Alloy Steel T91 Tubes – SA213 T91 Seamless Boiler & Superheater Tube Supplier
ASC LLP, Mumbai, supplies alloy steel T91 tubes to ASME SA213 / ASTM A213 Grade T91 (Type 1 or Type 2). We supply straight lengths, U-bends and coils for boiler superheaters, reheaters and HRSGs, with EN 10204 3.1 certificates and IBR or third-party inspection on request.
For the full material specification – composition, Type 1 vs Type 2, heat treatment and equivalents – see our SA213 T91 tubes page. This page covers supply: sizes, tube forms, inspection, documents and ordering.
T91 Tube Supply Range
- Specification: ASME SA213 / ASTM A213 T91, Type 1 or Type 2 (UNS K90901)
- OD: about 12.7 – 127 mm (½” – 5″); wall 1.5 – 12.7 mm, average or minimum wall
- Condition: normalised and tempered (N+T), hot-finished or cold-drawn
- Lengths: fixed lengths to boiler drawing, typically up to about 12 m; longer on request
- Testing: tension, flattening, flaring, hardness, hydro or eddy-current / UT, PMI
T91 Tube Forms We Supply
- Straight tubes – cut to exact length, ends square-cut or bevelled for welding.
- U-bend tubes – bent to drawing; for T91, bends are re-heat-treated (normalised and tempered, or tempered) as the code and bend radius require.
- Coils and serpentine sections – for superheater and reheater panels, to drawing.
- Header nipples and stub tubes – short lengths for headers and manifolds.
Inspection, IBR & Documents
- EN 10204 3.1 mill test certificate as standard; 3.2 with third-party inspection (TÜV, BV, SGS, Lloyd’s, EIL, etc.) on request.
- IBR – tubes for Indian boilers can be supplied with IBR certification (Form III-A).
- PMI of every tube or a sample to confirm Cr and Mo, to prevent mix-ups with T22 or carbon steel.
- Hardness check – 190 – 250 HBW on the certificate and on spot checks.
Buying guide: what to check before buying A213 T91 tubes.
Common T91 Tube Sizes & Weights
| OD (mm) | Wall (mm) | ID (mm) | Weight (kg/m) |
| 31.8 | 3.6 | 24.6 | 2.48 |
| 38.1 | 4.0 | 30.1 | 3.33 |
| 38.1 | 5.0 | 28.1 | 4.04 |
| 44.5 | 5.0 | 34.5 | 4.82 |
| 50.8 | 5.6 | 39.6 | 6.18 |
| 50.8 | 7.1 | 36.6 | 7.57 |
| 57.0 | 6.3 | 44.4 | 7.80 |
| 63.5 | 8.0 | 47.5 | 10.84 |
Typical superheater and reheater sizes – any OD × wall within the A213 range can be supplied. Tubes are ordered by OD × wall, not by pipe schedule; for NPS pipe sizes see A335 P91. Weights calculated at 7.77 g/cm³.
T91 Tube Mechanical Properties
| Property | SA213 T91 |
| Tensile strength, min. | 585 MPa (85 ksi) |
| Yield strength, min. | 415 MPa (60 ksi) |
| Elongation in 50 mm, min. | 20% |
| Hardness | 190 – 250 HBW (196 – 265 HV) |
T91 Chemical Composition (Summary)
| Element | SA213 T91 Type 1 (%) |
| Carbon (C) | 0.07 – 0.14 |
| 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 |
| Manganese (Mn) | 0.30 – 0.60 |
| Silicon (Si) | 0.20 – 0.50 |
| P / S, max. | 0.020 / 0.010 |
| Ni / Al / Ti / Zr, max. | 0.40 / 0.02 / 0.01 / 0.01 |
Type 2 has tighter residual limits. Full details and heat treatment: SA213 T91 tubes.
Physical Properties & Equivalent
| Property | Value (approx.) |
| Density | 7.77 g/cm³ |
| Thermal conductivity (20 °C) | ≈ 26 W/m·K |
| Thermal expansion (20 – 100 °C) | ≈ 10.5 – 11 µm/m·K |
| Equivalent EN grade | X10CrMoVNb9-1 (1.4903) |
Applications of Alloy Steel T91 Tubes
- Utility boilers: final superheater and reheater tubes, superheater outlet sections
- HRSGs: high-pressure superheater and reheater tubes in combined-cycle plants
- Industrial and waste-to-energy boilers: high-temperature superheater coils
- Headers and links: stub tubes and connecting tubes
More: T91 tubes in power generation, welding T91 tubes and T91 in steam environments.
How to Order T91 Tubes
- Specification and type: SA213 T91 Type 1 or Type 2
- OD × wall (state average or minimum wall) and length
- Form: straight, U-bend (radius, leg lengths) or coil (drawing)
- Inspection: IBR, third-party, PMI, extra NDT
- Quantity (number of tubes or metres)
Matching products: P91 pipes, WP91 fittings, F91 fittings and T11 tubes. Send your enquiry to sales@amardeepsteel.com, call 022-67439130 or contact us. See all our boiler tubes.
Frequently Asked Questions – Alloy Steel T91 Tubes
What sizes are alloy steel T91 tubes available in?
SA213 T91 tubes are supplied from about 12.7 to 127 mm (1/2″ to 5″) OD with walls from about 1.5 to 12.7 mm, in fixed lengths, U-bends or coils to drawing.
Can T91 tubes be supplied with IBR certification?
Yes. T91 tubes for boilers in India can be supplied with IBR certification (Form III-A), and third-party inspection can be arranged on request.
What should I check on a T91 tube test certificate?
Check the specification and type (SA213 T91 Type 1 or 2), normalising and tempering temperatures, full chemistry including Nb and N, tensile results, and hardness within 190–250 HBW.
Are T91 U-bends heat-treated after bending?
Depending on the bend radius and the applicable code, T91 U-bends are re-heat-treated after bending – either normalised and tempered or tempered – to restore the required structure and hardness.
What is the difference between T91 tubes and P91 pipes?
They are the same 9Cr-1Mo-V material. T91 is seamless tube to ASTM A213, ordered by OD × wall up to 5″ OD; P91 is seamless pipe to ASTM A335 in NPS sizes and schedules.
Where are T91 tubes used?
T91 tubes are mainly used for high-temperature superheater and reheater tubes in utility boilers and HRSGs, and for header stub tubes.
Global Reach
ASC LLP supplies alloy steel boiler tubes, pipes and fittings to boiler makers, power plants and EPC contractors in the USA, Europe, the Middle East and Asia, with secure packing and full documentation. Buyers worldwide rely on our alloy steel T91 tubes for certified material and traceability.
Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.
