1. What is Total Dynamic Head (TDH)?

Total Dynamic Head (TDH) is the total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe. It's a crucial parameter for selecting the right submersible pump for your application.

2. How Does the Calculator Work?

The calculator uses the fundamental TDH equation:

Where:

• \( Static\ Head \) — The vertical distance from the water surface to the discharge point (ft)
• \( Friction\ Loss \) — Pressure loss due to friction in pipes, fittings, and valves (ft)

Explanation: The equation combines the static lift requirement with the system's friction losses to determine the total head the pump must overcome.

3. Importance of TDH Calculation

Details: Accurate TDH calculation is essential for proper pump selection. An undersized pump won't deliver required flow, while an oversized pump wastes energy and may operate inefficiently.

4. Using the Calculator

Tips:

• Measure static head as the vertical distance from water surface to discharge point
• Calculate friction loss using pipe size, length, flow rate, and material
• Add safety factor (typically 10-20%) to account for system aging and uncertainties

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between static head and TDH?
A: Static head is just the vertical lift, while TDH includes both static head and friction losses in the system.

Q2: How do I calculate friction loss?
A: Use the Hazen-Williams equation or consult friction loss tables based on pipe diameter, material, and flow rate.

Q3: Why is TDH important for pump selection?
A: Pump performance curves show flow rate at various TDH values. Your system's TDH must intersect with the pump curve at your desired flow rate.

Q4: Does pipe diameter affect TDH?
A: Yes, larger diameters reduce friction loss, thereby lowering TDH requirements for the same flow rate.

Q5: Should I include pressure requirements in TDH?
A: Yes, if your system requires pressure at the discharge point (like for sprinklers), convert psi to feet of head (1 psi = 2.31 ft) and add to TDH.