Occasional Stress Case: Hot Sustained or sustained

[mw2005]

While calculating occasional stresses we separate out the effect of occasional loading such as Wind or psv force. It is then added to sustained case using the scalar combination. My question is if it should be added to hot sustained case which is the actual sustained case at operating position of the pipework (there could be a support lift off).

Any idea???

 

[MJCronin]

http://www.eng-tips.com/viewthread.cfm?qid=431654

http://www.eng-tips.com/viewthread.cfm?qid=246231

MJCronin
Sr. Process Engineer

 

[KevinNZ]

You should work out where the pipe is under operation temperature before applying the occasional loads. This will calculate how the occasional forces and movements create stress in the pipe starting form the operation temperature.

But do not add the thermal stresses to the occasional stresses.

 

[DSB123]

The sustained stress (due to Weight and pressure) should meet the Code limits under any operational condition. Hence the SUS+OCC case should meet the Code limits under any operational condition.