SKU: 13272506774

DuraVent Round Type B Gas Vent Model BV 20" Large Diameter Tall Cone Flat Flashing

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Description

DuraVent Round Type B Gas Vent Model BV 20" Large Diameter Tall Cone Flat FlashingOur non positional lock system on the Duravent BV Gas Vent is the best lock system on the market today. The incorporation of the DuraTab feature simply improves our lock system by adding flexibility and meeting market needs. The BV line of Duravent round vent pipe and fittings is designed for use on approved gas appliances in residential and light commercial and industrial applications. What's Included (1) Large Diameter Tall Cone Roof Flashing

Our non-positional lock system on the Duravent® BV Gas Vent is the best lock system on the market today. The incorporation of the DuraTab® feature simply improves our lock system by adding flexibility and meeting market needs.

The BV line of Duravent round vent pipe and fittings is designed for use on approved gas appliances in residential and light commercial and industrial applications.

What's Included

  • (1) Large Diameter Tall Cone Roof Flashing

Features

  • Used on flat roof surfaces.
  • The flashing with a tall cone fits flat to 1/12 roof pitches.

Specifications

Item Number 20BVFF
Series Round Type B Gas Vent Model BV (3" - 30")
Product Type Tall Cone Roof Flashing
Size (Diameter) 20"
A (I.D.) 21 9/16"
B (I.D.) 23 9/16"
C 36"

Technical Dimensions

Warranty

Duravent, Inc. (“Duravent”) provides this limited lifetime warranty for all of its products with the exception of Ventinox® (lifetime), and PolyPro® (ten years). Subject to the limitations set forth below, Duravent warrants that its products will be free from defects in material or manufacturing, if properly installed, maintained and used.

DuraVent, Inc. (“DuraVent”) provides this limited lifetime warranty for all of its products with the exception of Ventinox® (lifetime), and PolyPro® (ten years). Subject to the limitations set forth below, DuraVent warrants that its products will be free from defects in material or manufacturing, if properly installed, maintained and used. DuraVent products are fully warranted if installed only by a professional installer. This Warranty is transferable from the original homeowner to the buyer of the home. This warranty does not cover normal wear and tear, smoke damage or damage caused by chimney fires, acts of God, or any product that was: (1) purchased other than from an authorized DuraVent dealer, retailer or distributor; (2) modified or altered; (3) improperly serviced, inspected or cleaned; or (4) subject to negligence or any use not in accordance with the installation instructions included with the product as determined by DuraVent.

DuraVent provides the following warranties for its products: One Hundred Percent (100%) MSRP 15 years from the date of purchase, and Fifty Percent (50%) thereafter, except for the following limitations on: all Termination Caps and DuraBlack® are warranted at One Hundred Percent (100%) for five years. All warranty obligations of DuraVent shall be limited to repair or replacement of the defective product pursuant to the terms and conditions applicable to each product line. These remedies shall constitute DuraVent’s sole obligation and sole remedy under this warranty. This warranty provides no cash surrender value. The terms and conditions of this warranty may not be modified, altered or waived by any action, inaction or representation, whether oral or in writing, except upon the express, written authority of an executive officer of DuraVent.

Corn, bio-fuels, driftwood or other wood containing salt, preservative-treated lumber, plastic and household trash or garbage, or wood pellets containing such materials must not be burned in the appliance or fireplace. In case of a chimney fire, the chimney must be inspected and approved by a certified Chimney Sweep before reuse. After each annual inspection, maintenance, and cleaning, the certified Chimney Sweep must fill out and date the appropriate section of the warranty card provided with the chimney liner.

LIMITATIONS ON INTERNET SALES: Notwithstanding any other terms or conditions of this Limited Lifetime Warranty, DuraVent provides no warranty for the following specific products if such products are not installed by a qualified professional installer: DuraTech®, DuraTech® DTC, DuraTech® Premium, DuraPlus HTC®, DDW®, DuraChimney® II, PelletVent Pro®, DirectVent Pro®, FasNSeal®, FasNSeal® W2, FasNSeal® Flex, and PolyPro®, and DuraVent’s relining products including DuraLiner®, DuraFlex® (SW, Pro, 316, 304), and Ventinox®. For purposes of this warranty, a trained professional installer is defined as one of the following: licensed contractors with prior chimney installation experience, CSIA Certified Chimney Sweeps, NFI Certified Specialists, or WETT Certified Professionals.

