Metal-Fab 4PWT Premium Biomass Wall Thimble

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.


Premium Biomass factory-built 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. Tested and listed to UL 641, Premium Pellet Vent features a super ferritic corrosion resistant 444 stainless flue designed to operate in highly corrosive biofuel applications.  Our innovative inner flue locking design permits 130° of pipe rotation, allowing pipe seams to be aligned for an aesthetically pleasing installation.  Continuous laser-welded flue, casing, and integrated silicone gasket eliminate fly ash leakage and maximize product effectiveness, operational efficiency, and safety.


  • Provides the proper clearance for the pellet/corn pipe when it passes through a combustible wall.
  • Wall Thimble
  • Adjustable: 5 to 9.5"
  • Height: 10.13"


WARNING: Proposition 65