Calling All Mechanical Geniuses

Collecter size is not about pressure but volume. It takes four 1 inch pipes to move the same about of volume as one 2 inch pipe.
During my 10 years in plant maintainance I learned all sorts of crap.
We has a cummins diesel engine powered fire pump on the mill pond.
With a 12 inch header off the pump can you guess how many 3 inch gate valves were on there for fire hose hook ups ? I go ahaed and tell you.. Ten.
These were more for annual pump testing that use. There was another 12 inch line underground tied to the sprinkler system. I wont get into how those gate valves were configured on that header and why to avoid a hyjack here.
I built my own vacuum for our above ground pool that is power by my air compressor. The Y pipe velosity pressure principals make it work. Very well too :)