Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Super Duplex 2507 Flanges, UNS S32750 ASTM A182 F53
From TorqBolt (Mumbai, India): Super Duplex 2507 flanges in UNS S32750 (EN 1.4410) cover the weld-neck, slip-on, blind, socket-weld, threaded, lap-joint and reducing flange types used on super duplex piping systems for chloride and sour service. Flanges are forged from 2507 forged billet per ASTM A182 grade F53, then machined to ASME B16.5 (NPS 1/2" to 24") or ASME B16.47 series A or B (NPS 26" to 60"). TorqBolt holds 2507 flanges at the Mumbai warehouse with EN 10204 Type 3.1 mill certificates and Type 3.2 third-party-witnessed on request.
The flanges are supplied to ASTM A182 grade F53 for forged stainless steel piping components, dimensioned to ASME B16.5 / B16.47 / EN 1092-1. Sour-service certification per NACE MR0175 / ISO 15156-3 is available. NORSOK M-650 QTR is supplied where the project specification calls it out.
Super Duplex 2507 Flange Size and Class Range
| Flange Type | Size Range | Pressure Class |
|---|---|---|
| Weld neck (WN) | NPS 1/2" to 60" | 150, 300, 600, 900, 1500, 2500 |
| Slip-on (SO) | NPS 1/2" to 24" | 150, 300, 600 |
| Blind (BL) | NPS 1/2" to 60" | 150, 300, 600, 900, 1500, 2500 |
| Socket weld (SW) | NPS 1/2" to 4" | 150, 300, 600, 900, 1500 |
| Threaded (THD) | NPS 1/2" to 4" | 150, 300, 600 |
| Lap joint (LJ) | NPS 1/2" to 24" | 150, 300, 600 |
| Reducing (WN, BL) | NPS 1" x 1/2" to 24" x 12" | 150, 300, 600, 900, 1500 |
| Standard | ASME B16.5 to NPS 24", ASME B16.47 series A / B above | |
Super Duplex 2507 Flange Chemistry per ASTM A182 F53
Per ASTM A182 grade F53 / UNS S32750: 25Cr-7Ni-3.5Mo-0.3N. Copper is restricted to 0.50 max as residual, not intentional. PREN of 41 or higher.
| Element | F53 Min % | F53 Max % |
|---|---|---|
| Carbon | (no min) | 0.030 |
| Chromium | 24.0 | 26.0 |
| Nickel | 6.0 | 8.0 |
| Molybdenum | 3.0 | 5.0 |
| Nitrogen | 0.24 | 0.32 |
| Copper | (no min) | 0.50 max, residual, not intentional |
Super Duplex 2507 Flange Mechanical Properties
| Property | Minimum | Test Standard |
|---|---|---|
| Tensile strength | 795 MPa (115 ksi) | ASTM A370 |
| Yield strength | 550 MPa (80 ksi) | ASTM A370 |
| Elongation in 50 mm | 15 percent | ASTM A370 |
| Hardness | 32 HRC max forging, 28 HRC max NACE | NACE MR0175 |
| Charpy V-notch at minus 46 C | 45 J min full set, 35 J avg | NORSOK M-630, ASTM E23 |
| Ferrite content | 35 to 55 percent | ASTM E562 |
| Pitting (G48 Method A) | No pitting at 50 C, 24 h | ASTM G48 |
Forging and Heat Treatment
- Forging temperature 1100 to 1230 degrees Celsius. Final reduction must finish above 950 degrees Celsius so duplex microstructure stays balanced.
- Solution anneal at 1040 to 1100 degrees Celsius followed by water quench. Heavy flange hubs (above 250 mm thick) are quenched in agitated water to clear sigma-phase precipitation window.
- Machining to ASME B16.5 / B16.47 dimensions: face finish RMS 125 to 250 micro-inch (Ra 3.2 to 6.3 micron) for raised-face flanges per MSS SP-6.
- Ring-joint (RTJ) groove machined per ASME B16.20 for class 900 and above sealing.
Flange Face Types
- Raised face (RF): standard for class 150 to 600. Sealing surface raised 1.6 mm above flange face.
- Ring-joint (RTJ): oval or octagonal groove per ASME B16.20. Standard for class 900 and above where high pressure or sour service requires metal-to-metal sealing.
- Flat face (FF): used for connection to cast-iron or low-stiffness companions and for some lap-joint stub-end applications.
- Tongue and groove, male and female: used in proprietary high-pressure piping systems and on some heat-exchanger flanges.
Super Duplex 2507 Flange Applications
- Offshore platform topside piping: seawater, firewater, ballast, hydrocarbon process
- Subsea production manifolds, christmas tree connections, jumper end terminations
- FGD wet scrubber piping, slurry recirculation and outlet ductwork
- Desalination MSF and MED brine and high-pressure feed lines
- Pulp and paper bleach plant chlorine dioxide piping
- Chemical processing dilute acid and chloride service piping
Related Products and Standards
- Super Duplex 2507 pipe per A790
- Super Duplex 2507 fittings per A815 WP-S32750
- Super Duplex 2507 forgings per A182 F53
- Super Duplex 2507 stud bolts for flange bolting
- Super Duplex 2507 heavy hex nuts
- ASTM A182 F53 reference
Super Duplex 2507 Flange FAQ
Which standards cover 2507 flanges?
ASTM A182 grade F53 (forged stainless piping components), ASME B16.5 (pipe flanges and flanged fittings NPS 1/2" to 24"), ASME B16.47 series A and B (large-diameter flanges NPS 26" to 60"), EN 1092-1 (European pressure flange), NORSOK M-630 (material data sheet), NORSOK M-650 (manufacturer qualification) and NACE MR0175 / ISO 15156-3 for sour service.
What pressure classes are stocked?
Class 150, 300, 600, 900, 1500 and 2500 per ASME B16.5. The maximum allowable working pressure depends on temperature and the material rating curve in B16.5 Table 2-2.4 for super duplex group 2.8 alloys. At ambient temperature, a class 1500 weld-neck 2507 flange is rated to about 25.5 MPa (3705 psi).
When do I specify ring-joint vs raised-face?
Ring-joint (RTJ) is required by ASME B16.5 for class 900 and above on hydrocarbon service and is the default for sour-service piping per API 6A and many operator specs. Raised-face (RF) is standard for class 150 to 600 utility and water service. Flat-face (FF) only on specific cast-iron or low-stiffness companions.
Are 2507 flanges suitable for NACE sour service?
Yes, qualified per NACE MR0175 / ISO 15156-3 with hardness restricted to 28 HRC maximum and ferrite content within 35 to 65 percent. The application zone, H2S partial pressure and chloride limits are stated on the EN 10204 Type 3.1 or 3.2 certificate when ordered with NACE compliance.
Is NORSOK M-650 QTR required for 2507 flanges?
NORSOK M-650 (qualification of manufacturers of special materials) is mandatory for super duplex flanges supplied to projects on the Norwegian Continental Shelf and to many North Sea operators. The Qualification Test Record (QTR) is valid for 5 years subject to essential variable control (chemistry, heat-treatment cycle, section size, mill of origin).
Does 2507 flange contain copper?
No, copper is not an intentional alloying element in UNS S32750. ASTM A182 F53 permits 0.50 max as residual, not intentional. Copper-bearing super duplex grades are Zeron 100 (S32760, ASTM A182 F55) and Ferralium 255 (S32550), which are different alloys with different forging specifications and different ASME B16.5 rating envelopes.
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