PVElite 2011-Conical Head-With a Knuckle

[qwerasd]

Dear all,
I have a vessel with a conical head at the bottom , cylindrical shell at the middle and a torispherical dish at the top. Design Code:ASME Section VIII Div:01

The vessel is subjected to internal pressure of 2 bar(g) and external pressure Full vacuum.

Both ends of the conical head are not considered to act as line of support.I am designing the vessel in PVElite 2011.

The bottom conical head (with a knuckle=K.R greater 6% of dia) when subjected to internal pressure, shows 2 values of thickness in PVElite calculations

Pvelite choses the maximum of the two.

The first value comes from the formula from appendix 1-4 (f)

where does the second value come from???

Also the second value doesnt depend uopn the static head? it also remains unchanged if i change the value of knuckle radius?

Please Help.

[lubl]

any one have PVElite 2011 ?
please share it,
Tnx

[Ali366]

attach a copy of internal pressure calc's, otherwise this would be difficult to say what's the reason.