Dear all,
I have a question as shown below,
1 WW+HP HYD
2 W+D1+T1+P1 OPE T1 160 design condition
3 W+D2+T2+P1 OPE T2 60　　　 operate condition
4 W+D3+T3+P1 OPE T3 -18　　　minimum temperature
5　 W+P1 SUS
6 L2-L4 EXP
According ASME B31.3
Is it right to use case 3 to generate restrain load,
Or is case 3 only used as construction case for calculating expansion range.

Any response will be appreciated!

Why not for restraint load ? Pl. read B31.3 once more to see what it has to say on restraint load and you will know the answer.

Regards

319.3.1 Thermal Expansion Data
(b) Values for Reactions. Values of thermal displacements
to be used in determining total displacement
strains for computation of reactions on supports and
connected equipment shall be determined as the algebraic
difference between the value at maximum (or
minimum) temperature for the thermal cycle under
analysis and the value at the temperature expected
during installation.
I think T3 is mini temp, not maximum (or
minimum) temperature for the thermal cycle. so load case 4 needn't to output restrain loads.
many thanks!

Forgetting the code for a second as it is not a cookbook and using a little thought. The loads you report to your civil/structural team should be the highest loads experienced by your system. Generally this will occur at either you minimum or maximum temperature but sometimes in between. If the load will occur in the operation of the plant the civil steel better be designed to handle that load. In something like a heat exchanger using operating temperatures is a quite important check as the design temperatures will likely be the same for the heat exchanger, the inlet piping and the outlet piping but the actual operating temperature for all 3 will be different as the fluid cools. This can lead to quite different load distributions then an all hot or all cool case.

thanks for your help,
Then is it necessary to use load case 4 to check nozzle loads?
many thanks!

Miangun,

You yourself have answered your question by referencing the code.

Regards

thanks for your reply!