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SKU:4BVX5

DuraVent Round Type B Gas Vent Model BV 4" Increaser

DuraVent Round Type B Gas Vent Model BV 4" Increaser

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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

  • Increaser

Features

  • Use to increase vent diameter.
  • Replacement of Type B Gas Vent Model GV 4GVX5 and 4GVX6

Specifications

Brand DuraVent
Model 4BVX5(6)
Series Round Type B Gas Vent Model BV
Product Type
Increaser
Size
4"x5", 4"x6"

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.
Click to See Warranty Coverage and Limitations


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.

 

Download DuraVent Limited Lifetime Warranty here.

Documents & Files

Frequently Asked Questions

What are Type B (Model BV) Gas Vent Systems' Features?


Rugged Construction

Strong, durable galvanized steel outer pipe has internal spacing beads to assure a uniform insulating air space between pipe walls. Each end is die formed to assure uniform sizing for strong, easy to connect joints. In Canada, some lengths are available in galvalume steel outer pipe.

 

Assured Safety

The double wall (pipe within a pipe) construction with its built-in air space, provides permanent insulation and keeps the inner pipe hot and the outer pipe relatively cool. This construction creates quick, strong vent action reducing condensation in the pipe and overheating of nearby enclosure surfaces.

 

Fully Tested and Listed

DuraVent Model BV and BVO Type B Gas Vent has been tested and listed per UL 441 for installation as Type B and BW gas vents. These can be installed in single and multi-story buildings in accordance with the standards of NFPA 54 and NFPA 211. In Canada, DuraVent Model BV Type B Gas Vent has been tested and listed per CAN/ULC-S605 for installation as Type B and BW gas vents. It can be installed in single and multi-story buildings in accordance with CAN/CSA-B149.1.00.

 

Kits

  • 3″-6″ Termination Kits Include: DuraCap, Storm Collar, Adjustable Roof Flashing, Draft Hood Connector (Lengths sold separately)
  • 3″-4″ Vertical Heater Kit Includes: 12” & (3) 24” Galvalume Pipe Lengths, 90° Elbow, 4” Diameter Draft Hood Connector, 3” Draft Hood Connector, 3”-4” Increaser, Adjustable Flashing, Storm Collar & DuraCap
  • USA Only – 4″ Oval Kit Includes: (2) 24″ Lengths, Oval Base Plate, (2) Ceiling Spacers, Oval-Round Adapter

 

Lengths

  • 18″ Adjustable Lengths in 3″-6″ diameters
  • 12″ & 24″ Lengths in 10″-30″ diameters
  • Canada – Additional 24″ Galvalume Length (8BV24C)

 

Reducing Tees

  • Standard Tee paired with Low Profile Increasers
  • Increaser can be installed at the branch or the body
  • 3″ – 8″ diameter combinations

 

Low Profile Increasers

  • New space saving length where height restrictions apply.

 

Universal Male and Female Adapters

  • Male Adapter – Used to convert Model GV to Model BV
  • Female Adapter – Used to convert Model BV to Model GV
  • Available in 3″ – 8″ diameter sizes

 

Quick Grip Firestops / Supports

  • Combination Firestop and Vent Support
  • Supports up to 30′ of pipe
  • Available in 3″ -6 ” diameter sizes
  • Install above a framed opening

 

DuraConnect I – Expandable Flexible Connectors

  • Available in 3″ & 4″ diameters
  • Available in 3′ (expandable from 2′ – 3.5′) and 5′ (expandable from 2.5′ – 5′) lengths
  • Replaces Single Wall Connectors
  • Draft Hood Connector Incorporated

 


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 | 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 Type B (Model BV) Gas Vent Systems' Specifications?


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 the Type B (Model BV) Gas Vent Systems' Termination Guide?


How Size and Height Affect Stove Performance

  • The amount of heat the vent gases lose as they flow determines how much condensation will occur and how strong the draft will be. To control the heat loss, proper selection of venting materials is of vital importance.
  • Double-wall Type B Gas Vent, with an aluminum inner wall and a galvanized steel outer wall, has proven to be the ideal choice in venting materials. In Canada some lengths have a galvalume outer wall.

 

Vent Termination Chart

Listed Type B Gas Vent caps may terminate in accordance with this table.

