# Discontinuity in fluid friction as a function of Reynolds number

I have observed a discontinuity in the Fanning friction factor chart, at around Reynold's number of 2000.

I know that this is the region where laminar flow changes to turbulent flow, but a discontinuity seems rather weird to me. I could accept a non-differentiability or a sharp turn in the graph as plausible, but a discontinuity doesnt make sense to me. It seems as if a small change in Re around 2000 could result in a large change in the friction factor, which is absurd.

Am I missing something here? Any help would be appreciated.

• Please edit your question to give some background on what this graph represents and the meaning of the notation. E.g., we don't know what is meant by $\Delta P$. – Ben Crowell Jul 4 at 17:18
• @BenCrowell $\Delta P$ is change in pressure. Usually one works out a friction factor and calculates the pressure loss or drop for a given set of conditions, but for that chart the friction factor is given as the result of that expression... – user207455 Jul 4 at 17:46