No minimum.
Maximum depends on many things such as cleanliness, any liquid particles, length of pipeline / pipe, required or max pressure drop etc etc
Velocities could be realistically anything from 10 to 40 m/sec depending on your design code / standard and the issues noted above. Erosion can become your limiting factor, but then you need to decide how to calculate this. Many methods are inherently conservative. you need to know min and max pressures to be able to calculate actual density and velocity in the pipe. Any gas calculation needs that (pressure and density), you can't do it based on standard flowrates alone.
The issue of maximum fluid velocities is a contentious issue with many people stating figures plucked from thin air or written in different codes, standards and company recommended practices.
The vast majority are simply guidance.
There is never a "right" diameter. Only one which on balance satisfies the competing issues including cost, schedule and physical issues. Everyone has a different weighting for these issues so comes up with different answers.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.