Pipe Guide Supports

[iisanegineer]

Dear Friends,
I am new to the list and hope to contribute where I can. At this time I need a little help.
I am designing the pipe guide racks for pipes that have expansion bellows. I am using the "Standards of Expansion Joint Manuf." to locate and determine the loads on the pipe guides and therefore the racks.

My first question has to do with the spacing between the supports. The four diameter spacing to the first guide is not a difficult issue, it is the second spacing of 14 diameters that is difficult, because of all this different pipe diameters I am dealing with. Since the 14 diameters is a maximum distance is it possible to place the second guide support adjacent to the first (say 4 diameters)? Will this affect the magnitude of the load on the guide supports?

The second question has to do with the magnitude of the force. The lateral force that is given in the above mentioned reference is an average of 7% of the axial force to a max of 15%. How do you know what to use?

Thanks in advance

 

[bulkhandling]

My idea is that you need help from your piping engineer.
I think you are designing a pipe rack for many pipes and your first problem is the spacing of the rack beams. There is a thread in this group discussed this problem very well, you can search for it.
You can preliminarily space your columns and beams by your calculation of structural stability based on the piping loads (from piping engineer), wind load and earth quake load. You get 10 feet for instance. Then you check the pipe sizes. If all the piping are 2" and bigger, you may stay on 10 feet. If many are smaller piping that require smaller support space, you can make the space smaller like 8' or 7'. Another approach is to design the main frame based on your structural design and add miner frames (smaller size steel) to support the pipes that require smaller support space.
If you are designing rack for thermal piping, you can ask stress analyst give you the piping loads like gravity load, axial load, lateral load, and load at expansion joints if any thing special.