Hi,

I am using caesar version 5.3 for calculation purpose.

In some files I have seen that hoop stress has been calclutaed taking in to consideration mill tolerance & corrosion allowance values keyed in.

But in some files hoop stress has been calculated only based on wall thickness entered AND mill tolerance & corrosion allowances have not been considered even though values have been specified.

I am confused with this calculation methodology for hoop stress.

can anyone guide me on this topic?

Thanks in advance.

Regards,
Kaustubh

Kaustubh,

What code you're using? CAESAR II will follow the code's regulation.

Hi,

I am using caesar version 5.3 for calculation purpose.

I am using ASME B 31.8 for calculation.

In some files I have seen that hoop stress has been calclutaed taking in to consideration mill tolerance & corrosion allowance values keyed in.

But in some files hoop stress has been calculated only based on wall thickness entered AND mill tolerance & corrosion allowances have not been considered even though values have been specified.

I am confused with this calculation methodology for hoop stress.

can anyone guide me on this topic?

Thanks in advance.

Regards,
Kaustubh

Generally speaking:
Mill tolerance is only used in checking the pipe wall thickness calculation. You will not see it in any load or stress calculation.
Corrosion does not affect weight or stiffness calculations, corrosion affects only stress (i.e. the A in F/A and the Z in M/Z); and only certain stresses at that (e.g. B31.3 does not include corrosion in expansion stress calculation).

Dave is correct, corrosion and mill tolerance are not considered by the Piping Codes to affect system stiffness. However, for B31.8 Chapter VIII, all stress values are computed considering corrosion and mill tolerance for the "combined stress".

What I know is that CAESAR II does pipe wall thickness calculation in analysis only for determining whether the thickness input value is sufficient or not.

So the thinckness used in hoop stress calculation(PD/2t) is nominal, right?

And Pipe's I, K or so is not affected by any tolerance unless they're used for calculating SUS, OCC, EXP stresses(and it varies by which code we are using)

Yes, unless you're talking about B31.8 VIII combined stress.



Correct.

Thank you sir.