KROHNE VA FLOWMETERS EN - Manual (Page 5)

SAFETY INSTRUCTIONS
2
5
VA FLOWMETERS
www.krohne.com 11/2012 - 4000419904 MA VA Mech Ex AD R04 en
2.3 Protection types
Non-electrical variable area flowmeters are designed in the protection class "design safety 'c'"
in accordance with EN 13463-5.
The marking is: II 2GD c IIC TX II 2GD c IIC TX II 2GD c IIC TX II 2GD c IIC TX
2.4 Surface temperature
It is to be assumed that a combustible fuel / air mixture can contact the outer wall of the
measuring tube and process connections. Any temperature gradient between the internal wall in
contact with the product (product temperature) and the outer surface is not taken into
consideration.
The actual maximum surface temperature does not depend on the device itself, but instead on
the operating conditions. The device itself does not generate heat and, for this reason, the
surface temperature is determined by the product temperature and, in versions with heating
jackets, by the heating medium temperature as well.
A TX identifier on the nameplate refers to this in accordance with EN 13463-1:2009, section 9.3.2
f. The maximum permitted ambient and product temperature can be found in the standard
operating instructions.
The marking contains the following information: The marking contains the following information: The marking contains the following information: The marking contains the following information:
II IIII II Group II explosion protection
2222 Equipment category 2
G G G G Gas explosion protection
D D D D Dust explosion protection
cccc Protection through design safety
IIC IIC IIC IIC Gas group, Suitable for gas groups IIC, IIB and IIA
TX TX TX TX Surface temperature is determined by operating conditions
AD_VA_Mech_II2GD_R04_en_419904_PRT.book Page 5 Wednesday, November 7, 2012 8:43 AM