Classifica-
tion
Description
Combustible
materials
G
: Gases or vapors
D
: Dust (will not be discussed in any more detail here)
Note: The device may only be used in atmospheres susceptible to explosion
due to gases or vapors. Operation in dust-charged, potentially explosive atmos-
pheres is not permitted.
Type of pro-
tection
Identification code “Ex h” designated in the standard DIN EN ISO 80079-36 for non-
electrical equipment. A protection type established for electrical equipment is not
used.
Explosion
groups
Gases and vapors are divided into three Explosion groups based on their particular
ignition capability (IIA, IIB and IIC). The ignition power in this regard decreases from
Explosion group IIA to IIC. (The higher Explosion group, e.g. IIC incorporates the re-
spectively lower IIB and IIA).
Temperature
class
Classification of equipment depending on their maximum surface temperature, in ac-
cordance with assignment as follows:
Temperature class --> Maximum surface temperature/gas temperature:
● T1 --> +450 °C
● T2 --> +300 °C
● T3 --> +200 °C
● T4 --> +135 °C
● T5 --> +100 °C
● T6 --> +85 °C
The temperature class and the actual maximum surface temperature of the equip-
ment includes a safety margin to the minimum ignition temperature of the potentially
explosive atmospheres as stipulated in DIN EN ISO 80079-36.
EPL accord-
ing to
EN 60079
Equipment protection level
EPL Ga
: Equipment with “extremely high” protection level for use in potentially explo-
sive gas atmospheres in which no risk of ignition exists during normal operation, with
foreseeable or infrequent faults/malfunctions.
EPL Gb
: Equipment with “high” protection level for use in potentially explosive gas at-
mospheres in which no risk of ignition exists during normal operation, with foreseea-
ble faults/malfunctions.
EPL Gc
: Equipment with “extended” protection level for use in potentially explosive
gas atmospheres in which no risk of ignition exists during normal operation.
X
Special operating conditions must be observed! Special conditions and notes in the
operating instructions apply.
Ta
Permissible ambient temperature for operation of the vacuum pump prescribed on the
rating plate.
Tbl. 3:
ATEX designations
2.4.2 Potential hazards
The ignition hazard assessment for the Duo 11 ATEX was performed in accordance with the harmon-
ized standard ISO 80079-36 (Non-electrical equipment for explosive atmospheres - Basic method and
requirements). This assessment includes the identification of hazards described as follows which will
not occur if the system is operated properly with the respective safety measures.
Potential
hazard
Occurrence due to
Safety measures
Hot surfa-
ces
Heat generated as a re-
sult of friction and com-
pression in the pumping
system, and in particular
at increased intake pres-
sure
Operating fluid dissipates the heat which is produced in
the inside of the rotary vane pump on the components
cooled by convection. The installation conditions must be
observed.
Hot gases
Compression of the re-
quired gases
The gas temperatures were determined during tests car-
ried out under permissible application conditions. Observe
the information in the operating manual.
Mechanical
sparks
No mechanical sparks
will be produced during
normal operation with
normal use of the system
Surfaces on the inside of the rotary vane pump are wetted
with operating fluid to cool them.
Safety
16/58
