Alloy Steel P91 is a modified 9Cr - 1Mo grade micro-alloyed with vanadium, niobium and controlled nitrogen. The fine dispersion of carbonitrides that forms during normalising and tempering roughly doubles the allowable stress of P22 at high temperature, allowing thinner walls and lighter supports in ultra-supercritical power plant. Heat treatment control is critical and every piece is hardness tested.
Sarovar Tube Industries manufactures, stocks and exports Alloy Steel P91 Seamless Pipes from Mumbai to customers across the Middle East, South East Asia, Europe, Africa and the Americas. Every heat is verified by in-house testing before despatch and supported by complete documentation, so the material you receive is exactly the material you specified.
The table below sets out the standard manufacturing range for Alloy Steel P91 Seamless Pipes. Sizes and finishes outside this range are produced against firm orders.
| Parameter | Details |
|---|---|
| Size Range | NPS 1/8 inch to 24 inch (6 mm to 610 mm OD) |
| Wall Thickness | Sch 10, 20, 30, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS |
| Length | Single Random 4-7 m, Double Random 7-13 m, cut lengths on request |
| End Finish | Plain end, bevelled end (30 degrees), threaded and coupled |
| Manufacturing | Hot finished and cold drawn seamless |
| Surface | Black, mill finish, varnished, oiled, hot-dip galvanised |
| Dimensional Standard | ASME B36.10M |
| Tolerance | As per ASTM / ASME specification |
| Description | Details |
|---|---|
| Primary Standard | ASTM A335 / ASME SA335 Grade P91 |
| Grade Designation | Alloy Steel P91 (9Cr - 1Mo - V) |
| Equivalent Grades | UNS K90901, EN 10216-2 X10CrMoVNb9-1, DIN 1.4903, JIS STPA 28 |
| Product Category | Alloy Steel - Seamless Pipes |
| Certification | EN 10204 3.1 as standard, 3.2 with third party inspection on request |
| NPS (inch) | OD (mm) | Sch 40 WT (mm) | Sch 40 (kg/m) | Sch 80 WT (mm) | Sch 80 (kg/m) | Sch 160 WT (mm) | Sch 160 (kg/m) | XXS WT (mm) |
|---|---|---|---|---|---|---|---|---|
| 1/8 | 10.3 | 1.73 | 0.37 | 2.41 | 0.47 | - | - | - |
| 1/4 | 13.7 | 2.24 | 0.63 | 3.02 | 0.80 | - | - | - |
| 3/8 | 17.1 | 2.31 | 0.85 | 3.20 | 1.10 | - | - | - |
| 1/2 | 21.3 | 2.77 | 1.27 | 3.73 | 1.62 | 4.78 | 1.95 | 7.47 |
| 3/4 | 26.7 | 2.87 | 1.68 | 3.91 | 2.19 | 5.56 | 2.89 | 7.82 |
| 1 | 33.4 | 3.38 | 2.50 | 4.55 | 3.23 | 6.35 | 4.23 | 9.09 |
| 1 1/4 | 42.2 | 3.56 | 3.38 | 4.85 | 4.47 | 6.35 | 5.60 | 9.70 |
| 1 1/2 | 48.3 | 3.68 | 4.05 | 5.08 | 5.41 | 7.14 | 7.24 | 10.15 |
| 2 | 60.3 | 3.91 | 5.44 | 5.54 | 7.48 | 8.74 | 11.11 | 11.07 |
| 2 1/2 | 73.0 | 5.16 | 8.63 | 7.01 | 11.41 | 9.53 | 14.91 | 14.02 |
| 3 | 88.9 | 5.49 | 11.29 | 7.62 | 15.27 | 11.13 | 21.33 | 15.24 |
| 3 1/2 | 101.6 | 5.74 | 13.57 | 8.08 | 18.62 | - | - | - |
| 4 | 114.3 | 6.02 | 16.07 | 8.56 | 22.31 | 13.49 | 33.53 | 17.12 |
| 5 | 141.3 | 6.55 | 21.78 | 9.53 | 30.95 | 15.88 | 49.09 | 19.05 |
| 6 | 168.3 | 7.11 | 28.26 | 10.97 | 42.56 | 18.26 | 67.55 | 21.95 |
| 8 | 219.1 | 8.18 | 42.53 | 12.70 | 64.63 | 23.01 | 111.25 | 22.23 |
| 10 | 273.0 | 9.27 | 60.29 | 15.09 | 95.97 | 28.58 | 172.25 | 25.40 |
