DuraVent - This Aluminum 12" round rigid pipe with 4" inner diameter from the round gas vent series is a Type B gas component and contains the Duralock system for a tight seal. 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 a Type B gas vent.

The following appliances 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 vent connection. A 1" clearance (air space) to combustible materials must be maintained. To calculate outside diameter, add 5/8".