WIKA 232 - Safety Instructions for ATEX Pressure Gauges; Special Hazards; Labelling and Safety Marks

2.3 Safety instructions for pressure gauges per ATEX
WARNING!
Non-observance of these instructions and their contents may result in the loss of explosion
protection.
WARNING!
It is imperative that the application conditions and safety requirements of the EU-type examina-
tion certicate are followed.
 Pressure gauges must be grounded via the process connection.
Permissible ambient temperature.
Model 232/262/PG23CP: -40 ... +60 °C (unlled)
Model 233/263/PG23CP: -20 ... +60 °C (glycerine lling)
-40 ... +60 °C (silicone oil lling)
Attention! In the case of gaseous media, the temperature may increase due to compression warming.
In these cases it may be necessary to throttle the rate of change of pressure or reduce the permissible
medium temperature.
Permissible medium temperature
The permissible medium temperature not only depends on the instrument design, but also on the ignition
temperature of the surrounding gases, vapours or dusts. Both aspects have to be taken into account.
Potentially explosive gas atmosphere
Required temperature
class
(ignition temperature of
gas or vapour)
Maximum permissible medium temperature
(in the measuring system)
Models 232, PG23CP
(dry gauges)
Models 233, PG23CP
(liquid-lled gauges)
T6 (T > 85 °C) +70 °C +70 °C
T5 (T > 100 °C) +85 °C +85 °C
T4 (T > 135 °C) +120 °C +100 °C
T3 (T > 200 °C) +185 °C +100 °C
T2 (T > 300 °C) +200 °C +100 °C
T1 (T > 450 °C) +200 °C +100 °C
Hazardous dust atmosphere
For dusts, the procedure specied in ISO/IEC 80079-20-2 for determining the ignition temperature has to
be applied. The ignition temperature is determined separately for dust clouds and dust layers, respective-
ly. For dust layers, the ignition temperature depends on the dust layer thickness per IEC/EN 60079-14.
Ignition temperature of dust Maximum permissible medium temperature
(in the measuring system)
Dust cloud: T
Cloud
< 2/3 T
Cloud
Dust layer: T
Layer
< T
Layer
− 75 K − (Reduction depending on the layer thickness)
The permissible maximum medium temperature must not exceed the lowest determined value, even in
case of a malfunction.
Handling of materials
Avoid handling of materials that react dangerously with the materials used for the instrument, and
substances liable to spontaneous combustion.
Cleaning
Clean the measuring instrument with a moist cloth. Ensure that due to the cleaning no electrostatic charge
will be generated.
2.4 Special hazards
WARNING!
For hazardous media such as oxygen, acetylene, ammable or toxic gases or liquids, and refrig-
eration plants, compressors, etc., in addition to all standard regulations, the appropriate existing
codes or regulations must also be followed.
From pressure gauges which do not correspond to a safety version per EN 837 highly pressur-
ised media might leak out through the possibly bursting window in case of a component failure.
For gaseous media and operating pressures > 25 bar a pressure gauge with safety version S3 is
recommended per EN 837-2.
For additional important safety instructions see chapter “2.3 Safety instructions for pressure gauges per
ATEX”.
WARNING!
Residual media in dismounted pressure gauges can result in a risk to persons, the environment
and equipment. Take sucient precautionary measures.
2.5 Labelling / safety marks
Dial
 ATEX marking: II 2 GD c TX X
 Serial number
Product Label

Model

Year of manufacture
Before mounting and commissioning the instrument, ensure you read the operating
instructions!
Instruments bearing this mark on the dial are safety pressure gauges with solid bae wall per
EN 837 (S3).
 