Hello,
I got a question here. I got a sample of SAKHALIN II project but only the stress isometric drawing. The Temperatur Design = 60/-20 Celcius and The Pressure Design is 1 bar. My question is if the Temp. ambient 40 Celcius how much do i have to put in T1 and T2 on CAESAR II ?

dylan,

60.

-20.

consider changing installed temperature from the default.
you don't have to double post.
you don't have to shout (please - bold fonts are not necessary)
your problem is not big. check previous posts on this topic.

I'm sorry isn,t this is a forum where we all can learn and share our knowledge? and i'm new in pipe stress analysis so i hope that you understand.
O.k i have put 40 celcius as the ambient temperature so that T1=140 C and T2=-20 C but the output on Expansion case 1 was failed. So is there any other way?

How did T1 get to be 140? You stated above that T1 was 60 ...

If you fail in an Expansion case, your system needs more flexibility. Changing temperatures to resolve this issue not permitted. Your temperatures are your temperatures and you have no control over that.

dylan,

some times it seems this forum is place to bring problems and show a lack of understanding. That is all right, and it could result in learning.

so now it is a problem of failing the expansion case.

while T1 60 C or 140 C is not extreme, which value is it?

where did you change the ambient temperature? as a matter of confirmation what was the default ambient temperature of the configuration file?

expansion case failure usually results from not enough flexibilty - the geometry is too stiff. more information will be needed to describe the piping system being analyzed. CaesarII will calculate stresses and other results, but you or piping designer will need to modify piping system to pass the Code allowable expansion and sustained stresses, loads, movements.

other people may have comments. i will wait until tomorrow before further responding to this post.

I got this sample case from my trainer.The design temperature was 60/-20 celcius and the ambient temperature was 40 celcius. Thera are no information about the operation temperature, that's why i'm so confuse. How can i determine the T1 and T2 for input in CAESAR II?

Set your ambient temperature in the input under "Special Execution Parameters". If you wish all NEW jobs to use 40C as ambient, set ambient in the Configuration file.

Your design temperature/pressure pair will set your minimum wall thickness and, as you suggest, may not be the temperatures and pressures you use to evaluate code stress and structurally response. The process sets those values and you won't find them here.

Thanks dave, but i have do set 40 C in "Special Execution Parameters" but still the result in expansion case 1 was failed. I think it is right what Mr. Richard Ay said, i need more flexibility in this piping system. I will take a time & think of it and read Para 3019 ASME B31.3. Thanks a lot.

dylan,

It is good to hear that you have a ASME B31.3 Code to study. If you are referring to Paragraph 301.9 Reduced Ductility Effects, then you may not be understanding the causes of expansion case over-stress. The portions of Chapter II Part 5 paragraphs 319 Piping Flexibility, and in particular paragraph 319.7 could be of help to you.

The temperature for stress analysis will affect both the sustained analysis and the expansion analysis. So it is important to establish a set of real values for temperatures, or else the stress model will not behave as the actual piping.

Do you understand how the temperature has effects on the allowable stress (strength of material) for sustained stress?

Do you understand how the temperature has effects on the amount of expansion for the expansion case? Can you calculate what is the thermal expansion, and compare your calculated expansion to the CAESARII expansion displacement results? Please provide the calculated major expansion movements for your piping, and have your mentor check your calculations before posting the results here. Once the thermal displacements are known, then I will understand more and direct you further in evaluating and increasing the flexibility of your piping system.

Hint: The ASME B31.3 Code has Table C-1 in the back of the book with data for total thermal expansion given in inches / 100 feet deg F.
Expansion for carbon steel at 140 C (284 F) would be 1.69 inch/ 100 feet.
Contraction of carbon steel at -20 C (-4 F) would be -.52 inch/ 100 feet.
These figures are based on installation temperature of 70 F (20 C), so an estimate of your thermal expansion based on installed 20 C would be a starting point for this discussion.

Upps i,m sorry, i think i'm miss when try to write para 319 about flexibility system, but anyway thanks Richard yee, and i have solve the problem. I think this forum is really help a new user of CAESAR like me. Thanks anyway

dylan,

It is good to hear that you solved your problem.

How did you solve your problem? What did you learn? Can you share it with others? I learned there is a difference between the Configuration file temperature versus the Special Execution Parameter for installed temperature.


I'm sorry isn,t this is a forum where we all can learn and share our knowledge?

i am working on buried pipeline analysis, i have doubt , i have ambient temp min -5 centigrade, i found two option about ambient 1. in utlities and 2. in special execution parameters. 21 centigrade was default value over there. so what should i keep my ambient -5 centigrade and where. i considered -5 as installation temperature. in soil modelling i need to provide delta T. tht is operating temp - installation temp . which no i have to give what to take -5 or 21

Karun,

1) The "Configuration" module from the Utilities menu sets the values in the configuration file (Caesar.cfg) in your local data (working) directory. This particular value (ambient temperature) is used as the default when you create a new job (to set the value on Special Execution Parameters. Changing this value will not affect existing jobs.

2) For a given piping model, the ambient temperature used in the analysis is obtained from Special Execution Parameters. Once a job has been created, it is here that you would adjust the ambient temperature setting.