Explosion protection
Device cate-
Description
gory
1G
Devices of this category are designed for use in areas in which an
explosive atmosphere consisting of a mixture of air and gases, va-
pors or mists is present constantly or for long periods of time or of-
ten.
1D
Devices of this category are designed for use in areas in which an
explosive atmosphere consisting of a dust/air mixture is present
constantly or for long periods of time or often.
2G
Devices of this category are designed for use in areas in which it
is to be expected that an explosive atmosphere consisting of
gases, vapors or mists forms occasionally.
2/2G
Devices that extract from zone 1 and are designed for use in ar-
eas in which it is to be expected that an explosive atmosphere
consisting of gases, vapors or mists forms occasionally.
2/-G
Devices that extract from zone 1 but are not designed for installa-
tion in a potentially explosive atmosphere (zone).
2D
Devices of this category are designed for use in areas in which it
is to be expected that an explosive atmosphere consisting of a
dust/air mixture forms occasionally.
3G
Devices of this category are designed for uses in areas in which it
is to be expected that an explosive atmosphere resulting from
gases, vapors or mists occurs, though in all likelihood occurs only
seldom and for a very short length of time.
3/-G
Devices that extract from zone 2 but are not designed for installa-
tion in a potentially explosive atmosphere (zone).
3D
Devices of this category are designed for uses in areas in which it
is to be expected that an explosive atmosphere resulting from
stirred-up dust occurs, though in all likelihood occurs only seldom
and for a very short length of time.
20
4.3.2 Device categories for gas
The device category describes the frequency and the duration
of the occurrence of explosive atmospheres during operation.
Tab.6:
Translation of Originial Operating Instruction, KNF 339416-339418 02/23
Vacuum system SC820G / SC840G