DuraVent DuraFlex 316 Tee Kit: a side entry liner kit for more corrosive exhaust
The DuraVent DuraFlex 316 Tee Kit is a chimney liner kit for an appliance whose vent enters through the chimney wall. Its 316 stainless steel handles more corrosive exhaust, such as coal exhaust. The box holds a flexible liner coil, a top plate with a welded storm collar to shed rain, a removable chimney cap, and a tee with cap. The tee connects the appliance at the liner’s bottom, where its cap opens for cleaning. DuraFlex Stainless is DuraVent’s flexible stainless steel liner for relining a masonry chimney that vents a wood, pellet, oil, or gas appliance.
Choose a length of 15, 20, 25, 30, or 35 feet, then a diameter from 3 to 8 inches, including 5 1/2 inch. The fittings clamp around the liner’s ridges without drilling or riveting it. The tee attaches before the liner is lowered, and its branch passes through the wall opening. This liner serves residential stoves, inserts, furnaces, boilers, and water heaters, but not condensing gas appliances. Need a connector rather than a tee? See the DuraVent DuraFlex 316 Basic Kit with connector. The DuraVent DuraFlex 316 Tee Kit ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.
Details
SKU: 3DF316-15KT | 4DF316-15KT | 5DF316-15KT | 55DF316-15KT | 6DF316-15KT | 7DF316-15KT | 8DF316-15KT
SKU: 3DF316-20KT | 4DF316-20KT | 5DF316-20KT | 55DF316-20KT | 6DF316-20KT | 7DF316-20KT | 8DF316-20KT
SKU: 3DF316-25KT | 4DF316-25KT | 5DF316-25KT | 55DF316-25KT | 6DF316-25KT | 7DF316-25KT | 8DF316-25KT
SKU: 3DF316-30KT | 4DF316-30KT | 5DF316-30KT | 55DF316-30KT | 6DF316-30KT | 7DF316-30KT | 8DF316-30KT |
SKU: 3DF316-35KT | 4DF316-35KT | 5DF316-35KT | 55DF316-35KT | 6DF316-35KT | 7DF316-35KT | 8DF316-35KT
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).
FAQ
What comes in the DuraFlex 316 Tee Kit?
A Top Plate with welded Storm Collar, a Removable Vertical Cap, a stainless Tee with Cap and a DuraFlex 316 flex length of 15 to 35 feet. It is the kit for an appliance that enters the masonry chimney from the side through a thimble, with the tee’s cap serving as the clean-out at the base of the liner.
How do I pick the length and diameter?
Choose the flex length first, then the diameter from 3 to 8 inches on the second selector. Size the liner to the appliance outlet, never smaller, and measure from the tee at the thimble to a few inches above the chimney crown. The liner can be cut to length with a hacksaw or reciprocating saw, and joints and the tee are clamped as the instructions show.
Which appliances and fuels suit the 316 liner?
Wood-burning stoves, non-condensing gas and oil appliances, furnaces, boilers and water heaters; 316 is the alloy DuraVent recommends where flue gases are more corrosive, such as coal. It is an economical liner for chimneys with minimal offsets, listed to UL 1777 and ULC S635; for a flue with several bends the Pro tee kit is the more flexible choice.
Does a wood stove liner have to be insulated?
For wood burning, yes if you want the zero-clearance listing: a 1/2-inch ProFoil or Flexwrap blanket or 1 inch of TherMix between liner and masonry, otherwise 1 inch of clearance to the masonry is required. Gas, oil and pellet appliances are listed at zero clearance without insulation. Have a sweep confirm whether the masonry itself was built with clearance to combustibles.
How is the tee connected at the thimble?
The tee sits at the bottom of the liner inside the chimney with its branch pointing through the thimble; the stove’s connector pipe attaches to that branch with connectors designed for the liner, and the tee cap closes the bottom for cleaning. Keep single-wall connector pipe 18 inches from combustibles. Thimbles and connectors are in the DuraFlex Stainless category.