ASTM A182 F51 Flange UNS S31803 Duplex Steel Weld Neck Flange Forged WNRF Flange
ASTM A182 F51 / UNS S31803 Duplex Steel Weld Neck Flange ASME B16.5 Forged WNRF Flange
ASTM A182 F51 / UNS S31803 Duplex Steel Weld Neck Flange Forged WNRF Flange
| C | Mn | Si | P | S | Cr | Mo | Ni | N | Fe |
|---|---|---|---|---|---|---|---|---|---|
| 0.030 max | 2.00 max | 1.00 max | 0.030 max | 0.020 max | 22.0 – 23.0 | 3.0 – 3.5 | 4.50 – 6.50 | 0.14 – 0.20 | 63.72 min |
ASTM A182 F51 / UNS S31803 Duplex Steel Weld Neck Flange Forged WNRF Flange
| Density (g/cm 3) | Density (lb/in 3) | Melting Point (°C) | Melting Point (°F) |
|---|---|---|---|
| 7.805 | 0.285 | 1420 – 1465 | 2588 – 2669 |
Other Types of Duplex Steel Flange
| Duplex 2205 Flanges | EN TYPE | DIN |
WN – Welding Neck | EN-TYPE 11 | DIN 2631 |
| DIN 2632 | ||
| DIN 2633 | ||
| DIN 2634 | ||
| DIN 2635 | ||
| BL – Blind | EN-TYPE 05 | DIN 2527 |
| SO – Slip On | EN-TYPE 01/12 | |
LJ – Lap Joint | EN-TYPE 02/04 | DIN 2641 |
| DIN 2642 | ||
| DIN 2655 | ||
| DIN 2656 | ||
| LWN – Long Welding Neck / Integral | EN-TYPE 21 | |
| Welding Collars | EN-TYPE 32/34 | |
| Super Duplex 2507 Flat Flange for Welding | DIN 2573 | |
| DIN 2576 | ||
| SW – Socket Weld | EN-TYPE 14 | |
| THR – Threaded | EN-TYPE 13 | DIN 2566 |
| Super Duplex 2507 Lap Joint Short Stub End | DIN 2673 |
Dimensional & Pressure Standards
While the material is controlled by ASTM A182, the dimensions and pressure ratings are controlled by separate piping codes:
ASME B16.5: Covers WN flanges from NPS ½" up to NPS 24" for Classes 150, 300, 600, 900, 1500, and 2500.
ASME B16.47: Covers larger flanges (NPS 26" to 60") in Series A (MSS SP-44) or Series B (API 605).
Bore Schedule: The weld neck flange's inside diameter (bore) must match the pipe's schedule (e.g., Sch 40, Sch 80, Sch 160, or XXS) to ensure a seamless butt-weld connection.
Application
Due to its high strength and exceptional resistance to chloride pitting and stress corrosion cracking, this specific flange is widely used in:
Offshore Oil & Gas: Subsea manifolds, topside piping, and riser systems.
Chemical Processing: Heat exchangers and piping handling acetic, formic, and phosphoric acids.
Pulp & Paper Industry: Digester blow lines and recovery boilers.
Desalination Plants: High-pressure seawater reverse osmosis (SWRO) piping.
FGD (Flue Gas Desulfurization): Systems in coal-fired power plants.
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