Metal-Fab 6" x 12" Biomass Chimney L Vent Adjustable Length Pipe

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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.


Biomass factory-built chimney and vent intended for use with Biomass fuel appliances approved for Type L low-temperature venting systems in accordance with “Standard for Chimneys, Fireplaces, Vents, and Solid-Fuel Burning Appliances,” NFPA 211, and the International Mechanical Code.

Biomass Chimney features a corrosion-resistant 430 stainless flue and galvanized steel casing designed to operate in highly corrosive biofuel applications.  Our cutting-edge positive twist-lock design, locking tabs and rope gasket at each joint, prevents fly ash leakage and reduces installation time.


  • Adjustable length P12A is used when fixed pipe lengths are inappropriate.
  • Tested and Listed to UL 641.
  • Pipe and fittings in 4", 5", and 6" diameters.
  • Factory-built double-wall construction, using 430 stainless steel flue and galvanized steel outer casing.
  • Positive twist lock for easy assembly and disassembly without tools and without damage.
  • Rope gaskets at each joint to prevent fly ash leakage.

Note: Pipe overlaps 1½" when joined together. Assembled length is 1½" less than listed length


 Application For use with biomass fuels such as pellet, corn, wheat or other grassy and woody plants as specified by appliance manufacturers.
Clearance Minimum 3" clearance to combustibles
Flue Material Specifications: 430 stainless Steel
Casing Material Specifications: Galvanized Steel
Diameter: 6"
Height/Length: 12"
Adjustable:  4" to 8"


WARNING: Proposition 65