Duplex & Super Duplex Steel Flanges
Duplex stainless steels have a "duplex" microstructure consisting of both austenite and ferrite. This results in a material that provides the best of both worlds: the corrosion resistance of 300-series stainless steel and the high yield strength of carbon steel.
Grades and Performance
- Standard Duplex: ASTM A182 F51 / S31803 (2205).
- Super Duplex: ASTM A182 F53 / S32750 and F55 / S32760.
- Key Benefit: Extremely high resistance to Pitting and Crevice Corrosion in chloride-rich environments (seawater).
- Applications: Desalination plants, offshore platforms, chemical tankers, and subsea piping.
Dimensional chart — ASME B16.5 (Duplex)
Because of the high strength of Duplex steel, these flanges often allow for reduced wall thickness in piping systems without compromising safety.
| NPS | Class | Outside Diameter | Thickness (t) | Raised Face | Bolt Circle | Holes |
|---|---|---|---|---|---|---|
| 1" | 150 | 110 mm | 14.3 mm | 50.8 mm | 79.4 mm | 4 |
| 2" | 300 | 165 mm | 22.4 mm | 92.1 mm | 127.0 mm | 8 |
| 4" | 600 | 275 mm | 38.1 mm | 157.2 mm | 215.9 mm | 8 |
| 6" | 1500 | 395 mm | 82.6 mm | 215.9 mm | 317.5 mm | 12 |
PREN Value: Our Super Duplex flanges (F53/F55) are guaranteed to have a Pitting Resistance Equivalent Number (PREN) > 40, ensuring maximum longevity in marine spray zones.