Can I do Finite element analysis for a certain section of the pipe using CAESAR II?!
If the answer is yes, I appreciate if you can give me some guidance how to use CAESARII to do so!!
Thank you

CAESAR II is a finite element program, it just happens to be restricted to the "3D Beam" element. You have no other element options.

If you're looking to mesh the pipes using quad or bricks, the answer to your question is "no".