costly downtimes or safety hazards.

Corrosivity classes

Galvanic corrosion

Pressure classes

Ventilation systems must be designed to handle varying pressure levels depending on the industrial processes and facility requirements. Different pressure classes indicate the system’s ability to manage high or low-pressure conditions without compromising structural integrity. Correctly specifying pressure classes ensures that the ductwork and components can withstand operational stresses, preventing leaks, and maintaining efficient air flow. This is essential for achieving optimal performance and energy efficiency.

At big negative pressure there is a risk for a ventilation system to collapse. This risk is greater the bigger dimensions you have.
In order to increase the strength of the ducts you can e.g. increase their sheet metal thickness. This is a simple solution but the effect is rather small. It exists other ways with higher result. For bigger dimensions then the ducts may be stronger than the fittings.
In order to increase the strength of the fittings other ways than thicker sheet metal thickness are more suitable.
Lindab has experience and knowledge about this and is willing to offer help at special cases. We can, as special, deliver duct systems that can withstand at
least 5 000 Pa negative pressure.