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When a vent is less than 10 feet high, the vent should be at least as large as the flue collar outlet.b) Vents for draft hoods or flue collars 12 inches in diameter or less should NOT be reduced more than one pipe size.
The inner wall is recessed to eliminate. damage in handling. Type B Gas Vent has been engineered to heat up rapidly. It. remains hot during the operation of the appliance with minimal. condensation in the appliance and vent system. Pipe lengths. are available in multiple lengths, 6 to 60 inches, with a full. complement of adjustable and rigid 5ttings. Type B gas vents are not suitable for use with wood-burning or. coal applications, industrial ovens, exhaust ranges and hoods, grease or pollution ducting, or as free-standing exhaust vents for.