on all orders to the lower 48 states
AL 29-4C 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.
Since 1983, furnace and vent manufacturers have specified AL29-4C alloy in high efficiency furnace and venting designs (typically 86% 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.
What is AL29-4C alloy in a stainless chimney liner?
"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. AL294C flexible chimney liners 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 Chimney Liner?
When there are heating appliances that are rated at 86% 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 chimney liners 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: the AL294C 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 chimney 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 liner.