Zone classification describes how often and for how long an explosive atmosphere may be present. Zone 1 covers areas where an explosive gas atmosphere may occur occasionally in normal operation; Zone 2 covers areas where it is unlikely or, if it occurs, persists only briefly.
What should be considered?
Zone 2 equipment must not be installed in a Zone 1 area. Protection concept, equipment category, gas group and temperature class are equally critical.
Process expansions and ventilation changes can affect classification, so older designs should be verified against an up-to-date risk assessment.
Technical note
The information on this page is general guidance. Final equipment selection must be verified against the project risk assessment and product certificate.