PD CEN/TR 15281:2022

Potentially explosive atmospheres. Explosion prevention and protection. Guidance on inerting for the prevention of explosions. | Status: Current

1 Scope Inerting is a preventive measure to avoid explosions or fire to happen. By feeding inert gas into a system, which is to be protected against an explosion or a fire, the oxygen content is reduced below a certain limit or completely replaced by an inert gas, depending on the inert gas, on the fuel and the process until no explosion or fire can occur or develop. Inerting can be used to prevent fire and explosion by reducing the O2 content.

NOTE Inerting can also be used to prevent and to extinguish smouldering nests and glowing fires which are a primary source of ignition in pulverized fuel storage and handling facilities, substituting air by sufficient inert gas inside the equipment.

The following cases are not covered by the guideline:

• — admixture of an inert solid powder to a combustible dust;
• — inerting of flammable atmospheres by wire mesh flame traps in open spaces of vessels and tanks;
• — firefighting;
• — avoiding an explosive atmosphere by exceeding the upper explosion limit of a flammable substance;
• — anything related to product quality (oxidation or ingress of humidity) or product losses;
• — any explosive atmosphere caused by other oxidizing agents than oxygen.

Other technologies might be used in combination with inerting such as floating screens made of independent collaborative floaters consisting of an array of small floaters non-mechanically linked but overlapping each other in order to form a continuous layer covering the liquid surface. Product oxidation or evaporation reduction is directly proportional to the surface area covering ratio and quality of the inerting.