904L Pipes & Pipe Fittings
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Stainless Steel 904L Pipes & Fittings Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier, importer, and stockist of Stainless Steel 904L pipes and fittings in Mumbai, India. We supply seamless and welded pipes with matching buttweld fittings manufactured to the ASTM B366 and A312 standards.
UNS N08904 (Werkstoff 1.4539 / EN X1NiCrMoCu25-20-5) is a super austenitic stainless steel with a high alloy content. Its composition of 23 to 28% Ni, 19 to 23% Cr, 4 to 5% Mo, and 1 to 2% Cu was originally developed for dilute sulfuric acid resistance. Copper provides reducing acid resistance while high molybdenum delivers a PREN of ~34. Extra-low carbon (≤0.020%) prevents carbide precipitation and maintains intergranular corrosion resistance in the welded condition without niobium stabilisation. Minimum tensile strength reaches 490 MPa (71 ksi) with yield at 220 MPa (31 ksi) and 35% elongation. 904L is fully austenitic and non-magnetic. Cryogenic toughness is exceptional, with Charpy V-notch exceeding 100 J at -196°C. Solution anneal at 1095-1150°C, followed by water quench. Maximum service temperature is ~400°C (750°F) for continuous aqueous corrosion duty.
904L is an economical option, while providing comparable sulfuric acid performance at moderate concentrations. We provide pipes as per ASTM A312, and fittings as per B366 standard. UNS N08904 pipes and fittings are used in industries like chemical processing, pharmaceutical, oil & gas, pulp & paper, and more, as explained below.
Stainless Steel 904L Pipes & Fittings Specifications
904L pipe specifications, including standards, dimensions, schedule, and conditions, are covered in detail in the table below:
| Pipes specifications | |
|---|---|
| Field | Details |
| Pipe & Tube Standards | ASTM B677, B673, B775, B674, A312 TP904L, A213 TP904L / ASME SB677, SB673, SB674 |
| Grades | UNS N08904 (904L) |
| Size Range | NPS 1/2″ to 24″; OD 6.35-609.6 mm |
| Wall / Schedule | SCH 5S, 10S, 40S, 40, 80S, 80, 120, 160, XXS |
| Condition | Solution annealed 1095-1150°C + water quench |
| Fittings specifications | |
| Field | Details |
| Fittings Standards | Buttweld Fittings: ASTM B366 / ASME SB366 |
| Dimensions | ASME B16.9 |
| Size | BW Size: NPS 1/2″ to 48″ |
Chemical Composition of 904L (UNS N08904) Pipes & Fittings
904L (UNS N08904) chemical composition, and its key alloying elements are covered in detail in the table below:
| Material / Element | Nickel (Ni) | Chromium (Cr) | Molybdenum (Mo) | Copper (Cu) | Carbon (C) | Manganese (Mn) | Silicon (Si) | Nitrogen (N) | Phosphorus (P) | Sulfur (S) | Iron (Fe) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 904L (N08904) % | 23.0-28.0 | 19.0-23.0 | 4.0-5.0 | 1.0-2.0 | 0.020 max | 2.00 max | 1.00 max | 0.10 max | 0.045 max | 0.035 max | Balance |
Extra-low carbon (≤0.020%) prevents carbide precipitation, giving excellent IGC resistance in the welded condition without Nb stabilisation. High Mo (4-5%) delivers PREN ≈34, superior to 316L (24) and 317L (28). Copper (1-2%) improves reducing acid resistance, particularly dilute sulfuric acid. Non-stabilised, unlike Alloy 20, which relies on Nb. Fully austenitic and non-magnetic in all conditions.
Mechanical Properties of 904L (UNS N08904) Pipes & Fittings
The mechanical properties of SS 904L pipes and fittings, including tensile and yield strength, hardness, and elongation, in the solution-annealed condition, are covered below:
| Property | Tensile Strength (min) | Yield Strength 0.2% (min) | Elongation (min) | Hardness |
|---|---|---|---|---|
| Value | 490 MPa (71 ksi) | 220 MPa (31 ksi) | 35% | 70-90 HRB |
Excellent cryogenic toughness: 904L retains good toughness at low temperatures due to its fully austenitic structure. Impact testing may be supplied if specified in the purchase order.
