Heat Exchanger Tube Material Selection Guide
Heat exchanger tubes operate under demanding conditions — high temperatures, corrosive fluids, mechanical vibration, and thermal cycling. This guide helps you select the right tube material for your shell-and-tube heat exchanger application.
Tube Material Selection Matrix
| Material | Tube Side Service | Shell Side | Temp Limit | Key Reason |
|---|---|---|---|---|
| 304L (S30403) | Cooling water (fresh) | Hydrocarbon process | 400°C | Most economical for non-corrosive service |
| 316L (S31603) | Cooling water (brackish/seawater) | Hydrocarbon/steam | 400°C | Mo for chloride pitting resistance |
| 321H (S32109) | High-temp process (>500°C) | Hydrocarbon/steam | 900°C | Ti-stabilized, excellent creep strength |
| Alloy 825 (N08825) | Sulfuric acid (<40%) | Process fluid/steam | 540°C | Cu enhances H₂SO₄ resistance |
| Inconel 625 (N06625) | Mixed acid / high chloride | Steam or process | 980°C | PREN > 45, universal acid+Cl resistance |
| Duplex 2205 (S32205) | Chloride SCC or weight-critical | Various (refinery, offshore) | 300°C | Double 316L yield, Cl-SCC immune |
| Super Duplex 2507 (S32750) | Seawater, hot brine | Steam / hot process | 300°C | Seawater + high pressure strength |
Key Tube Selection Guidelines
- Start with 304L: If fluid is freshwater or non-corrosive hydrocarbon at < 400°C, 304L is almost always sufficient.
- Upgrade to 316L: When chlorides are present OR operating temperature exceeds 400°C.
- Consider Duplex: When Cl > 1,000 ppm AND weight OR Cl-SCC is a concern. 2205 doubles yield strength vs 316L.
- Go Nickel Alloy: When acids (H₂SO₄, HCl, HF) are present at elevated temperatures.