| 12 | 323.8 | 10.31 | 79.72 | 17.48 | 132.01 | 33.32 | 238.72 | 25.40 |
| 14 | 355.6 | 11.13 | 94.49 | 19.05 | 158.08 | 35.71 | 281.68 | - |
| 16 | 406.4 | 12.70 | 123.29 | 21.44 | 203.48 | 40.49 | 365.30 | - |
| 18 | 457.0 | 14.27 | 155.91 | 23.83 | 254.59 | 45.24 | 459.51 | - |
| 20 | 508.0 | 15.09 | 183.37 | 26.19 | 311.17 | 50.01 | 564.81 | - |
| 22 | 559.0 | - | - | 28.58 | 373.83 | 53.98 | 672.26 | - |
| 24 | 610.0 | 17.48 | 255.14 | 30.96 | 442.08 | 59.54 | 808.22 | - |
Dimensions as per ASME B36.10M and weights as per the Sarovar Tube Industries catalogue chart, NPS 1/8 inch to 24 inch. Sch 10, 20, 30, STD, XS, 60, 100, 120 and 140 wall thicknesses also supplied — refer to our catalogue or ask for the full schedule chart.
Composition limits in weight percent as required by ASTM A335 / ASME SA335 Grade P91. Every heat is verified by spectrographic analysis and positive material identification.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.08 - 0.12 |
| Manganese (Mn) | 0.30 - 0.60 |
| Phosphorus (P) | 0.020 max |
| Sulphur (S) | 0.010 max |
| Silicon (Si) | 0.20 - 0.50 |
| Chromium (Cr) | 8.00 - 9.50 |
| Molybdenum (Mo) | 0.85 - 1.05 |
| Vanadium (V) | 0.18 - 0.25 |
| Niobium (Nb) | 0.06 - 0.10 |
| Nitrogen (N) | 0.030 - 0.070 |
| Nickel (Ni) | 0.40 max |
| Aluminium (Al) | 0.02 max |
Minimum room temperature properties in the supplied condition. Results for the actual heat supplied are recorded on the mill test certificate.
| Property | Value |
|---|---|
| Tensile Strength | 585 MPa (85,000 psi) min |
| Yield Strength | 415 MPa (60,000 psi) min |
| Elongation | 20% min |
| Hardness | 190 - 250 HB |
| Heat Treatment | Normalise 1040-1080 degrees C, temper 730-800 degrees C |
| Density | 7.76 g/cm3 |
Material is released only after the following checks are completed and recorded:
Alloy Steel P91 Seamless Pipes is specified across the following industries and services:
All material is manufactured and tested to ASTM A335 / ASME SA335 Grade P91. Equivalent grades include UNS K90901, EN 10216-2 X10CrMoVNb9-1, DIN 1.4903, JIS STPA 28. The governing standard is printed on every mill test certificate.
Every consignment ships with an EN 10204 3.1 mill test certificate covering heat-wise chemical analysis and mechanical properties. Type 3.2 certification with third party inspection by TUV, SGS, BV or Lloyd's is available when specified at the enquiry stage.
Yes. Beyond the standard range shown above we manufacture to customer drawings and specifications, including special lengths, non-standard wall thickness and machined profiles. Share your drawing with the enquiry and our technical team will confirm feasibility and lead time.
Stock items are despatched within three to five working days of order confirmation. Made-to-order material typically takes four to six weeks depending on grade, size and heat treatment requirements. Export documentation and packing are handled in house.
Custom fabrication, special sizes and complete export documentation are handled in house. Send us your drawing or specification and our technical team will come back with a detailed offer, usually within one working day.