100% Made In The USA

Rock-Flex Furnace, Boiler, and Corn Appliance Pipe Kits AL29-4C

AL29-4C chimney liner

APPLICATIONS: HIGH EFFICIENCY boilers, oil, gas, furnace, and corn burning appliances

Since 1983, furnace and vent manufacturers have specified AL29-4C alloy in high efficiency furnace and venting designs (typically 90% or greater efficiency). High efficiency furnaces extract so much heat from the exhaust that the highly acidic water vapor in the exhaust condenses. This moisture accumulation is corrosive and damaging to standard stainless liners and chimneys.

AL29-4C is a stainless steel alloy designed for extreme resistance to corrosion, pitting and stress corrosion cracking. This resistance makes it an ideal choice for venting the corrosive condensation in high efficiency furnaces. Its low alloy content and corrosion resistance makes it an economical choice, and by using AL 29-4C, manufacturers have benefited by being able to extend their warranties.

round chimney liner kit
How this page works:

  • Select pipe size and length in step 1.
  • Select kit components for your application in steps 2-4.
  • Click on Add To Cart at the end for total cost.

Step 1 - Select your AL29-4C stainless steel venting pipe below. (Click here for help with liner size.)

Note: The sizes give in the menu below are inside diameters.
Liner thickness is .006.
Add 1/4" for the outside diameter of the pipe.

Step 2 - Select one stainless steel bottom connector per venting pipe selected in step 1.

stainless steel chimney linerFlexible chimney liner Tee with removable snout and clean out cap

Standard Tee
with removable snout
and clean out cap
(No additional charge)

chimney linerChimney liner appliance connector

vertical connector
(No additional charge)

Step 3 - Select one stainless steel top plate / rain cap per venting pipe selected in step 1.

No Sag Top Plate
& Round Rain Cap

13x13 Top Plate - $0
13x18 Top Plate - $35
18x18 Top Plate - $45

Flat Top Plate
& Round Rain Cap

13"x13" Top Plate - $0
13"x18" Top Plate - $35
18"x18" Top Plate - $45
24"x24" Top Plate - $86

Terra Cotta Top Plate
& Round Rain Cap

8"x8" Top Plate - $40
8"x13" Top Plate - $45
13"x13" Top Plate - $55
13"x18" Top Plate - $60
(See our Sizing Chart)

Deluxe Flat Top Plate
with Hinged Rain Cap

Deluxe Terra Cotta Top Plate
with Hinged Rain Cap

8"x8" Top Plate - $85
8"x13" Top Plate - $90
13"x13" Top Plate - $100
(See our Sizing Chart)

What is AL29-4C alloy in a stainless venting pipe?
"AL" stands for Allegheny Ludlum a unique patented alloy. This alloy was developed to prevent corrosion and breakdown in high efficient gas, oil, and corn burning chimney appliances such as furnaces and boilers. AL29-4C flexible venting pipes offer extreme resistance to chloride pitting, sulfuric acid, crevice corrosion, chloride stress-corrosion cracking and general corrosion.

When should I use an AL29-4C Stainless Steel Flex Vent Pipe?
When there are heating appliances that are rated at 90% efficiency or higher, it is a good idea to use AL29-4C. This flue liner provides better corrosion resistance to condensed flue acids that are formed using this type of appliance.

These venting pipe kits are intended for use with HIGH EFFICIENCY GAS, OIL, and CORN burning appliances. The flue gases from these appliances are cooler and create exceptionally high amounts of moisture which in turn promotes formation of an especially corrosive acid.

Note: AL29-4C is the best option when burning corn. Pesticides used to grow corn have been proven to produce gases that deteriorate all types of liners. However this flue liner will last 7 to 10 years when corn is the fuel source. We offer no warranty on any of our chimney liners when corn is used in the flue.

Venting Pipe Kits Include:

  • Heavy Duty AL29-4C Stainless Steel Vent Pipe
  • Quick Connect, No Sag Top Plate with Quick Connect Collar
  • Quick Connect Rain Cap with screen and wind guard
  • Tee and Tee Cap (clean out) with a removable snout for easy installation OR you have the option of a vertical appliance connector if you are connecting vertically (see illustrations above for the option that best fits your needs))
  • Complete how to install chimney liners installation instructions
  • Lifetime transferable warranty when used with any fuel other than corn fueled appliances

Note: The top plate and rain cap are 316L SS. The venting pipe and Tee are AL29-4C SS

Click here to learn more about chimney insulation

High temp caulk to seal the top plate chimney silicone adhesive

We offer the best protection for you and your home. Air and water tight chimney liners, seven ply seams that lock moisture and flue gases in the flexible flue liner which keeps them from leaking into the home.

Guards against corrosion - Certified Rock Flex stainless steel chimney liners protect against hostile acids which deteriorate masonry clay tile chimneys.

What About Creosote? - Our chimney flue liners do not allow creosote to leach though the liner unlike masonry, clay tile flues, or liners not made of prime stainless. Creosote can catch fire, thanks to Rock Flex this harmful creosote is minimized and contained.

Seals Off Carbon Monoxide - When it comes to safety our flexible chimney liners will protect the structure of your home from moisture damage and the very real potential of carbon monoxide poisoning.

UL listed in the USA and CANADA - Our stainless steel flue liners and components are UL tested and listed to UL1777 standard, Underwriter Laboratories. UL is the leader and most recognized in the United States; don't settle for less.

Lifetime Transferable Warranty - The best warranty anywhere, transferable to new homeowner if you decide to sell. You're going to feel good about this purchase, plus you're adding value to your home.

Rockford carries a complete selection of chimney liner supplies. Our hearth liner kits, chimney liner insulation kits, and all chimney lining kit components are premium stainless-steel, and they are 100 percent manufactured in the USA. Buy chimney liners online at Rockford Chimney Supply and you are guaranteed to be getting the best chimney liner supply and lining system available. Our service, price, & quality is unmatched, anywhere.

Canadian customers use our US Border Depots at no cost to you.

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