FGD
Fire & Gas Dampers
Typical Applications
are welded to bosses that are securely pinned to the
Heavy duty aggressive process environments, where
shafts.
integrity, strength and corrosion resistance are of
primar y importance,
Removable linkage cover plates are fitted where required.
Seals
Description
Tight air shut off is achieved by sprung stainless
AO A60 and H0 H120
steel grade 316L (1.4404) side seals and welded
Casing
top and bottom angle stops.
The 300 mm deep frame is formed into rigid chan-
Controls for Operation
nel sections that are fully welded, sheet steel thick-
Manual Spring Release Latching Mechanism
nesses range from 3-10 mm. Dampers over 1000
Pneumatic Actuator
mm wide have welded vertical mullions and dampers
Electric Actuator
over 1176 mm high have horizontal transoms.
Temperature Sensitive Trigger
Flanges are punched in accordance with the Wozair
For full details see Controls Section page 12.
standard or to specific client requirements. Where it
is difficult to access the bolt holes behind the con-
Options
trol enclosure, welded nuts will be provided. Casings
are provided with 20 mm diameter lifting holes as stan-
Material: Stainless or Galvanised Mild Steel Frames
dard.
Bearings: Roller or ball race
Ear th Continuity Bosses
Dampers smaller than 150 mm or required for cir-
Lifting Lugs
cular connection are supplied with either 3 mm thick
Pre-insulated controls enclosure
studded transition plates stitch welded to each side
Client specific requirements
or circular spigots 50 mm deep. This increases the
inser tion depth by either 6 or 100 mm.
Leakage rates
Blades
The fire and gas damper has been designed to min-
imise leakage with the blades in the closed position.
The blades are double skin aerofoil type manufac-
To put a precise figure on the leakage rate is not
tured from 1.5 mm thick stainless steel sheet and
practical due to variations in configuration, aspect
are welded to 19 mm diameter continuous shafts.
ratio, number of blades and perimeter length of
Blade shafts rotate in high temperature oil impreg-
dampers with equivalent face areas. Extensive test-
nated sintered bronze bearings fitted into welded
ing on single module dampers of size 1000 mm wide
housings. Other bearing options are available.
x 1000 mm high, has indicated a mean leakage rate
For nuclear applications where the casing penetra-
of 0.081 m3/sec/m2 at a differential pressure of
tions need to be sealed, lip seal bearings are fitted
2000 Pa. Specific requirements regarding leakage
into the bearing housing on the drive side. Blind
should be discussed with our engineers.
bearing bosses are fitted on the non
drive side.
Linkage
Dampers over 300 mm high have mul-
tiple blades that are linked together to
provide opposed motion. Robust blade
links are welded to the drive shafts and
connected together by flat bar and
stainless steel pins. The linkage
arrangement is contained within the
flanges of the damper frame.
The drive shaft is extended and fitted
with a welded machined boss for con-
nection to the actuating mechanism.
As an option, particularly for nuclear
applications removable linkages can
be specified whereby the blade links