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5. Components of ignition probability
5.1 Presence and efficiency
In simplified terms, for each ignition source, the probability of ignition depends on two components:
the probability that the source is present at the same time as the flammable cloud; this parameter is often referred to in the literature as the "presence factor";
the probability that the source will be of sufficient energy to ignite the cloud over a given time interval; this parameter is often referred to in the literature as the "strength factor".
By way of example, if we consider a low-energy torch whose utilization rate is 20% (i.e. the torch operates 20% of the time), and if we assume that for such a source the probability of the cloud...
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Components of ignition probability
Some data bank values
Bibliography
Digital media
ARIA – Technological accident database.
French Ministry of Ecology, Energy, Sustainable Development and Town and Country Planning (MEEDDAT) http://www.aria.developpement-durable.gouv
Standards
- Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas - NFPA 497 -
- Explosive atmospheres – Explosion prevention and protection – Part 1: Basic concepts and methodology - NF EN 1127-1 -
- Explosive atmospheres: substance characteristics for gas and vapour classification – Test methods and data...
Regulations
Arrêté du 29 septembre 2005 relatif à " l'évaluation et à la prise en compte de la probabilité d'occurrence, de la cinétique, de l'intensité des effets et de la gravité des conséquences des accidents potentiels dans les études de dangers des installations classées soumise à autorisation ".
JO n° 234 du 7 octobre 2005 – NOR DEVP0540371A.
Directory
Organizations
Accidental Risk Assessment Methodology for Industries in the framework of SEVESO II directive http://aramis.jrc.it
Center for Chemical Process Safety (CCPS) http://www.aiche.org/ccps
...
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