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 Gas Vent

    Zero Clearance Gas Vent


    System features



    DWFL-ZC Zero Clearance

    Inner Material

    Inner liner made of high-grade ASTM 444 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


    Product data sheets and catalogs:

    DWFL & SWFL Catalog


    Installation Manuals:

    Installation FL and KL Systems – All



    Sample Specifications – DWFL-ZC Gas Vent


    Submittal Records:

    DWFL Submittal- All-in One Exhaust System

    UL Summaries:



    Main features

    • Eliminates the need for fire dampers in HVAC ducts and fume venting applications.
    • 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 accurate factory pressure calculations.
    • Zero clearance and two-hour fire rated so it eliminates the requirements for an additional fire rated shaft.


    • Stainless steel and factory-insulated zero clearance assembly for special gas vent.
    • For use as gas vents, laundry exhausts, make-up air ducts, dryer exhausts, fume venting, HVAC ductwork, and other exhaust systems.
    UL Listings (and ULC)

    UL-1738 Standard, Venting Systems for Gas-Burning Appliances, Categories II, III & IV (ULC-S636 Standard for Type BH Gas Venting Systems)


    UL-2221 Zero Clearance to combustibles and two-hour fire rated-resistive enclosure assembly 


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


    UL-441 Standard, Gas Vents (ULC-S605 Standard for Gas Vents)


    90” W.C. Pressure Listing for all Applications

    25 years warranty!