dear friends

I am working for calculating the piping loads imposed on steel piperack, After calculation I will send the loads on beams, columns etc. to engineering firm who will design the steel pipe rack.


As you know it is a very long and tedius procedure to calculate the forces on restraint for each pipe and give a total force imposed on each beam or column of rack.


is there an easy way to export piping loads imposed on a steel piperack?

Or can caesar II structural input option be used for such situation?

Thanks

In case the piping and structural design jobs are split between different companies there is always the same classical problem that you are having now.

From my experience one option to solve this problem is to use iteration in load reporting and letting the structural design company about what you are doing.

I guess you know the locations of the support beams and columns, and you can determine vertical support locations of piping. This will give you the opportunuty of reporting possible vertical loads and their locations if you have pipe sizes, thicknesses, contents, insulation/lining type and thickneses etc...

After that report the structural design company will have the opportunuty to priliminary size the beams and columns. They will add wind and seismic loading to the structure at this stage by using the the mass of pipng and the wind area on the structure.

Second, start running preliminary analyses of piping groups to determine locations of the lateral and axial pipe supports. After reporting this the structural company will do second order analysis to finalise the sizes of the beams, columns and braces necessary. Braces need a clash check with piping route at this stage.

Third, your final piping analysis will validate the piping loads that you have forwarded earlier. You need to report the final loads as well. If there is no change the structural analysis is final. Otherwise there will be some minor modifications on the structure to suit the loading.

Of course there will be some communication mishaps during this process. You need to very close to the structural design company or vica versa to eliminate problems.

If you can provide the final piping analysis in early stage, the communication problems can disappear and you can expect the structural and civil design can finish the job earlier. Shorter design process time is the benefit for the companies.

Hope it helps.

Ibrahim Demir

I guess I left one of your questions open. Caesar II structural option is very effective to consider the stiffness of the structure under pipe loading. Of course this make the pipe calculation more accurate.

However, Caesar II does not give you the option to size the structure under loading. To use the analysis option you need to have the beam, column and brace sizes and loactions ready to imput into your analysis. So, they need to be designed by a structural person earlier than your piping analysis.

Therefore, I believe that you do not have the chance to use this option at all.

Regards,

Ibrahim Demir

thanks very much for the detailed answer.
actually my boss suggested a similar procedure to follow, but during the process I realized that for a piperack carrying more than 60 diffrent lines, "arranging the loads coming from diffrent lines and creating a format that is readable by the steel design firm" takes much more time than modeling the lines and calculating the loads.
I wondered if Caesar II have such kind of productivitiy tools to decrease the time.
thanks again

There is no short-cut. You still need to go through each line support loads and drawing (this could be a plan arrangement drawing which has the support nodes, and line numbers and coordinate system marked) and provide a load summary to the structural engineer to use.

Structural engineers mainly (in case there is no other effects) would like to receive the support loads with the following format:
- Pipes empty
- Pipes full with contents (Dead load)
- Operation load(s)/thermal load(s)
- Seismic load
- Wind loads
The best is to get the involvement of the structural engineer for the required load cases.

You may either create the load cases (which you normally would not create for the analysis seperately) in Caesar II in addition to other load cases and get summary report for all those above from Caesar or use a spreadsheet to create them from the cases you use in the analysis.

If you use the first option transfer the Restraint Summary into Spreadsheet through CAESAR II word or notepad options. Controling and manipulation of the loads, adding information next to the nodes/loads are a lot easier this way if required.

Hope it helps.

Ibrahim Demir

I guess you do not want to model the lines at the beginning, and still want to give the loads to the structural engineer. In such case, use my first post paragraph 3 for the iterative load summary transfer to the structural engineer.

Ibrahim Demir