8. DUCT-SLEEVE CONNECTIONS
Traditional Breakaway Style Transverse Joints
Transverse joints illustrated at right have always been
approved as breakaway connections. SMACNA testing
has also approved the following variations as breakaway
connections.
• The breakaway connections shown to the right (
Fig.
12
) can be applied with maximum of two #10 (19mm)
sheet metal screws on each side and on the bottom
located in the center of the slip pocket and penetrating
both sides of the slip pocket.
• Transverse joints illustrated
can be applied as top and
bottom joints with Drive Slip -
side joints in duct heights up
to 20 inches (508mm) see
Fig. 11
.
Round and Oval Duct Breakaway Connections
Round or flat oval ducts connected to Type R or O damper
collars shall be attached with #10 (19mm) sheet metal
screws as follows:
• Ducts to 22 in. (558mm) wide or diameter and smaller
shall have three screws.
• Ducts larger than 22 in. wide (558mm) or diameter
up to and including 36 in. (914mm) wide or diameter
shall have five screws.
NOTE:
All breakaway connections described may have duct
sealant applied, PA2084T duct sealant adhesive
manufactured by Precision, DP1010 water base duct
sealant manufactured by Design Polymetrics, Grey
Pookie, or Ductmate PROseal
®
, or CL Ward S Seal
in accordance with SMACNA recommendations.
Drive Slip Joint
Fig. 11
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)
Fig. 12
Fire Damper Sleeve
Neoprene or Butyl gasket
between all angles
Flanged system angles
(Attach per
manufacturer's
instructions)
Duct
3/8 in. bolts in
corners are optional
6 in. long 1/16 in. max.
thickness plastic cleats;
12 in. c-c (min. 1 per side)
Fig. 13
Proprietary Flange System Breakaway Connections
(TDC by Lockformer, TDF by Engle)
TDC and TDF systems are approved as breakaway
connections when installed as described in the TDC or
TDF addendum to the SMACNA
Duct Construction. Standard 6 in.
(152mm) metal clip may be used
with spacing as shown in diagram
(
Fig. 14 & 15
). 3/8 in. (9.5mm)
metal bolts and nuts may be used
to fasten together corner pieces.
(see
Fig. 16
)
Duct
Sleeve
6 in.
Std. Clip
Length
CL
Duct
60 in. Duct
4 Req’d.
48 in. Duct
3 Req’d.
36 in. Duct
3 Req’d.
24 in. Duct
2 Req’d.
18 in. Duct &
Smaller
1 Req’d.
Clip Spacing
Typical TDC/TDF joint
6 in.
6 in.
9 in.
7 in.
7 in.
5 in.
5 in.
5 in.
5 in.
Fig. 14
Manufactured Flanged System Breakaway Connections
(Fig. 13)
Flanged connection systems manufactured by Ductmate,
DuroDyne, Ward, and Nexus are approved as breakaway
connections when installed as illustrated (
Fig. 13
).
Fig. 15
Duct
Sleeve
6 in.
Std. Clip
Length
CL
Duct
60 in. Duct
4 Req’d.
48 in. Duct
3 Req’d.
36 in. Duct
3 Req’d.
24 in. Duct
2 Req’d.
18 in. Duct &
Smaller
1 Req’d.
Clip Spacing
Typical TDC/TDF joint
6 in.
6 in.
9 in.
7 in.
7 in.
5 in.
5 in.
5 in.
5 in.
Duct End
Flange
Corner Piece
3/8 in. bolt
(optional)
Fig. 16
34