503.7.9 Size of single-wall metal pipe.
FGC § 503.7.9
A venting system constructed of single-wall metal pipe shall be sized in accordance with one of the following methods and the appliance manufacturer's instructions: 1. For a draft-hood-equipped appliance, in accordance with Section 504.
2.For a venting system for a single appliance with a draft hood, the areas of the connector and the pipe each shall be not less than the area of the appliance flue collar or draft hood outlet, whichever is smaller. The vent area shall be not greater than seven times the draft hood outlet area.
3.Other approved engineering methods.
