Wholesale Duct

TDF Ductwork Here's why contractors are going to the four-bolt connections for all their ductwork needs. It's faster, better and more economical because:
  1. Most of the connection work is done at the shop-not at the site. You control the work better.
  2. Spot welding and frame assembly are eliminated.
  3. Less labor required at both shop and site.
It means lower costs, better bids, more profit. TDF flange connections have been tested by an independent laboratory. The test showed less air leakage detected at 15"W.G. pressure. Test data available on request.

Method of Fabrication
Two "L" shaped sections are assembled in the field to form the finished joint of ductwork. This allows ductwork to be shipped in a knocked down connection requiring less cartage and easier handling. Ductwork can also be ordered in one piece, U-shaped or 4-piece.
Straight Duct

1. The corner pieces snap in...and stay in.
Lances roll formed in the flange lock-in the corners. This feature speeds the work at shop or job site. The corners will not fall out during installation. An exclusive TDF feature. Optional crimping of corners may be needed for light gauge material.

2. The corners fit better.
That's because the flange lip is roll formed inwards. This profile minimizes the differences in material thickness in securing reinforcing bar when required. This flange is roll formed in 26 through 18 ga. galvanized steel.

3. Less air leakage.
Note the metal tab left in the male notch. This metal remains and reduces air leakage at the corners. This is an important feature of the TDF (Transverse Duct Snap Flange System).

Available Options At No Extra Cost
  • Pittsburgh Lock: 18 ga. thru 26 ga.
  • Button Punch Snap Lock: 20 ga. thru 26 ga.
  • Drive Cleats turned on ends.
  • Reinforcing bead as per SMACNA.

Available Options for Ductwork-fittings
  • 1" Insulation comes standard 1-1/2 lb. density
  • 1/2" Insulation comes standard 2 lb. density
  • Also available 1" - 3 lb. density upon request
  • 100% adhesive coverage with mechanical fasteners
  • S/D & TDF accessories
  • Ductmate or welded
  • Assembled or knocked down
  • Sealant in female lock available on request

Rectangular Fittings

Made to order-check with factory for price & availability. Quoted price will vary with type of duct ordered and total poundage.

Round & Rectangle Custom Fabrication For All Your Needs
  • Food Processing
  • Industrial and Commercial Ventilation
  • Dust Collection
  • Kitchen Works
  • Composites
  • Specialty Metals


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Wholesale Duct

Call us at 800.657.6923  Our team of specialists are ready
to assist you. No matter how large or small your projects
are, Winona Heating and Ventilating can help. 
We are committed to quality and customer satisfaction.