DuraVent | Low Profile Double Wall Increaser Type B Gas Vent 3"-8" Inner Diameter

Save $14.83
DuraVentSKU: 3BVLX4

Regular price$59.33 Sale price$74.16

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Size: 3"x4"
⛟ Estimated Delivery Date: Between and to all states excl. Alaska & Hawaii.

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Elevate your HVAC system to new heights with the DuraVent 3"-8" Low Profile Gas Vent Increaser. As the premier company in the venting industry, DuraVent has consistently delivered innovative, safe, and professional products. With the DuraVent Low Profile Gas Vent Increaser, we're setting the standard once again.

Designed for those who demand the best, our DuraVent Low Profile Gas Vent Increaser boasts cutting-edge technology. The DuraLock system ensures a lock-tight connection, providing you with peace of mind and unparalleled performance. No need to worry about alignment; you can feel the ends grasp together, and with a satisfying snap, the connection firmly locks into place.


  • Efficient Space Utilization: The DuraVent Low Profile Gas Vent Increaser is perfect for tight installations, optimizing space without compromising on safety or performance.

  • Built for Durability: Crafted from strong and durable galvanized steel, this increaser features internal spacing beads that create a uniform insulating air space between pipe walls, guaranteeing longevity and reliability.

  • Enhanced Safety: The double-wall construction maintains the inner pipe's temperature while keeping the outer pipe relatively cool. This ensures quick, strong vent action, reducing condensation and the risk of overheating nearby surfaces.

  • Fully Certified: DuraVent Model BV and BVO Type B Gas Vent have been rigorously tested and listed per UL 441, meeting the highest industry standards for safety and performance.

  • Easy Installation: With die-formed ends for uniform sizing and DuraLock technology for a secure connection, installation has never been easier.

Key Features

  1. DuraLock System: Provides a secure, lock-tight connection for worry-free installation.

  2. Rugged Construction: Galvanized steel outer pipe with internal spacing beads ensures durability and uniform insulation.

  3. Double-Wall Design: Maintains inner pipe temperature while preventing outer pipe overheating.

  4. UL Certified: Meets UL 441 standards for safety and performance.

  5. Easy Installation: Die-formed ends and DuraLock technology simplify installation.


The DuraVent Low Profile Gas Vent Increaser is a versatile solution suitable for various applications. Use it with natural gas or liquid propane Category I appliances, draft hood-equipped appliances, and those tested and listed for Type B Gas Vent use. Common applications include natural gas fireplaces, gas-fired furnaces, boilers, water heaters, and wall or space heating systems.


Model Size
3BVLX4 3" x 4"
3BVLX5 3" x 5"
3BVLX6 3" x 6"
3BVLX7 3" x 7"
3BVLX8 3" x 8"
4BVLX5 4" x 5"
4BVLX6 4" x 6"
4BVLX7 4" x 7"
4BVLX8 4" x 8"
5BVLX6 5" x 6"
5BVLX7 5" x 7"
5BVLX8 5" x 8"
6BVLX7 6" x 7"
6BVLX8 6" x 8"
7BVLX8 7" x 8"
Clearances 1" to combustibles in single and multi-family dwellings
Listings UL Listed to UL 441
Warranty Limited lifetime warranty


About the Manufacturer

Consistently the first to market with new innovations in venting systems, DuraVent has captured a leadership position in emerging markets. DuraVent has patents for several products and continues to design safe and technologically advanced venting.The company’s research into solving problems with corrosion, when biofuels such as corn are used, led to the break-through patent for PelletVent Pro.

Order Confirmation:

Upon placing your order, you will promptly receive an email confirmation. Subsequently, we will conduct a thorough inventory check to ensure all items are in stock and available for immediate shipment. If your order aligns with the advertised delivery timeframe, we will promptly process it for shipment to our warehouse. In cases where the expected delivery time extends beyond the advertised timeframe, we will reach out to you via email and/or phone for confirmation.

Order Shipment:

Within one business day of your item being shipped, you will receive an email confirmation containing a tracking number. If you do not receive tracking information within six business days of placing your order, please don't hesitate to get in touch with us for assistance.

Estimated Time of Arrival:

Our typical delivery timeframe ranges from 2 to 10 business days. Custom-made products generally require 3 to 5 weeks for delivery. If the expected delivery date for your order would fall outside of the advertised 2-10 business day time frame, our customer service team will contact you to ensure your agreement with the revised timeline.

Covered Areas:

Please note that all estimated delivery dates and shipping costs advertised on our website apply exclusively to the Contiguous United States. For inquiries regarding shipping to Hawaii or Alaska, kindly reach out to our customer service team. While we do not offer direct shipping to Canada, we are more than willing to ship your order to the freight carrier of your choice.


It is very important that you inspect the packaging of your items when they arrive and check if you received all boxes listed on the delivery receipt. If you notice any damage or shortage of packages, you must make note of it on the bill of lading, take pictures, and refuse delivery. Your note should say "refused due to damage". You must also take photos of all sides of the box and send them to us within 2 days. If there are no damages visible before opening the box, you must note "subject to further inspection may contain concealed damage". If you notice any damage after receiving the delivery, do not throw the box away, and contact us with the photos. After we receive information from you about the refused delivery or concealed damage, we immediately initiate a claim with the shipping company or with the manufacturer. After the claim is fully processed, we ship all replacements at absolutely no cost to you.

Cancellations & Refunds:

We offer free order cancellations before the shipping label or Bill of Lading is generated, or prior to the commencement of production for custom orders. Please note that custom-made items are not eligible for refunds once production has begun. To be eligible for a return, the item must be unused and in its original condition, with all packaging intact and in perfect condition. Orders delivered outside of the United States are not eligible for refunds. If your order arrives damaged, please refer to the "Damages" section. Our refund policy extends for 30 days. If 30 days have elapsed since your purchase, regrettably, we cannot process a refund. Prior to returning an item, please contact us to discuss shipping details. All refunds will be credited to the original credit card or PayPal account used for the purchase, within two days of receiving the returned items at our warehouse.

Please contact sales@belleflame.com for any questions regarding shipping time.

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