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Mechanical EngineeringP0

Friction Loss Calculator

Calculate friction head loss in pipes per 100m using Hazen-Williams C-factor for water systems.

Inputs
Enter your values below

New steel: 120, PVC: 150, Old cast iron: 80-100

Result
Friction Head Loss
—
Enter values and click Calculate
Formula
10.67 × flow^1.852 ÷ (c^1.852 × diameter⁴.8704) × length
Result unit: m

Hazen-Williams (SI): hf = 10.67 × Q^1.852 / (C^1.852 × D^4.8704) × L. Q in m³/s, D in m, L in m; result in meters of water head loss.

Introduction

Calculate friction head loss in water pipes using the Hazen-Williams formula, commonly used in water distribution and fire sprinkler system design. C-factors: new steel=120, PVC/HDPE=150, copper=140, old cast iron=80-100.

Calculation Example

50 m³/h through 100mm C=120 steel pipe: ~4m head loss per 100m.

Inputs: flow=50, c=120, diameter=100, length=100
Result: 4.05 m (of water)

Engineering Applications

  • •Water distribution
  • •Fire sprinkler design
  • •Irrigation systems
  • •Plumbing design

Frequently Asked Questions

What C-factor should I use?

New steel pipe: 120; PVC/HDPE: 150; copper: 140; 20-year-old steel: 100; old cast iron: 80. Conservative design uses lower values.

When is Hazen-Williams applicable?

Only for water at 40-75°F (5-25°C) in turbulent flow. Use Darcy-Weisbach for other fluids or higher accuracy.

Related Calculators

Pressure Drop Calculator (Darcy-Weisbach)Darcy-Weisbach Pressure Drop CalculatorHead Loss Calculator

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Disclaimer: Calculations are for reference and educational purposes only. Always verify results independently for engineering design. See full disclaimer.