Metal-fab M6A7 Type B Gas Vent Adapter 7x6 in Twist Lock

Product Description

The METAL-FAB M6A7 is a double-wall, round Type B gas vent adapter designed to connect and transition B-vent flue sections in residential and light commercial gas appliance installations. Built with an aluminum alloy inner wall at 0.012 inches thick and a G90 galvanized steel outer wall at 0.018 inches thick, this adapter delivers durable corrosion resistance suited to the demands of vented gas appliance systems. The 7-inch by 7-inch adjustable adapter features a twist-lock connection with an integrated locking tab, eliminating the need for sheet metal screws and speeding up field assembly. HVAC technicians and sheet metal contractors rely on this fitting for reliable, code-compliant B-vent runs.

The M6A7 is intended for use with Type B gas vent systems serving approved gas appliances such as furnaces, boilers, and water heaters. The adjustable design accommodates 6-inch length configurations, making it practical for connecting vent sections where precise spacing is required. The hemmed flue and casing construction is engineered to maximize product durability while minimizing installation time on the job. This adapter is appropriate for both new construction and retrofit B-vent installations where UL 441-listed components are required by the authority having jurisdiction.

Key Features

• Twist-lock connection with integrated locking tab eliminates sheet metal screws
• Double-wall construction: aluminum alloy inner wall and G90 galvanized steel outer wall
• Hemmed flues and casings for enhanced durability and reduced installation time
• Listed to UL 441 for approved gas appliances
• Meets NFPA 54/211 applicable standards
• Adjustable 6-inch length on a 7-inch diameter round profile

Compatibility

Designed as an OEM-style replacement and standard fitting for Type B double-wall gas vent systems serving approved gas appliances listed under UL 441.

Installation Notes

Installation of Type B gas vent components should be performed by a licensed HVAC technician or qualified sheet metal contractor in accordance with NFPA 54, NFPA 211, and local mechanical codes. Shut off the gas supply and allow the appliance and vent system to cool completely before beginning any service or installation work. Verify twist-lock engagement and locking tab seating at every joint before restoring the system to operation. Do not mix Type B vent components from different manufacturers within the same vent run unless listed for such use by the applicable standard.

Technical Specifications

• Size: 7 inches x 7 inches
• Length: 6 inches
• Type: Double Wall, Round
• Inner Wall Material: Aluminum Alloy
• Outer Wall Material: G90 Galvanized Steel
• Inner Wall Thickness: 0.012 inches
• Outer Wall Thickness: 0.018 inches
• Locking Connection Type: Twist Lock
• Applicable Standard: UL 441, NFPA 54/211

Standard Information

• Brand: METAL-FAB
• Manufacturer Part Number: M6A7