DuraVent DuraFlex 316 Top Plate and Cap Kit: remove the cap without releasing the liner
The DuraVent DuraFlex 316 Top Plate and Cap Kit is a chimney relining kit with a flexible 316 stainless steel liner, top plate, removable cap, and bottom connector. The plate has a welded storm collar, a ring whose band grips the liner and supports its full weight. The rain cap clamps onto that ring. You can remove the cap for inspection or sweeping without loosening the liner. DuraFlex Stainless is DuraVent’s flexible stainless steel liner for relining a masonry chimney that vents a wood, pellet, oil, or gas appliance.
The top plate seals the chimney’s masonry top, called the crown. Its edges can be trimmed or folded over the brick, with high temperature silicone underneath. The 316 liner suits chimneys with few bends and offers the corrosion resistance needed for coal or high sulfur oil. On this page, choose 25 or 35 feet of liner first, then a 4, 5 1/2, or 6 inch diameter. Insulation is sold separately. Need more sizes with the same parts? See the DuraVent DuraFlex 316 Basic Kit. The DuraVent DuraFlex 316 Top Plate and Cap Kit ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.
Details
SKU: 4DF316-25VCK | 55DF316-25VCK | 6DF316-25VCK
SKU: 4DF316-35VCK | 55DF316-35VCK 6DF316-35VCK
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 is the DuraFlex 316 Top Plate/Cap Kit?
A reline kit with a Top Plate and welded Storm Collar, a Removable Vertical Cap, a connector and a DuraFlex 316 liner, built so the flex stays secured to the top plate when the cap section is lifted off for inspection or sweeping. It is offered in 25 or 35 foot lengths with 4, 5.5 or 6 inch diameters on the selectors.
Why choose 316 stainless?
DuraFlex 316 is an economical single-wall liner for chimneys with minimal offsets, and DuraVent recommends 316 rather than 304 where corrosion resistance matters, for example coal-fired appliances. It is intended for wood-burning, non-condensing gas and oil appliances and is listed to UL 1777 and ULC S635. Chimneys with several offsets are better served by DuraFlex Pro.
What clearance and insulation rules apply?
Gas, oil and pellet appliances: zero clearance to the masonry, insulation optional but helpful for draft on exterior chimneys. Wood: 1 inch to the masonry, or a 1/2-inch ProFoil or Flexwrap blanket (1 inch of TherMix) for the zero-clearance listing, with the ProMesh Insulation Kit sold separately. Never fill the gap with ordinary building insulation.
How is the top plate fitted?
Pull the liner so 2 to 3 inches show above the crown, slide the top plate down over it, bed the plate in RTV silicone on the masonry, tighten the clamp band and trim the excess, then lock the removable cap onto the plate. At the bottom the connector joins the liner to the appliance or its connector pipe, as DuraVent’s L253 instructions detail.
Can the liner be cut or ovalized?
Yes, cut it with a hacksaw or reciprocating saw with a metal blade, and ovalize a round liner that will not pass the flue tiles, noting the reduced cross-section per DuraVent’s L1244 guidance. Have the chimney cleaned and inspected first. Matching tees, connectors and insulation are in the DuraFlex Stainless category.