Sierra Instruction Manual ATEX Certified Units: 640S-EEX & 780S-EEX
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2. Type Approval Standards
The Sierra Instruments Ex approved flow meters have an EC Type examination certificate
issues by KEMA and have been approved to the following standards:
EN 60079-0 : 2004
EN 60079-1 : 2004
EN 50281-1-1 : 1998 + A1
3. Zone, Gas Group, Category and Temperature class
The Sierra Instruments 640S-EEX and 780S-EEX have been certified ATEX II 2 GD EX d IIC
T6-T2 T280°C (Tamb. -20°C to +50°C). This means that the units can be installed in locations
with the following conditions.
3.1.
Area Classification
Zone 1
Area in which an explosive gas atmosphere is
likely to occur in normal operation occasionally
Zone 2
Area in which an explosive gas atmosphere is
not likely to occur in normal operation and if it
does occur, is likely to do so only infrequently
and will exist for a short period only
Zone 21
Place in which an explosive atmosphere in the
form of a cloud of combustible dust in air is
likely to occur in normal operation occasionally
Zone 22
Place in which an explosive atmosphere in the
form of a cloud of combustible dust in air is not
likely to occur in normal operation but, if it does,
will persist for a short period only
3.2.
Gas Grouping
Group IIA
Propane
Group IIB
Ethylene
Group IIC
Hydrogen and Acetylene
3.3.
Equipment Category
2GD (Zone 2 suitable for Gasses and Dust explosive environments)