KROHNE OPTISWIRL 4070 ATEX II2G EN - Manual (Page 6)

2
DEVICE DESCRIPTION
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OPTISWIRL 4070
www.krohne.com 04/2013 - 4000077105 MA OPTISWIRL4070 II2G AD R05 en
2.4 Flammable products
Atmospheric conditions
An explosive atmosphere is defined as a mixture of air and flammable gases, vapours, mists or
dusts under atmospheric conditions with the values
T
atm
= -20...+60°C / -4...+140°F and P
atm
= 0.8...1.1 bar.
Outside of this range, no key data are available as to ignition behaviour for most mixtures.
Operating conditions
Vortex flowmeters operate outside of atmospheric conditions, which means that explosion
protection according to Directive 94/9/EC (ATEX) – regardless of the zone assignment – is
fundamentally not applicable due to the lack of key safety data for the interior of the measuring
unit.
2.5 Equipment category / EPL
Vortex flowmeters are designed according to EN 60079-0, EN 60079-1 and EN 60079-11 in
category II 2 G for use in zone 1. The inside of the measuring unit is also approved for zone 1.
Vortex flowmeters are designed according to the "IECEx-Scheme" as per "Equipment Protection
Level [EPL] Gb".
For more information see the chapter entitled "Flammable products".
WARNING!
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
for ensuring that the flowmeter is operated safely as regards 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 as per EN 1127-1, Annex 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.
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