Duplex & Super Duplex Steel Flanges
Kalp Alloys is a trusted manufacturer, supplier and exporter of Duplex & Super Duplex Steel Flanges, part of our complete range of Flanges. Duplex & Super Duplex offers high mechanical strength with outstanding resistance to chloride pitting and stress-corrosion cracking, making it well suited to demanding industrial service.
Every batch is produced under strict quality control to ASTM, ASME, DIN, EN and BS standards and supplied with full material test certificates (EN 10204 3.1) and third-party inspection on request. We export worldwide with fast lead times and custom sizes on order.
Standards: ASME B16.5, ASME B16.47, DIN, EN 1092-1, BS 4504 · Class 150 – 2500
Specifications
| Product | Duplex & Super Duplex Steel Flanges |
|---|---|
| Category | Flanges |
| Material Grade | Duplex & Super Duplex |
| Standards | Standards: ASME B16.5, ASME B16.47, DIN, EN 1092-1, BS 4504 · Class 150 – 2500 |
| Condition | New, factory finish |
| Test Certificate | EN 10204 3.1 / 3.2 on request |
| Origin | India — exported worldwide |
Types of Duplex & Super Duplex Steel Flanges We Manufacture
We produce the full range of Duplex & Super Duplex Steel flange types to ASME B16.5 and B16.47, in raised face (RF), flat face (FF) and ring-type-joint (RTJ) facings.
Weld Neck Flange (WNRF)
Long tapered hub butt-welded to pipe. Preferred for high-pressure, high-temperature and cyclic service.
Slip On Flange (SORF)
Slides over the pipe and is fillet-welded inside and out. Easy alignment, lower cost, moderate pressure.
Blind Flange (BLRF)
Solid disc used to close off the end of a piping system, valve or vessel opening.
Socket Weld Flange (SWRF)
Pipe inserted into a socket bore, then fillet-welded. Used on small-bore, high-pressure lines.
Threaded / Screwed Flange
Tapered internal thread joins to pipe without welding. Ideal for flammable or explosive areas.
Lap Joint Flange
Used with a stub end so the flange can rotate freely for quick bolt-hole alignment.
Orifice Flange
Fitted with pressure tappings for flow measurement across an orifice plate.
Ring Type Joint (RTJ)
Grooved face with a metal ring gasket for critical high-pressure, high-temperature sealing.
Spectacle Blind Flange
Figure-8 plate that isolates or opens a line by rotating between the two ends.
Reducing Flange
Connects two different pipe sizes without a separate reducer fitting.
Long Weld Neck (LWN)
Extended neck used as a nozzle or barrel connection on vessels and columns.
Plate / Plain Flange
Flat plate flange for low-pressure water, HVAC and general utility service.
Available Duplex & Super Duplex Steel Grades
Chemical Composition (%)
| Grade | C | Cr | Ni | Mo | N | Others |
|---|---|---|---|---|---|---|
| F51 (2205, S31803) | 0.030 max | 21.0–23.0 | 4.5–6.5 | 2.5–3.5 | 0.08–0.20 | — |
| F60 (S32205) | 0.030 max | 22.0–23.0 | 4.5–6.5 | 3.0–3.5 | 0.14–0.20 | — |
| F53 (2507, S32750) | 0.030 max | 24.0–26.0 | 6.0–8.0 | 3.0–5.0 | 0.24–0.32 | — |
| F55 (S32760) | 0.030 max | 24.0–26.0 | 6.0–8.0 | 3.0–4.0 | 0.20–0.30 | Cu, W |
Mechanical Properties
| Grade | Tensile Strength (MPa, min) | Yield Strength (MPa, min) | Elongation (%, min) | Hardness (HB, max) |
|---|---|---|---|---|
| Duplex 2205 | 620 | 450 | 25 | 293 |
| Super Duplex 2507 | 795 | 550 | 15 | 310 |
| S32760 | 750 | 550 | 25 | 270 |
Size, Class & Facing Range
| Size Range | 1/2" (15 NB) to 24" (600 NB); up to 48" (1200 NB) on request |
|---|---|
| Pressure Class | 150#, 300#, 600#, 900#, 1500#, 2500# · PN6, PN10, PN16, PN25, PN40, PN64 |
| Standards | ASME B16.5, ASME B16.47 (Series A & B), B16.48, DIN, EN 1092-1, BS 4504, API 605 |
| Facing | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove, Male & Female |
Testing & Quality Assurance
Material Traceability
Mill Test Certificate as per EN 10204 3.1 / 3.2 with full heat-number traceability.
Non-Destructive Testing
Radiography, ultrasonic flaw detection, magnetic particle and dye penetrant inspection.
Hydrostatic & Dimensional
Hydro pressure testing and dimensional checks to the applicable ASME / EN standard.
Third-Party Inspection
NACE MR0175 available. Inspection by SGS, BV, TUV or Lloyd on request.
Frequently Asked Questions
Duplex 2205 (F51 / S31803, F60 / S32205) and Super Duplex 2507 (F53 / S32750) and S32760 (F55) to ASTM A182 / ASME SA182, for high-strength, chloride-resistant service.
Duplex and super duplex offer roughly double the yield strength of 316L plus far better resistance to chloride stress-corrosion cracking and pitting (higher PREN), ideal for seawater, offshore and chemical service.
ASME B16.5, ASME B16.47 Series A and B, B16.48, DIN, EN 1092-1, BS 4504 and API 605, in Class 150 to 2500 and PN6 to PN64.
Standard sizes from 1/2 inch (15 NB) up to 24 inch (600 NB), with larger diameters up to 48 inch (1200 NB) available on order.
Material Test Certificates per EN 10204 3.1 and 3.2, ferrite content check, corrosion testing (ASTM A923 / G48) and NACE MR0175, plus radiography, ultrasonic, magnetic particle and hydrostatic testing on request.
Yes. We regularly export to the UAE, Dubai, Abu Dhabi and the wider GCC along with 100+ countries, with correct export documentation and on-time delivery.
