How European buyers decide between stainless steel 316L and duplex 2205/2507 for EN 1092-1 flanges.
📘 What you’ll learn:
- ✅ Why 316L stainless is standard but not always sufficient
- ⚡ When EU projects specify duplex 2205 or super duplex 2507
- 📊 Side-by-side comparison: corrosion, strength, lifecycle cost
- 📝 How to specify EN 10204 certificates for duplex flanges
In Europe, 316L stainless steel is the most common material for EN 1092-1 flanges. It offers corrosion resistance and cleanability, making it ideal for pharma, food, and water systems. But in more aggressive conditions, 316L reaches its limit. That’s where duplex steels (2205, 2507) come in.
Stainless vs Duplex — Property Comparison
| Property | 316L Stainless | Duplex 2205 | Super Duplex 2507 |
|---|---|---|---|
| Yield Strength | ~220 MPa | ~450 MPa | ~550 MPa |
| Pitting Resistance (PREN) | 24 | 35 | 40+ |
| Chloride SCC Resistance | Moderate | High | Excellent |
| Cost (Relative) | 1.0x | 1.4x | 1.8x |
| Common EU Applications | Food, pharma, clean water | Desalination, chemical, offshore | Oil & gas, subsea, nuclear |
When EU Buyers Should Upgrade to Duplex
- ✔ Chloride-rich environments (seawater, desalination)
- ✔ Offshore platforms or subsea lines
- ✔ Chemical plants with aggressive media
- ✔ Projects needing higher pressure with smaller flange size (saves weight)
Need duplex or super duplex EN 1092-1 flanges with EN 10204 3.2 certification?
Request Your DDP Quote →Checklist for Buyers
- PN rating (PN16, PN40, PN63)
- Flange type (weld neck, slip-on, blind)
- Material grade (316L, 2205, 2507)
- Certificate: EN 10204 3.1 or 3.2
Conclusion
316L stainless steel works well in most EU applications, but duplex flanges offer higher strength and superior corrosion resistance when conditions demand more. The key is knowing when to upgrade — and making sure your PO specifies the right grade, PN, and certificate.
See our Europe flange page or request a duplex flange quote today.
