electrical six: Chapter Specialpracticefor oilr gts and chemical 'tankersTanker Classification HazanlousZones Electricallgnition of Gas ApparatusGasGrouPs TemperetureClass Typesof ExplosionProtection Ex'd' FlameproofEnclosure Ex'i' IntrinsicSafetY SafetY Ex'e' Increased Ex'n'Non-Sparking Ex'q'Sand Filled Ex'o'Oil lmmersed Enclosure Ex'p' Pressuriscd SpecialProtection Ex's' Certifi cationand ldentification Areas ElectricalTestingin Hazardous Mrintenrnce of Ex-protectedApparatus

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codes special are of Shipsthat transportbulk quantities oil, gasandliquid chcmicals subiectto and classification of practiceregardingtheir electricalinsiallations'Statutoryauthorities on geneially base rheir recommendations Publication92 of the lnternational soc'ieties of is The Commission. objectof all suchguidance to preventthe hazards firc Electrotechnical and explosionoccurringon board thesetank ships' to mixturesmay bc expected be presentare called gas-air in Spaces tankerswherJexplosive '.iung"rour' or 'hazardout'.ntt other areasbeingregarded 'safe" The bestway to avoid as in the explisions causedby electricalequipmentis simply not to install such equipment and this chapterwill areas.However. specialebcrrical "quipt"nt is pxirmitted hazardous equipment' (Ex)'prote.cted of providea guideto the rangean{ maintenance suchexplosion

Tanker clrssificetion areasis to divide thc areasinto three zones(0'l'2) which Shore practicefor hazarclous gas-airmixture ...ogni... the degreeof hazartlby indicatingthe tikelihoodof an explosive used Jn t"nk"r*. However, electricalequipment is bein! present. This practice is not on manufaclured the basisof suchzones- seelater sectionon zones. A space'or.'normally-safe'spaceS' as On tankers.areasare designate{ either'{angerous normally bc mixtureswould spaceis {efined asan areawhereflammablegas-air ldangerous The degreeof hazarrtor danger preselled by a dangerousspace is expicted r.' occur. cargoof the tanker'On thisbasir'four initially.by theiature of the flammable deiermined, typesof tanker are recognised: havinga oil in for intentletl rhe carriage bulk of non'boiling cargoes TypE A - Oil rankers gasoline carriers,-etc' carriers, Theseincludecrudeoil test)of 60'C or less. flashpoinr(closed a having flash oil in carriage bulk of non-boiling cargoes inre TypE B - Oil rankers ntled'ftlr for carrying bituminousor of point (closed test) in excess 6{)"C.These include tankers fuel