Double Wall Spiral Duct Specifications

These holes effectively channel system noise flanking noise and cross talk noise into the insulation layer where it is absorbed.

Double wall spiral duct specifications.

Double wall flat oval duct and fittings are also available in carbon steel paintable galvanized steel and a luminized steel. 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. 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. Standard lengths of longitudinal seam k27 duct are 5 and 6 feet.

Dual wall double wall insulated spiral is available with solid or perforated liners. Aluminum double wall flat oval duct and fittings are available in larger sizes and greater metal thicknesses on special order. K value is 0 27. Mylar barrier is available as a barrier between perforated liner and insulation.

Double wall fittings are manufactured on our state of the art fabrication equipment. Smc constructs each piece with an inner shell perforated or solid surrounded by a layer of insulation and covered by a solid outer shell. This requirement is applicable to 20 gauge or less in thickness and 3 w g. E z flange with barrel clamp 26 to 96 diameter.