Hi Mike, thank you for your comments, you have made these points clear now. Additionally, I have checked Section II for a pipe material and I think as long as I avoid selection of a pipe with G5 comment it should be good to go. The only question I have got in my head is the calculations o flange rigidity in accordance with 2-14. Is this mandatory? I believe not. In my opinion definitely not for flanges calculated to UG-34, but I might be wrong.