Hello everybody!

i am concerned about the difference between European Code (EN-13445) and ASME VIII, when calculating Spherical heads. My results shows a difference from 2 mm (diamter = 4000 mm) to almost 5mm (diameter = 10000 mm)in the required thickness of the spherical head. My question is if anybody has experience designing with european code and what this difference imply? Is the European code safe comparing with ASME? Is ASME too conservative? In other parts of the vessels (cylinder, conical,etc) the differences are much lower.

Thanks in advance.