SACS -Appurtenances

Hi

I am wondering about the general practice/procedure for modelling piping (as well as electrical/ instrumentation/ tech-safety/ architectural) loads for global analysis of combined jacket-topside structure. How do you model piping loads? In case you want to model the actual piping loads then you will have to model pipe supporting steelwork which will involve too much detailing for topside modelling (imagining the pipework and other loads supported on topside).

Even, alternatively, if you just want to transfer the reactions thus received then still it's a lot of modelling.

How are they applied? If taken from weight control report then how do you compare it with reality?!


Please elaborate...

Thanks.

  • Piping loads can be applied in a variety of ways and it usually depends upon what you are trying to analyze.

    You certainly can model every pipe supporting structure and then model the reaction loads from the structure. SACS even has an Autopipe interface to facilitate the importing of pipe reaction loads for this very purpose. This can be very useful for doing a detailed design of the topsides structure.

    If you want to design the primary steel for supporting the piping loads, you can model the piping loads as distributed loads using some general area loading which is an approximate estimate for the piping + support weight on the structure.

    In order to the match the weight control report (typically for substructure design), you can factor the distributed loads you applied for the topsides primary steel design to match the reported piping weight and then either apply a cog correction load for the pipe weight or apply an overall cog correction load for the total weight.

    Regards,

    Geoff