To calculate the installed length of Dura Plus pipe lengths, subtract 1-1 2 from each length of chimney pipe. Dura Plus Chimney is the metal chimney that does the three things a firesafe chimney must do Stay cool on the outside, provide a hot draft on the inside, with a firesafe design that protects both the chimney and building. Dura Plus chimney is designed for appliances that are tested and listed for use with a 2100°F HT chimney system, such as wood stoves, fireplaces, furnaces, boilers, stoves, ranges, water heaters, or other appliances fueled by wood, oil, coal, or gas.2 Air clearance to combustibles for all diametersADA Compliant: No Collection: DuraPlus Fuel Type: Coal, Gas, Oil, Wood Height: 4 Inner Wall: 0.02 Stainless Steel Insulation: Ceramic Blanket with Air Gap Intermediate Wall: 0.02 Aluminized Steel Liner Joint Connection Overlap: 1-1 2 Joint Connection Type: Twist-Lock standard on all diameters Length: 8-1 4 Material: Galvanized Steel Outer Wall: 0.02 Thick Stainless Steel or 0.02 Thick Galvanized Steel Pipe Class: Class A Pipe Inside Diameter: 8 Pipe Shape: Round Style: Functional UL Listed: Yes Vent Construction: Triple Wall Weight: 6 Width: 8-1 4