Depending which code you use. Some codes require any pressure in excess of 85 PSI must be lowered to this pressure. There is no real “normal” pressure
Now FYI try to get the actual size and material of your piping (Potable supply) and then figure out the velocity FPS based on Pressure and size giving you a GPM then you can find out the FPS as anything over 8 FPS should be avoided.. Sometimes you need the extra pressure to over come friction losses and and to have certain applications work properly LIKE A flushometer or a fire supression system piped off the domestic main.
Basically 60+ PSI should cover the majority of applications, again depending on the building height and the lenth of piping involved.