The type B designation is assigned to gas venting systems that meet the safety requirements of Underwriters Laboratories, Inc. The AmeriVent all-metal, double-wall gas vent is listed as type B by UL and is approved for residential and commercial applications such as Category 1 water heaters, boilers, furnaces, space heaters, or wall heaters. UL-approved type B gas vent products form a continuous passageway from an approved gas appliance to the termination of the vent above the roof of the structure.

AmeriVent® Attic Shield, 4 in Nominal, 14 in W x 18 in H x 3-5/8 in D

• AmeriVent pipe are lightweight and rugged feature, made of corrosion-resistant galvanized steel and aluminum
• Ends have a snap-lock coupling
• 1 in minimum clearance to combustibles
• To disengage the locking tab - align the seams and pull apart
• Locking tab - to ensure a secure fit, push in the locking tab to lock the pipes together
• Engagement - snap-lock joints overlap - to calculate height deduct 1 in for each joint
• Used on a single-story building or on the top story of a multi-story building for type BW gas vent
• The 26 ga galvanized sheet metal extends down from the attic to the top of the ceiling plate
• Required by Los Angeles code and UMC

• Catalog https://assets.unilogcorp.com/267/ITEM/DOC/AmeriVent_7VPH_Catalog.pdf
• Instruction/Installation Manual https://assets.unilogcorp.com/267/ITEM/DOC/AmeriVent_4E12A_Manual.pdf