DuraVent must be notified and given the opportunity to inspect defective product prior to replacement under the terms of this limited lifetime warranty. All warranty claims must be submitted with proof of purchase. Labor and installation costs are not covered under this warranty. To obtain warranty service contact: DuraVent Warranty Service, 877 Cotting Ct., Vacaville CA 95688, or call 800-835-4429.

WHERE LAWFUL, DURAVENT DISCLAIMS ALL OTHER WARRANTIES, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL DURAVENT BE LIABLE FOR INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR SPECIAL DAMAGES OR DIRECT OR INDIRECT LOSS OF ANY KIND, INCLUDING BUT NOT LIMITED TO PROPERTY DAMAGE AND PERSONAL INJURY. DURAVENT’S ENTIRE LIABILITY IS LIMITED TO THE PURCHASE PRICE OF THIS PRODUCT. SOME STATES DO NOT ALLOW LIMITATIONS ON IMPLIED WARRANTIES, OR THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATIONS AND EXCLUSIONS MAY NOT APPLY TO YOU. THIS LIMITED WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, AND YOU MAY ALSO HAVE OTHER RIGHTS THAT VARY FROM STATE TO STATE.

Documents & Files

Videos

Frequently Asked Questions

What is DuraVent Type B Gas Vent (Model BV)?

Applications

Duravent’s Type B Gas Vent system. Use with natural gas or liquid propane Category I and draft hood equipped appliances, and appliances tested and listed to use Type B Gas Vent. Applications include: natural gas fireplaces, gas-fired furnaces, boilers, water heaters, and wall or space heating applications.

Materials and Construction

Round Type B Gas Vent 3″ – 8″ and Oval 4″ – 6″: Aluminum .012″ inner wall, galvanized .018″ outer wall, in Canada, the lengths have a galvalume .018″ outer wall. The 3″ – 8″ Round gas vent features DuraLock® and DuraTab® . The Oval gas vent features the button lock.

Round Type B Gas Vent 10″ – 18″: Aluminum .014″ inner wall, galvanized .018″ outer wall. DuraLock® feature for 10″ and larger diameters.

Round Type B Gas Vent 20″ – 30″: aluminum .023″ inner wall, galvanized .018″ outer wall. DuraLock® feature for 10″ and larger diameters.

Clearances

Clearances to combustible materials in single and multi-family dwellings:

  • 1″ Clearance – USA – 3″ to 30″
  • 1″ Clearance – Canada – 3″ to 24″
  • 2″ Clearance – Canada – 26″ to 30″

Annular insulating air space

  • 3″ – 8″ Round Vent: 1/4″ air space
  • 4″ – 6″ Oval Vent: 1/4″ air space
  • 10″ – 30″ Round Vent: 1/2″ air space 

Diameters

  • 3″- 30″ Round Diameter.
  • 4″, 5″ and 6″ Oval (USA only)

Listings

 UL Listed to UL 441 and CAN/ULC-S605 (MH2848 and MH17667).

What is DuraVent Type B Gas Vent (Model BV)'s Typical Installation?

