Installation, use and maintenance
8.1
DEFINITION OF CLASSIFIED ZONES
FOREWORD
ZONE 0
ZONE 1
ZONE 2
ZONE 20
ZONE 21
ZONE 22
ZONE 1
ZONE 2
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Definition of zones as shown in directive 99/92/EC
Place where an explosive atmosphere made up of a mix of air and inflam-
mable substances in the form of gas, vapour or mist is continuously pres-
ent, either for long periods or frequently.
Note: Generally speaking, said conditions, when they occur, involve the in-
side of tanks, pipes and containers, etc.
Place where it is probable that an explosive atmosphere, made up of a mix
of air and inflammable substances in the form of gas, vapour or mist, can
occur occasionally during normal operation.
Note: Said zone can also include:
- places in the immediate vicinity of zone 0;
- places in the immediate vicinity of supply openings;
- places in the immediate vicinity of filling and and emptying openings;
- places in the immediate vicinity of appliances, protection systems and fragile glass
and ceramic components, or components made of other similar materials;
- places in the immediate vicinity of inadequately sealed stuffing boxes,
e.g., on pumps and valves with stuffing box.
Place where it is improbable that an explosive atmosphere, made up of a
mix of air and inflammable substances in the form of gas, vapour or mist,
can occur during normal operation, but which, if it does occurs, only per-
sists for a short time.
Note: Said zone can include, among others, places surrounding the zones 0 or 1.
Place where an explosive atmosphere in the form of a cloud of combus-
tible powders in the air is continuously present, either for long periods or
frequently.
Note: Generally speaking, said conditions, when they occur, involve the in-
side of tanks, pipes and containers, etc.
Place where it is probable that an explosive atmosphere, in the form of a cloud of com-
bustible powders in the air, can occur occasionally during normal operation.
Note: Said zone can include, for example, among others, places in the immediate
vicinity of powder loading and emptying points and places where powder layers
form or which, during normal operation, could produce an explosive concentra-
tion of combustible powders mixed with the air.
Place where it is improbable that an explosive atmosphere, in the form of
a cloud of combustible powders in the air, occur during normal operation
but which, if it does occur, only persists for a short time.
Note: This zone can comprise, among others, places near appliances,
protections systems and components containing powder, out of which the
powder can come out due to leaks with the formation of powder deposits
(e.g., milling salt, where the powder comes out of the mills and deposits).
ZONE 0
ZONE 20
ZONE 21
ZONE 22
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