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explosion protection

2.the basic physic principles and definitions

8 > explosion pressure resistant construction > avoiding flammable substances(replacement technologies) > explosion relief devices > explosion suppression by means of extinguishers The principle of integrated explosion protectionrequires following explosion protection measures in a certain sequence. Preventing explosive atmospheres(Primary Explosion Protection) The term primary explosion protection refers to all precautions, which prevent a hazardous explosive atmosphere from being created.This can be achieved by: > inerting (addition of nitrogen,carbon dioxide etc.) Mitigation of the explosion effects(Constructive Explosion Protection) If hazardous explosive atmospheres cannot be safelyavoidedand theirignition cannot beexcluded, then measures must be taken which limit the effect of explosions to a safe degree, e.g. by means of: > limitation of the concentration by means ofnatural or technical ventilation Avoiding ignition of explosive atmospheres If the danger of explosion cannot be completely or only partly avoided by measures of preventing the formation of an hazardous explosive atmo- sphere, then measures must be taken that avoid the ignition of the explosive atmosphere. The required safety level of these measuresdepends on the possible danger potential in the installation location.The hazardous areas are therefore divided into zones, according to the probability of an explosive atmosphere being formed (see Section 3.2.2).In the USA and other countries, hazardous locations are classified into Classes and Divisions (see Section 6.2). For locations classified in this way, requirements must be met concerning the apparatus, which are approved for use in these locations. In addition, it is also necessary to prove that these requirements have been met.
Fig. 3: Basic principles of explosion protection

Integrated explo-sion protection

The basics of explosion protection - 9224 123

Preventing theformation of an explosive atmosphereAvoidance of theignition of an explosive atmosphereMitigation of the effectsof an explosion to an acceptable extent R.STAHL explosion protection