MFDS(P)
Fire Suppression Damper Pneumatic
Typical Applications
position (35 to 90 seconds) to allow over pressure to
Building Ser vices Fire Suppression Systems.
The Damper is Fire Rated to BS476 for 4hrs.
be exhausted from the room before closing and main-
taining fire integrity. Local pointers indicate open and
closed status. Actuation is pneumatic power open,
Description
spring return, rated for a maximum air pressure of 10
bar g.
Casing
Note: The fire suppression agent discharge pressure
that is typically 200 bar g, must be regulated to the
The damper frame is formed from sheet steel into
8 bar g operating pressure of the actuator. This is the
rigid channel sections that are welded and riveted
responsibillity of the installer.
together. Dampers over 1200 mm wide have welded
ver tical mullions and dampers over 1000 mm high
Options
have horizontal transoms. Flanges are punched in
Material: Stainless or Galvanised Mild Steel Frames mate-
accordance with the Wozair standard or to specific
rial thickness 2 mm
client requirements. Where it is difficult to access the
Case Depth: 200 mm
bolt holes behind the control enclosure, welded nuts
Continuous blade shafts
will be provided. Casings are provided with 20 mm diam-
Ear th Continuity Bosses
eter lifting holes as standard.
Lifting Lugs
Blades
Client specific requirements
Leakage Rates
The blades are double skin aerofoil type from 1.2 mm
thick sheet steel and are welded or bolted to 19 mm
The MFDFS(P) damper has been designed to minimise
diameter stub shafts. Blade shafts rotate in high tem-
leakage with the blades in the closed position. To put
perature oil impregnated sintered bronze bearings fit-
a precise figure on the leakage rate is not practical
ted into the damper frame. The damper free area is a
due to variations in configuration, aspect ratio, num-
function of size that is typically 75 to 85% of the area
ber of blades and perimeter length of dampers with
of the duct.
equivalent face areas. Extensive testing on single
module dampers of size 1000 mm wide x 1000 mm
Linkage
high, has indicated a mean leakage rate of 0.081
Dampers with multiple blades are fitted with a link-
m3/sec/m2 at a differential pressure of 2000 Pa.
age to provide an opposed motion. Robust blade
Specific requirements regarding leakage should be
links are welded to the drive shafts and connected
discussed with our engineers.
together by flat bar and stainless 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 connection to
the actuating mechanism.
Removable linkage cover plates are fitted
where required.
Seals
Tight air shut off is achieved by sprung
stainless steel grade 316L (1.4404) side
seals and welded top and bottom angle
stops.
Controls for Operation
The MFD Damper is designed to open on
release of the fire suppression agent which
also provides the energy source to operate
the actuator.
Timer valves control the speed of opening
the damper (0.5 to 6 seconds) and the peri-
od of the damper remaining in the open