Hi all,

Our clients want to do cold spring to one of the high temperature line. When I did the stress analysis with CAESAR, I found out that if the cold spring element is in different location, the stress is different.

Can anybody tell me why or did I do anything wrong?

Thanks,

What do you mean by "a different location"?

Please see attached sketch for clarificaiton.

I need to do cold spring between the two anchors. If I specifiy the cold spring element at location1, the stresses will be difference with the cold spring at location 2. The highest stress point has a higher stress with cold spring element at location 1.

Thanks,

Yes you can get different results. Consider a system like this:


where the base of each leg is anchored, and points "a" and "b" on the horizontal run are the same distance from the elbows. If you put the cold spring at "a", the section of piping "ab2" is more flexible (to point "a") than the section of pipe "a1". Conversely if you put the cold spring at "b", the section of piping "ba1" is more flexible (to point "b") than the section of pipe "b2". This will cause different results, on the order of a percent or two, when comparing the two locations.

If the system wasn't symmetric, the differences could be much larger. Items like expansion joints and axial stops can further complicate matters.