Hi

We experience the problem with the thermal expansion coefficient – the coefficient in the model doesn’t match the numbers from the material database.

We are using X60 steel with 30deg operation temperature and 0deg installation temperature. The properties from the database gives roughly 11*10^(-6) expansion coefficient for 30deg temperature.

In the model, the thermal expansion coefficient is 325*10^(-6).

So the main question is why the thermal expansion coefficient in the model doesn’t match with the value from the database?

And the second question – can we input the thermal expansion manually? How to do it?

Thanks, Polina

Yes you can input the coefficient directly into the temperature field on the spreadsheet. Determine the coefficient in units of length/length (you multiply by delta T) and put that in the appropriate TEMPx edit boxes.

What exact CAESAR II material are you working with (what is the material number) and what piping code?

In the temperature field on the spreadsheet (box called Edit Operating Conditions) the expansion coefficient box is highlighted in yellow (as the background of the box) and the value CAN NOT be changed (while all other input boxes highlighted in white and it is possible to input values manually there).

Material number is 322, design code – B31.4.

That "expansion coefficient" field is display only. In the actual "TEMPx" fields, if you specify a value less than the ALPHA_TOLERANCE (set in the configuration file) CAESAR II will assume this is an expansion coefficient.

As an example, with the default value of the ALPHA_TOLERANCE set to 0.05, if you input a value of 1 it will be considered 1 deg. If you input a value of 0.04, it will be assumed to be an expansion coefficient in units of length/length.