Duct to Sleeve Connection
Sleeve Gauge and Connection Type Requirements
Sleeve Gauge
Duct Dimension
Type of Duct to Sleeve
Connection Permitted
14 ga. (0.075 in.) - 10 ga. (0.138 in.)
[2 mm - 3.5mm]
All duct sizes
Rigid or Breakaway
16 ga. (0.060 in.) [1.5 mm]
36 in. (914 mm) max. width
24 in. (610 mm) max. height
24 in. (610 mm) diameter
Rigid or Breakaway
16 ga. (0.060 in.) [1.5 mm]
All duct sizes
Breakaway only
18 ga. (0.048 in.) [1.2 mm]
85 in. (2159 mm) wide and over
20 ga. (0.036 in.) [0.9 mm]
55 in. - 84 in. wide
(1397 mm - 2134 mm)
22 ga. (.030 in.) [0.76 mm]
31 in. - 54 in. wide
(787 mm - 1372 mm)
24 ga. (0.024 in.) [0.6 mm]
13 in. - 30 in. wide
(330 mm - 762 mm)
26 ga. (0.018 in.) [0.46 mm]
12 in. wide and under (305 mm)
See Breakaway Connection section for additional information.
UL Standard 555 requires all ducts to terminate at fire damper sleeves.
The size of the damper/duct determines the required sleeve gauge and the required duct to sleeve connection (see
table to the right). The sleeve thickness must also not be less than the gauge of the connecting duct. Any duct
connection other than the breakaway connections described below are considered rigid.
Approved Breakaway Connections
All breakaway connections described below may utilize the
following duct sealants: PA2084T duct sealant adhesive
manufactured by Precision, DP1010 water base duct sealant
manufactured by Design Polymerics, Grey Pookie, Ductmate
PROseal®, or CL Ward S Seal in accordance with SMACNA
recommendations.
Transverse Joints
The transverse joints shown below are approved as breakaway
connections.
• A maximum of two #10 (19 mm) sheet metal screws on each
side and on the bottom may be used. The screws should be
located in the center of the slip pocket and penetrate both
sides of the slip pocket.
• Dampers up to 20 in. (508 mm) high may use transverse joints
on the top and bottom and Drive Slip joints (
see Figure 16
) on
the sides.
Plain “S” Slip Hemmed “S”
Slip Double “S”
Slip
Inside Slip Joint Standing “S” Standing “S” (Alt.)
Standing “S” (Alt.) Standing “S” Standing “S”
(Bar Reinfor
ced) (Angle Reinfor
ced)
Figure 15 - Transverse Joints
Drive Slip Joint
Figure 16
Round and Oval Duct Breakaway Connections
Round or flat oval ducts connected to Type R or O damper
collars shall be attached with #10 (19 mm) sheet metal screws
as follows:
• Ducts up to 22 in. (558 mm) wide (or dia.) and less shall
have three screws.
• Ducts larger than 22 in. (558 mm) wide (or dia.) up to and
including 36 in. (914 mm) wide (or dia.) shall have five
screws.
Factory furnished duct collars, type R and O, are also
considered breakaway
(see Figure 17)
.
Wall or Floo
r
Sleeve
Duct
Damper
Type B
Wall or Floo
r
Sleeve
Duct
Damper
Type R, O
Type R and O
factory furnished
duct collars qualify
as breakaway
connections.
Figure 17: Type R and O Transition
Curtain Fire Dampers
9
®
