[yow]

I've read several threads and the User's Guide on operating pressure and am very confused. I want to use basic examples to clear my confusion.

Based on my understanding, operating pressure is environment pressure? For example, if operating pressure is 2MPa, and I have a tank with 3MPa abs pressure inside, does that mean 1MPa gauge pressure inside?

Furthermore, if I have standard atmospheric pressure environment and a pipe with inlet 2MPa and outlet to atmosphere, could I set operating pressure to 2MPa, set velocity inlet BC with initial gauge pressure as 0, and pressure outlet BC with gauge pressure as -1.9MPa?

Thank you!