Hi all,
I am doing the stress analysis for a bitumen line at temperature of 180.The line is hot oil traced all over and the ambient min temp is 5.
I have considered 21 for the installation temperature .Because the line is traced so one of our engineers is telling that we don't need the line to be analysed for the expansion between 5 and 180?
What do you think? Should we need to consider it in our work?


Thanks,

No bady could answering me yet???

Pegah,

The data is not sufficient to answer this.....
Can you brief on this calculation like Line Size, Temp Unit's (C or F), Pressure, pipe thickness,Material,line connected to which equipment.



Regards,
---------------
Manjunath Shet

manju,
The line size is different from 8"-12"and the pressure is about 1200 Kpa and the thichness is standard ,Material is Carbon steel and the Equipments are tank and Pump.The tempreture Unit is C .Ok what do you think now???

Thanks,
Pegah

Hi Pegah,

I'll strongly recommend you to do Stress Analysis for this system,
There are some criteria based on which Critical line lists are prepared as follows:
1.All Lines above 4” connected to rotating equipment
2.lines connected to tank with settlement of more than 15mm
3.line size above 6” with more than 150 deg C

This all system comes under class A for computer programme check

I hope this all points may be covered in your stress design criteria or Project design basis.

Regards,
---------------
Manjunath Shet

Manju,

You are quoting from only one project or engineering company's procedures.

Critical line selection is a matter for the owner and often the engineering contractor. There is no global agreement on this or when computer analysis is required, and client's requirements differ dramatically. Some codes give guidance, but generally not too specific.

Pegah,

Your stress range is 5 to 180 degress, regardless of the installation temp, so calcs should be based on that range. You might for instance do 21 to 5 and 21 to 180 deg. loadcases then add stresses, and use 21 to 180 deg. for your restraint / equipment loads.

Hi MoverZ,
Thats the point .

Regards,
Pegah