Metal-Fab 8" to 5" Direct Vent Reducer Adapter

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

✔ Same-Day Order Processing
✔ Free Returns
✔ No Restocking Fees
✔ Financing Options Available

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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 which 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 on 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.


Direct vent systems are balanced pressure systems acquiring intake air from outside the dwelling while exhausting combustion gases through the sealed flue.  UL 2112 tested and listed, Metal-Fab Direct Vent products are designed for safety, strength, and reliability, generating a product that lasts a lifetime. The precision design and construction of the 430 stainless steel flue eliminate the need for gaskets and reduce leaks, enhancing product dependability and safety.  Our innovative male-to-female slip connection design with flared female connections yields a product that is easy to install, reducing cost and installation time.


  • Stainless steel inner flue, superior to aluminum for high heat applications.
  • Unitized construction eliminates field assembly of inner flue and casing.
  • Twist connections with SureLock™ provide quick, positive, fastener-free installation on 4X6 components.
  • Precision pipe and fittings have been engineered for optimum appliance performance in both horizontal and vertical configurations. Field-applied sealant is not required.
  • Laboratory tested and listed with each appliance.
  • Wind, rain, and thermal performance-tested for safer, dependable operation.
  • All elbows swivel for easy alignment of system components.
  • Single multi-adjustable length.

New Technology

The special double-wall construction of Metal-Fab Direct Vent allows direct vent stoves and fireplaces to operate without using air from inside the building. These direct vent appliances draw combustion air in from outdoors through the direct vent system, meaning that warm inside air is not being used to fuel the appliance. The appliance burns efficiently without creating fumes, condensation or smoke in the room.

Better Design, Better Construction


 Application Designed for use only with Direct-Vented gas-fired appliances that comply with “ANSI Z21” Standards.
Listings/Standards International Building Code
UL 2112
Flue Material Specifications: 430 Stainless Steel
Casing Material Specifications:
Galvanized Steel
Top Inner Diameter:  5.07"
Top Outer Diameter:  8.01"
Bottom Inner Diameter:  8.03"
Bottom Outer Diameter:  11"
Height:  11.5"
Width:  11"
Limited Lifetime Warranty
Click to see Warranty Details

The Metal-Fab Direct Vent factory-built gas vent system, when installed according to manufacturer's instructions, as prescribed by Underwriters Laboratories Standard 2112, and when properly and regularly cleaned and maintained as set forth below, are warranted by Metal-Fab Inc. under normal residential use against defects in material or workmanship of the product for parts only for as long as the original consumer owns the venting system. During the first ten years of the warranty, Metal-Fab will provide replacement vent components at no charge. During the balance of the warranty, Metal-Fab will provide replacement vent components at 50% of the current retail price in effect at the time of the warranty claim. The defective part(s) must be returned with all transportation charges prepaid by the owner to the Customer Service Department, Metal-Fab Inc., 3025 May Avenue, Wichita, Kansas 67213. Metal-Fab Inc. will in turn ship the repaired or replacement part to the owner, freight collect, with the owner to be responsible for all freight charges. This warranty does not cover any labor or other service charges incurred by the owner, or any parts not manufactured by Metal-Fab Inc.

It is the OWNER'S RESPONSIBILITY to establish:

  1. the date of the original installation of the product;
  2. the name of the original purchaser;
  3. the name of the installer; and
  4. that the product was installed according to the manufacturer's instructions.


Safety Information: See CA Prop 65 Warning