Reinforce a Toris head for external pressure

[farzam]

Dear All,

How can I design a reinforcing bar for a head against ext, pressure? Applying a reinforcing ring on head can not not be done by pv-elite.

Thanks in advance

 

[TomBarsh]

How would you analyze this by hand? How will the bar help the head resist buckling? These are not easy questions to answer (for me, at least).

It is common in some types of construction (perhaps not pressure vessels) to brace a dished surface against pressure by using radial ribs. It can be seen intuitively that this will brace the head against buckling: only a "dimple" of size that can fit in between the ribs may be formed, and there are some theoretical bases on which to determine the buckling pressure. A ring may not actually provide much additional resistance to buckling since it may force the head to "oil can"...collapse in the axial direction.

 

[farzam]

Dear Tombarsh

Actually it is a in service vessel that has radial ribs on his head, and now its required to calculate min. required thk. for head.

 

[jte]

farzam-
farzam-

Yes, there are times when your standard vessel design software will not have a module where you just plug in numbers and get the answers. These are the times which "separate the men from the boys." You could do some hand calc's, but FEA will be a better approach. Follow the guidelines for protection against buckling in the 2007 editions of either VIII Div. 2 or API 579-1 / ASME FFS-1. If you are within the original corrosion allowance, then you can work the evaluation as an alteration; otherwise you are probably in the world of Fitness For Service.

jt

 

[farzam]

Dear jte,

Thanks for the comment from Men to boy,
Actually I performed FEA, but I just asked to know if its possible with Pv-elite or compresss.

Kind Regards