1. What is Total Dynamic Head?

Total Dynamic Head (TDH) is the total equivalent height that a fluid needs to be pumped, accounting for static head, friction losses, and pressure head. It's a crucial parameter in pump selection and system design.

2. How Does the Calculator Work?

The calculator uses the Engineering Toolbox method:

Where:

• Static Head — Vertical distance from liquid surface to discharge point (ft)
• Friction Loss — Head loss due to pipe friction and fittings (ft)
• Pressure Head — Additional pressure required at discharge (converted to ft of head)

Explanation: The equation sums all resistance components that the pump must overcome to move fluid through the system.

3. Importance of TDH Calculation

Details: Accurate TDH calculation is essential for proper pump selection, ensuring the pump can deliver the required flow rate against the system resistance.

4. Using the Calculator

Tips: Enter all values in feet. Static head is the vertical elevation change. Friction loss can be calculated separately using pipe sizing charts. Pressure head is optional (use 0 if not applicable).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between static head and dynamic head?
A: Static head is just the elevation difference, while dynamic head includes all resistances (friction, pressure, velocity head).

Q2: How do I determine friction loss?
A: Use the Darcy-Weisbach equation or Hazen-Williams formula based on pipe material, diameter, length, and flow rate.

Q3: When is pressure head needed?
A: When the discharge is under pressure (like into a pressurized vessel), convert psi to feet (1 psi = 2.31 ft for water).

Q4: Does this include velocity head?
A: This basic calculator doesn't include velocity head (v²/2g), which is often negligible in most systems.

Q5: What safety factor should I add?
A: Engineers typically add 10-20% safety factor to the calculated TDH for pump selection.