Metal-Fab 4" x 12" Adjustable Length Type B Double Wall Round Gas Vent Pipe UL Listed with SureLock Technology (#4M12A)

Metal-Fab's Type B Round and Oval Vent is listed by Underwriters Laboratories for use with approved Category 1 gas furnaces, heaters, and boilers. A Category 1 appliance operates on non-positive vent static pressure. The B-vent's double-wall design allows the product to be used in homes and commercial buildings with close distance to combustibles. 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 bending the chimney and casing; Assembly and disassembly, without tools, using positive twist lock; -- UL Listed to mate with other specifically identified and listed round gas vent, 3" to 6" diameters, allowing you to add a new Metal-Fab B-vent run to an existing run of common vent. Metal-Fab's 3"-6" diameter B-vent pipe is now standard with the new Surelock B-Vent locking system. The patented locking system provides a secure lock with the push of a tab, and can be easily disassembled by pulling the tab outward.