Dear Nag,
what code are you using? ASME B31.3?
First of all check if you are inside the code scope because CAESAR II applies the code rules; if you are outside you could perform some FEA to calculate sifs and stiffnesses.
For large piping, sometime we use rigid element between the centerline and pipe walls. There are pros and cons of this solution. If you search in this forum, there are some threads about this topic.
Finally I strongly advise you to give your model to a senior stress engineer for his evaluations.
Best regards
Corrado Vannella