All the pressures in PVElite are gauge pressures. OK.
But I don´t know how can I enter in Pvelite a gauge pressure of -5psi, because PVElite doesn't let me write negative pressures. PVElite changes the pressure from -5psi to 5 psi. Is that correct?

Should you need any other detail, please let me know.

Hi Eduardo,

PV Elite will only accept positive values for both Internal and External pressures. A full vacuum would be entered in as 15 psig. A partial vacuum would be less than 15 psig and greater than 0.

In the ASME Code Section VIII Division 1, there are examples showing the use of the external pressure rules in Appendix L.