Pipe Flow Calculations Forum

when i use the pipe flow calculator, there are some values that i am not sure of, and i don't know how to get them or estimate them or how important they are they are dynamic viscosity, kinematic viscosity, pipe roughness (kr) and resistance coefficient (K) the formula used is not displayed so i can...

I know the pressure drop, pipe dimensions, butt he flow calculator won't let me calculate flow - what am i missing