Manufacturer, stockist & exporter · Girgaon, Mumbai · ISO 9001:2015 certifiedEN ES PT · +91 99207 55510 · WhatsApp · sales@kanaksteeleng.com
super duplex stainless steel · Flanges · ASTM A182 F53

Super Duplex 2507 FlangesASTM A182 F53 · Manufacturer, stockist & exporter, India

Also sold as UNS S32750 · W.Nr 1.4410 · F53 · SAF 2507

Super Duplex 2507 flanges are forged to ASTM A182 F53 and machined to ASME B16.5 (½"–24", Class 150–2500) or ASME B16.47 for larger sizes. It is a super duplex stainless steel, chosen for seawater and high-chloride service where strength also matters. 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

Price & availability

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What is Super Duplex 2507 Flanges?

Super Duplex 2507 flanges is a super duplex stainless steel supplied as flanges to ASTM A182 F53 (UNS S32750). Buyers specify it for seawater and high-chloride service where strength also matters. It is also sold as UNS S32750, W.Nr 1.4410, F53.

What it is
Super duplex stainless steel
Material
ASTM A182 F53
Dimensions
ASME B16.5 · B16.47 · EN 1092-1
Classes
150 · 300 · 600 · 900 · 1500 · 2500
Facing
RF · FF · RTJ
Best at
Seawater and high-chloride service where strength also matters
Line drawing of Super Duplex 2507 flanges with key dimensionsLine drawing of Super Duplex 2507 flanges with key dimensions ODthickness hub → butt-weld to piperaised facebore = pipe ID
DRG · KS-2507-FLSPEC · ASTM A182 F53COND · ANNEALEDρ · 7.8 g/cm³

Super Duplex 2507 Flanges Specification & Sizes

Material standardASTM A182 F53
Dimensional standardsASME B16.5 (½"–24") · B16.47 Series A / B (26"–60") · B16.36 orifice · B16.48 line blanks · EN 1092-1
Pressure classesClass 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100
FacingRaised face (RF) · flat face (FF) · ring type joint (RTJ) · tongue & groove
BoreTo match the pipe schedule — specify it on the order
TypesWeld 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
TestingPMI · dimensional · UT of forgings · IGC on request
DocumentsEN 10204 3.1 · 3.2 with third-party inspection

Super Duplex 2507 Flange Pressure–Temperature Rating

The class is not a pressure: the allowable pressure for 2507 flanges comes from the ASME B16.5 table for its material group, and falls as temperature rises (how ratings work). ASTM A182 F53 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.

Class 600Class 300Class 150 temperature →bar ↑
P–T RATING · GROUP 2.8schematic, not to scale

Bolting & Gaskets for 2507 Flanges

For Super Duplex 2507 flanges the usual bolting is B7 (coated), B8M or duplex studs, as the project specifies — see Super Duplex 2507 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.

bolt holes on the bolt circle tapered hub → butt weld bore = pipe ID (schedule) RF flange thickness FACINGS Raised face (RF)Flat face (FF)Ring type joint
FLANGE ANATOMYASME B16.5 weld neck · schematic

Super Duplex 2507 Flanges Chemical Composition

Under technical review for TDS.

ElementCurrent requirement
ChromiumAs specified
NickelAs specified
MolybdenumAs specified
NitrogenAs specified
CopperAs specified
CarbonAs specified
ManganeseAs specified
SiliconAs specified
PhosphorusAs specified
SulphurAs specified
IronAs 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 S32750.

Super Duplex 2507 Flanges Mechanical Properties

Under technical review for TDS.

PropertyCurrent requirement
Tensile strengthAs specified
Yield strength 0.2%As specified
ElongationAs specified
HardnessAs 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 S32750 — Solution-annealed plate & sheet.

Density & Physical Properties

PropertyValue
Density7.8 g/cm³
Melting range1350 – 1400 °C
MagneticMagnetic (ferritic phase)
PREN (approx.)≈ 42

Super Duplex 2507 Equivalent Grades

UNSS32750
W.Nr1.4410
ENX2CrNiMoN25-7-4
Forging gradeF53
Trade namesSAF 2507

Super Duplex 2507 flange dimensions — ASME B16.5 Class 150 & 300

Outside dimensions depend only on size and class, not on the alloy, so 2507 flanges bolt to any B16.5 flange of the same size and class. Values in mm; thickness excludes the 1.6 mm raised face.

