Water Flow Firefighting

Overview

Engineering reference data for Water Flow Firefighting in material science and properties.

Key Formulas

Stress

$\sigma = \frac{F}{A}$

Force per unit area.

Strain

$\varepsilon = \frac{\Delta L}{L_0}$

Change in length per original length.

Hooke's Law

$\sigma = E \varepsilon$

Stress proportional to strain in elastic region.

Thermal Expansion

$\Delta L = \alpha L_0 \Delta T$

Length change due to temperature.

Variables

Symbol	Description	Unit
$\sigma$	Stress	Pa
$\varepsilon$	Strain	—
$E$	Young's modulus	Pa
$\alpha$	Thermal expansion coefficient	1/°C
$\Delta T$	Temperature change	°C

Additional Firefighting Water Demand Formula

A common formula for estimating the required water flow rate for firefighting based on population is:

$Q = 1020 \cdot n^{1/2} \left(1 - 0.01 \cdot n^{1/2}\right)$

Where:

• $Q$ = required water flow rate for firefighting (gpm)
• $n$ = population of the area (in thousands of people)

Unit Conversion

For reference, the following conversion factor is useful:

• $1 \text{ U.S. gal/min (gpm)} = 0.227 \text{ m}^3/\text{h}$

References

• Original Source