Type B Gas Vent
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 Underwriters Laboratories, Inc. and is approved for such residential and commercial applications 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.
Double-Wall Construction
Double-wall metal construction provides protection for health and safety, as well as benefits of economy, ease of installation, efficiency, and protection from property damage. Designers of vent systems should take particular note of the fact that vents constructed of brick, cement, asbestos, and mass-insulated metal require lengthy warm-up periods, whereas double-wall metal vents reach operating temperatures almost instantly for rapid removal of the flue gases.
The Amerivent System
Amerivent Type B gas vent uses a double wall of metal pipe for insulation and safety. The inner pipe of reflecting aluminum heats quickly, containing the warm flue gases inside. The airspace between the inner and the outer pipes provides insulation against heat loss to keep the warmer flue gases on the rise. The outer pipe of corrosion-resistant galvanized steel ensures strength, safety, and durability.
If the flue gases are kept rising at the proper rate, the structure is kept free from pollution, and condensation damage is eliminated. Although a large portion of the flue gas is composed of water vapor, Amerivent Type B gas vent carries it out of the structure before it can condense.
One of the fire safety features of double-wall Type B gas vent is that its outer wall, insulated by the airspace beneath it, requires only 1” clearance to combustible material in the structure.
Amerivent is a complete gas venting system, from 3” to 30” pipe diameters in 7 different pipe lengths, to single- to multi-appliance hook-ups. The Amerivent gas vent line allows you to create almost any system from our more than 350 coordinated parts. Featuring Snap-Lock joints that are quick and easy to disconnect, the Amerivent Type B gas vent system is lightweight with no sacrifice in strength, and is available in large sizes, adjustable components, and multi-story Type BW venting installation.
Specifications and Dimensions
Available Pipe Sizes and Lengths
Round
Sizes: 3”, 4”, 5”, 6”, 7”, 8”
Lengths: 6”, 12”, 18”, 24”, 3’, 4’ (except 8” size), 5’
Sizes: 9”, 10”, 12”, 14”, 16”, 18”, 20”, 22”, 24”, 26”, 28”, 30”
Lengths: 12”, 18”, 24”, 3’
Oval
Sizes: 4”, 5”
Lengths: 6”, 12”, 18”, 24”, 3’, 4’, 5’
Size: 6”
Lengths: 6”, 12”, 18”, 24”, 3’
Usage
Amerivent Type B gas vent is used for venting all
Category 1 listed gas appliances having draft hoods and other appliances listed to be used with Type B Gas Vent. For information on venting unlisted gas appliances or appliances burning solid or liquid fuels, request our Amerivent Hearth catalog which includes All-Fuel Chimneys.
Material
Inner Wall: Aluminum Alloy 1100, 3003, or 3015
Outer Wall: Galvanized Steel
Double-wall corrugated aluminum with B vent ends can be used anywhere B vent is used, except where it passes through walls, floors, ceilings, and inside enclosures. May be compressed to fit.
Diameter Sizes: 3", 4", 5" Lengths: 24", 3', 4', 5'
- Single-wall corrugated aluminum easily connects from the appliance to AmeriVent Type B gas vent
- May be compressed 4" per foot to shorten length
- Sturdy galvalume ends offer proven snap-lock design
- This product can only be used in the room with the equipment in occupied spaces, not in unoccupied spaces such as attics or crawl spaces
- It cannot be used to pass through a wall, roof or ceiling, and cannot be totally enclosed
The single-wall appliance connector is sized to fit outlet. Use sheet metal screws for code-approved appliance connection.
The single-wall universal adapter provides a short slip connection with the AmeriVent single-wall snap-lock base.
The single-wall increaser is used to increase the connector diameter.
The branch, trunk, and base diameters of the standard single-wall wye are the same size.The reduction single-wall wye features a branch and/or base with a diameter smaller than the trunk size. Convenient connection for furnace and water heater into a common connector.
