Which piping Standard shall be refered for pipe sizes greated than DN 2000 for checking the ovality, dent, thickness tolerance..etc., since API 5L Standard covers up to DN 2000. I know this is not the place to ask this question, but i require your suggestions.

AWWA covers large diameter fabricated pipe to some extent. Your size indicates that this will be a fabrication from plate. I also suggest you look at the PFI they may have some guidance as well.

thnx sir, the pipe size is 120 inch.