Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
Tubewell Steel & Engg. Co. is a Mumbai-based manufacturer, stockist and supplier of chromium-molybdenum alloy steel pipes. Our range covers every ASTM A335 seamless grade from P5 to P92 together with ASTM A691 EFW pipes in large diameters – all supplied with full heat traceability, IBR documentation and EN 10204 3.1 certificates.
Chromium-molybdenum pipes engineered for heat, pressure and hydrogen service
Alloy steel pipes are ferritic chromium-molybdenum (Cr-Mo) steels designed to retain strength at temperatures where carbon steel begins to creep, oxidise or suffer hydrogen attack. Chromium (0.80% to 10%) builds resistance to oxidation, sulphidation and high-temperature hydrogen attack, while molybdenum (0.30% to 1.13%) raises creep-rupture strength. Advanced grades such as P91 and P92 are further micro-alloyed with vanadium, niobium, nitrogen and, in P92, tungsten and boron to deliver creep strength enhanced ferritic (CSEF) performance up to around 650°C.
Tubewell supplies seamless pipes to ASTM A335 / ASME SA335 in hot-finished and cold-drawn forms from 1/2" to 24" NB, and electric-fusion-welded pipes to ASTM A691 / ASME SA691 rolled from ASTM A387 plate up to 48" NB. Every pipe is heat treated as required by the specification, marked with grade and heat number, and dispatched with mill test certificates per EN 10204 3.1, IBR Form III-A on request and third-party inspection by BV, TÜV, SGS, Lloyd's or EIL.
Standard supply range for alloy steel pipes
| Parameter | Details |
|---|---|
| Seamless Standard | ASTM A335, ASME SA335 |
| Welded Standard | ASTM A691, ASME SA691 (plate to ASTM A387) |
| Seamless Grades | P5, P9, P11, P12, P22, P91, P92 |
| Welded Grades | A691 1CR, 1-1/4CR, 2-1/4CR, 5CR, 9CR, 91 |
| Type | Seamless (Hot Finished / Cold Drawn), EFW, LSAW, ERW |
| Size (NB) | Seamless 1/2" – 24" NB; Welded 6" – 48" NB |
| Outer Diameter | 21.3 mm to 1219 mm |
| Wall Thickness | SCH 10, 20, 30, 40, STD, 60, 80, XS, 100, 120, 140, 160, XXS |
| Length | Single Random, Double Random, Cut Length (up to 12 m) |
| Ends | Plain End, Bevelled End (ASME B16.25), Threaded |
| Heat Treatment | Annealed, Normalized & Tempered, Subcritical Annealed (as per grade) |
| Dimension Standard | ASME B36.10M |
| Testing | Hydrostatic, Ultrasonic, Eddy Current, Radiography (welded), Flattening, Hardness, PMI |
| Certificates | EN 10204 3.1 / 3.2, IBR Form III-A, TPI Reports |
International equivalents of ASTM A335 grades
| Grade | ASTM | UNS | EN | DIN / W.Nr. | JIS | BS |
|---|---|---|---|---|---|---|
| P5 | A335 P5 | K41545 | X11CrMo5 | 1.7362 | STPA 25 | 3604 HFS 625 |
| P9 | A335 P9 | K90941 | X11CrMo9-1 | 1.7386 | STPA 26 | 3604 HFS 629-470 |
| P11 | A335 P11 | K11597 | 13CrMo4-5 | 1.7335 | STPA 23 | 3604 HFS 621 |
| P12 | A335 P12 | K11562 | 13CrMo4-5 | 1.7335 | STPA 22 | 3604 HFS 620-460 |
| P22 | A335 P22 | K21590 | 10CrMo9-10 | 1.7380 | STPA 24 | 3604 HFS 622 |
| P91 | A335 P91 | K91560 | X10CrMoVNb9-1 | 1.4903 | STPA 28 | 3604 HFS 91 |
| P92 | A335 P92 | K92460 | X10CrWMoVNb9-2 | 1.4901 | STPA 29 | — |
Weight %, as per ASTM A335 (P ≤ 0.025, S ≤ 0.025 unless noted)
| Grade | C | Mn | P | S | Si | Cr | Mo | Others |
|---|---|---|---|---|---|---|---|---|
| P5 | 0.15 max | 0.30 – 0.60 | 0.025 max | 0.025 max | 0.50 max | 4.00 – 6.00 | 0.45 – 0.65 | — |
| P9 | 0.15 max | 0.30 – 0.60 | 0.025 max | 0.025 max | 0.25 – 1.00 | 8.00 – 10.00 | 0.90 – 1.10 | — |
| P11 | 0.05 – 0.15 | 0.30 – 0.60 | 0.025 max | 0.025 max | 0.50 – 1.00 | 1.00 – 1.50 | 0.44 – 0.65 | — |
| P12 | 0.05 – 0.15 | 0.30 – 0.61 | 0.025 max | 0.025 max | 0.50 max | 0.80 – 1.25 | 0.44 – 0.65 | — |
| P22 | 0.05 – 0.15 | 0.30 – 0.60 | 0.025 max | 0.025 max | 0.50 max | 1.90 – 2.60 | 0.87 – 1.13 | — |
| P91 | 0.08 – 0.12 | 0.30 – 0.60 | 0.020 max | 0.010 max | 0.20 – 0.50 | 8.00 – 9.50 | 0.85 – 1.05 | V 0.18–0.25, Nb 0.06–0.10, N 0.030–0.070, Ni 0.40 max, Al 0.02 max |
