KROHNE DK 37-H250 M8 ATEX II2G Ex i EN - Manual (Page 7)

DEVICE DESCRIPTION
2
7
DK37/M8 - H250/M8
www.krohne.com 09/2013 - 4000760402 MA DK37 M8 AD II2G R02 en
2.4 Flammable products
Atmospheric conditions: Atmospheric conditions: Atmospheric conditions: Atmospheric conditions:
An explosive atmosphere is a mixture of air and flammable gases, vapours, mists or dusts under
atmospheric conditions. The following values define it
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.
Installation conditions: Installation conditions: Installation conditions: Installation conditions:
Variable area 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 section.
2.5 Device category
The flowmeters are designed in Category II 2G according to EN 60079-0 and EN 60079-11 for use
in Zone 1.
2.6 Types of protection
The variable area flowmeter is designed with type of protection intrinsic safety, level of
protection "ia" as per EN 60079-11.
The marking II 2G Ex ia IIC T6 Gb II 2G Ex ia IIC T6 Gb II 2G Ex ia IIC T6 Gb II 2G Ex ia IIC T6 Gb contains the following information:
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. When using the device version H250/C...
(PTFE-liner, nonconductive) the min. conductivity of the medium must be 10
-8 S/m, in order to
avoid the electrostatic charge.
II IIII II Explosion protection Group II
2222 Device category 2
G G G G Gas explosion protection
ia ia ia ia Intrinsically safe, level of protection "ia"
IIC IIC IIC IIC Suitable for gas groups IIC, IIB and IIA
T6 T6 T6 T6 Suitable for temperature classes T6 ...T1
Gb Gb Gb Gb EPL, suitable for zone 1 or zone 2
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