FLAMEPROOFING - HAZARDOUS AREAS
Hazardous areas are classified in two distinct groups.
Flammable gases, vapours and liquids make up one group,
which traditionally had been known as class 1. Dusts, fibres
and flyings make up the second group. This group was previously
known as class 2. Hazardous areas are broken up into zones
dependant upon the length of time the hazard is present
or likely to be present. The table below show the current
zones as specified in the Australian Standards AS2430.1
and AS/NZ 61241.3
NOTE: Mobile material handling equipment is not permitted
in Zone 0 or Zone 20
Zones applicable for flammable gases, vapours and liquids
(previously known a Class 1)
ZONE 0 |
Flammable atmosphere continuously present,
or present for long periods
(more than 1000 hours/year). |
ZONE
1
|
Flammable atmosphere is likely to occur
in normal operation
(more than 10 hours/year but less
than 1000 hours/year). |
ZONE
2
|
Flammable atmosphere is unlikely to occur
in normal operation
(less than 10 hours/year). |
Zones applicable for dusts, fibres and flyings (previously
known a Class 2)
ZONE
20
|
Area in which conbustible dust, as a
cloud is continuously or frequently present. |
ZONE
21
|
Area not classified Zone 20 in which
combustible dust, as a cloud is likely to occur during
normal operation. |
ZONE
22
|
Area not classified Zone 21 in which
combustible dust clouds may occur infrequently and
persist for only a short period. |
|
