JO
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Transitioned Damper
Dimensions
When a fire/smoke damper is being used in conjunction with round or oval ductwork, the
SMD-401 can be supplied in a factory sleeve with round or oval transitions on both ends
of the sleeve. Dampers should be ordered to the duct dimensions. Drawings below show
overall damper size.
*
These dimensions are furnished approximately
1
/
4
in. (6mm) undersize, except round and oval dimensions which are approximately
1
/
8
in. (3mm) undersize.
T
s
= (2)(Sleeve Thickness)
Smoke Dampers meeting the following specifications
shall be furnished and installed where shown on plans
and/or as described in schedules. Dampers shall meet the
requirements of NFPA 92A, 92B, 101, & 105 and further shall
be tested, rated and labeled in accordance with the latest
edition of UL Standard 555S. Smoke dampers shall be of low
leakage design qualified to UL 555S Leakage Class I.
Each damper /actuator combination shall have a UL555S
elevated temperature rating of 250°F (121°C) minimum and
shall be rated to operate at maximum design airflow at its
installed location. Each damper shall be supplied with an
appropriate actuator installed by the damper manufacturer
at the time of damper fabrication. Damper actuator shall be
(specifier select one of the following) electric type for 120, 24,
or 240 Volt operation
or
pneumatic type for 25 psi minimum
(30 psi maximum operation.
Damper blades shall be hollow extruded aluminum airfoil
type with structural reinforcing tube running full length of
each blade. Damper frame shall be galvanized steel formed
into a structural hat channel shape with reinforced corners.
Bearings shall be sintered bronze sleeve type rotating in
extruded holes in the damper frame. Blade edge seals shall
be silicone rubber designed to inflate and provide a tighter
seal against leakage as pressure on either side of the damper
increases. Jamb seals shall be stainless steel compression
type.
Damper must be rated for mounting vertically (with blades
running horizontal) or horizontally and be UL 555S rated for
leakage and airflow in either direction through the damper.
The basis of design is Greenheck Model SMD-401.
Damper Sizing Information
Dampers larger than maximum single section size are supplied as a factory
assembly of two or more sections of equal size.
The following figure shows the size damper section that has been qualified
for operation with a single actuator. Larger sizes can be accommodated using
multiples of these assembles.
Specifications
D* + 2 in. (51mm) +T s
D*
TYPE R
16 in. (406mm)
Min.
2
1
/
8
in.
D* + 2 in. (51mm)+T s
TYPE O
W
*
H*
W*
+ 2 in. (51mm)+T s
H* + 2 in. (51mm)+T s
W*
H*
TYPE C
H* + 2 in. (51mm)+T s
(54mm)
16 in. (406mm)
Min.
2
1
/
8
in.
(54mm)
16 in. (406mm)
Min.
W* + 2 in. (51mm)+T s
(54mm)
2
1
/
8
in.
Copyright ©2007 Greenheck Fan Corporation
SMD-401 Rev. 5 April 2007