Small Diameter – Vertical Installations

Item Clearance - See Note 1 Max Height Outer Tube Ø Materials Locking Device UL Listing
Type B Vent Round 3″-8″ (USA) 1 inch 100 feet 1/2″ larger than ID Inner – .012″ Aluminum Outer – .018″ Galvanized  DuraLock & DuraTab MH2848
Type B Vent Round 3″-8″ (CAN) 1 inch 100 feet 1/2″ larger than ID Inner – .012″ Aluminum Outer – .018″ Galvalume* DuraLock & DuraTab MH2848
Round 10" to 18" - See note 2 1 inch 100 feet 1″ larger than ID Inner – .014″ Aluminum Outer – .018″ Galvanized DuraLock MH2848
Round 20″ to 30″ (USA) See note 2 1 inch 100 feet 1″ larger than ID Inner – .023″ Aluminum Outer – .018″ Galvanized DuraLock MH2848
Round 20″ to 24″ (CAN) See note 2 1 inch 100 feet 1″ larger than ID Inner – .023″ Aluminum Outer – .018″ Galvanized DuraLock MH2848
Round 26″ to 30″ (CAN) See note 2 2 inch 100 feet 1″ larger than ID Inner – .023″ Aluminum Outer – .018″ Galvanized DuraLock MH2848
Oval Type B Gas Vent 4″ and 5″ 1 inch - See Note 5 See Note 3 4": 2 1/2″ x 7 1/4″ or 5": 3 1/8″ x 10 7/8″ Inner – .012″ Aluminum Outer – .018″ Galvanized DuraLock MH2848
Oval Type B Vent 6″ 1 inch - See Note 5 See Note 3 3 1/4″ x 12″ Inner – .012″ Aluminum Outer – .018″ Galvanized DuraLock MH2848
DuraConnect I Flex 3″ and 4″ 1 inch See Note 4 NA .012″ Aluminum Flexible .018″ Galvalume Fittings DuraLock & DuraTab MH17667
DuraConnect II Flex 3″ to 5″ 1 inch See Note 4 1/4″ larger than ID .006″ 2 Ply Aluminum Flex .018″ Galvalume Fittings DuraLock & DuraTab MH17667

*In Canada, the outer tube material is galvalume for 3″ to 8″ pipe length. All other 3″ to 8″ fittings have a galvanized outer tube.

Notes: Gas Vent Specification Chart

  1. Clearance to combustibles is the air space between vent and combustibles.
  2. For maximum height refer to the appliance manufacturer installation instructions and the National Fuel Gas Code NFPA 54 or the Canadian Fuel Gas Installation Code CSA-149.1-00. For taller applications refer to Duravent Sizing Handbook.
  3. When oval is used on wall furnaces, minimum height required from bottom of furnace to cap is 12′, minimum 16″ stud space.
  4. Limited by sizing tables.
  5. BVO 4″ & 5″ oval can be installed in a 2″ x 4″or a 2″ x 6″ stud wall. BVO 6″ oval can be installed in a 2″ x 6″ stud wall.
What are the DuraVent product lines?

DuraVent offers the following product lines:

DuraTech 5″-8″: All-fuel, double-wall chimney system. UL 103 HT and ULC S604.

DuraTech LDC 10″-24″: All-fuel, double-wall chimney system. UL 103.

DuraTech Canada is a double-wall, all-fuel chimney system for use with wood stoves, wood fireplaces, and other appliances using wood, oil, gas, or coal.

DuraPlus: Triple-wall all-fuel chimney with two layers of insulation.

DuraPlus HTC: Double-wall all-fuel chimney built to Canadian standards.

DuraChimney II: Double-wall air-cooled chimney for pre-fabricated masonry chimneys.

Combustion Air Systems: DuraVent’s exclusive, patent-pending system is designed to bring in outside combustion air directly to your wood or pellet stoves.

DuraBlack: Single-wall stovepipe.

DVL: Double-wall stovepipe.

DuraLiner: Double-wall factory insulated masonry relining system.

DuraFlex: Flexible stainless steel liners.

DuraFlex Aluminum: Flexible aluminum relining for masonry chimney. UL 1777 and ULC S635.

Ventinox: Flexible stainless steel liner.

CVS: Provides Ortal Branded Fireplace Systems and as a Direct Vent for Pellet Stoves.

PelletVent: Multi-fuel vent.

PelletVent Pro: Vents appliances using oil, wood pellets, corn, and other biofuels.

DirectVent Pro: Unitized, co-axial venting system for direct vent gas or propane stoves, heaters, and fireplaces.

Type B Gas Vent: Vents natural gas, liquid propane category I, and draft-hood equipped appliances

FasNSeal: Single, double-wall, flex, and concentric venting for category II, III, and IV appliances.

FasNSeal 80/90: Combined Category I and IV venting for Gas-Burning Appliances.

PolyPro: Single-wall, flex, and concentric venting made of polypropylene for category II and IV condensing appliances that operate up to 248 degrees.

PolyPro Flex: PolyPro double-wall flex lining system. Environmentally safe venting system for high-efficiency appliances, including water heaters, condensing boilers, and warm air furnaces. ULC S636.

