2
DEVICE DESCRIPTION
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OPTISWIRL 4200
www.krohne.com
01/2017 - 4004274302 - AD OPTISWIRL4200 Ex-II2G R02 en
2.4 Flammable products
Atmospheric conditions
An explosive atmosphere is a mixture of air and flammable gases, vapours, mists or dusts under
atmospheric conditions.
It is defined by the following values T
atm
= -20...+60
°
C / -4...+140
°
F and P
atm
= 0.8...1.1 bar /
11.6...15.9 psi.
Outside of this range, for most mixtures no key figures are available for the ignition behaviour.
Operating conditions
Vortex flowmeters operate outside of atmospheric conditions, which means that explosion
protection according to the ATEX directive, regardless of the zone assignment, is fundamentally
not applicable due to the lack of key safety data for the interior of the measuring section.
2.5 Equipment category / EPL
Vortex flowmeters are designed in category II 2 G and EPL Gb according to EN 60079-0 and
EN 60079-11 for use in zone 1. The inside of the measuring unit is also permitted for zone 1.
Vortex flowmeters are designed according to the "IECEx-Scheme" acc. to "Equipment Protection
Level [EPL] Gb".
CAUTION!
Operation with flammable products is only permitted as long as no explosive fuel/air mixture
builds up on the inside of the flowmeter under operating conditions. The operator is responsible
to ensure that the flowmeter is operated safely in terms of the temperature and pressure of the
products used.
In case of operation with flammable products the measuring units must be included in the
periodic pressure tests of the system.
INFORMATION!
Definition of zone 1 acc. to EN 1127-1, Appendix B:
An area in which an explosive atmosphere may occasionally occur as a result of the mixture of
flammable substances in the form of gas, steam or mist with air under normal operation.
