Duplex 2205 FlangesASTM A182 F51 · Manufacturer, stockist & exporter, India
Also sold as UNS S32205 / S31803 · W.Nr 1.4462 · F51 / F60 · SAF 2205
Duplex 2205 flanges are forged to ASTM A182 F51 / F60 and machined to ASME B16.5 (½"–24", Class 150–2500) or ASME B16.47 for larger sizes. It is a duplex (austenitic-ferritic) stainless steel, chosen for strength with chloride resistance at a stainless-steel budget. Kanak Steel & Engineering Co. supplies it with EN 10204 3.1 mill certificates from Mumbai to buyers across India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- Stock & mill supply
- EN 10204 3.1 / 3.2
- PMI on request
- NACE MR0175 on request
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is Duplex 2205 Flanges?
Duplex 2205 flanges is a duplex (austenitic-ferritic) stainless steel supplied as flanges to ASTM A182 F51 / F60 (UNS S32205). Buyers specify it for strength with chloride resistance at a stainless-steel budget. It is also sold as UNS S32205 / S31803, W.Nr 1.4462, F51 / F60.
- What it is
- Duplex (austenitic-ferritic) stainless steel
- Material
- ASTM A182 F51 / F60
- Dimensions
- ASME B16.5 · B16.47 · EN 1092-1
- Classes
- 150 · 300 · 600 · 900 · 1500 · 2500
- Facing
- RF · FF · RTJ
- Best at
- Strength with chloride resistance at a stainless-steel budget
Duplex 2205 Flanges Specification & Sizes
| Material standard | ASTM A182 F51 / F60 |
|---|---|
| Dimensional standards | ASME B16.5 (½"–24") · B16.47 Series A / B (26"–60") · B16.36 orifice · B16.48 line blanks · EN 1092-1 |
| Pressure classes | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | Raised face (RF) · flat face (FF) · ring type joint (RTJ) · tongue & groove |
| Bore | To match the pipe schedule — specify it on the order |
| Types | Weld neck flange · Slip-on flange · Blind flange · Socket weld flange · Threaded flange · Lap joint flange · Long weld neck flange · Orifice flange · Spectacle blind · Reducing flange · Ring type joint flange · Expander flange · Anchor flange · Swivel ring flange |
| Testing | PMI · dimensional · UT of forgings · IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
Duplex 2205 Flange Pressure–Temperature Rating
The class is not a pressure: the allowable pressure for 2205 flanges comes from the ASME B16.5 table for its material group, and falls as temperature rises (how ratings work). ASTM A182 F51 / F60 is in material group 2.8.
Take the actual pressures from the B16.5 rating table for group 2.8. A class is not a project pressure rating — your piping class sheet and design conditions govern.
Bolting & Gaskets for 2205 Flanges
For Duplex 2205 flanges the usual bolting is B7 (coated), B8M or duplex studs, as the project specifies — see Duplex 2205 fasteners. Spiral-wound gaskets for this service usually use a winding in the same or a higher alloy, so the gasket does not corrode first. Facing and gasket options are compared in the flange guide.
Duplex 2205 Flanges Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Molybdenum | As specified |
| Nitrogen | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
| Iron | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A240 for UNS S32205.
Duplex 2205 Flanges Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
| Hardness | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A240 for UNS S32205 — Solution-annealed plate & sheet.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.8 g/cm³ |
| Melting range | 1385 – 1445 °C |
| Magnetic | Magnetic (ferritic phase) |
| PREN (approx.) | ≈ 35 |
Duplex 2205 Equivalent Grades
Duplex 2205 flange dimensions — ASME B16.5 Class 150 & 300
Outside dimensions depend only on size and class, not on the alloy, so 2205 flanges bolt to any B16.5 flange of the same size and class. Values in mm; thickness excludes the 1.6 mm raised face.
| NPS | Cl 150 OD | Cl 150 thickness | Cl 150 bolt circle | Cl 150 bolts | Cl 300 OD | Cl 300 thickness | Cl 300 bolt circle | Cl 300 bolts |
|---|---|---|---|---|---|---|---|---|
| ½" | 90 | 9.6 | 60.3 | 4 × ½" | 95 | 12.7 | 66.7 | 4 × ½" |
| 1" | 110 | 12.7 | 79.4 | 4 × ½" | 125 | 15.9 | 88.9 | 4 × ⅝" |
| 1½" | 125 | 15.9 | 98.4 | 4 × ½" | 155 | 19.1 | 114.3 | 4 × ¾" |
| 2" | 150 | 17.5 | 120.7 | 4 × ⅝" | 165 | 20.7 | 127.0 | 8 × ⅝" |
| 3" | 190 | 22.3 | 152.4 | 4 × ⅝" | 210 | 27.0 | 168.3 | 8 × ¾" |
| 4" | 230 | 22.3 | 190.5 | 8 × ⅝" | 255 | 30.2 | 200.0 | 8 × ¾" |
| 6" | 280 | 23.9 | 241.3 | 8 × ¾" | 320 | 35.0 | 269.9 | 12 × ¾" |
| 8" | 345 | 27.0 | 298.5 | 8 × ¾" | 380 | 39.7 | 330.2 | 12 × ⅞" |
| 10" | 405 | 28.6 | 362.0 | 12 × ⅞" | 445 | 46.1 | 387.4 | 16 × 1" |
| 12" | 485 | 30.2 | 431.8 | 12 × ⅞" | 520 | 49.3 | 450.8 | 16 × 1⅛" |
Full chart: ASME B16.5 flange dimensions.
