Generally, elliptical dished heads____________________?

A. Are manufactured on 2:1 ratio of major to minor axis and is recommended to be used for
pressure vessels operating above a pressure of 1.5 MN/m2
B. Resist half the pressure rating compared to hemi spherical head provided on the cylindrical
shell of the same thickness and diameter
C. Are approximately as strong as seamless cylindrical shell having the corresponding I.D and
O.D
D. All A., B. and C.