Minimum height
Roof Pitch
Feet Meters
Flat to 7/12 1 0.3
Over 7/12 to 8/12
1.5 0.46
Over 8/12 to 9/12
2 0.61
Over 9/12 to 10/12
2.5 0.76
Over 10/12 to 11/12
3.25 0.99
Over 11/12 to 12/12
4 1.22
Over 12/12 to 14/12
5 1.52
Over 14/12 to 16/12
6 1.83
Over 16/12 to 18/12
7 2.13
Over 18/12 to 20/12
7.5 2.29
Over 20/12 to 21/12
8 2.44
What is the Type B (Model BV) Gas Vent Systems' Large Diameter Installations?


Large Diameter – Vertical Installations

What is the Type B (Model BV) Gas Vent Systems' Small Diameter Installations?


Small Diameter – Vertical Installations

What are B Vent Frequently Asked Questions?


1. What is the clearance for BW Oval?
Clearance is 1” or as determined by using the Ceiling Plate Spacer and the Firestop Spacer.

2. Can I put screws in Type B Gas Vent?
Yes, if desired, but DO NOT PUNCTURE THE INNER LINER! From 3” through 8”, the screw should be located approximately 1/4” from overlapped edge and must be a maximum 1/4” in length so they do not pierce or deform the inner liner. On diameters of 10” through 30” the screw must be a maximum of 1/2” in length so they do not pierce or deform the inner liner.

3. Can Type B Gas Vent terminate horizontally on a wall?
No, only Cat III 1738 and ULC-S636 approved systems can terminate on a side wall.

4. What flashing do I use for pitches over 7/12?
An Adjustable Steep Roof Flashing for roof pitch of 6/12 to 12/12.

5. Which support do I use: round or square support?
A variety of supports are available: Support Assembly and the Quick Grip Firestop Support are used on top of the ceiling joist; the Round Bucket Support is installed at the ceiling level. The Band Collar is clamped securely to the pipe and the pipe lowered into the Bucket Support so the Band Collar sits firmly inside of the Bucket Support.

6. What is the inner liner made of?
Diameters 3” to 8” – .012” thick aluminum; Diameters 10” to 18” – .014” thick aluminum; Diameters 20” to 30” – .023” thick aluminum

7. Is Oval Type B Gas Vent UL listed in 2 x 4 wall?
Yes, 4” and 5” is approved centered in a 2×4 wall space; 6” is for 2×6 walls only. When oval vent is installed in a stud wall, the Firestop Spacer must be used. When connected to a wall furnace, the Hold Down Plate, Ceiling Plate Spacer and Firestop Spacer must be used.

8. Can I common vent 2 gas fireplaces?
No. Common vent tables only cover furnace or water heater common venting.

9. Is this L-Vent?
No, L-Vent needs stainless steel inner liner.

10. Can I use Type B Gas Vent on an oil furnace?
No. Oil requires stainless steel inner liner.

11. How often do I support the pipe?
Support every 5’ for diameters 3” through 8” and every other floors for diameters 10” through 30”. Use a Wall Support Band, Support Plate, Quick Grip or Round Bucket Support. Support components can support 30’ – 35’, see individual supports for exact amount. Vertical runs must have firestops and stability every 8’ – 10’ and need only be supported near the bottom. Provide lateral support at least every 5’. All gas vents extending above the roof  more than 5’ must be securely braced. Use a Wall Support Band, Support Plate, Quick Grip or Round Bucket Support.

12. Is a draft hood connector needed?
Some water heaters require one; it is optional for furnaces or gas fireplaces. A Draft Hood is available from 3” to 18”.

13. What is the maximum temperature?
400°F (205°C) + AMB (room temperature) to a maximum of 470°F (245°C) operating temperature.

14. Does horizontal venting require an upward pitch?
A ¼ inch per foot minimum pitch is required to vent horizontally. No  downward dips or sags are allowed.

15. Is there a firestop plate?
Yes, it is called the Firestop Spacer, and is required at every floor/ceiling level penetrated.

16. What is minimum termination height?
There is a 1’ minimum for up to 7/12 roof pitch. See Table 1 in the instructions if over 7/12.

17. Is the Male & Female Adapter UL Listed for use with other UL Listed Type B Gas Vents?
Yes. It is listed for use with most UL listed competitors Type B Gas Vents.

18. How do I size my appliance?
For (2) or more appliances, use the sizing handbook or the tables found in the National Fuel Gas Code NFPA 54 and the Canadian Fuel Gas Installation Code CSA-B149.1.00.

19. How do I order a reduction tee?
Specify main body and branch size to Customer Service.

20. What is the overlap of pipe?
You must deduct 1 ½” overlap per connection for 3” through 8” and 1” for 10” through 30” per end of pipe.

21. What flashing do I use for flat roof?
Tall cone flashing is for flat (0/12) roof pitch.

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 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.

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