Conversion of pressure units



Conversion of volume units



Conversion of volume flow units

Pressure drop in a tube

The volume flow Q of a liquid with dynamic viscosity η in a tube with length L and inner diameter D causes a pressure drop Δp

The pressure drop in laminar case is calculated as follows:



Calculation








m/s

Conversion


mm²/s
g/ml
mPas

Viscosity

Dynamic viscosity η: 1 mPas = 1 cP (P = Poise)
Kinematic viscosity ν: 1 mm²/s = 1 cSt (St = Stokes)

Examples of viscosities

Liquid η [mPas]
water, liquid, 0 °C 1,79
water, 20 °C 1
water, 50 °C 0,55
water, 80 °C 0,36
water, liquid, 100 °C 0,28
Liquid η [mPas]
Acetone0,36
Benzene0,65
Ethanol1,2
Methanol0,58
Toluene0,59