QF In-Line Back Draft Damper

QF In-Line Back Draft Dampers are used to reduce backward air flow in the line. They are designed for use in a horizontal line. Please specify if a vertical operation and upward air flow is required in the application. Manufactured with 16 or 18 ga Galv. and 18 or 20 ga. 304SS.
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Quick Fit In-Line Back Draft Dampers are used to reduce backward air flow in the line. They are designed for use in a horizontal line. Please specify if a vertical operation and upward air flow is required in the application.

QF In-Line Back Draft Dampers are manufactured as follows

  • In 3 to 24 inch diameters, with standard 16, and 18- gauge Galvanized or standard 18 and 20 gauge 304SS Stainless Steel
  • The longitudinal seam is lapped, spot welded, and caulked
  • Collars are located on the exterior side of each port and considered as air flow non-directional. A raised lap seam and spot weld are used for attaching the collar to the body and no caulking is used
  • The 3 to 24 inch diameter Dampers come with standard QF ends, with diameters of 26 inches and larger come with standard Angle Flanged ends
  • Standard QF ends can be changed to Raw with a defined ID dimension (RawID), Raw with a defined OD dimension (RawOD), No Fitting or just a raw end (NoFit), Flexible hose adapter (RawFlex), Flat Flange (FFL), Angle Flange (ANGFL), or Van Stone (VanStone).
Size
in.
Galvanized
ga.
304SS
ga.
Weight
lbs.
Length
in.
Length (B)
in.
Rolled Edge
nom.in.
3 18 N/A 2.25 17.5 7 0.2
4 18 20[18] 3.00 18.5 7 0.2
5 18 20[18] 3.50 19.5 7 0.2
6 18 20[18] 4.00 20.5 7 0.2
7 18 20[18] 4.50 21.5 7 0.3
8 18 20[18] 5.00 22.5 7 0.3
9 18 20[18] 10.00 23.5 7 0.3
10 18 20[18] 20.00 24.5 7 0.3
11 18 20[18] 25.00 25.5 7 0.3
12 18 20[18] 30.00 26.5 7 0.4
13 18 20[18] 36.00 32.5 12 0.4
14 18 18 42.00 33.5 12 0.4
15 18 18 49.00 34.5 12 0.4
16 18 18 59.00 43.5 20 0.4
17 18 18 63.00 44.5 20 0.4
18 18 18 72.00 45.5 20 0.4
20 16 18 78.00 47.5 20 0.4
22 16 18 85.00 49.5 20 0.4
24 16 18 90.00 51.5 20 0.4
26 16 18 100.00 57.5 24 AF
28 16 18 110.00 59.5 24 AF
30 16 18 115.00 61.5 24 AF
32 16 18 120.00 63.5 24 AF
34 16 18 130.00 65.5 24 AF
Galvanized Gauge Metal Thickness
Gauge Inches Millimeters
18 0.0516 1.31
16 0.0635 1.613
Stainless Gauge Metal Thickness
Gauge Inches Millimeters
20 0.0375 0.95
18 0.050 1.270
NOTES:
  1. At temperatures ranging between 390° F and 480° F, the zinc-iron alloy layers in the galvanized steel will continue to provide a high level of protection from corrosion. However, there may be some peeling, changes in mechanical properties, and reduction in the corrosion protection. Recommended maximum service temperature is 390° F.
  2. For 304 SS metal, bluing may occur at temperatures of 800° F and above.
  3. Rock River Silicone Sealant and Red Devil HVAC/R High Temperature Silicone Sealant are not able to be painted.
Item Material Compliance/Rating
QF In-Line Back Draft Damper Galvanized ASTM A653 with a G-90 Rating
304 SS Finish meets ASTM A240
316 SS Finish meets ASTM A240
3M Scotch Seal Metal Sealant 2084 Acetone blend AAMA Specification 801.1
3M Polyurethane Sealant 560 Polyurethane ASTM E 162
Bombardier SP 800-C
Rock River Silicone Sealant 100% Silicone ASTM C920 Class 25
TT-S-00230C Class A and TT-S-001543A
FDA No. 421 CFR 117.2600, conforms to FDA requirements
Red Devil HVAC/R High Temperature Silicone Sealant Silicone ASTM C920 Class 25
TT-S-00230C Class A and TT-S-001543A
CEBTP 432.6 140-2
Mil Spec 46106A
CGSB 19C9-9B
DIN 18540 Part 2
OREX 150031-2
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