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Pump Calculator

Pump Calculator

Free Online Tool to Calculate Pipe Friction Loss and TDH

Calculate your head loss and friction loss easily with our online tool. This pump system calculator helps you determine the total dynamic head (TDH) based on pipe length, diameter, flow rate, and material. Ideal for sizing pumps for irrigation, drainage, and industrial systems. Provided by Hung Pump Group Taiwan — your trusted partner in water pump solutions.

How to Use the Pipe Head Loss Calculator

Overview

This calculator determines the head loss (friction loss) in a pipe using the Hazen-Williams equation. It helps engineers and technicians calculate pressure drops in piping systems, which is essential for proper pump selection and system design.

Step-by-Step Instructions

Step 1: Enter Pipe & Flow Parameters

Flow Rate

  • Enter the flow rate of water through the pipe
  • Use the dropdown to select your preferred unit:
    • m³/s (cubic meters per second)
    • L/s (liters per second)
    • GPM (gallons per minute)
    • L/min (liters per minute)
  • Example: For a typical residential water supply, you might enter 5 L/s

Pipe Diameter

  • Enter the internal diameter of the pipe
  • Select the unit from the dropdown:
    • mm (millimeters)
    • inches
    • cm (centimeters)
  • Important: Use the internal diameter, not the external diameter
  • Example: For a 2-inch pipe, enter 50.8 mm or 2 inches

Pipe Length

  • Enter the total length of the pipe run
  • Select the unit:
    • meters
    • feet
  • Note: Include the total horizontal and vertical distances
  • Example: For a 100-meter pipeline, enter 100

Pipe Material

  • Select the material from the dropdown menu
  • Each material has a different Hazen-Williams C-factor:
    • New Steel/Iron (C=150) - For new, smooth steel pipes
    • Old Steel/Iron (C=100) - For older, corroded steel pipes
    • Concrete (C=130) - For concrete pipes
    • PVC (C=150) - For plastic pipes
    • Copper (C=140) - For copper pipes
  • Tip: The C-factor affects friction - higher values mean smoother pipes with less friction

Step 2: Optional Fittings (Advanced)

Add the quantity of fittings in your piping system. Each fitting adds equivalent length to your pipe, increasing head loss:

Common Fittings:

  • 90° Elbows: Standard right-angle turns
  • 45° Elbows: Gentler angle turns (less head loss)
  • Tee (Through): Straight flow through a tee junction
  • Tee (Branch): Flow turning 90° at a tee junction
  • Gate Valves: Fully open gate valves
  • Globe Valves: Globe-style valves (higher head loss)
  • Check Valves: One-way flow valves

How to Use:

  1. Count each type of fitting in your system
  2. Enter the quantity for each fitting type
  3. Leave at "0" for fittings not present in your system
  4. The calculator automatically converts fittings to equivalent pipe length

Step 3: Calculate Results

  1. Click the "Calculate Head Loss" button
  2. Review the results in the green results section:

Results Explanation:

Flow Velocity (v):

  • Shows the speed of water through the pipe
  • Measured in m/s (meters per second)
  • Recommended range: 0.5 - 3.0 m/s for most applications
  • Too high: May cause noise, erosion, or water hammer
  • Too low: May allow sediment buildup

Head Loss (hf):

  • The pressure loss due to friction in the pipe
  • Measured in meters of water column
  • This is the key result for pump selection
  • Use this value to calculate Total Dynamic Head (TDH)

Equivalent Length from Fittings:

  • Additional pipe length equivalent caused by fittings
  • Shows how much extra "pipe length" your fittings add
  • Helps understand the impact of fittings on system pressure loss

Practical Applications

For Pump Selection:

  1. Calculate head loss for your piping system
  2. Add static head (elevation difference)
  3. Add pressure head requirements
  4. Total = Total Dynamic Head (TDH) for pump selection

For System Design:

  1. Compare different pipe diameters
  2. Evaluate the impact of fittings
  3. Optimize pipe routing to minimize head loss
  4. Ensure adequate pump capacity

For Troubleshooting:

  1. Verify calculated vs. actual system performance
  2. Identify high-loss sections in existing systems
  3. Evaluate upgrade options (larger pipes, smoother materials)

Tips for Accurate Calculations

  1. Use actual internal pipe dimensions - Don't use nominal sizes
  2. Account for all fittings - Even small fittings add up
  3. Consider pipe age and condition - Older pipes have higher friction
  4. Check flow velocity - Ensure it's within recommended ranges
  5. Add safety factor - Consider 10-20% extra capacity for pump sizing

Common Mistakes to Avoid

  • Using external instead of internal pipe diameter
  • Forgetting to include minor fittings
  • Not accounting for pipe roughness over time
  • Using wrong units (always double-check unit selections)
  • Ignoring elevation changes in the system

Need Help?

If you need assistance with:

  • Pump selection based on your calculations
  • System design optimization
  • Custom pump solutions
  • Technical specifications

Contact Hung Pump's engineering team for expert consultation on your specific application.

This calculator is provided by Hung Pump, Taiwan's leading water pump manufacturer with 35+ years of OEM experience. For professional pump solutions, visit our product catalog or contact our technical support team.