Which statement about Total Dynamic Head (TDH) is true?

• A. The static pressure alone
• B. The sum of friction loss, elevation head, and suction lift.
• C. The nozzle pressure plus friction loss
• D. The residual pressure only

Answer: (B)

Total Dynamic Head is the total energy the pump must supply to move water through a system, accounting for all resistance and lifting that the fluid experiences. This includes the vertical distance the water must be raised (elevation head), the pressure losses from moving water through pipes and fittings (friction loss), and the extra head needed to draw water from the source to the pump (suction lift). Adding these components gives the head the pump has to overcome. Static pressure alone misses the losses along the path, and nozzle or residual pressure don’t represent the full demand on the pump. So the statement that TDH is the sum of friction loss, elevation head, and suction lift is the correct description.