Forged ASME B16.5 / B16.47, EN 1092-1, NORSOK L-005 flanges in F61 (UNS S32550) for super duplex piping
A flanged joint is the most common point-of-failure on a process piping system: stud-bolt corrosion, gasket leak, flange-face damage, or galvanic dissimilarity at the bolted interface. The fix is to specify matched-grade hardware throughout: super duplex pipe meets a super duplex flange via a super duplex weldneck, with a graphite or PTFE-spiral wound gasket and ASTM A193 S6 stud bolts with A194 S7 nuts. Ferralium 255 (UNS S32550, EN 1.4507) flanges are forged to ASTM A182 grade F61 with ASME B16.5 dimensional for sizes 1/2 inch through 24 inch and ASME B16.47 series A or B for sizes 26 inch through 60 inch. Per-heat EN 10204 type 3.2 MTC. RFQ: info@torqbolt.com / WhatsApp +91-22-66157017.
| Type | Standard | Size envelope | Pressure class |
|---|---|---|---|
| Weldneck (WN) raised face | ASME B16.5, B16.47 | 1/2" to 60" NPS | 150, 300, 600, 900, 1500, 2500 |
| Slip-on (SO) raised face | ASME B16.5 | 1/2" to 24" NPS | 150, 300, 600 |
| Blind (BL) raised face | ASME B16.5, B16.47 | 1/2" to 60" NPS | 150 to 2500 |
| Socketweld (SW) | ASME B16.5 | 1/2" to 4" NPS | 150, 300, 600, 1500, 2500 |
| Threaded NPT | ASME B16.5 | 1/2" to 4" NPS | 150, 300 |
| Lap joint (LJ) | ASME B16.5 | 1/2" to 24" NPS | 150, 300, 600 |
| Ring-type joint (RTJ) | ASME B16.5 | 1/2" to 24" NPS | 600, 900, 1500, 2500 |
| Spectacle blind / spacer / paddle | ASME B16.48 | 1/2" to 24" | per line class |
| EN 1092-1 type 11 / 01 / 05 / 35 | EN, metric | DN15 to DN600 | PN6 to PN160 |
| NORSOK L-005 compact flange | NORSOK | per L-005 | per L-005 SP rating |
Closed-die forging from forged bar billet with a minimum 4:1 reduction ratio per NORSOK M-650 develops the wrought ferrite-austenite microstructure required for super duplex pressure-containing service. Forging is performed in the 1050 to 1200 °C austenitisation range, finish-forge above 950 °C. Solution-anneal at 1080 °C with water quench follows, then machining of the bore, raised face, ring-groove (for RTJ), and bolt-hole pattern per ASME B16.5 paragraph 6. Surface finish on the raised face is Ra 3.2 to 6.3 μm with a phonographic spiral or concentric serration per ASME B16.5 paragraph 6.4 to seat the spiral-wound or compressed-fibre gasket.
