Dear All,

As per "Non Mandatory App EE-Half pipe Jkts" EE-1 says there has to be positive pressure inside the shell or head and there has to be positive pressure inside the half pipe jacket.

What about vacuum inside the shell ?

In that case how one proceeds?

Please help.
Regards
ASD23789

Dear friend

Yes, Appendix EE is only applicable if shell side and half pipe have positive pressure.

If shell side is vaccum, then you have to use another code reference or FEM method.

In past for vaccum pressure i have used following codes in which vacuum pressure is allowed.
1) Ad martblett
2) IS 2825 - An Indian Code

Regards
Sajit Patel

Can you suggest, how to do calculation using nps 3.5 pipe & half pipe jacket on cone?

Hello Mr.Patel,

Thanks for your reply.

I am using IS 2825 for lipet design (Appendix P).

The formulas are okay for both shell and limpet having positive pressures.

It also holds good for shell side vacuum and limpet side positive for calculation of fs4 only.(local bending stress)

In case of vacuum inside the shell or inside the limpet coil, how on should proceed for certain formulas? (Since fc1 - Hoop stress in coil ,fc2-longitudinal stress in coil, fst-total hoop stress in main shell, fs2-longitdinal stress in shell etc are stresses because of the internal pressure)

Hello Mr.patel,

Attached are the pictures.