13
4.1.2
Dangerous areas classification
The ATEX 2014/34/EU Directive classifies the protection system (in this case the non‐return valve)
into 3 categories, with different protection levels, guaranteed to the related protection.
Protection Level
Plant
Dust Category
Very High
1D (zone 20)
High
2D (zone 21)
Normal
3D (zone 22)
4.2
ATEX code description
The non‐return valve is marked according the European Directive 2014/34/EU:
II 1D/2D Ex h IIIB T85
O
C Da/Db
II D St 1
Ta= ‐20
O
C to +60
O
C
In which:
CE
:
CE‐marking and number of the noticed (monitoring) body (1026) (not for equipment
category 3)
Ex
:
Explosive protection symbol (ATEX)
II
:
Equipment group II for use above ground
1
:
Equipment category (Category 2)
2
:
Equipment category (Category 2)
D
:
Explosive atmosphere (dust)
Ex
:
Explosive protection marking
h
:
Type of protection
IIIB :
Equipment group (Electrical apparatus group III, subgroup IIIB (non‐conductive dust),
intended for use in areas where an explosive dust atmosphere is to be expected, other than mines
susceptible to firedamp)
T85
0
:
Surface temperature
Da :
Equipment Protection Level (EPL Da; equipment with very high protection level)
St 1 :
Suitable as explosion isolation flap valve for dust explosion class St 1
Ta :
Allowed ambient temperature range
