Consider steady flow of an incompressible fluid through two long and straight pipes of diameters d₁, and d₂ arranged in series. Both pipes are of equal length and the flow is turbulent in both pipes. The friction factor for turbulent flow though pipes is of the for, f = K(Re)^–n, Where K and n are known positive constants and Re is the Reynolds number. Neglecting minor losses, the ratio of the frictional pressure drop in pipe

1 to that in pipe 2.		∆P1		, is given by
		∆P2