Actual Installed load

I am a junior learner from CAESAR 2 almost one year and have a question about the hanger spring.I has known about the definition of the Actual Installed load and Theoretical Installed load.But I am not clear about in which situations are these two kinds of loads different?why is different?
I hope to get the apply.Thanks!

The following paragraph is from the Caesar2 Technical Reference Manual available in the Help menu. Refer the help documents with words like "theoretical installed" etc
....The theoretical cold, or installed, load is the load on the spring when the pipe has exactly zero displacement. The actual installed load may differ from the theoretical installed load by (K)(d), where (K) is the spring stiffness and (d) is the displacement of the pipe in the installed condition. In essence, the actual installed load is calculated by taking the piping system and "freezing" all displacements at zero. With the pipe in this condition, the hangers are installed and the theoretical cold load is applied. The pipe is then "defrosted" and allowed to adjust its weight position due to the hanger, restraint, and anchor stiffnesses and the installed hanger loads. Once the system settles out, the total load on each of the hangers is read and recorded as the "actual" hanger installed load.....

Great answer, Shiny. Essentially (and you have hit the nail on the head) we design spring hangers to support the proper weight load at any given location in the operating case. The hangers are installed on cold piping that is restrainted to a theoretical position. If they are variable hangers, the theoretical cold load accounts for the movement to the operating position, and so does not match the required support force to restrain the pipe.

But, if there are a significant number of variable springs (or if the weight of the pipe, valves, and insulation is not as the analyst assumed) the pipe will self-adjust its own position so that the weight is exactly equal to the sum of the support forces. This will cause many variable spring supports to move to the actual installed position.

Pipe stess software is remarkably good at calculating this actual installed cold load case, but unfortunately nobody can provide you with weights for valves and piping that are sufficiently accurate to design a lot of spring supports and have none of them move off the theoretical cold load when the pins are removed.

I find if the pipe has no content,the Actual Installed load on that node is equal to the value that SUS(W+P+H) displays(Restraints Summary),what the
relationship with the Actual Installed load,Theorectical Installed load and the value in SUS?

The case for "actual installed load" is WNC+H. This is the reason.

HOW TO DEFINE THE LOAD CASE IN CAESAR FOR HANGER SO THAT WE CAN SEE THE "ACTUAL INSTALLED LOAD IN HANGER REPORT

Generally we design in this way
W+H - hanger stiffness-Rigid
W+D1+T1+P1+H -Hanger stiffness- Ignore
then you can view the Field installed load field some values will appear but you will get "0" in the Actual installed load " filed .

Please can any one tell me how can i define the same in load case so that in the hanger report i can see the Actual Installed load.

In the Piping Input, on the menu: click on Model, then Hanger Design Control Data. Check the second box, Calculate Actual Cold Loads. (There's also a Toolbar Button for this control data.)
You will have to reset your load cases to build the extra analysis.

What is the Field installed load? Is the same as the Theoretical Installed load?

hi,xue.,
There is a web "http://bbs.pipingsoft.com", you can access it and ask some question about CII in Chinese. A lot of topic about HANGER problems in there...