Dear Mr. Richard Ay,

Thank you for your answer.

An error in a post is fully understandable and practically inoffensive.
Unfortunately, I still claim there is an error in the calculation.

The "gasket seating" results and "operating condition" results must be practically the same for a very small pressure value as load.

Please try with a small pressure value, let's say 0.1 psig as a pressure load (and by the way, this wouldn’t be referred as "design pressure" load, it is an "operating pressure" load- in my opinion, the terminology is quite confusing).
The discrepancy (between the "operating" and "seating" results) cannot be real.

With the hope you’ll correct also the software,
My best regards.


PS. I just suggest you to carefully evaluate the equations. As I said in that thread, the gasket load at p_max is HG=2 * b * Pi * G * m * P_max , but this is not an equation for all "p".