Vacuum Stiffener Interrupted By a Nozzle. 1

[polani82342]

We have a case where a vacuum ring got interrupted by a large integral nozzle / boot. Vessel diameter is 17' horizontal. Boot diameter is 8'. This obviously exceeds code allowed interruption. Is there a calculation method available to ensure the adequate moment of inertia provided by nozzle?

Or, can cases 13 or 14 of Roark 4th Edition of Chapter 14 on Elastic Stability provide a suitable solution? ( Case 12 is the basis for ASME formula for vac. rings I suppose).

Other approach could be if an FEA provide an answer?

your comments are appreciated.

 

[jte]

Consider CC 2286 (I think its stilll in effect for Div. 1) or Div. 2 approach using the age-old U-2(g) argument to go with an FEA, then use Div. 2 guidance on FEA for colllapse loads in 5.4.1.

jt

 

[polani82342]

Dear JTE,
Appreciate your prompt reply which is quite helpful. In fact the vendor has submitted FEA and we are evaluating it. I am checking to see if there is any direct reference to such a situation any where in Eng-Tips.

Janaki.