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DuraVent Concentric Vent System 3" x 5" x 12"-18" Telescoping Adjustable Galvalume Vent Pipe Length

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Original Price $255.68

Current Price $204.54
SKU 35CVS-18TA
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An economical venting solution for condensing and noncondensing appliances, the Concentric Venting System (CVS) features a UL1738 approved super-ferritic stainless steel inner wall. The proprietary twist-lock connection eliminates use of clamps or mechanical fasteners and saves installation time. Only one penetration is needed through the roof or the wall for both exhaust and combustion air. Multiple pipe lengths and telescoping pipe extensions eliminate field cutting of pipe. CVS is the only concentric vent system to incorporate o-rings on the inner wall and outer casing to prevent exhaust or combustion air leakage. Custom adapters are available to transition from co-linear to coaxial venting systems. The built-in condensate management system prevents standing condensation. The Concentric Venting System is a fully sealed, gas tight system to deliver superior performance with the heating unit.

DuraVent Concentric Vent System has a 3” inner diameter and 5” outer diameter.

What's Included

  • 12"-18" Adjustable Vent Length

Features

  • Use to add length to straight lengths of CVS pipe.
  • Requires at least ½” overlap for a secure connection.

Specifications

Brand DuraVent
Model 35CVS-18TA
Series 3" x 5" Concentric Vent System
Product Type Adjustable Vent Pipe
Inside Diameter 3"
Outside Diameter
5"
Length (A) 12" - 18"

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 Concentric Vent System's Specifications?


Applications

Concentric Venting System (CVS) (direct vent or two-pipe system) for use with condensing natural gas or propane Categories II, III and IV appliances or Canada’s Type BH Gas Vent Systems, (having a maximum rated operating temperature of 500°F). For use with Stoves and inserts of Type L gas, pellet, oil, corn and biofuel (Rated to a continuous use flue temperature up to 570°F). CVS can be used on a wide range of appliances, including: gas boilers, warm air furnaces, water heaters, unit heaters, tankless water heaters, pellet stoves, direct vent gas or propane stoves, heaters, and fireplaces.

 

Materials and Construction

Unitized concentric construction. Inner: Laser-welded UL approved 444 super-ferritic stainless steel .012″ Outer: Laser-welded, paintable, zincalume .018″ Silicone O-ring seals on inner liner and outer wall. Precision twist-lock connection on outer wall.

 

Clearances

CVS is listed to 0” clearance as a double-wall vent system for Category II, III, and IV appliances, for flue temperature of up to 400°F for horizontal enclosures, and up to 480°F for vertical enclosures. CVS must maintain 1” clearance to combustibles when used with pellet fuel. When CVS is used as a concentric/direct vent system on gas, the clearance to combustibles is specified by the appliance manufacturer.

 

Diameters

3″ inner and 5″ outer.

 

Listings

CVS vent pipe is listed to UL 1738 (MH25700) as a double-wall vent system for Category II, III and IV appliances. It is pressure rated to 10 WC for the inner pipe. This product is also intended to be used as a direct vent system for Listed to UL 1738 (DGSH.MH25700) and ULC S636 (DGSH7.MH25700). Pressure rated to 10” W.C. Listed to UL 641 (DFTX.MH8381), ULC S609 (DFTX7.MH8381), and ULC/ORD 441 (DFVAC.MH21150). Listed in combination with gas appliances, has been tested and listed as a decorative gas appliance system or as a direct vent heater system. Check with your appliance manufacturer for approval.

What is Concentric Venting System's Typical Installation?


Horizontal Gas Installation

Vertical Gas Installation

Horizontal Pellet Installation

Vertical Pellet Installation

 

Advantages of Concentric

A concentric (or direct-vent, or two-pipe) system maintains indoor air quality by reducing drafts with one penetration, and allows for better humidity level control inside a dwelling. Concentric venting brings to the heating appliance outdoor air as combustion air through an air-tight, sealed system that is safe.

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.

An economical venting solution for condensing and noncondensing appliances, the Concentric Venting System (CVS) features a UL1738 approved super-ferritic stainless steel inner wall. The proprietary twist-lock connection eliminates use of clamps or mechanical fasteners and saves installation time. Only one penetration is needed through the roof or the wall for both exhaust and combustion air. Multiple pipe lengths and telescoping pipe extensions eliminate field cutting of pipe. CVS is the only concentric vent system to incorporate o-rings on the inner wall and outer casing to prevent exhaust or combustion air leakage. Custom adapters are available to transition from co-linear to coaxial venting systems. The built-in condensate management system prevents standing condensation. The Concentric Venting System is a fully sealed, gas tight system to deliver superior performance with the heating unit.

DuraVent Concentric Vent System has a 3” inner diameter and 5” outer diameter.

What's Included

  • 12"-18" Adjustable Vent Length

Features

  • Use to add length to straight lengths of CVS pipe.
  • Requires at least ½” overlap for a secure connection.

Specifications

Brand DuraVent
Model 35CVS-18TA
Series 3" x 5" Concentric Vent System
Product Type Adjustable Vent Pipe
Inside Diameter 3"
Outside Diameter
5"
Length (A) 12" - 18"

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 Concentric Vent System's Specifications?


Applications

Concentric Venting System (CVS) (direct vent or two-pipe system) for use with condensing natural gas or propane Categories II, III and IV appliances or Canada’s Type BH Gas Vent Systems, (having a maximum rated operating temperature of 500°F). For use with Stoves and inserts of Type L gas, pellet, oil, corn and biofuel (Rated to a continuous use flue temperature up to 570°F). CVS can be used on a wide range of appliances, including: gas boilers, warm air furnaces, water heaters, unit heaters, tankless water heaters, pellet stoves, direct vent gas or propane stoves, heaters, and fireplaces.

 

Materials and Construction

Unitized concentric construction. Inner: Laser-welded UL approved 444 super-ferritic stainless steel .012″ Outer: Laser-welded, paintable, zincalume .018″ Silicone O-ring seals on inner liner and outer wall. Precision twist-lock connection on outer wall.

 

Clearances

CVS is listed to 0” clearance as a double-wall vent system for Category II, III, and IV appliances, for flue temperature of up to 400°F for horizontal enclosures, and up to 480°F for vertical enclosures. CVS must maintain 1” clearance to combustibles when used with pellet fuel. When CVS is used as a concentric/direct vent system on gas, the clearance to combustibles is specified by the appliance manufacturer.

 

Diameters

3″ inner and 5″ outer.

 

Listings

CVS vent pipe is listed to UL 1738 (MH25700) as a double-wall vent system for Category II, III and IV appliances. It is pressure rated to 10 WC for the inner pipe. This product is also intended to be used as a direct vent system for Listed to UL 1738 (DGSH.MH25700) and ULC S636 (DGSH7.MH25700). Pressure rated to 10” W.C. Listed to UL 641 (DFTX.MH8381), ULC S609 (DFTX7.MH8381), and ULC/ORD 441 (DFVAC.MH21150). Listed in combination with gas appliances, has been tested and listed as a decorative gas appliance system or as a direct vent heater system. Check with your appliance manufacturer for approval.

What is Concentric Venting System's Typical Installation?


Horizontal Gas Installation

Vertical Gas Installation

Horizontal Pellet Installation

Vertical Pellet Installation

 

Advantages of Concentric

A concentric (or direct-vent, or two-pipe) system maintains indoor air quality by reducing drafts with one penetration, and allows for better humidity level control inside a dwelling. Concentric venting brings to the heating appliance outdoor air as combustion air through an air-tight, sealed system that is safe.

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.