You are kidding, don't you? How did you designed a pressure vessel to ASME VIII if you don't know the type/ratio of dished end you were using? You mentioned the ASME B16.9 standard, did you bother at least to check in the standard what shape is the ellipsoidal pipe cap? How do you know the design you made is safe? Do you care?
I can't believe that the forum can tolerate this behaviour and we can be held accomplices to potential unsafe design, by simply answering a naive? question.