The plumbing code (ie IPC) limits the velocity of piping with a maximum velocity. We always ask for it on shop drawings/calculations in additon to sprinkler calcs.
The IPC has maximum velocities:
all piping 1/2 inch or smaller = 5 feet/sec.
copper, 5/8" - 1-1/4" = 5 feet/sec.
CPVC, 5/8" - 1" =...