Assemblies consist of a single-wall flexible connector with an appliance connector and a universal adapter pre-attached. An assembly allows easy connection from an appliance to any brand of B vent.
The AmeriVent oval pipe offers all the advantages of AmeriVent round pipe, and may be used for the following types of installation.
The adjustable length telescopes onto standard pipe sections to permit adjustments from 3" to 10".
45 Degree Standard Elbow
- Used in pairs where offsets are desired in 1" minimum clearance enclosures or open spaces, such as attics or basements.
- Add pipe sections between pairs to produce additional offset
45 Degree Flat Elbow
- Used in pairs where offsets are desired in 1" minimum clearance enclosures or open spaces, such as attics or basements.
- Add pipe sections between pairs to produce additional offset.
- Model OCA - Locking
- Model OC - Universal
- The 5" and 6" oval vents use an Oval to Round Adapter (0E) and a Round Cap (CW or ECW)
The oval-to-round adapter is used for conversion of vent from oval to round.
The all-pitch flashing is installed either parallel or perpendicular to the roof ridge, and fits roof pitches flat to 5/12.
The firestop spacers center vent in 16" O.C. stud space and serve as a firestop at the ceiling level. This is a required component for Type B 2 x 4 and multi-story Type BW installations.
- The Type BW hold-down plate is required for connecting Type BW vent to a wall furnace outlet.
- Included in the BW Installation Kit
- Size: 4" only
The increaser permits increasing of vent from 4" oval to 5" oval.
Type BW plate spacers are required at the first ceiling level above a wall furnace to center and space vent properly and to provide the required opening between floors. Firestop spacers must be used at subsequent levels.
- Used just above the flashing to provide protection from the weather
- Seal the inner edge with sealant against pipe
- The branch size and trunk size have equivalent diameter
- The tee branch access either double or single wall pipe
The branch size and trunk size have the same effective area. The tee branch accepts either double- or single-wall pipe.
Sizes: 4" Tee, 3" Branch
The branch size of the reducing tee is one inch smaller than the trunk size.
The tee cap is used for closing off the bottom of the tee.
The tee support is used to support and center the tee.
The tee collar may be used to cover the rough wall opening and the exposed double-wall branch of the tee. The 3-40TVC collar features a knock-out for a 3" or 4" single-wall connector.
- Used on a single-story building or on the top story of a multi-story building for Type BW gas vent
- The 26 gauge galvanized sheet metal extends down from the attic to the top of the ceiling plate
- Required by Los Angeles Code and UMC
- The Type BW installation kit contains:
- One pair of Type BW plate spacers (40PS)
- One BW hold-down plate (40HD)
- The bucket support and hanger is used for starting a vent at ceiling level.
- Supports provide proper clearance and automatic positioning.
- Designed to fit between 16" O.C. joists.
- Buckets only are available in sizes 9" through 22".
- Does not act as a firestop. Use firestop (FS).
- Supports up to 30 feet.
- Galvanized Steel Construction
- The AmeriVent cap is the first engineered vent cap to gain recognition across the country for its performance.
- Millions of them are now installed on homes and business structures to protect against wind conditions that can cause waste gases to spill back into the structure through the appliance draft hood.
- The AmeriVent cap is UL-listed, and its patented design of ports and baffles keep rain and debris out of the vent.
- AmeriVent caps permit termination of vents at the minimum height necessary above the roof surface.
- The AmeriVent Cap is used as a ventilation cap as well as a Type B gas vent termination.
AmeriVent pipe and fittings are lightweight and feature rugged, double-wall construction of corrosion resistant galvanized steel and aluminum. Ends have a snap-lock coupling.
Sizes: 3", 4", 5", 6", 7", 8" Lengths: 6", 12", 18", 24", 3', 4' (except 8" size), 5'
Sizes for 12" lengths: 3" through 8", adjustable from 3" through 10" Sizes for 18" lengths: 9" through 12", adjustable from 3" through 16" Sizes for 18" lengths: 14" through 30", adjustable from 5" through 16"
Adjustable lengths telescope onto standard AmeriVent pipe sections.
