Draw pipe with SSDCP?

I finished drawing some pipe wall rail and, at the end of the program, it said that if I wanted to draw the polyline as a pipe I had to choose Block E-21 or pick bevel lines, then pick the line width. Where is Block E-21? Can someone describe the process of changing the line within the bevel lines/line width command? Is there anyway to pick pipe and the program will just draw it automatically or do I have to physically draw it on the screen. Any help would be appreciated. Please be specific as I am just starting to learn this program and am somewhat stupid at the moment. Thanks, Carolyn