DuraSeal: Single-Wall and Double-Wall Special Gas Vent Boiler Adapters.

DuraStack: A modular double-wall, positive pressure chimney for use with boiler breeching and stack, engine exhaust, and grease duct (DIS only)

DuraStack Pro: Models DIS and DAS. Modular Double-Wall Positive Pressure Chimney for Boiler Breeching, Stack, and Engine Exhaust.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 13272506774

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★★★★★ 5
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This ball has been a boredom buster lifesaver. On the first day my 15 week golden retriever puppy played with it for a good 2 hours straight. I was nervous he would immediately get bored with it but nope, he searches for it every day. It has helped with his puppy teething, he's more likely to play with this ball than come up and use my hand/arm/clothes to teethe on. The battery lasts a good amount of time and is quick to charge but I did wish it lasted a bit longer. Overall I'm very happy. We live in a top floor apartment but the noise doesn't seem to be too bad for the neighbors. It's good quality and seems durable. Edit: The velcro for the sleeve wears out within a couple uses. It keeps falling off. It was my puppies FAV thing about the toy because of the pull tag thing. So now it's ineffective for him. Not sure if there's a way to get a new sleeve or not.
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Reviewed in the United States on April 2, 2025
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Jill
Draper, US
★★★★★ 5
One of the best dog toys I’ve bought off Amazon in a long time
Color: Green
My dog Rosie is a heavy tower so it is difficult to find balls she doesn’t destroy quickly. I came across this item on Amazon and it is honestly one of the best pet toys I’ve ever bought on Amazon. After a long day of work sometimes I come home and Rosie has a lot of energy. I turn this ball on fast mode and she has so much fun. I do worry about how much shaking in her mouth. I don’t wanna give her a headache, lol but there’s also a slow mode that you can press for the ball to slowly move around, but it’s a really good toy and I’m happy. I purchased it if you have a heavy tower, I wouldn’t worry about them breaking it because we’ve had it for a couple weeks now and she’s doing great.
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Reviewed in the United States on March 15, 2026
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Jason S.
Omaha, US
★★★★★ 4
Not indestructible, but dogs love it
Color: Green
My dog LOVES this toy. Unfortunately, she loves it so much she destroys it. I have now purchased FOUR of these, but if left unattended for 5 minutes, my American terrier breaks this apart. She loves it so much though, I keep buying replacements. This is a wonderful enrichment toy, but you must keep an eye on your toothy friend.
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Reviewed in the United States on December 29, 2025
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Simm in Seattle
Phoenix, US
★★★★★ 3
Engaging and Fun, But Lacks Durability for Strong-Gripped Dogs
Color: Green
The internal mechanism of this toy works very well, and the ball’s movement immediately caught the attention of my Boxer pup. He was absolutely fascinated and spent hours each day playing with it. However, while the toy’s design is engaging, the durability of the exterior leaves much to be desired—especially for dogs who tend to pick things up with a firm grip. We didn’t know what to expect since our pup hadn’t previously played with an interactive ball, so we supervised playtime and made sure to store the ball in a safe spot when we couldn’t keep an eye on him. Despite this, the ball didn’t hold up. Our pup wasn’t intentionally chewing it. He simply carried the ball in his mouth when we moved downstairs or to another room, yet the grip while he carried the ball caused significant damage to the exterior. Within about a week of regular use (approximately 40 hours in total), the ball’s outer layer became deeply gouged by his teeth. To clarify, my pup wasn’t biting down hard or trying to destroy it, but his natural grip while carrying the ball left deep grooves in the surface. In just days, these gouges made the exterior sharp to the touch and compromised the structure. By the end of the week, we couldn’t screw the cover back together after removing it to recharge the ball, which made it unusable. And I was dismayed that there aren’t replacements readily available. Overall, my pup absolutely loved this toy — it was engaging and kept him entertained for hours. However, if your dog has a strong grip or frequently carries toys in their mouth, this may not hold up as well as expected. It’s a great concept but needs a more durable outer layer and replacement hard covers to make it a long-term investment.
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Reviewed in the United States on January 3, 2025
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My dog loves this ball
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The battery on this lasts forever. The random on/off motion and when it gets touched inducing motion just keeps my dog guessing and occupied for a long time. My dog's tail is wagging the whole time.
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