hooking up expansion tank?

I'd like to know how to hook up an expansion tank properly. Some of these tanks have 3 inlet/outlets. Could someone make a simple drawing of whats gettin' plugged in where?

[ame="http://www.youtube.com/watch?v=NHXrGEO4GWM"]Dan Gurney Sweed Savage Cuda AAR 1970 Trans Am Car - YouTube[/ame]