DuraVent DuraFlex Stainless – 316 Basic Kit

$650.23

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SKU: 3DF316-15K Categories: , , Brand:

DuraVent DuraFlex 316 Basic Kit: a chimney liner kit for harsher exhaust

The DuraVent DuraFlex 316 Basic Kit is a liner and fittings package for an old masonry chimney. Its 316 stainless steel handles more corrosive exhaust than 304, including coal or high sulfur oil. It suits chimneys with few bends. DuraFlex Stainless is DuraVent’s flexible stainless steel liner for relining a masonry chimney that vents a wood, pellet, oil, or gas appliance. The box includes the liner coil, a chimney top plate with a welded rain collar, a removable cap, and a bottom connector. For several chimney bends, the Pro liner offers tighter bending than 304 or 316.

Choose a length of 15, 20, 25, 30, or 35 feet, then a diameter of 3, 4, 5, 5 1/2, 6, 7, or 8 inches. Gas, oil, and pellet liners can touch the masonry without insulation. Wood liners need 1 inch of air space or a half inch ProFoil blanket wrap to touch the masonry. Insulation is separate. Connecting through the chimney wall? Choose the DuraVent DuraFlex 316 Tee Kit with a side connection instead of the bottom connector. The DuraVent DuraFlex 316 Basic Kit ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.

Details

SKU: 3DF316-15K | 4DF316-15K |5DF316-15K |55DF316-15K | 6DF316-15K | 7DF316-15K | 8DF316-15K

SKU: 3DF316-20K | 4DF316-20K |5DF316-20K |55DF316-20K | 6DF316-20K | 7DF316-20K | 8DF316-20K

SKU: 3DF316-25K | 4DF316-25K |5DF316-25K |55DF316-25K | 6DF316-25K | 7DF316-25K | 8DF316-25K

SKU: 3DF316-30K | 4DF316-30K |5DF316-30K |55DF316-30K | 6DF316-30K | 7DF316-30K | 8DF316-30K

SKU: 3DF316-35K | 4DF316-35K |5DF316-35K |55DF316-35K | 6DF316-35K | 7DF316-35K | 8DF316-35K

Applications

  • DuraFlex Pro ultra flexible relining for masonry chimney. Use with gas, wood pellet, oil, or wood appliances. Applications include: fireplace inserts, furnaces, boilers, and water heaters.
  • DuraFlex SW smooth wall flexible relining for masonry chimney. Use with gas, wood pellet, oil, or wood appliances. Applications include: fireplace inserts, furnaces, boilers, and water heaters.
  • DuraFlex 316 flexible relining for masonry chimney. Use with gas, wood pellet, oil, or wood appliance. Applications include: fireplace inserts, furnaces, boilers, and water heaters. 316 is designed for use in harsher conditions, for more resistance to corrosion, such as coal.
  • DuraFlex 304 flexible relining for masonry chimney. Use with gas, wood pellet, oil, or wood appliances. Applications include: fireplace inserts, furnaces, boilers, and water heaters.

Materials and Construction

DuraFlex Pro: Single-wall .005″ 316 stainless steel.

DuraFlex SW: Single-wall .005″ overlapped 316 stainless steel (totalling .010″). Overlapped to create smooth inner wall.

DuraFlex 316 & 304: Single-wall .005” 316 or 304 stainless steel.

Clearances

DuraFlex Pro: 0″ clearance for gas, oil, and pellet applications. 1″ clearance to masonry for wood-burning applications. Insulation is required for 0″ clearance to masonry for wood-burning.

DuraFlex SW: Clearances 0″ clearance for gas, oil, and pellet applications. ” clearance to masonry for wood-burning applications. Insulation is required for 0” clearance to masonry for wood-burning.

DuraFlex 316 & 304: 0″ clearance for gas, oil, and pellet applications. 1″ clearance to masonry for wood-burning applications. Insulation is required for 0″ clearance to masonry for wood-burning.

