Flammable Products - KROHNE DK32 Supplementary Instructions Manual

VA FLOWMETERS

2.4 Flammable products

Atmospheric conditions:
The standard atmospheric conditions under which it may be assumed that Ex equipment can be
operated are:
• Temperature: -20...+60°C / -4...+140°F
• Pressure: 80...110 kPa (0.8...1.1 bar) / 11.6...15.9 psi
• Air with normal oxygen content, typically 21%v/v
Ex equipment operating outside the standard temperature range must be tested and certified
(e.g. for ambient temperature range -40...+65°C / -40...+149°F).
Ex equipment operating outside the standard atmospheric pressure range and standard oxygen
content is not permitted.
Operating conditions:
The measuring unit of variable area flowmeters operate outside the standard atmospheric
pressure range, which means that explosion protection, regardless of the zone assignment, is
fundamentally not applicable for the measuring unit (piping).
WARNING!
Operation with flammable products is only permitted as long as no explosive fuel/air mixture
builds up inside of the piping at the same time the atmospheric conditions are exceeded.
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 piping.
The max. allowable operating pressure PS printed on the nameplate is to be considered.
The following versions require dust-free gases or liquids. Gases containing solid particles or
liquid droplets are not permitted. The products must reach the stated minimum conductivity.
The limit of the stated maximum nominal flow rate must be observed.
Device type
H250/C...
VA40
GA24
DK46 / DK47
DK48 / DK800
DK46PV / DK47PV
DK48PV / DK800PV
Table 2-1: Minimum conductivity of product and maximum flow for the device type
09/2022 - 4000419908 - AD VA Mech Ex Gb-Db R08 en
Minimum conductivity in µS/m
0.01
0.001
-
-
0.001
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DEVICE DESCRIPTION
Maximum flow rate Q
-
5-times
10-times
20-times
20-times
2
max
11