Hivris,
Please understand that this forum is not supporting any program. We would not accept any marketing or advertising here.
In inspection we have noticed that all commercially available programs have their pros and cons. And they all have mistakes, and limits of reasonable applicaitions.
Your key question would be to find our which program gives the best results based on your typical vessels, problems, materials, design details and your style of working. A program with a bug in a flange calculation can be perfectly find for you when your vessels are not flanged, while the same program can be useless for a manufacturer of flanged vessels.
So better try your typical design before looking on the prize tag.
A source of freeware used to be on
www.pveng.com, with limited application of course.