Dear Sirs,

I have to check a jacketed piping system with 1 barg in technological pipe and 6 barg in the jacket. My question is: How can I do that, because the total pressure in technological pipe is negative (inside pressure 1 barg, and external pressure 6 barg), and my version of CAESAR doesn’t correctly work with negative values for pressure (according its help)? There is any technical documentation for that kind of problem? I specify that I already checked the interior pipe thickness for external pressure and it is ok. I want to check the piping system for longitudinal stress in usual load cases (operating, sustained, etc.).

Thank you in advance,
Dragos