Heat Loss Steam Pipes

Overview

Engineering reference data for Heat Loss Steam Pipes in heat transfer.

Key Formulas

Fourier's Law

$q = -k \nabla T$

Heat flux proportional to temperature gradient.

Convective Heat Transfer

$Q = hA(T_s - T_\infty)$

Heat transfer between surface and fluid.

Stefan-Boltzmann Law

$q = \varepsilon \sigma T^4$

Radiative heat flux from a surface.

Thermal Resistance

$R_{th} = \frac{L}{kA}$

Resistance to heat conduction.

Variables

Symbol	Description	Unit
$q$	Heat flux	W/m²
$k$	Thermal conductivity	W/(m·K)
$h$	Convection coefficient	W/(m²·K)
$T$	Temperature	K
$\varepsilon$	Emissivity	—
$\sigma$	Stefan-Boltzmann constant	5.67×10⁻⁸ W/(m²·K⁴)

Heat Loss Data for Bare Uninsulated Steam Pipes

The following data applies to horizontal bare uninsulated steam pipes in still air conditions with surrounding air temperatures ranging from 50°F to 70°F.

Unit Conversion

To convert from Imperial to SI units:

$1 \text{ Btu/h·ft} = 0.96 \text{ W/m}$

Notes on Heat Loss Factors

The heat loss from steam pipes depends on several factors:

• Pipe size — Larger diameter pipes have greater surface area and higher total heat loss
• Insulation quality — Bare pipes lose significantly more heat than insulated pipes
• Steam temperature/pressure — Higher temperature steam has greater temperature differential to surroundings
• Ambient temperature — Greater temperature difference (ΔT) between steam and surrounding air increases heat loss rate
• Air conditions — Still air vs. moving air affects convective heat transfer coefficients

Interactive Charts

References

• Original Source