Metal-Fab's round and oval Type-B vent is listed by Underwriters Laboratories for use with approved category 1 gas furnaces, heaters, and boilers. A category 1 appliance operates with a non-positive vent static pressure. The double wall design of B-vent enables the product to be used in homes and commercial buildings at close clearance to combustible. Metal-Fab's B-vent design incorporates features that make installation quick, easy, and safe. Some of those features are:
Elimination of sharp edges by hemming the flue and casing.
Assembly & disassembly, without tools, using positive twist lock.
360 degree rotation of small diameter fittings using swivel tees, wyes, and elbows.
Space savings inside standard stud walls using oval pipe.
UL listed to mate with other specifically identified and listed round gas vent, 3"-6" diameters, allowing you to add a new run of Metal-Fab B-vent to an existing run of common vent. Metal-Fab 3"-6" diameter B-vent pipe is now standard with our new Surelock® B-Vent Locking System . The patented locking system provides a secure lock with just the push of a tab, and can be easily disassembled by pulling the tab back out. Commercial Vent or "BIG Vent" is available in round sizes of 14" - 30". Big Vent sections (in 16" - 30" diameters) are joined together using Metal-Fab's quick connect locking system.