Phone: +1 678-388-2740

    Double wall stainless steel exhaust systems

    Chimneys made of stainless steel with high quality insulation material, available in different designs, materials and colors.

    DWFL-ZC Grease Duct

    Zero Clearance & Fire Rated Grease Duct

    System features



    DWFL-ZC UL-2221 Zero Clearance & Fire Rated Grease Duct

    Inner Material

    Inner liner made of high-grade ASTM 316L stainless steel.

    Outer Jacket Material

    Outer jacket made of ASTM 304 stainless steel

    Wall thickness


    6” through 36” = 0.035” thick



    6” through 24” = 0.025” thick

    26” through 36” = 0.035” thick


    Inner diameter

    6'' - 36'' I.D. 


    3.25” thick compressed ceramic fiber insulation


    Inner connection is a 1.25” overlapping joint with added ½” rolled flange and vee band connection.


    Supplied sealant is used in the vee band to make seal.


    Blanket insulation and outer band completes the joint assembly.


    Locking band

    Attached to each part

    Main features

    • Extremely rugged made in all-stainless with 25-year warranty
    • Leak proof high-pressure joints
    • Cut length available for maximum field flexibility
    • Smooth flow and known resistance for perfected factory pressure calculations
    • Zero clearance and 2-hour fire rated so it eliminates the requirements for an additional fire rated shaft.


      • Stainless steel and factory insulated zero clearance and fire rated duct assembly for Kitchen Ventilation Systems and Special Gas Vent.
      • Eliminates the need for fire dampers in HVAC ducts, laundry, and fume venting applications.
      UL Listings (and ULC)

      UL-2221 Standard, Fire Resistive Grease Duct Enclosure Assemblies

      UL-1978 Standard, Grease Duct (ULC-S662 Standard for Factory-Built Grease Ducts)

      90” W.C. Pressure Listing for all Applications

      25 years warranty!