Depends on the piping material as Hazen Williams formula kicks in for friction losses
Approx 73,167
6
that's what she said
1200
300 gallons per minute
2.5 gallons per minute
0 gallons per minute will flow threw any pipe at 0 psi.
Depends on what is flowing through the pipe and the temperature of the pipe.
Flow = Pressure / surface S = PI * ( Diameter / 2 ) ^ 2 now you can do the math... I can't tell with gallons, inch and psi.
We need to know what pipe material will be used.
With no pressure (that being the P in PSI), it is next to impossible for any liquid, let alone gallons of liquid, to pass through piping at any length.
That's going to depend on the substance flowing and the pressure behind it. Beer -- more Molasses -- less etc.