7
individual items and to earth and the connected process structure. An earthing resistance
higher than 10
Ω
may indicate bad earth connections;
−
An earth connection is provided externally on both sides and a lid of the valve. The external
earth connections shall be used to bond other process parts with a equipotential bonding
conductor of at least 4 mm
2
;
−
The valve should only be exposed to organic or non‐metallic dust;
−
Ambient temperature range: from ‐20
o
C to +60
o
C;
−
Parameters of the dust: organic non‐metal dust, K
st,max
=200 bar.m.s
‐1
, MIE=13mJ, MIT=430
o
C.
−
DN 200 – 400: Pull and Push, stright pipes or 2x90
o
bend is allowed between the protected
vessel and the flap;
−
DN 450 – 1000: Pull flow situation, straight pipes between the protected vessel and the flap
and venting on the protective vessel only non‐reclosing vent devices. (this excludes e.g.
suppression and venting with reclosing vent devices);
−
The maximal speed flow is 25 m.s
‐1
;
−
The maximum dust concentration in the ducting is witout the limit;
−
The product has to be installed so that the propagating brush discharges on the extrenal
surface of the device are avoided:
−
The electrical devices installed together with the back pressure flap must have th etype of
protection corresponding with the defined explosive zone;
−
Flap position is horizontal.
Parameters dependent on the size of the flap:
Parameters of flap (unit):
Sizes DN (mm):
200
250 ‐ 400
450 ‐ 600
650 ‐ 1000
p
red, max
(bar)
0,50
0,50
p
max
(bar) design pressure ‐ EN 14460
1
1
0,8
0,70
minimal vessel volume (m
3
)
0,46
0,96
6
6
minimal installation distance (m)
2,2
3,1
4
4
maximal installation distance (m)
7,2
7,2
7,2
7
maximum allowable opening angle of the blade
to the vertical
60
o
60
o
60
o
50
o
inclination of flap valve
horizontal
maximal speed flow (m.s
‐1
)
25
max. dust concentration in duct where device
will be installed
Without limits