Six-digit Harmonized System heading (iron and steel, chapter 72–73). Your country adds its own digits — confirm with your customs broker. All HS codes.
How to Verify Duplex 2205 Flanges with PMI
Positive material identification with a handheld XRF gun confirms the alloy on the piece itself, in seconds, before it is cut or welded. Duplex 2205 is most often mixed up with Super Duplex 2507 — the table shows which elements tell them apart.
Handheld XRF does not measure carbon or nitrogen, so it cannot confirm the nitrogen that duplex depends on: that comes from the mill certificate or optical emission (OES) testing. PMI can be arranged on request — state it on your enquiry.
Under technical review for TDS.
| Element | Duplex 2205 | Super Duplex 2507 |
|---|---|---|
| Nickel | As specified | As specified |
| Chromium | As specified | As specified |
| Molybdenum | As specified | As specified |
| Copper | — | As specified |
| Iron | As specified | As specified |
| Manganese | As specified | As specified |
Duplex 2205 Flanges Price — What Decides It
Two quotes for "2205 flanges" can differ by 20% and both be fair. We quote 2205 flanges per kg for full sizes and per piece for cut sizes. These six things move the price per kg, so you can compare offers like for like.
Duplex 2205 flanges by type
Duplex 2205 Flanges Applications
Duplex 2205 is specified when the cheaper grade will not survive the service but a higher alloy would be more than the job needs. These are the jobs our buyers use it for.
Duplex 2205 Flanges vs 316L, 904L and 2507
| Grade | Flanges standard | PREN (approx.) | Pick it when |
|---|---|---|---|
| SS 316 / 316L | ASTM A182 F316L | ≈ 24 | Chloride-bearing process fluids, marine air and pharmaceutical service |
| SS 904L | ASTM A182 F904L | ≈ 35 | Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water |
| Duplex 2205 | ASTM A182 F51 / F60 | ≈ 35 | Strength with chloride resistance at a stainless-steel budget |
| Super Duplex 2507 | ASTM A182 F53 | ≈ 42 | Seawater and high-chloride service where strength also matters |
PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.
Duplex 2205 Corrosion Resistance — Element by Element
Each alloying addition has a job. Knowing which one protects against your medium is the quickest way to judge whether 2205 fits.
A roughly 50/50 austenite-ferrite structure gives about twice the yield strength of 316L, so walls can be thinner.
Chromium, molybdenum and nitrogen give a PREN around 35 — well above 316L.
The ferrite phase gives far better resistance to chloride stress-corrosion cracking than austenitic grades.
Keep service below about 300 °C to avoid embrittlement.
How your 2205 flanges order runs
- 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
- 02Heat selection & PMI — the mill certificate is checked against your order; PMI before processing is available on request.
- 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
- 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
- 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.
Standards on this page
Welding & Fabricating Duplex 2205 Flanges
Duplex 2205 welds by all common arc processes. A few points our buyers ask about:
| Matching filler | ER2209 (AWS A5.9) |
|---|---|
| Over-alloyed filler | Control heat input 0.5–2.5 kJ/mm to keep the phase balance |
| Preheat | Not required; keep interpass temperature low |
| Cutting | Thermal or abrasive cutting; grind off heat-tinted edges before welding |
Follow your approved WPS; this is general guidance. See also 2205 fittings and 2205 flanges for the matching pipe-system parts.
How to Order Duplex 2205 Flanges: RFQ Checklist
Get an accurate quote the first time. Copy this list into your enquiry:
- Flange type and dimensional standard (B16.5 / B16.47 / EN 1092-1)
- Size, pressure class and facing
- Bore / schedule for weld neck and socket weld flanges
- Material standard and grade marking
- Certificate type and extra tests
- Delivery port, Incoterm and required date
Duplex 2205 flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiDuplex 2205 flanges — questions buyers ask
Is Duplex 2205 the same as UNS S32205 / S31803?
UNS S32205 / S31803, W.Nr 1.4462, F51 / F60 are names used for Duplex 2205 (W.Nr / EN numbers and older UNS variants are the closest designations; their limits can differ slightly, so specify the UNS number and ASTM grade on the order), and flanges is ordered to ASTM A182 F51 / F60 whichever name is on the enquiry.
Which standard covers Duplex 2205 flanges?
ASTM A182 F51 / F60 is the material specification for the forging; dimensions follow ASME B16.5 for ½"–24" and ASME B16.47 for 26" and above. European projects use EN 1092-1.
What pressure can a Duplex 2205 Class 300 flange take?
It depends on temperature. ASTM A182 F51 / F60 is in ASME B16.5 material group 2.8; read the Class 300 column of that group's table at your design temperature.
Which bolts should I use with Duplex 2205 flanges?
Usually B7 (coated), B8M or duplex studs, as the project specifies. In corrosive or sour service the bolting material is set by the project specification.
Can a Duplex 2205 flange be welded to a different pipe material?
Yes — ER2209 or ER309L(Mo) is used when joining it to carbon steel, under a qualified WPS. Weld neck bores must match the mating pipe schedule.
Can Duplex 2205 flanges be supplied to NACE MR0175?
Duplex 2205 is covered by NACE MR0175 / ISO 15156-3 within the environmental limits, heat-treatment conditions and hardness limits that standard sets for it. State the requirement on the order so that condition and hardness are verified and reported on the certificate.
Duplex 2205 or Super Duplex 2507 — which should I choose?
Duplex 2205 is chosen for strength with chloride resistance at a stainless-steel budget. Super Duplex 2507 is the step up when you need more pitting resistance or strength. See the comparison table on this page, or ask us with your process conditions.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026