3'' x 18'' DuraVent Type B Round Rigid Pipe - 3GV18

Use for venting listed natural gas or liquid propane Category I, draft hood appliances, or appliances that have been specifically tested and listed to use Type B Gas Vent. The appliances listed typically use Type B Gas Vent systems, but not always: Furnaces, Water Heaters, Boilers, Room Heaters, Decorative Gas Appliances, and Unit Heaters. To calculate installed length, subtract 1 1?2" from each connection of vent. A 1" clearance (air space) to combustible materials must be maintained. To calculate OD add 5?8".