Diameters

DuraFlex Pro & SW: 3″ – 12″.

DuraFlex 316 & 304: 3″ – 8″.

Listings

DuraFlex Pro: Listed to UL 1777 and ULC S635 (MH45609).

DuraFlex SW: Listed to UL 1777 (MH45609).

DuraFlex 316 & 304: Listed to UL 1777 and ULC S635 (MH45609).

Instructions

Product Resources

Catalogs

Bulletins

Brochures

Sales Sheets

FAQ

What is in the DuraFlex 316 Basic Kit?

A DuraFlex SS Top Plate with welded Storm Collar, a Removable Vertical Cap, a DuraFlex SS Connector and one length of DuraFlex 316 liner in your choice of 15, 20, 25, 30 or 35 feet. Select the length and then the diameter (3 to 8 inches) on the page; the liner must match the appliance outlet and reach the chimney top.

When is the 316 liner the right choice?

DuraFlex 316 is the lighter, more economical liner for chimneys with few or no offsets, and DuraVent recommends 316 over 304 where corrosion resistance matters more, such as coal-fired appliances. It is intended for wood-burning, non-condensing gas and oil appliances and is listed to UL 1777 and ULC S635. For a flue with several offsets, DuraFlex Pro is the more flexible option.

What clearance and insulation does it need?

Zero clearance to the masonry for gas, oil and pellet appliances, with insulation optional but recommended for draft on exterior chimneys. For wood burning keep 1 inch to the masonry, or insulate with a 1/2-inch ProFoil or Flexwrap blanket (or 1 inch of TherMix) to reach the zero-clearance listing; the ProMesh Insulation Kit is sold separately.

Can the liner be shortened or squeezed to fit?

Yes. Cut DuraFlex 316 with a hacksaw or a reciprocating saw with a metal blade, and ovalize a round liner that will not pass the flue, remembering that ovalizing reduces the cross-section; DuraVent’s L1244 guidance covers it. Have a certified sweep inspect and clean the chimney before the liner goes in.

Basic Kit or Tee Kit for my appliance?

The Basic Kit’s connector suits a liner that drops straight to a fireplace insert or a stove in the fireplace opening; an appliance connected through the chimney wall from the side needs the 316 Tee Kit with its clean-out tee instead. Both share the top plate and cap; all versions are in the DuraFlex Stainless category.

Shipping / Freight / Return Info

Same-Day / 24 hour shipping

Same-Day/24 hour shipping - If we have the product in stock, we can ship same day if ordered before 12pm Monday - Friday (CST).

Freight Claims Policy

Please follow these very important steps when it comes to Freight Items that are damaged or missing
  • Open and inspect the order while the delivery driver is present. If delivery driver does not provide sufficient time to do so, please notate the delivery receipt.
  • By signing the delivery receipt without noting any damage or missing items, you confirm that your order arrived complete and in excellent condition.
  • Record any damage or missing pieces directly on the delivery receipt.
  • Do not discard damaged item(s) or any original packaging. For severe damage, write “Refused due to damage” on the delivery receipt and contact us immediately.
  • Report any damage within two business days, including delivery details and photos showing the issue
  • Damaged item(s) must be returned within 30 days. Failure to return them will result in a charge to the original payment method.

Return Merchandise Authorization Policy

Please follow these very important steps when Returning Items. Contact our team.
  • Submit your return request within 30 days of delivery.
  • You will receive an email within 1-2 business days confirming whether your return request has been approved or denied.
  • Please also note that a 20% restocking fee may apply to approved returns
  • If approved, you will receive an itemized Return Authorization, return shipping labels (if requested), and detailed instructions within 1–2 business days
  • From the date this email is received, you will have 14 days to return the product.
  • Once our distributor receives and inspects the returned item(s), your refund will be issued within 1–2 weeks
  • Items returned outside of this process or time frame are not eligible for a refund.

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