Double Wall Spiral Duct Specifications

Smc double wall round spiral duct is a dependable erosion resistant alternative to lined round spiral duct providing improved protection for insulation exposed to the airstream.

Double wall spiral duct specifications.

Mylar barrier is available as a barrier between perforated liner and insulation. When noise reduction is required the inner wall of dual wall spiral pipe is perforated with thousands of 3 32 holes on 3 16 centers. Dual wall double wall insulated spiral is available with solid or perforated liners. This requirement is applicable to 20 gauge or less in thickness and 3 w g.

All double wall fittings are fabricated with stiffening beads on duct sizes 19 wide and larger which have more than 10 square feet of unbraced panel. Double wall flat oval duct and fittings are also available in carbon steel paintable galvanized steel and a luminized steel. K value is 0 27. In double wall round spiral duct a metal inner liner insures that high airflow velocities cannot separate insulation by pulling away from the duct s outer wall and creating erosion or airflow problems.

Aluminum double wall flat oval duct and fittings are available in larger sizes and greater metal thicknesses on special order. These holes effectively channel system noise flanking noise and cross talk noise into the insulation layer where it is absorbed. 1 2 and 3 insulation thicknesses are available. Standard lengths of longitudinal seam k27 duct are 5 and 6 feet.