Description
Table Of Content
Stainless Steel Flange
Duplex 2205 Stainless Steel Flanges are precision-engineered flanges made from a duplex stainless steel alloy consisting of approximately 22% chromium, 5% nickel, and 3% molybdenum. This unique composition provides outstanding resistance to pitting, crevice corrosion, and chloride-induced stress corrosion cracking. Compared to standard austenitic stainless steels like 316L, Duplex 2205 offers roughly twice the yield strength, allowing for lighter designs without compromising performance.
These flanges are available in various types such as weld neck, slip-on, blind, socket weld, lap joint, and threaded configurations to meet different piping system requirements. They are commonly used in offshore oil and gas platforms, chemical and petrochemical plants, desalination facilities, pressure vessels, and marine environments where both high mechanical strength and corrosion resistance are critical.

Specifications of Duplex 2205 Flanges
| Specifications | ASTM A182 / ASME SA182 |
|---|---|
| Class | 150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc. |
| Size | 1/2″ (15 NB) to 48″ (1200NB) |
| Standards | ANSI/ASME B16.5, B16.48, BS4504, B 16.47 Series A & B, BS 10, EN-1092, DIN, etc. |
Size Range of Duplex Steel 2205 Pipe Flange
| Nominal Pipe Size | Outside Diameter of Flange | Thickness of Flange | Diameter of Raised Face | Diameter of Hub at Base | Length Thru Hub | Diameter or Bore | Diameter of Hub at Bevel | Radius of Fillet | Depth of Socket | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Welding Neck | Slip-On Threaded Socket | Lap Joint | Slip-on Socket | Lap Joint | ||||||||
| O | Q | R | X | Y | Y | Y | W | B | H | r | Z | |
| 1/2 | 3-1/2 | 7/16 | 1-3/8 | 1-3/16 | 1-7/8 | 5/8 | 5/8 | .88 | .90 | .84 | 1/8 | 3/8 |
| 3/4 | 3-7/8 | 1/2 | 1-11/16 | 1-1/2 | 2-1/16 | 5/8 | 5/8 | 1.09 | 1.11 | 1.05 | 1/8 | 7/16 |
| 1 | 4-1/4 | 9/16 | 2 | 1-15/16 | 2-3/16 | 11/16 | 11/16 | 1.36 | 1.38 | 1.32 | 1/8 | 1/2 |
| 1-1/4 | 4-5/8 | 5/8 | 2-1/2 | 2-5/16 | 2-1/4 | 13/16 | 13/16 | 1.70 | 1.72 | 1.66 | 3/16 | 9/16 |
| 1-1/2 | 5 | 11/16 | 2-7/8 | 2-9/16 | 2-7/16 | 7/8 | 7/8 | 1.95 | 1.97 | 1.90 | 1/4 | 5/8 |
| 2 | 6 | 3/4 | 3-5/8 | 3-1/16 | 2-1/2 | 1 | 1 | 2.44 | 2.46 | 2.38 | 5/16 | 11/16 |
| 2-1/2 | 7 | 7/8 | 4-1/8 | 3-9/16 | 2-3/4 | 1-1/8 | 1-1/8 | 2.94 | 2.97 | 2.88 | 5/16 | 3/4 |
| 3 | 7-1/2 | 15/16 | 5 | 4-1/4 | 2-3/4 | 1-3/16 | 1-3/16 | 3.57 | 3.60 | 3.50 | 3/8 | 13/16 |
| 3-1/2 | 8-1/2 | 15/16 | 5-1/2 | 4-13/16 | 2-13/16 | 1-1/4 | 1-1/4 | 4.07 | 4.10 | 4.00 | 3/8 | 7/8 |
