Here we are basically talking about stovepipe and chimney, parts and components, for the different types of fuels that you may be venting. Listed by appliance fuel type.

PELLET

Pellet vent is a double wall constructed pipe with a stainless inner pipe and a galvenized outer pipe. We sell a high grade that is capable of venting all biomass fuels, such as corn and wheat, which have more corrosive characteristics.

GAS
Gas vent can be either B-vent or direct vent depending on the design of the heater. B-vent is the same type of pipe used to vent utility appliances, like water heaters, and is a double wall construction with an aluminum inner wall and a galvy outer wall, designed to provide low clearances to combustables. Direct vent, on the other hand, is designed to bring combustion air in from the outdoors and expell exhaust back out through the same pipe. It also has an aluminum inner and galvy outer walls but with a larger space between the two, for providing intake air. Also called co-axial pipe.

WOOD