Surface Treatments
Certifications
- ISO 9001:2015
- NORSOK M-650
- NACE MR0175
- ISO 15156-3
- PED 2014/68/EC
- EN 10204 type 3.2
- AD 2000 W2/W7/W10
Ferralium 255 Seamless Pipe (UNS S32550): ASTM A790
Ferralium 255 seamless pipe (UNS S32550 / EN 1.4507) is supplied per ASTM A790 (Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe). Solution-annealed at 1100 °C with water quench. Per-heat MTC (EN 10204 type 3.2) documents chemistry, mechanical properties, ferrite content per ASTM E562, hydrostatic test result, and PREN calculation. Same ASTM A790 spec also covers Duplex 2205 pipe (UNS S31803/S32205), Super Duplex 2507 (S32750), and Zeron 100 (S32760), Ferralium 255 sits in the super-duplex tier (PREN ≥ 40) above standard duplex 2205 (PREN ~35).
Pipe Size Range & Schedules
| NPS | OD | Common schedules | Wall thickness range |
|---|---|---|---|
| 1/2" | 21.3 mm | SCH 10S / 40S / 80S / 160 / XXS | 2.11–7.47 mm |
| 1" | 33.4 mm | SCH 10S / 40S / 80S / 160 / XXS | 2.77–9.09 mm |
| 2" | 60.3 mm | SCH 10S / 40S / 80S / 160 / XXS | 2.77–11.07 mm |
| 4" | 114.3 mm | SCH 10S / 40S / 80S / 120 / 160 / XXS | 3.05–17.12 mm |
| 6" | 168.3 mm | SCH 10S / 40S / 80S / 120 / 160 / XXS | 3.40–21.95 mm |
| 8" | 219.1 mm | SCH 10S / 40S / 80S / 120 / 160 / XXS | 3.76–22.23 mm |
| 12" | 323.9 mm | SCH 10S / 40S / 80S / 120 / 160 | 4.57–33.32 mm |
| 24" | 609.6 mm | SCH 10S / 40S / 80S | 6.35–24.61 mm |
ASTM A790 Inspection & Testing Requirements
- Chemical analysis per heat (heat analysis + product analysis verification when specified)
- Tensile test per ASTM A370 / E8, yield ≥ 550 MPa, tensile ≥ 760 MPa, elongation ≥ 15%
- Hydrostatic test per A790 paragraph 14 (or NDE substitution per S2 / S5 supplementary requirements)
- Ferrite content per ASTM E562 (35–55% per NORSOK M-630)
- Intergranular corrosion test per ASTM A923 method A or C (when specified)
- Critical Pitting Temperature per ASTM G48 method A (when specified for sour service)
- Hardness test (Rockwell HRC ≤ 32 for NACE MR0175 sour service)
- Per-heat Mill Test Certificate per EN 10204 type 3.1 or 3.2
Seamless vs Welded Ferralium 255 Pipe
ASTM A790 covers both seamless (manufactured by extrusion / pilger / cold-pilger) and welded (manufactured by autogenous TIG, plasma, or with filler addition). Welded pipe must meet additional weld-zone ferrite balance requirements (35–65% per NORSOK M-630) and heat-input control (typically 0.5–2.5 kJ/mm). For NORSOK M-650 qualified seamless pipe, the QTR documents pilger pass-schedule and final solution-anneal cycle. For sour-service applications (NACE MR0175), seamless is generally preferred to eliminate weld-zone variability.
Typical Ferralium 255 Pipe Applications
- Seawater intake / outfall piping for offshore platforms, FPSOs
- Subsea flowlines and risers (NORSOK M-650 qualified)
- Oil & gas downhole tubing in sour-service NACE MR0175 environments
- Hypochlorite generation system piping
- Desalination brine-disposal piping
- Chemical processing reactor circulation loops in HCl / H2SO4 service (Cu advantage of Ferralium 255)
- Firewater system high-pressure piping on offshore platforms
Ferralium 255 Pipe vs Duplex 2205 Pipe: Service Boundary
For seawater service above 30 °C, sour-gas service exceeding standard-duplex NACE MR0175 limits, or service involving reducing acids, upgrade from Duplex 2205 pipe (UNS S31803, PREN ~35) to Ferralium 255 pipe (UNS S32550, PREN ≥ 40) is justified. See Ferralium 255 vs Duplex 2205 upgrade guide for full selection criteria. Both grades supplied to identical ASTM A790 spec; super-duplex pipe simply has higher chemistry / PREN / CPT margin.
TorqBolt Documentation & Compliance
Per-heat EN 10204 type 3.2 MTC with chemistry, mechanical properties, ferrite content, PREN calculation, hydrostatic test certificate. NORSOK M-650 QTR available on request per material data sheet MDS D55. NACE MR0175 / ISO 15156-3 sour-service compliance certified per heat. Contact info@torqbolt.com or +91-22-66157017 for quotation, lead time, and project-specific spec compliance.
Need Ferralium 255 pipe? Email info@torqbolt.com or WhatsApp +91-22-66157017 with form, dimensions, quantity, ASTM/EN spec, MTC level (3.1 / 3.2). NACE MR0175 sour-service stamp on every heat. NORSOK M-650 QTR on request. Per-heat EN 10204 type 3.2 MTC included with every consignment.
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