PI * D^2/4 * H gives the volume in a cylinder. This should be accurate enough if you are not using this for custody transfer. If you are, and have a lot of tanks, then consider some type of tank terminal management software. Goggle Varec, Rosemount, AC2.
I have tried to determine the computational basis for vortex breaker design since 1990 and have found the following:
There is very little in the non-proprietary literature on the subject. Sulzer has published some of their work in their pump handbook.
The important factors are the velocity in...
Any valve suitable for HF service will work. Pacific makes them, as does Crane. There are others, I'm sure. Ask if the valves in question conform to either the UOP or Phillips HF specs.
Good Luck!
Tom
Pumparound trays remove heat. Model the pumpround section as one theoretical tray and install 3 to 5 real trays in the tower. The "efficiency" of P/A trays doesn't matter - after all you are moving heavy material up the tower which is exactly opposite of what the tower is supposed to...