| P92 | 0.07 – 0.13 | 0.30 – 0.60 | 0.020 max | 0.010 max | 0.50 max | 8.50 – 9.50 | 0.30 – 0.60 | W 1.50–2.00, V 0.15–0.25, Nb 0.04–0.09, N 0.030–0.070, B 0.001–0.006, Ni 0.40 max |
Minimum values at room temperature, as per ASTM A335
| Grade | Tensile Strength | Yield Strength (0.2%) | Elongation (Long.) | Elongation (Trans.) | Hardness |
|---|---|---|---|---|---|
| P5 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 20% min | — |
| P9 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 20% min | — |
| P11 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 20% min | — |
| P12 | 415 MPa (60 ksi) min | 220 MPa (32 ksi) min | 30% min | 20% min | — |
| P22 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 20% min | — |
| P91 | 585 MPa (85 ksi) min | 415 MPa (60 ksi) min | 20% min | 13% min | 190 – 250 HBW |
| P92 | 620 MPa (90 ksi) min | 440 MPa (64 ksi) min | 20% min | 13% min | 250 HBW max |
Typical values by grade family (for reference)
| Property | P11 / P12 / P22 | P5 / P9 | P91 / P92 |
|---|---|---|---|
| Density | 7.75 – 7.85 g/cm³ | 7.70 – 7.75 g/cm³ | 7.77 – 7.85 g/cm³ |
| Melting Range | 1450 – 1510 °C | 1450 – 1500 °C | 1420 – 1500 °C |
| Modulus of Elasticity | 205 GPa | 213 GPa | 218 GPa |
| Thermal Conductivity (100°C) | 36 – 38 W/m·K | 26 – 30 W/m·K | 26 – 27 W/m·K |
| Mean Thermal Expansion (20–300°C) | 12.4 – 12.6 µm/m·°C | 11.5 µm/m·°C | 11.2 µm/m·°C |
| Specific Heat | 0.46 J/g·°C | 0.46 J/g·°C | 0.45 J/g·°C |
| Max. Service Temperature | ≈ 565 – 600 °C | ≈ 650 °C | ≈ 620 – 650 °C |
As per ASME B36.10M – wall thickness (mm) / weight (kg/m)
| NPS | OD (mm) | SCH 40 WT | SCH 40 Wt | SCH 80 WT | SCH 80 Wt | SCH 160 WT | SCH 160 Wt |
|---|---|---|---|---|---|---|---|
| 1/2" | 21.3 | 2.77 | 1.27 | 3.73 | 1.62 | 4.78 | 1.95 |
| 3/4" | 26.7 | 2.87 | 1.69 | 3.91 | 2.20 | 5.56 | 2.90 |
| 1" | 33.4 | 3.38 | 2.50 | 4.55 | 3.24 | 6.35 | 4.24 |
| 1 1/4" | 42.2 | 3.56 | 3.39 | 4.85 | 4.47 | 6.35 | 5.61 |
| 1 1/2" | 48.3 | 3.68 | 4.05 | 5.08 | 5.41 | 7.14 | 7.25 |
| 2" | 60.3 | 3.91 | 5.44 | 5.54 | 7.48 | 8.74 | 11.11 |
| 2 1/2" | 73.0 | 5.16 | 8.63 | 7.01 | 11.41 | 9.53 | 14.92 |
| 3" | 88.9 | 5.49 | 11.29 | 7.62 | 15.27 | 11.13 | 21.35 |
| 4" | 114.3 | 6.02 | 16.07 | 8.56 | 22.32 | 13.49 | 33.54 |
| 6" | 168.3 | 7.11 | 28.26 | 10.97 | 42.56 | 18.26 | 67.56 |
| 8" | 219.1 | 8.18 | 42.55 | 12.70 | 64.64 | 23.01 | 111.27 |
| 10" | 273.1 | 9.27 | 60.29 | 15.09 | 95.98 | 28.58 | 172.33 |
| 12" | 323.9 | 10.31 | 79.71 | 17.48 | 132.05 | 33.32 | 238.76 |
| 14" | 355.6 | 11.13 | 94.55 | 19.05 | 158.10 | 35.71 | 281.70 |
| 16" | 406.4 | 12.70 | 123.30 | 21.44 | 203.53 | 40.49 | 365.35 |
| 18" | 457.0 | 14.27 | 155.80 | 23.83 | 254.55 | 45.24 | 459.37 |
| 20" | 508.0 | 15.09 | 183.42 | 26.19 | 311.17 | 50.01 | 564.81 |
| 24" | 610.0 | 17.48 | 255.41 | 30.96 | 442.08 | 59.54 | 808.22 |
WT = Wall Thickness in mm, Wt = Weight in kg/m. Values are nominal; actual weights may vary within ASTM tolerances. Welded pipe sizes above 24" NB are listed on the Alloy Steel Welded Pipes page.
Where alloy steel pipes are used
Main steam, hot and cold reheat lines in subcritical, supercritical and USC units.
Heater transfer lines, crude and vacuum units, hydro-treaters and cokers.
Reformers, crackers and hydrogen-rich process lines at elevated temperature.
Headers, superheater links and HRSG piping under sustained heat and pressure.
High-temperature shell, nozzle and connection piping for exchangers.
Ammonia, urea and methanol plant lines needing hydrogen-attack resistance.
Quality you can verify on every heat
Large inventory for fast dispatch
MTC EN 10204 3.1 / 3.2
Positive material identification
Pan-India & export shipping
Quick answers about alloy steel pipes
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