Minimum Nozzle Thickness on Non-Circular (Flat) Plates

[ReliabilityGuy90]

Hey all,

I'm in the process of reverse-engineering minimum required thicknesses for every pressure vessel component in our refinery in order to establish retirement dates/suitability-for-service.

My current issue revolves calculating minimum thicknesses for nozzles located on flat surfaces. The most common scenarios of this nature occur with Fin-Fans (AKA Air Cooled Exchangers) and nozzles located on blind flanges, however we have miscellaneous other configurations as well.

My question is this, how would you go about modeling a minimum thickness requirement for a nozzle located on vessel like mentioned above? We establish our calculations per ASME Section VIII-I, UG-45, however this approach's code references primarily have guidance for attachments on circular vessel walls.

I have spoken to various SMEs on the matter but the only solution I've seen so far is to model these nozzles in an FEA simulation and do a stress analysis, we dont have access to said tools so that option is out.

Thoughts?

 

[SnTMan]

RG90, under Sec VIII, Div 1 the nozzle thickness will be the thickest required by:

1) UG-16
2) UG-27
3) and / or UG-28
4) UG-45
5) Thickness required to provide adequate opening reinforcement per UG-37 and / or UG-39.
(Could also invoke Appendices 1-7, 1-9 & 1-10 I suppose)

Note that the required nozzle thickness is generally unrelated to the type of component is it mounted on. For example the language in UG-45 states "..shell or head..".

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand