Our Galvanized Sheet Metal Duct, or sometimes referred to as KD pipe is manufactured from high quality galvanized steel in convenient 3 foot lengths for easy handling. KD is referenced to "knock down" because upon installation the pipes seam is left open for cutting and fitting to your application such as vent piping and appliance, water heater or furnace. Once you snap the pipe together the connection is permanent. The connection of the sheet metal pipe is crimped for easy fitting of consecutive duct joints or to sheet metal fittings and Flexible duct. The seam on our galvanized sheet metal duct is formed on a snap-lock machine which allows ease of assembly on your job site. Just simply snap the seam together and install to your adjoining items.
Duct Installation Tips & Tricks — In order to snap the seam together, start at one end and work your way toward the other end, making sure you hear the snap of the seam as it goes together. This snap feature will prevent the seam from easily coming apart. We recommend that you seal this seam with a duct sealant to prevent air leakage. This will improve the efficiency of your system and lower your monthly utility bills. When attaching to sheet metal fittings slide the crimped end of the duct into the straight end of the fitting and secure with sheet metal Sheet Metal Screws at about 4" on center. We also recommend that you seal this joint with a duct sealant. All sheet metal ducts used for Supply Air in your heating or air conditioning system should be insulated on the outside by wrapping a fiberglass insulation blanket around the sheet metal duct.