Inerting is a measure to prevent explosions. By feeding inert gas into a system which is to be protected
against an explosion, the oxygen content is reduced below a certain concentration until no explosion can
occur. The addition of sufficient inert gas to make any mixture non-flammable when mixed with air (absolute
inerting) is only required in rare occasions. The requirements for absolute inerting will be discussed. Inerting
may also be used to influence the ignition and explosion characteristics of an explosive atmosphere.
The guidance given on inerting is also applicable to prevent an explosion in case of a fire.
The following cases are not covered by the guideline:
admixture of an inert dust to a combustible dust;
inerting of flammable atmospheres by wire mesh flame traps in open spaces of vessels and tanks;
fire fighting;
avoiding an explosive atmosphere by exceeding the upper explosion limit of a flammable substance.
Inerting which is sufficient to prevent an explosion is not a protective measure to prevent fires, self-ignition,
exothermic reactions or a deflagration of dust layers and deposits.
BS PD CEN/TR 15281:2006 Referenced Document
EN 1127-1:1997 Explosive Atmospheres - Explosion Prevention and Protection - Part 1: Basic Concepts and Methodology
EN 14034-4 Determination of explosion characteristics of dust clouds - Part 4: Determination of the limiting oxygen concentration LOC of dust clouds*， 2011-01-01 Update
EN 50104 Electrical apparatus for the detection and measurement of oxygen - Performance requirements and test methods*， 2010-06-01 Update
IEC 61508-1 Functional safety of electrical/electronic/programmable electronic safety-related systems - Part 1: General requirements*， 2010-04-01 Update