- Used to offset installation to avoid obstructions such as rafters & joists
- Size 3" through 14" adjust easily from 0° to 45°
- Sizes 16" through 30" are non-adjustable
- See the Gas Vent Offset Chart
Sizes 3" through 14" adjust easily from 0° to 45°. Sizes 16" through 30" are nonadjustables
- The adjustable 90° elbow is constructed of four sections for smoother bends and less resistance.
- The elbow adjusts from 0° to 90° easily in order to clear rafters or ceiling joists.
The draft hood connector connects Type B gas vent directly to an appliance draft hood. The flexible inlet can be shaped to fit oval draft hood outlets.
Flashing - Standard The standard flashing fits flat to 5/12 pitch roof, and is made of double-seamed construction for protection from leakage. For a standard flashing with a 6" skirt, the Model No. reads the size and EFFU or RFFU.
Flashing - Steep Pitch The flashing with a steep pitch fits 6/12 to 12/12 pitch roofs.
Flashing - Tall Cone The flashing with a tall cone fits flat to 1/12 roofs, and is used on flat roofs in snowpacked areas to reduce pressure.
UL-listed as a support and firestop, the gripper support is strong enough to hold up to 30 feet of vent pipe. It installs very quickly and allows for adjustment of the pipe to wherever needed. A ring on the bottom provides the UL-required, one-inch clearance to combustibles (3" to 6" only; 7" to 10" are not UL-listed). No tools are required.
The increaser is used to increase vent size.
- Used just above the flashing to provide protection from the weather
- Seal the inner edge with sealant against pipe
The reducing tee features a branch with a smaller diameter than its trunk size, and provides a convenient connection of the furnace and water heater to a common vent.
Branch and trunk diameters of the standard tee are the same size. For small branch sizes, use a reducing tee up to 6" size. For larger sizes, use an increaser with a standard tee.
The tee cap provides closure for the branch of the trunk of the tee.
Sizes: 3", 4", 5", and 6" diameters in male and female end models.
The universal adapter offers secure, listed connections between AmeriVent Type B gas vent and gas vents of other manufacturers.
- The vent collar provides a cover for a rough wall opening
- Fits double-wall pipe only.
- Used to install pipe though an interior wall and provide proper clearance from combustibles
- The wall thimble adjusts for various wall thicknesses from 4" to 6"
Standard Wye
The standard wye features the branch, trunk, and base diameter with the same size.
Reduction Wye
The reduction wye features a branch and/or base with a smaller diameter than the trunk size, and provides a convenient double-wall connection to furnace or water heater in a common connector.
- The Firestop Support Package (FSP) supports Type B gas vent starting at the appliance ceiling level and includes a Support Bracket and Firestop.
- The Support Bracket (SB) and Firestop (FS) are also available separately.
- Supports up to 20 feet.
The support plate is designed to provide strength and durability for supporting large size pipe sections, and serves as a firestop. Supports up to 30 feet. The support plate supports tee sizes 3" through 6", and is used as a base for Type B gas vent.
VPH Vent Pipe Hanger provides 11/2" spacing (order same size as AmeriVent)
SBA Vent Pipe Hanger provides 2" spacing (order same size as AmeriVent)
These hangers provide support and resupport for offsets and horizontal runs of AmeriVent or transite.
Convenient solution for a variety of rooftop vent, flue*, and B-vent installations
- Self-centering, adjustable design means a quick, easy installation
- Worm Gear Clamp with one-tool adjustability
- Three sizes fit pipes with outside diameters from 3” to 8.5”
- Helps prevent rain, debris, and most birds from entering the vent
- Aluminum construction for rust and corrosion resistance
- Includes separate instruction sheet
- Listings: UL 441 and CAN/ULC-605
*Not to be used with solid fuel