Pipe thermal expansion calculator
Free thermal expansion of a straight pipe run: ΔL = α × L × ΔT.
Expansion—
Per 100 m—
In inches—
α values are mean coefficients 20–100 °C; α rises with temperature, so for hot service use ASME B31.3 Table C-1 total expansion values. Restrained pipe develops stress instead — design loops or expansion joints.
Frequently asked questions
How much does steel pipe expand per 100 °C?
Carbon steel expands about 1.2 mm per metre per 100 °C; austenitic stainless about 1.6–1.7 mm.
Why does stainless steel expand more than carbon steel?
Austenitic stainless has a coefficient around 16–17 × 10⁻⁶/°C versus about 12 × 10⁻⁶/°C for carbon steel.
Last updated 2026-11-02