Fire Dampers are provided on air / gas ducts to control
flow under normal circumstances and to isolate areas,
connected by duct, from the fire affected area.
Dampers are manufactured with single flap / multilouvers.
The louvers are connected through suitable linkage to
a controlling actuating device, such as electrical actuator
/ solenoid valve / pneumatic cylinder / fusible link.
Louver / flap shaft are provided with bearings with greasing
facility to enable smooth rotation.
Louvers / flaps are made of mild steel. The louvers /flaps
are designed in the form of a box and are sandwiched with
high grade insulating material which can withstand 9800
C for period of 90 minutes, conform to UL - 555, thereby
acting as effective barrier in closed position to the
flame path between air duct and fire effected area.
shape of the louver / flap is somewhat complex in nature
for multifold purposes :
a) The complex shape reduces the leakage factor
b) Fire exposed surfaces are backed-up by insulating
c) Due to special insulating material, the strength
of the louver / flap is retained at high
temperature, thereby reducing
the possibility of leakages.
d) The shape provided, enables thermal expansion
of the louver /
flap without affecting
POSITIVE SEALING LINKAGE :
LInkage provided with spring return device for positive
shut-off pressure on each louver / flap, enabling reduction
In leakage factor.
Z sections are provided at mating surfaces are designed
to create a heavy pressure drop during leakage, because
the air / gas has to take two sharp right angle turns.
This gives a low leakage factor during damper operation.
SEALING EFFICIENCY :
The sealing efficiency of damper Is 98 % approximately
on cross sectional area.
Dampers with G. I. Construction are also available.