| 4 | 9 | 15/16 | 6-3/16 | 5-5/16 | 3 | 1-5/16 | 1-5/16 | 4.57 | 4.60 | 4.50 | 7/16 | 15/16 |
| 5 | 10 | 15/16 | 7.5/16 | 6-7/16 | 3-1/2 | 1-7/16 | 1-7/16 | 5.66 | 5.69 | 5.56 | 7/16 | 15/16 |
| 6 | 11 | 1 | 8-1/2 | 7-9/16 | 3-1/2 | 1-9/16 | 1-9/16 | 6.72 | 6.75 | 6.63 | 1/2 | 1-1/16 |
| 8 | 13-1/2 | 1-1/8 | 10-5/8 | 9-11/16 | 4 | 1-3/4 | 1-3/4 | 8.72 | 8.75 | 8.63 | 1/2 | 1-1/4 |
| 10 | 16 | 1-3/16 | 12-3/4 | 12 | 4 | 1-15/16 | 1-15/16 | 10.88 | 10.92 | 10.75 | 1/2 | 1-5/16 |
| 12 | 19 | 1-1/4 | 15 | 14-3/8 | 4-1/2 | 2-3/16 | 2-3/16 | 12.88 | 12.92 | 12.75 | 1/2 | 1-9/16 |
| 14 | 21 | 1-3/8 | 16-1/4 | 15-3/4 | 5 | 2-1/4 | 3-1/8 | 14.14 | 14.18 | 14.00 | 1/2 | 1-5/8 |
| 16 | 23-1/2 | 1-7/16 | 18-1/2 | 18 | 5 | 2-1/2 | 3-7/16 | 16.16 | 16.19 | 16.00 | 1/2 | 1-3/4 |
| 18 | 25 | 1-9/16 | 21 | 19-7/8 | 5-1/2 | 2-11/16 | 3-13/16 | 18.18 | 18.20 | 18.00 | 1/2 | 1-15/16 |
| 20 | 27-1/2 | 1-11/16 | 23 | 22 | 5-11/16 | 2-7/8 | 4-1/16 | 20.20 | 20.25 | 20.00 | 1/2 | 2-1/8 |
| 24 | 32 | 1-7/8 | 27-1/4 | 26-1/8 | 6 | 3-1/4 | 4-3/8 | 24.25 | 24.25 | 24.00 | 1/2 | 2-1/2 |
Chemical Composition of Duplex S32205 Flanges
| S31803 / S32205 | C | N | P | Si | Mn | Mo | Fe | Cr | S | Ni |
| 1.0 | 0.03 | 0.02 | 2.0 | 3.0 – 3.5 | 22.0 – 23.0 | 0.03 | 4.5 – 6.5 | 0.14 – 0.2 | Bal |
Mechanical & Physical Characteristics of Duplex SS 2205 Flange
| S31803 / S32205 | Density | Melting Point | Yield Strength (0.2%Offset) | Tensile Strength | Elongation |
| 7.8 g/cm3 | 1350 °C (2460 °F) | Psi – 80000 , MPa – 550 | Psi – 116000 , MPa – 800 | 15 % |
Types of Duplex Stainless Steel 2205 Pipe Flange
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| Blind Flanges | Lap Joint Flanges | Long Weld Neck Flanges | Plate Flanges |
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| Reducing Flanges | Ring Type Joint Flanges | Slip On Flanges | Socket Weld Flanges |
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| Weld Neck Flanges | Tongue & Groove Flanges | Threaded / Screwed Flanges | Spectacle Blind Flanges |
Duplex Steel 1.4462 Flanges Equivalent Grades and Standards
| STANDARD | UNS | WERKSTOFF NR. |
| Duplex S31803 | S31803 | 1.4462 |
| Duplex S32205 | S32205 | 1.4462 |
Dimensions of Duplex F51 Flanges
| Nominal Size | Outside Diameter (OD) | Min. Thickness (T) | RF Dia. (R) | No. of Bolt Holes | Diameter of Holes | Bolt Circle (BC) | SO Bore ID (SB) | WN Bore ID (WB) | Dia. Hub Base (HB) | Dia. of Hub Top (HT) | SO LTH (SL) | WN LTH (WL) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1⁄2 | 3.50 | 0.38 | 1.38 | 4 | 0.62 | 2.38 | 0.88 | 0.62 | 1.19 | 0.84 | 0.56 | 1.81 |
