Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
IBR approved seamless chrome-moly tubes for superheaters, reheaters, waterwalls and economisers in utility, industrial and HRSG boilers.
Tubewell Steel & Engg. Co. manufactures, stocks and supplies seamless alloy steel boiler tubes to ASTM A213 / ASME SA213 in grades T11, T12, T22 and T91, with T5 and T9 available on request. Our tubes are supplied with IBR Form III-A for Indian boiler projects and serve superheater, reheater, waterwall and economiser sections of power and process boilers.
Matching the right chrome-moly grade to each boiler zone
Boiler tubes run under high internal steam pressure, high fire-side heat flux and metal temperatures well above the creep range of carbon steel. Alloy steel boiler tubes add chromium and molybdenum so they keep their strength, resist creep and stand up to steam-side oxidation. Grades are graded by temperature: T12 and T11 suit economisers, waterwalls and low-temperature superheaters, T22 suits final superheaters and reheaters, and T91 covers the hottest sections of supercritical and ultra-supercritical boilers.
All boiler tubes are seamless, hot finished or cold drawn, and heat treated to ASTM A213, with general requirements per ASTM A1016. For projects under the Indian Boiler Regulations (IBR), we supply tubes from IBR well-known mills with Form III-A certification. Each tube is hydrostatically or electrically (eddy current) tested, stencilled for traceability, and supplied with EN 10204 3.1 certificates.
Standard supply range for alloy steel boiler tubes
| Parameter | Details |
|---|---|
| Standard | ASTM A213, ASME SA213 |
| General Requirements | ASTM A1016 / A1016M |
| Grades | T11, T12, T22, T91 (T5, T9, T23 on request) |
| Type | Seamless – Hot Finished / Cold Drawn |
| Outside Diameter | 12.7 mm to 101.6 mm (1/2" – 4"); larger ODs on request |
| Wall Thickness | 1.65 mm to 12.7 mm, minimum or average wall |
| Length | Single Random, Double Random, Cut Length (up to 18 m) |
| Form | Straight, Bent, Serpentine Coils, Swaged Ends |
| Ends | Plain End, Bevelled End |
| Heat Treatment | As per A213 – Annealed / Normalized & Tempered (T91: N 1040–1080°C, T 730–800°C) |
| Surface | Black Painted, Varnished, Anti-rust Oil, Pickled |
| Testing | Hydrostatic or Eddy Current, Ultrasonic, Flattening, Flaring, Hardness, Tensile, PMI |
| Certificates | IBR Form III-A, EN 10204 3.1 / 3.2, TPI Reports |
International equivalents of common boiler tube grades
| Grade | ASTM | UNS | EN | DIN / W.Nr. | JIS | BS |
|---|---|---|---|---|---|---|
| T11 | A213 T11 | K11597 | 13CrMo4-5 | 1.7335 | STBA 23 | 3604 HFS 621 |
| T12 | A213 T12 | K11562 | 13CrMo4-5 | 1.7335 | STBA 22 | 3059 620-460 |
| T22 | A213 T22 | K21590 | 10CrMo9-10 | 1.7380 | STBA 24 | 3059 622-490 |
| T91 | A213 T91 | K90901 | X10CrMoVNb9-1 | 1.4903 | STBA 28 | – |
Weight %, as per ASTM A213
| Grade | C | Mn | P | S | Si | Cr | Mo | Others |
|---|---|---|---|---|---|---|---|---|
| T11 | 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 | – |
| T12 | 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 | – |
| T22 | 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 | – |
| T91 | 0.07 – 0.14 | 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 |
Minimum values at room temperature, as per ASTM A213
| Grade | Tensile Strength | Yield Strength (0.2%) | Elongation in 2" | Hardness (max) |
|---|---|---|---|---|
| T11 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 163 HBW / 85 HRB |
| T12 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 163 HBW / 85 HRB |
| T22 | 415 MPa (60 ksi) min | 205 MPa (30 ksi) min | 30% min | 163 HBW / 85 HRB |
| T91 | 585 MPa (85 ksi) min | 415 MPa (60 ksi) min | 20% min | 250 HBW / 25 HRC |
Typical values (for reference)
| Property | T11 / T12 | T22 | T91 |
|---|---|---|---|
| Density (g/cm³) | 7.85 | 7.83 | 7.77 |
| Modulus of Elasticity (GPa) | 205 | 206 | 218 |
| Thermal Conductivity at 100°C (W/m·K) | 37 | 36 | 26 |
| Mean Thermal Expansion 20–300°C (µm/m·°C) | 12.4 | 12.5 | 11.2 |
| Specific Heat (J/g·°C) | 0.46 | 0.46 | 0.46 |
| Approx. Max. Service Temperature | 565 – 595 °C | ≈ 600 °C | ≈ 650 °C |
Tube OD vs wall thickness (BWG / mm) – weight in kg/m
| OD (inch) | OD (mm) | 16 BWG (1.65) | 14 BWG (2.11) | 12 BWG (2.77) | 10 BWG (3.40) | 8 BWG (4.19) |
|---|---|---|---|---|---|---|
| 1/2" | 12.70 | 0.45 | 0.55 | 0.68 | 0.78 | – |
| 5/8" | 15.88 | 0.58 | 0.72 | 0.90 | 1.05 | – |
| 3/4" | 19.05 | 0.71 | 0.88 | 1.11 | 1.31 | 1.54 |
| 1" | 25.40 | 0.97 | 1.21 | 1.55 | 1.84 | 2.19 |
| 1 1/4" | 31.75 | 1.22 | 1.54 | 1.98 | 2.38 | 2.85 |
| 1 1/2" | 38.10 | 1.48 | 1.87 | 2.41 | 2.91 | 3.50 |
| 1 3/4" | 44.45 | 1.74 | 2.20 | 2.85 | 3.44 | 4.16 |
| 2" | 50.80 | 2.00 | 2.53 | 3.28 | 3.97 | 4.82 |
| 2 1/2" | 63.50 | 2.52 | 3.19 | 4.15 | 5.04 | 6.13 |
| 3" | 76.20 | 3.03 | 3.86 | 5.02 | 6.10 | 7.44 |
| 3 1/2" | 88.90 | 3.55 | 4.52 | 5.88 | 7.17 | 8.75 |
| 4" | 101.60 | 4.07 | 5.18 | 6.75 | 8.23 | 10.06 |
Column headings show BWG gauge with wall thickness in mm; values are weight in kg/m, calculated as (OD − WT) × WT × 0.02466. Heavier walls for high-pressure boilers are available on request. Values are nominal; actual weights may vary within ASTM A1016 tolerances.
Where alloy steel boiler tubes are used
Primary, platen and final superheater coils in T11, T22 and T91.
Low- and high-temperature reheater banks for hot reheat steam.
Furnace waterwall and membrane panels exposed to high heat flux.
Feedwater economiser coils recovering heat from flue gas.
Heat recovery modules behind gas turbines and process furnaces.
Utility, cogeneration and captive power boilers in steel, cement and sugar plants.
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 boiler tubes
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