DuraVent DuraFlex 304 Tee Kit: for an appliance connected through the chimney wall
The DuraVent DuraFlex 304 Tee Kit is a liner kit for a stove or furnace connected through the side of a masonry chimney. Its tee sits at the liner’s bottom and turns toward the appliance. The tee’s bottom cap opens for cleaning. You get a coil of 304 stainless liner, the tee and cap, a chimney top plate with a welded rain collar, and a removable chimney cap. DuraFlex Stainless is DuraVent’s flexible stainless steel liner for relining a masonry chimney that vents a wood, pellet, oil, or gas appliance. The 304 is the lightest liner and suits chimneys with few bends.
Choose a length from 15 to 35 feet, then a diameter from 3 to 8 inches. The 20 foot length has no 4 inch option. Before lowering the liner from above, the chimney needs cleaning, inspection, and repairs to loose brick or damaged mortar. The tee clamps on before lowering. The fittings have built in bands that tighten around the liner’s ridges without drilling or riveting it. Need a connector instead of a tee? See the DuraVent DuraFlex 304 Basic Kit with connector. The DuraVent DuraFlex 304 Tee Kit ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.
Details
SKU: 3DF304-15KT | 4DF304-15KT | 5DF304-15KT | 55DF304-15KT | 6DF304-15KT | 7DF304-15KT | 8DF304-15KT
SKU: 3DF304-20KT | 5DF304-20KT | 55DF304-20KT | 6DF304-20KT | 7DF304-20KT | 8DF304-20KT
SKU: 3DF304-25KT | 4DF304-25KT | 5DF304-25KT | 55DF304-25KT | 6DF304-25KT | 7DF304-25KT | 8DF304-25KT
SKU: 3DF304-30KT | 4DF304-30KT | 5DF304-30KT | 55DF304-30KT | 6DF304-30KT | 7DF304-30KT | 8DF304-30KT
SKU: 3DF304-35KT | 4DF304-35KT | 5DF304-35KT | 55DF304-35KT | 6DF304-35KT | 7DF304-35KT | 8DF304-35KT
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: 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 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 does the DuraFlex 304 Tee Kit include?
A Top Plate with welded Storm Collar, a Removable Vertical Cap, a stainless Tee with Cap and a DuraFlex 304 flex length from 15 to 35 feet, with diameters from 3 to 8 inches chosen on the second selector. The tee lets a stove or furnace connect through the side of the masonry chimney and gives a clean-out cap at the bottom of the liner.
Is 304 stainless suitable for a wood stove?
Yes, DuraFlex 304 is intended for wood-burning, non-condensing gas and oil appliances and is listed to UL 1777 and ULC S635. It is the economical choice for a chimney with minimal offsets; choose 316 for corrosive fuels such as coal or DuraFlex Pro for a flue with several bends. Match the liner diameter to the stove outlet.
What clearance and insulation does a wood liner need?
One inch of clearance between the liner and the masonry, or a 1/2-inch ProFoil or Flexwrap blanket (1 inch of TherMix) around the liner to be listed at zero clearance to the masonry, with the ProMesh Insulation Kit sold separately. Gas, oil and pellet appliances are listed at zero clearance without insulation. Ordinary building insulation must never fill the gap.
How is the tee installed?
The tee attaches to the bottom of the liner inside the chimney with its branch aligned to the thimble opening; the stove connector pipe joins that branch and the tee cap closes the base for sweeping. Single-wall connector pipe needs 18 inches to combustibles. DuraVent’s L253 instructions cover the thimble opening and the clamps.
Can the liner be cut, and does the warranty need anything?
Cut it with a hacksaw or reciprocating saw with a metal blade, and ovalize if the flue is tight per DuraVent’s L1244 guidance. The limited lifetime warranty requires installation per the instructions, a cap, annual inspection and cleaning by a qualified sweep and no chemical cleaners. Thimbles and connectors are in the DuraFlex Stainless category.