ATX PRODUCT CATALOG 001

s40/02/95FZone 0 Zone 1 Zone 2 Non-Hazardous ZoneDefinition of Zones : see page G13.Typical guide for liquid hydrocarbon storages40/03/95F3 m3 m3 mTanker truck unloading station.Mobile tank filling deviceCompulsory protection measuresThe risk of explosion must be safe guarded by the concurrent use ofspecific protection measures :• Internal overpressure in the room,• Continuous dilution,• Intake at the source.The latter two measures are only possible when the maximumdischarge flow is known accurately.Measures must be taken to compensate for a possible failure in theparticular measures used :• Light and/or sound alarm,• Measures necessary to repair and restart the protection device asquickly as possible,• Automatic power off device controlled by :– A tester that checks that overpressure, dilution or ventilationdevices are working correctly,– Or an atmosphere tester (fixed explosion meter withcontinuous operation) that switches power off at a controlthreshold set to 25% of the LEL (lower explosive limit) ifno personnel are present and 10% of the LEL if there arepersonnel present.Appleton adviceThe additional measures are difficult and expensive, so that Zone 1equipment is frequently used over entire sites.This equipment covers explosion risks at all times, regardless ofuncontrollable environmental variations.This position was adapted by same significant oil companies.G:15Hazardous Locations Guide