3. DUCT TO SLEEVE CONNECTIONS
Dampers are supplied with sleeves and actuators from
the factory and can be installed without the need for
additional field installed sleeves.
Gauge of factory furnished sleeve determines the type
of duct to sleeve connections required (see table below).
Any duct connection other than those breakaway
connections described on page 6 are considered rigid.
Factory furnished duct collars, type R and O, are also
considered breakaway (see
Fig. 2
).
Sleeve Gauge
Duct Dimension
Type of Duct
to Sleeve
Connection
Permitted
14 ga. (0.075 in.)
- 10 ga. (0.138
in.)
[2mm - 3.5mm]
All duct sizes
Rigid or
Breakaway
16 ga. (0.060 in.)
[1.5mm]
36 in. (914mm) max. width
24 in. (610mm) max. width
24 in. (610mm) diameter
Rigid only
16 ga. (0.060 in.)
[1.5mm]
All duct sizes
Breakaway only
18 ga. (0.048 in.)
[1.2mm]
85 in. (2159mm) wide and
over
20 ga. (0.036 in.)
[0.9mm]
55 in. - 84 in. wide
(1397mm - 2134mm)
22 ga. (.030 in.)
[0.76mm]
31 in. - 54 in. wide
(787mm - 1372mm)
24 ga. (0.024)
[0.6mm]
13 in. - 30 in. wide
(330mm - 762mm)
26 ga. (0.018 in.)
[0.46mm]
12 in. wide and under
(305mm)
See page 6 for additional information on breakaway sleeve connections.
Sleeve thickness must not be less than the gauge of the connecting duct.
UL Standard 555 requires all ducts to terminate at fire damper sleeves.
4. SECURING THE DAMPER/SLEEVE ASSEMBLY TO
WALL OPENINGS
Damper/sleeve assemblies must be installed in wall
openings using retaining angles on at least one side of
the wall as described below:
• Retaining angle must be a minimum of 16 gauge
(1.5mm) steel and have a minimum of 1
1
/
2
in. x 1
1
/
2
in.
(38mm x 38mm) legs.
• Retaining angle must be attached to the damper using
one or more of the following methods of attachment
(refer to label on outside of sleeve for ‘No Screw’
area):
• Tack or spot welds
• #10 (
3
/
4
in. max. [19mm]) sheet metal screws
•
1
/
4
in. (6mm) bolts and nuts
•
3
/
16
in. (5mm) steel pop rivets
A minimum of two connections per side, top, and
bottom, 12 in. (305mm) O.C. maximum for openings of
48 in. W x 32 in. H (1219mm x 812mm) and less, and
6 in. (152mm) O.C. for openings 100 in. W x 32 in. H
(2540mm x 32mm) or less. The angles must be attached
to all 4 sides of the sleeve with butt joints at each
corner. A minimum of two attachments are required
on each side, top and bottom. Ensure that attachment
device does not interfere with the operation of the
damper and the free movement of the damper blades.
The angles need not be attached to each other at the
corners. Do not secure the retaining angle to the fire
separation (see
Fig. 3
).
• Retaining angles must completely cover the
clearance space between the damper and the wall
opening, plus overlap the wall a minimum of 1 in. This
coverage includes all corners.
• Retaining angles should not be fastened to the wall
material. The angles should only sandwich the wall
and allow for damper expansion during periods of
intense heat.
Damper
Model
Maximum Single
Section Size
Maximum Multiple
Section Size
FSD-311V
50 x 32
100 x 32
Type R and O
Factory Furnished
Duct Collars Qualify
As Breakaway
Connections
Duct
Damper
Sleeve
Wall or Floor
Type C, O, R
Fig. 2
Damper with type R or O transition factory
furnished.
2 in.
Max.
6 in.
Max.
Sleeve
Retaining
Angle
Damper
Duct
Min. 1 in.
Overlap*
Wall or
Floor
Retaining
Angle
*only applicable for damper sizes above 36 in. x 36 in.
6 in.
Max.
2 in.
Max.
Both vertical and horizontal damper installations are
typified by these drawings.
Fig. 3
4
