Venting Gas
You can use either an aluminum or 316ti stainless steel liner when venting an appliance with an AFUE (efficiency rating) of 83% or less. If you are venting an appliance with an AFUE of greater than 83% it is a good idea to use AL29-4C. This provides better corrosion resistance to condensed flue acids that are formed.

Venting Oil
You can vent your oil appliance with a 316ti stainless steel alloy liner. You may also opt to use an Al29-4C alloy liner.

Connecting to the liner
In order to connect your appliance to the liner you need to use connecting pipes. The most comon method is to use galvanized steel pipe.