Pipe Thermal Expansion Calculator
Calculate pipe expansion and contraction from temperature changes for expansion loop sizing.
Results
Visualization
How It Works
All pipes expand when heated and contract when cooled. PEX expands 8-10 times more than copper. Expansion must be accommodated with loops, offsets, or expansion joints to prevent stress on fittings.
The Formula
Delta_L = alpha x L x Delta_T
Variables
- Delta_L — Change in length
- alpha — Coefficient of linear expansion (in/in/F)
- L — Original pipe length
- Delta_T — Temperature change in degrees F
Worked Example
100 ft of copper with 100F temperature rise: 0.0000094 x 100 x 100 = 0.094 ft = 1.13 inches of expansion.
Practical Tips
- PEX expands about 8x more than copper — always use expansion loops
- Hot water risers need expansion compensation every 30-50 feet
- Install at mid-temperature when possible to halve expansion range
- Use guides and anchors to direct expansion movement