Seismic Load and Nozzle Loading

Posted by: marchie

Seismic Load and Nozzle Loading - 04/03/19 11:33 PM

Dear All,

I just want to know, Do I need to subject the vessel connected to the pipe for seismic analysis OR just the pipe only?

Also, Do I have to evaluate the nozzle loads of vessel with seismic loadcase?

Please I need your opinion and expertise.

Thank you.

Regards,
Marco
Posted by: anubis512

Re: Seismic Load and Nozzle Loading - 04/04/19 05:55 AM

I would think the vessel anchorage/support system should have been designed to the applicable seismic activity.

I would say you're performing pipe stress analysis; emphasis on pipe. Model the piping system and model the vessel nozzles per standard practice using rigids and Cnodes.
Posted by: Dave Diehl

Re: Seismic Load and Nozzle Loading - 04/04/19 07:01 AM

The seismic load on your piping should in some way address the contribution from your connection points. Oftentimes your piping support points such as your vessel nozzle will have a maximum displacement associated with the seismic event. One would include those maximum seismic displacements (e.g., D4) with the "seismic g load" load case (e.g., ...+U1+D4).
Posted by: marchie

Re: Seismic Load and Nozzle Loading - 04/06/19 11:38 PM

Dear Mr. Dave,

Where can I get those "Seismic Displacement" that you mentioned?
What if in the model/simulation of my input in Caesar II the vessel is already modeled as rigid pipe do, do I still need to imposed that "Seismic Displacement"?

Lastly, do you think it is needed to evaluate the nozzle for Seismic Loadcase?

Thank you and I hope for your usual support.

Regards,

Marco
Posted by: anubis512

Re: Seismic Load and Nozzle Loading - 04/16/19 07:45 AM

Marchie,

I would expect that data to come from the structural group who designed the equipment support structure.