S31803 Pipes & Pipe Fittings
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Duplex S31803 Pipes & Fittings Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier of Duplex Stainless Steel S31803 pipes and fittings based in Mumbai, India. We supply seamless and welded pipes with matching buttweld fittings manufactured in accordance with ASTM A790/A789 (seamless), A928 (EFW).
Duplex S31803 typical composition is approximately Cr 21.0-23.0%, Ni 4.5-6.5%, Mo 2.5-3.5%, N 0.08-0.20%. UNS S31803 (Werkstoff 1.4462 / ASTM A815 WPS31803) is the original Duplex 2205 grade and is still the most widely used duplex stainless steel piping material worldwide. Its mixed austenitic-ferritic structure (about 50/50) gives high strength: about 620 MPa tensile strength and 450 MPa yield strength. The PREN value is usually between 30 and 34, depending on the exact composition. EN 10216-5 / 10217-7 (1.4462). Fittings are made to ASTM A815 (buttweld). The critical pitting temperature (CPT) in 1M NaCl is about 35-45°C. The ferrite phase gives excellent resistance to chloride stress corrosion cracking compared to austenitic grades. The maximum recommended continuous service temperature is about 300°C (570°F). Above this, there is a risk of 475°C embrittlement and sigma phase formation, so ASTM A923 testing is used to confirm that these harmful phases are not present.
Modern mills typically produce S31803 to composition ranges that also meet S32205 (F60), enabling dual certification. Always request dual-certified S31803/S32205 material for best corrosion performance. Available sizes are NPS 1/2″ to 36″ in schedules 5S through XXS.
Duplex S31803 Pipes & Fittings Specifications
Key technical specifications for Duplex S31803 pipes and fittings, covering seamless, welded, and tubular products across common sizes and schedules:
| Pipes Specifications | |
|---|---|
| Parameter | Details |
| Pipe & Tube Standards | ASTM A790, A789, A928 / ASME SA790, SA789, SA928 (UNS S31803) |
| EN Standard | EN 10216-5, EN 10217-7 (1.4462) |
| Size Range | NPS 1/2″ to 36″; OD 6.35-914.4 mm |
| Wall / Schedule | SCH 5S, 10S, 40S, 40, 80S, 80, 120, 160, XXS |
| Condition | Solution annealed 1020-1100°C + rapid quench |
| Fittings Specifications | |
| Parameter | Details |
| Fittings Standards | Buttweld Fittings: ASTM A815 / ASME SA815 (WPS31803) |
| Dimensions | ASME B16.9, B16.28 |
| Size | BW Size: NPS 1/2″ to 48″ |
Chemical Composition of Duplex S31803 Pipes & Fittings
The chemical composition of Duplex S31803 Pipes & Fittings, along with their proportions, is listed in the table below:
| Material / Element | Chromium (Cr) | Molybdenum (Mo) | Nitrogen (N) | Nickel (Ni) | Carbon (C) | Manganese (Mn) | Silicon (Si) | Iron (Fe) |
|---|---|---|---|---|---|---|---|---|
| S31803 (%) | 21.0-23.0 | 2.5-3.5 | 0.08-0.20 | 4.5-6.5 | 0.030 max | 2.00 max | 1.00 max | Balance |
S31803 has a wider allowable range. Material at the lower end (21% Cr, 2.5% Mo, 0.08% N) has significantly lower PREN than material at the upper end. When ordering S31803, always request material that also meets S32205 limits. This guarantees PREN ≥34 and optimum corrosion resistance, particularly for welded constructions where HAZ performance depends on composition.
Mechanical Properties of Duplex S31803 Pipe & Fitting
Mechanical performance criteria for Duplex S31803 pipes and fittings, based on minimum values specified in ASTM A790 after solution annealing:
| Property | Tensile Strength (min) | Yield Strength 0.2% (min) | Elongation (min) | Hardness (max) | Charpy Impact |
|---|---|---|---|---|---|
| Value | 620 MPa (90 ksi) | 450 MPa (65 ksi) | 25% | 293 HBW (~31 HRC) | 27 J at -40°C (ASTM A923 Method B) |
The 450 MPa yield is approximately 2x that of 316L (220 MPa), allowing thinner wall pipe that cuts weight and cost. Good impact toughness down to -50°C. Hardness cap of 293 HBW satisfies NACE MR0175 sour service. Mechanical requirements are identical for S31803 and S32205.
