Noncircular jacketed vessel

[Kovisten]

Dear All!

I am trying to calculate according to ASME VIII div 1 a non-circular vessel that is jacketed with bars between the jacket and the inner shell of the vessel. The head is special, too. Appendix 13 only applies to single wall vessels, and jacketed vessel only applies to circular vessels. Since the inspector said that only calculations are permissibl, not finite element analysis, we are bumped, hence we ran over through the standard a couple of times again and again. The second issue is, that there can be a few load cases, pressure inside the inner vessel, and inside the jacket ( the same amount), atmospheric pressure outside, atmospheric pressure inside the vessel, overpressure inside the jacket and atmospheric around the outer side. Anyone could help me with this issue or link or send a sample to this exact aned specific problem?

Thanks in advance.

 

[r6155]

"Single wall" mean "one solid plate", "one layer". Jacketed vessel is not multi-layer.

Regards
r6155

 

[richard15]

Kovisten,

You need to calculate the vessel (inner shell) per Appendix 13 using internal pressure and external pressure ( jacket internal pressure + atmospheric). Then calculate the second vessel (jacket) per appendix 13 using ( jacket internal pressure ) and external pressure (atmospheric ).

Richard.

 

[MikeG7]

As per Richard this is exactly what I have done in the past. I don't think atmospheric pressure outside has anything to do with it if you are talking about gauge pressure. I mean when the jacket is internally pressurized, then you are reading the gauge pressure relative to atmospheric. That is my understanding.

So I would consider these cases:
internal pressure only in the main vessel
external pressure only on the vessel walls
internal pressure on the jacket (stayed)
and, if it exists, internal vacuum in the vessel with external pressure in the jacket portion, which the net effect of both of these is a more severe external pressure.

App 13 has a check for the back closure which you might be aware of.

The above is from an almost identical design I recently did.

Michael