Metal-Fab 3" Diameter x 5' Length Flexible Connector

Estimated Arrival: Between and . (To All Contiguous States)

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Metal-Fab provides complete and comprehensive venting solutions to the HVAC, Hearth and Plumbing markets.  Founded in 1958 on the premise that offering better products and services would be the key to our success.

Metal-Fab continues to operate today as a privately held entity with the same core values that lead to success while creating steady, stable growth over the past six decades.

Customer needs are the highest priority at Metal-Fab that is why every customer receives a unique experience while choosing from a full line of high-quality venting products for commercial, residential and industrial applications. 

Cutting-edge manufacturing systems, innovative designs, patent products, unmatched product quality, and a focus for detail have resulted in a leadership position within the industries Metal-Fab serves.  Our constant product improvement process and experience in developing and engineer products for safe, efficient appliance operation sets Metal-Fab apart from the competition.


Flexible Aluminum Chimney Liners intended for field-installation into new or existing tile-lined or unlined masonry chimneys, venting natural active Category I gas-fired appliances which burn natural gas or propane.  Chimney liners are intended to be installed in accordance with the “Standard for Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances,” NFPA 211; “National Fuel Gas Code,” NFPA 54/ANSI Z223.1 or Canada, CAN-B149.1.

Flexible Aluminum Chimney Liners are tested and listed to UL 1777 and ULC –S635 for approved new or existing masonry relining chimney applications.  Flexible aluminum liners are manufactured from a durable aluminum alloy, ensuring maximum flexibility and strength.


  • Also available in 3", 4", 5", and 6" Diameter.
  • 2-Ply Aluminum Flex
  • Twist Lock B-Vent Male Connection
  • Stainless Steel Single Wall Connection
  • Use of the MLCK Flexible Connector eliminates the need to cut, crimp, or screw-fasten sections of the rigid single wall connector
  • Simply pre-stretch the MLCK connector to the desired length (up to 5') and install between appliance and inlet to Type B Gas vent
  • MLCK connector is UL listed


  • Flexible connector is not designed to be enclosed (unless it is enclosed within a masonry chimney, factory-built chimney, or Type B Gas Vent)
  • Flexible connector is not designed to pass through a combustible area such as a wall, ceiling, roof joist, floor, or crawl space
  • Flexible connector must be installed in compliance with applicable clearance to combustible
  • MLCK Flexible connector is not listed for use in Canada


    For use with Category-1 gas-fired furnaces, fireplaces, water heaters, wall heaters, etc.
    Clearances See Installation Instructions
    Listing Standard NFPA 211
    NFPA 54
    UL 1777
    ULC – S635
    Flue Material Specifications: double ply aluminum alloy; .0055 thick each layer.


    WARNING: Proposition 65