NPSCl 150 ODCl 150 thicknessCl 150 bolt circleCl 150 boltsCl 300 ODCl 300 thicknessCl 300 bolt circleCl 300 bolts
½"909.660.34 × ½"9512.766.74 × ½"
1"11012.779.44 × ½"12515.988.94 × ⅝"
1½"12515.998.44 × ½"15519.1114.34 × ¾"
2"15017.5120.74 × ⅝"16520.7127.08 × ⅝"
3"19022.3152.44 × ⅝"21027.0168.38 × ¾"
4"23022.3190.58 × ⅝"25530.2200.08 × ¾"
6"28023.9241.38 × ¾"32035.0269.912 × ¾"
8"34527.0298.58 × ¾"38039.7330.212 × ⅞"
10"40528.6362.012 × ⅞"44546.1387.416 × 1"
12"48530.2431.812 × ⅞"52049.3450.816 × 1⅛"

Full chart: ASME B16.5 flange dimensions.

HS code for Super Duplex 2507 flanges: 7307.21
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 Super Duplex 2507 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. Super Duplex 2507 is most often mixed up with Duplex 2205 — 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.

ElementSuper Duplex 2507Duplex 2205
NickelAs specifiedAs specified
ChromiumAs specifiedAs specified
MolybdenumAs specifiedAs specified
CopperAs specified—
IronAs specifiedAs specified
ManganeseAs specifiedAs specified

Super Duplex 2507 Flanges Price — What Decides It

Two quotes for "2507 flanges" can differ by 20% and both be fair. We quote 2507 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.

01 · Metal priceThe alloy price sets the forging cost.
02 · TypeWeld neck and long weld neck flanges carry more metal than slip-on and plate flanges.
03 · Size & classWeight rises steeply with class — a Class 1500 flange weighs several times a Class 150.
04 · Facing & boreRTJ grooves and special bores add machining.
05 · Testing & documentsUT, IGC or a 3.2 certificate add inspection cost.
06 · QuantityBatching sizes together lowers forging cost.

Super Duplex 2507 Flanges Applications

Super Duplex 2507 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.

Super Duplex 2507 Flanges vs 2205, 625 and C276

GradeFlanges standardPREN (approx.)Pick it when
Duplex 2205ASTM A182 F51 / F60≈ 35Strength with chloride resistance at a stainless-steel budget
Super Duplex 2507ASTM A182 F53≈ 42Seawater and high-chloride service where strength also matters
Inconel 625ASTM B564≈ 51Seawater, high strength and high temperature in one alloy
Hastelloy C276ASTM B462 / B564≈ 68The most aggressive mixed acids, wet chlorine and hypochlorite

PREN = Cr + 3.3 Mo + 16 N, from mid-range chemistry. A screening guide, not a substitute for corrosion data on your medium.

Super Duplex 2507 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 2507 fits.

PREN > 40Seawater pitting

High chromium, molybdenum and nitrogen put PREN above 40 — the usual threshold for seawater service.

DuplexVery high strength

Much higher yield strength than 316L.

FerriteChloride SCC

Excellent resistance to chloride stress-corrosion cracking.

LimitTemperature

Keep service below about 250 °C.

How your 2507 flanges order runs

  1. 01Enquiry review — we confirm size, standard edition and documents against your MR or drawing.
  2. 02Heat selection & PMI — the mill certificate is checked against your order; PMI before processing is available on request.
  3. 03Processing — cutting, machining or bevelling to your specification, with heat numbers marked.
  4. 04Inspection — your third-party inspector witnesses, or we share photos and test reports.
  5. 05Packing & dispatch — seaworthy packing from Nhava Sheva (JNPT), Mumbai, FOB or CIF, documents sent before the vessel sails.

Welding & Fabricating Super Duplex 2507 Flanges

Super Duplex 2507 welds by all common arc processes. A few points our buyers ask about:

Matching fillerER2594 (AWS A5.9)
Over-alloyed fillerTight heat-input control and ferrite checks on procedure qualification
PreheatNot required; keep interpass temperature low
CuttingThermal or abrasive cutting; grind off heat-tinted edges before welding

Follow your approved WPS; this is general guidance. See also 2507 fittings and 2507 flanges for the matching pipe-system parts.

How to Order Super Duplex 2507 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
Send this checklist as an RFQ →

Super Duplex 2507 flanges for export

FOB / CIF · Nhava Sheva (JNPT), Mumbai

Super Duplex 2507 flanges — questions buyers ask

Is Super Duplex 2507 the same as UNS S32750?

UNS S32750, W.Nr 1.4410, F53 are names used for Super Duplex 2507 (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 F53 whichever name is on the enquiry.

Which standard covers Super Duplex 2507 flanges?

ASTM A182 F53 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 Super Duplex 2507 Class 300 flange take?

It depends on temperature. ASTM A182 F53 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 Super Duplex 2507 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 Super Duplex 2507 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 Super Duplex 2507 flanges be supplied to NACE MR0175?

Super Duplex 2507 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.

Super Duplex 2507 or Hastelloy C276 — which should I choose?

Super Duplex 2507 is chosen for seawater and high-chloride service where strength also matters. Hastelloy C276 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.

Reviewed by the technical team, Kanak Steel & Engineering Co.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026
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