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In fluid dynamics, Total Dynamic Head (TDH) is the total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe.
TDH = Static Height + Static Lift + Friction Loss
Static Height is the maximum height reached by the pipe after the pump (also known as the 'discharge head').
For a relatively incompressible fluid such as water, TDH is simply the pressure head difference between the inlet and outlet of the pump, if measured at the same elevation and with inlet and outlet of equal diameter.