Round and Oval Duct Breakaway
Connections
Factory furnished duct collars, type R and O, are also
considered breakaway
(see Figure 12)
.
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.
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 12:
Type R and O Transition
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 Reinforced) (Angle Reinforced)
Figure 10
Drive Slip Joint
Figure 11
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 11
) on the sides.
Out of Wall Fire and Combination Fire Smoke Dampers
8
®
