Here is a site with lots of calculations. But I can't vouch for any of them. You will need to verify calculations yourself.
https://www.enground.com/ I believe separators here use GPA procedures.
Please note that most available calculations use the same set of equations that are readily understood. It's the criteria that matters! And most use what I call "poke & hope". And it's impossible to determine equations in a spreadsheet using cell formulas. And most online calculations use Java Script which is jumble except to the developer.
I recently completed a desktop application for sizing vertical separators. I will post it on my website in the next several days for download. You only need to register and login for access. It's for US units only. There are already online apps for SI units. No login is required. With all, there is an Excel workbook to produce a datasheet complete with drawing from the results. And there is lots of other stuff, too. If you download them and use them, and you experience any problems, let me know via email. My website URL is in my profile.
The sample provided for horizontal separator has not been updated for a few years, but the sizing is pretty good. Check it out!
Bobby
Edited by Bobby Strain, 11 March 2024 - 10:46 PM.