Physical Properties of 904L (UNS N08904) Pipes & Fittings
904L physical properties like density, melting point, thermal conductivity, elastic modulus, and other important properties are provided below:
| Property | Density | Melting Range | Thermal Conductivity (20°C) | Modulus of Elasticity | CTE (20-100°C) | Magnetic |
|---|---|---|---|---|---|---|
| Value | 8.0 g/cm³ (0.289 lb/in³) | 1300-1390°C (2370-2535°F) | 12.2 W/m·°C | 190 GPa (27.5 × 10³ ksi) | 15.8 µm/m·°C | No — fully austenitic, non-magnetic |
904L (UNS N08904) Equivalent Grades
The standard equivalent designation of 904L is UNS N08904, and its Werkstoff Nr. is 1.4539. The EN designation is also covered in the table below:
| Property | UNS | Werkstoff Nr. | EN |
|---|---|---|---|
| Designation | N08904 | 1.4539 | X1NiCrMoCu25-20-5 |
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Types of 904L Pipes & Fittings
904L pipes are manufactured for piping systems handling moderate-to-severe corrosive media, particularly dilute sulfuric acid, phosphoric acid, and chloride-bearing environments where standard austenitic grades fail.
904L Seamless Pipe
904L Welded Pipe
904L Welded Tube
904L ERW / EFW Pipe
904L Elbow (45° / 90° / 180°)
904L Pipe Tee
904L Reducer (Concentric / Eccentric)
904L Cap & Stub End
Industries Using 904L Pipes & Fittings
- 904L is specified where piping handles dilute sulfuric acid, phosphoric acid, and chloride-bearing media at moderate temperatures.
- Dilute sulfuric acid piping, mixed acid handling, organic chemical production, and process heat exchangers.
- Wet phosphoric acid piping with Cl⁻ and F⁻ impurities, superphosphate production, and ammonium sulfate process lines.
- Pharmaceutical reactor piping, food-grade processing, and brewery equipment, where corrosion resistance and cleanability are both required.
- Gas scrubbing, amine units, and sour water handling where sulfuric and mixed acid conditions exist.
- Bleaching systems and ClO₂ generation piping in chloride-rich pulp mill environments.
- Seawater heat exchangers and condenser tubing where PREN ~34 provides adequate pitting resistance.
- Moderate acid leach piping and acid mine drainage handling.
How to Order 904L Pipes & Fittings from Nicorex Alloys
To place an order for 904L pipes and fittings, provide the following documents:
- Product Form — Seamless / Welded Pipe / Fittings (Elbow, Tee, Reducer)
- Size — OD x WT or NPS x Schedule
- End Type — PE / BE / BW
- Material Grade — 904L Super-Austenitic SS / UNS N08904 / W.Nr. 1.4539
- Quantity — Pieces or total weight in kg / MT
- Standard — ASTM B677 (pipe) / ASTM B366 (fittings), ASME B16.9
- Additional Requirements — NACE, PMI, solution annealed, low carbon (C ≤ 0.02%)
- Documentation — MTC 3.1/3.2, PMI Report, TPI Certificate
- Packaging — VCI wrap, ISPM 15 compliant export crating
- Delivery — Domestic / International (specify destination)
Frequently Asked Questions
What is 904L Pipe Fitting Used for?
904L fittings are used in sulfuric acid piping, phosphoric acid production, pharmaceutical processing, and chloride-bearing chemical environments where 316L fails from pitting or SCC.
What is the Difference Between 904L and Alloy 20?
904L has lower Ni (23-28% vs 32-38%), lower Cu (1-2% vs 3-4%), and is non-stabilised (relies on ultra-low carbon alone for IGC resistance). Alloy 20 uses Nb stabilisation and offers better concentrated sulfuric acid resistance. 904L is the more economical choice for moderate acid concentrations.
Is 904L Better than 316L?
Yes, in acid and chloride service. 904L’s PREN of ~34 vs 316L’s 24 means far superior pitting resistance. Higher Ni (23-28% vs 10-14%) provides chloride SCC resistance that 316L lacks.
Is 904L Pipe Magnetic?
No. It is essentially non-magnetic in the annealed condition; a slight magnetic response may occur after severe cold work.
What Welding Filler is used for 904L Pipe?
Use matching filler ER385 (GTAW/GMAW) or E385 (SMAW). Over-alloyed fillers such as ERNiCrMo-3 (Inconel 625) can be used for dissimilar joints.
What Is the Price of 904L Pipe in India?
904L is a premium super austenitic grade, but more economical than Alloy 20 due to lower nickel content. Contact Nicorex Alloys for current pricing from Mumbai stock.