| 3⁄4 | 3.88 | 0.44 | 1.69 | 4 | 0.62 | 2.75 | 1.09 | 0.82 | 1.50 | 1.05 | 0.56 | 2.00 |
| 1 | 4.25 | 0.50 | 2.00 | 4 | 0.62 | 3.12 | 1.36 | 1.05 | 1.94 | 1.32 | 0.62 | 2.12 |
| 11⁄4 | 4.62 | 0.56 | 2.50 | 4 | 0.62 | 3.50 | 1.70 | 1.38 | 2.31 | 1.66 | 0.75 | 2.19 |
| 11⁄2 | 5.00 | 0.62 | 2.88 | 4 | 0.62 | 3.88 | 1.95 | 1.61 | 2.56 | 1.90 | 0.81 | 2.38 |
| 2 | 6.00 | 0.69 | 3.62 | 4 | 0.75 | 4.75 | 2.44 | 2.07 | 3.06 | 2.38 | 0.94 | 2.44 |
| 21⁄2 | 7.00 | 0.81 | 4.12 | 4 | 0.75 | 5.50 | 2.94 | 2.47 | 3.56 | 2.88 | 1.06 | 2.69 |
| 3 | 7.50 | 0.88 | 5.00 | 4 | 0.75 | 6.00 | 3.57 | 3.07 | 4.25 | 3.50 | 1.12 | 2.69 |
| 31⁄2 | 8.50 | 0.88 | 5.50 | 8 | 0.75 | 7.00 | 4.07 | 3.55 | 4.81 | 4.00 | 1.19 | 2.75 |
| 4 | 9.00 | 0.88 | 6.19 | 8 | 0.75 | 7.50 | 4.57 | 4.03 | 5.31 | 4.50 | 1.25 | 2.94 |
| 5 | 10.00 | 0.88 | 7.31 | 8 | 0.88 | 8.50 | 5.66 | 5.05 | 6.44 | 5.56 | 1.38 | 3.44 |
| 6 | 11.00 | 0.94 | 8.50 | 8 | 0.88 | 9.50 | 6.72 | 6.07 | 7.56 | 6.63 | 1.50 | 3.44 |
| 8 | 13.50 | 1.06 | 10.62 | 8 | 0.88 | 11.75 | 8.72 | 7.98 | 9.69 | 8.63 | 1.69 | 3.94 |
| 10 | 16.00 | 1.12 | 12.75 | 12 | 1.00 | 14.25 | 10.88 | 10.02 | 12.00 | 10.75 | 1.88 | 3.94 |
| 12 | 19.00 | 1.19 | 15.00 | 12 | 1.00 | 17.00 | 12.88 | 12.00 | 14.38 | 12.75 | 2.12 | 4.44 |
| 14 | 21.00 | 1.31 | 16.25 | 12 | 1.12 | 18.75 | 14.14 | 13.25 | 15.75 | 14.00 | 2.19 | 4.94 |
| 16 | 23.50 | 1.38 | 18.50 | 16 | 1.12 | 21.25 | 16.16 | 15.25 | 18.00 | 16.00 | 2.44 | 4.94 |
| 18 | 25.00 | 1.50 | 21.00 | 16 | 1.25 | 22.75 | 18.18 | 17.25 | 19.88 | 18.00 | 2.62 | 5.44 |
| 20 | 27.50 | 1.62 | 23.00 | 20 | 1.25 | 25.00 | 20.20 | 19.25 | 22.00 | 20.00 | 2.81 | 5.62 |
| 22 | 29.50 | 1.75 | 25.25 | 20 | 1.38 | 27.25 | 22.22 | 21.25 | 24.25 | 22.00 | 3.07 | 5.82 |
| 24 | 32.00 | 1.81 | 27.25 | 20 | 1.38 | 29.50 | 24.25 | 23.25 | 26.12 | 24.00 | 3.19 | 5.94 |
Duplex Stainless Steel Flange Pressure Rating
| Temp. ℃ | Pressure-temperature rating for ASME B16.47 by class, bar | |||||
| 75 | 150 | 300 | 400 | 600 | 900 | |
| -29 to 38 | 10.0 | 20.0 | 51.7 | 68.9 | 103.4 | 155.1 |
| 50 | 9.8 | 19.5 | 51.7 | 68.9 | 103.4 | 155.1 |
| 100 | 8.8 | 17.7 | 50.7 | 67.5 | 101.3 | 152.0 |
| 150 | 7.9 | 15.8 | 45.9 | 61.2 | 91.9 | 137.8 |
| 200 | 6.9 | 13.8 | 42.7 | 56.9 | 85.3 | 128.0 |
| 250 | 6.0 | 12.1 | 40.5 | 53.9 | 80.9 | 121.4 |
| 300 | 5.1 | 10.2 | 38.9 | 51.8 | 77.7 | 116.6 |
| Temp, ℃ | Pressure-temperature rating for ASME B16.5 by class, bar | ||||||
| 150 | 300 | 400 | 600 | 900 | 1500 | 2500 | |
| -29 to 38 | 20.0 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 50 | 19.5 | 51.7 | 68.9 | 103.4 | 155.1 | 258.6 | 430.9 |
