currently, I am working on a 150lb piping system with internal pressure of 12 bars. I check the flange connections in equivalnet pressure method and all are ok except one so I check it in CII feature "flnage" I am pretty sure that all data about the dimensions and materials of bolt and gasket are correctly entered. what surprises me is that with even an internal pressure of 1 bar and no external load, this flange connection goes bust! gasket is a spiral wound gasket with thickoness of 4.5mm the material group of the flange is 1.1
the problem is that the maximum average and longitudinal hub are too much.
I wonder if anyone could give some advice in this regard.
thanks