Energy and Hydraulic Grade Lines
The Energy Grade Line is a plot of the sum of the three terms from the Work-Energy equation or Bernoulli theorem:
EGL (Total Fluid Head) = Velocity Head + Pressure Head + Elevation head
EGL = v²/2g + P/y + elevation
v = velocity
g = acceleration due to gravity
P = pressure
y = fluid density
The Hydraulic Grade Line is a plot of the sum of two terms from the Work-Energy equation or Bernoulli theorem, namely the Pressure head and Elevation head:
HGL (Total Fluid Head – Velocity Head) = Pressure Head + Elevation head
HGL = P/y + elevation
P = pressure
y = fluid density