| 100 | 17.7 | 50.7 | 67.5 | 101.3 | 152.0 | 253.3 | 422.2 |
| 150 | 15.8 | 45.9 | 61.2 | 91.9 | 137.8 | 229.6 | 382.7 |
| 200 | 13.8 | 42.7 | 56.9 | 85.3 | 128.0 | 213.3 | 355.4 |
| 250 | 12.1 | 40.5 | 53.9 | 80.9 | 121.4 | 202.3 | 337.2 |
| 300 | 10.2 | 38.9 | 51.8 | 77.7 | 116.6 | 194.3 | 323.8 |
Dimensions Tolerance of Duplex Ss Flanges
| Outside Diameter ≤ 24 = 1.6 mm | > 24 = ± 3.2 mm | Inside Diameter not applicable |
| Diameter of Contact Face 1.6 mm Raised Face = ± 0.8 mm 6.35 mm Raised Face, Tongue & Groove / Male-Female = ± 0.4 mm | Outside Diameter of Hub ≤ 12 = + 2.4 mm / – 1.6 mm | ≥ 14 = ± 3.2 mm |
| Diameter of Counterbore not applicable | Drilling Bolt Circle = 1.6 mm | Bolt Hole Spacing = ± 0.8 mm Eccentricity of Bolt Circle with Respect to Facing ≤ 2½ = 0.8 mm max. | ≥ 3 = 1.6 mm max. |
| Thickness ≤ 18 = + 3.2 mm / – 0 | ≥ 20 = + 4.8 mm / – 0 | Length thru Hub ≤ 18 = + 3.2 mm / – 0.8 mm | ≥ 20 = + 4.8 mm / – 1.6 mm |
Weight Chart for Duplex 2205 Flanges
Note: The actual weight may vary slightly depending on exact dimensions, flange thickness, neck length, and manufacturing tolerances.
| Standard | Class | Diameter | Bolt Circle Diameter | Number of Bolts | Bolt Size | Diameter of Bolt Hole |
|---|---|---|---|---|---|---|
| AS4087 | PN14 | 95 | 67 | 4 | M12 | 14 |
| AS 2129 | Table C | 95 | 67 | 4 | 13 | 14 |
| Table D | 95 | 67 | 4 | 13 | 14 | |
| Table E | 95 | 67 | 4 | 13 | 14 | |
| Table F | 95 | 67 | 4 | 13 | 14 | |
| Table H | 114 | 83 | 4 | 16 | 17 | |
| Table J | 114 | 83 | 4 | 16 | 17 | |
| ANSI B16.5 | ANSI 150 | 89 | 60 | 4 | 13 | 16 |
| ANSI 300 | 95 | 67 | 4 | 13 | 16 | |
| ANSI 600 | 95 | 67 | 4 | 13 | 16 | |
| ANSI 900 | 121 | 83 | 4 | 19 | 22 | |
| ANSI 1500 | 121 | 83 | 4 | 19 | 22 | |
| ISO 7005 (DIN) | PN6 | 80 | 55 | 4 | M10 | 11 |
| PN10 | 95 | 65 | 4 | M12 | 14 | |
| PN16 | 95 | 65 | 4 | M12 | 14 | |
| PN20 | 90 | 60.5 | 4 | M14 | 16 | |
| PN25 | 95 | 65 | 4 | M12 | 14 | |
| PN40 | 95 | 65 | 4 | M12 | 14 |
Possible Alternative Grades in Place of 2205 SS Duplex Flange
904L | Better formability is needed, with similar corrosion resistance and lower strength. |
UR52N+ | High resistance to corrosion is required, e.g. resistance to higher temperature seawater. |
6%Mo | Higher corrosion resistance is required, but with lower strength and better formability. |
316L | The high corrosion resistance and strength of 2205 are not needed. 316L is lower cost. |
Heat Resistance of 2205 Duplex Flanges
| Heat Resistance | 300°C |


























