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Pump Head Formula:
Total Dynamic Head (TDH) is the total equivalent height that a fluid is to be pumped, taking into account static head, friction losses, and pressure head. It's a crucial parameter in pump selection and system design.
The TDH formula consists of three main components:
Where:
Details: Accurate TDH calculation is essential for selecting the right pump size, ensuring proper system operation, and avoiding energy waste or insufficient pumping capacity.
Tips: Enter all values in feet. Static head is the vertical distance, friction loss can be calculated from pipe flow calculations, and pressure head is any additional pressure requirement converted to feet of head (1 psi = 2.31 ft of water).
Q1: How do I calculate friction loss?
A: Friction loss can be calculated using the Darcy-Weisbach equation or Hazen-Williams formula based on pipe diameter, length, flow rate, and pipe material.
Q2: What if my system has no pressure requirement?
A: If there's no additional pressure requirement at the discharge point, the pressure head component can be set to zero.
Q3: Why is TDH important for pump selection?
A: Pumps are selected based on their performance curves which show flow rate versus TDH. The operating point should be within the pump's efficient range.
Q4: How does elevation affect TDH?
A: Higher elevations reduce atmospheric pressure, which may require additional pressure head in open systems.
Q5: What's the difference between static head and TDH?
A: Static head is just the vertical component, while TDH includes all resistance the pump must overcome including friction and pressure requirements.