Duplex S31803 Equivalent Grades
Equivalent international standards and designations for Duplex S31803 stainless steel pipes and fittings across UNS, EN, Werkstoff, and related systems:
| Property | UNS | Werkstoff Nr. | EN | AFNOR |
|---|---|---|---|---|
| Designation | S31803 | 1.4462 | X2CrNiMoN22-5-3 | Z3CrNi22-05Az |
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Types of Duplex S31803 Pipes & Fittings
Duplex S31803 pipes are the most widely used duplex stainless steel piping material globally, specified for piping, offshore platforms, desalination plants, and chemical process equipment.
Duplex S31803 Seamless Pipe (ASTM A790)
Duplex S31803 Welded Pipe
Duplex S31803 Seamless Tube
Duplex S31803 ERW / EFW Pipe
Duplex S31803 Elbow (45° / 90° / 180°)
Duplex S31803 Tee (Equal / Reducing)
Duplex S31803 Reducer (Concentric / Eccentric)
Duplex S31803 Cap & Stub End
Industries Using Duplex S31803 Pipes & Fittings
Duplex S31803 accounts for over 80% of all duplex stainless steel consumption worldwide. High strength, chloride resistance, and moderate cost make it the default choice whenever austenitic grades cannot handle the environment.
- Oil & Gas: Platform process piping, topsides piping, seawater injection, fire-fighting ring mains, produced water handling, and sour gas piping per NACE MR0175.
- Chemical Processing: Heat exchangers, reactor piping, organic acid piping, and moderate chloride-bearing process streams. Replaces 316L where SCC risk exists.
- Desalination & Water Treatment: RO plant piping, seawater intake, brine handling at moderate temperatures, and flash distillation piping.
- Pulp & Paper: One of the largest consuming industries. Digesters, black liquor heaters, bleaching components, brownstock washers, evaporators, and ClOâ‚‚ generators.
- Marine & Shipbuilding: Chemical tanker cargo tanks, ballast piping, seawater piping. Classification society approved (ABS, DNV, BV, Lloyds).
- Food & Pharmaceutical: High-strength hygienic piping where SCC risk eliminates 316L. Brewery equipment and food processing heat exchangers.
- Power Generation & FGD: FGD scrubber piping, absorber towers, cooling water systems with chloride contamination, and biomass plants.
How to Order Duplex S31803 Pipes & Fittings from Nicorex Alloys
To order Duplex S31803 Pipes & Fittings, follow these important details:
- Product Form: Seamless / Welded Pipe or Fittings (Elbow, Tee, Reducer, End Cap, Stub End)
- Size: Pipes — OD x WT or NPS x Schedule / Fittings — NPS x Schedule
- End Type / Connection: Pipes: PE / BE / TE / Fittings: Butt Weld
- Material Grade: Duplex Stainless Steel / UNS S31803 / W.Nr. 1.4462 / F51
- Quantity: Number of pieces or total weight in kg / MT
- Standard: Pipes — ASTM A790 / ASME SA790 / Fittings — ASTM A815 / ASME SA815, ASME B16.9, ASME B31.3
- Documentation: MTC EN 10204 3.1/3.2, PMI Report, Ferrite Number (FN) Report, Mechanical Properties Report, IGC Test Report, Charpy Impact Test Report, TPI Certificate
- Packaging: PVC end caps on pipes / individual polybag per fitting, bundled with steel strapping, ISPM 15 compliant export crating with VCI wrap and full labelling
- Delivery Destination: Domestic
Frequently Asked Questions
What is Duplex S31803 Pipe Used For?
Duplex S31803 pipe is used for chloride-bearing process piping, offshore platform systems, seawater handling, desalination plants, and chemical process equipment where 316L cannot handle chloride SCC and pitting risks.
What industries commonly use Duplex S31803 Piping Systems?
Oil and gas, chemical processing, desalination, pulp and paper, marine/shipbuilding, food/pharmaceutical, and power generation (FGD). S31803 accounts for over 80% of global duplex stainless steel consumption.
What is the difference between S31803 and S32205 Fittings?
Composition control. S32205 (F60) has tighter minimum limits for Cr (22% vs 21%), Mo (3.0% vs 2.5%), and N (0.14% vs 0.08%). Mechanical properties are identical. Request dual-certified material.
What testing is performed on S31803 Fittings?
Hydrostatic test, chemical analysis, tensile/hardness testing, impact testing, ASTM A923 Method A/B/C (intermetallic phase detection), ferrite count, and corrosion testing. NACE MR0175 compliance for sour service.
What standards apply to S31803 Pipes?
ASTM A790 / ASME SA790 (seamless/welded pipe), A789/SA789 (tube), A928/SA928 (EFW pipe), A815 (buttweld fittings), and EN 10216-5 / EN 10217-7 for European 1.4462 specifications.