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