Metal-fab 4M45/60 B-vent Double Wall 4 Inch Adjustable Elbow

Product Description

The METAL-FAB 4M45/60 is a double-wall B-vent elbow fitting designed to redirect gas appliance exhaust flue piping at either a 45-degree or 60-degree angle. This adjustable elbow is used in Type B gas vent systems, which are the standard venting method for naturally drafting gas furnaces, boilers, and water heaters. The fitting accepts 4-inch diameter vent pipe and accommodates installers who need a single fitting to serve two common offset angles. Licensed HVAC technicians and plumbers install this type of fitting during new vent runs or service replacements.

This elbow is suited for residential and light commercial installations where Type B double-wall vent pipe is required by code. It fits into straight runs where a direction change is needed to route flue gases around structural framing, through floors, or along ceiling lines before exiting the building. The adjustable 45/60-degree design reduces the need to stock two separate elbow fittings on the service vehicle.

Key Features

• Adjustable elbow covers both 45-degree and 60-degree offset angles in a single fitting
• Double-wall construction maintains flue gas temperature and reduces exterior surface heat
• Designed for 4-inch Type B gas vent systems
• Metal construction for durability in continuous venting applications
• Lightweight at 0.50 pounds for easy one-hand installation in tight chases

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 4-inch Type B double-wall gas vent pipe systems in residential and light commercial gas appliance applications.

Installation Notes

Installation of B-vent fittings should be performed by a licensed HVAC technician or plumber in accordance with NFPA 54 and local mechanical codes. Shut off the gas supply and allow the appliance to cool completely before servicing any vent components. Ensure all joints are fully seated and secured per the vent system manufacturer's instructions, and verify that the completed vent run maintains the required clearances to combustibles. Do not use Type B vent fittings as a substitute for listed venting in high-temperature or direct-vent applications.