The fluid head resistance can also be expressed a pressure loss.


Metric units:  bar  = h fluid  x p x g / 100000


h = head loss (m)

p = fluid density (kg/m³)

g = acceleration due to gravity (m/s ²)


Imperial units:  psi  = h fluid  x SG x 2.311


h = head loss (ft)

SG = specific gravity of the fluid