You may need to use elbows for your Class A chimney for various reasons. You may want to go around an eave instead of cutting a hole through it with the double wall pipe. Or you may be in the attic and need to avoid a rafter or another obstacle.
The Class A Elbows come in 15 degree or 30 degree kits. A double wall elbow kit has two elbows to make the pipe then turn vertical again. The elbow kit also includes a necessary bracket. Below is a chart that helps you determine the elbows you need for your factory built chimney.
This elbow offset chart is for 5″-8″ Class A chimney pipe.
You can use this chart to the left to figure out the length of Class A chimney pipe you need to install between the two double wall elbows and the degree of elbows you need in your specific application.
You cannot have more than 72″ of double wall chimney pipe between the two elbows. If you have more than one section of Class A chimney pipe in between the elbows, a second elbow strap is required.