Free Engineering Tool

Pipe Thermal Expansion & Flexibility Calculator

Calculate thermal expansion, required expansion loop dimensions, and thermal stress for piping systems per EN 13480 / ASME B31.3.

EN 13480 ASME B31.3 Expansion Loop

Pipe Run Length (m)

Material

Temperature Change ΔT (°C)

Pipe OD (mm)

Wall Thickness (mm)

Allowable Stress (MPa)

Quick presets

Results

Total Thermal Expansion

—

Required Loop Length (L_loop)

—

Loop Width (perpendicular)

—

Unrestrained Thermal Stress

—

Stress Check

—

Thermal Expansion

The total thermal expansion of a pipe run is:

α — coefficient of thermal expansion (µm/m/°C)
L — pipe length (m)
ΔT — temperature change (°C)

Expansion Loop Sizing

The required expansion loop leg length to absorb the expansion without exceeding allowable stress:

D — pipe outside diameter (mm)
Δ — thermal expansion to be absorbed (mm)
S_a — allowable stress range (MPa)

Guided Cantilever Method

The unrestrained thermal stress if the pipe is rigidly fixed at both ends:

CTE Reference Table

Material	α (µm/m/°C)	E (GPa)
Carbon Steel	12.0	200
SS 304	17.3	193
SS 316	16.0	193
Copper	16.5	117
Inconel 625	12.8	207
Titanium Gr.2	8.6	105

Example — 6″ Carbon Steel at 180°C

Given: L = 30 m, CS (α = 12.0), ΔT = 180°C, OD = 168.3 mm, S_a = 138 MPa

Δ = 12.0 × 30 × 180 / 1000 = 64.8 mm

L_loop = √(3 × 168.3 × 64.8 / 138) = √(236.1) = 4.85 m

⚠️ Note: This is a simplified guided cantilever calculation. Actual piping flexibility analysis requires considering branch connections, multiple directional changes, support locations, and should be performed with pipe stress analysis software for critical systems.

Pipe Thermal Expansion & Flexibility Calculator | EN 13480 | Free Online Tool

Published by Nikolai Shelkovenko on February 15, 2026 February 15, 2026

Results

Thermal Expansion

Expansion Loop Sizing

Guided Cantilever Method

CTE Reference Table