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ASTM A213 T91 Alloy Steel Seamless Tubes

Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes

ASTM A213 T91 Chrome Moly Seamless Tube (9Cr-1Mo-V-Nb)

ASME SA213 Grade T91 CSEF alloy steel boiler, superheater and reheater tubing


ASTM A213 T91 creep-strength-enhanced ferritic alloy steel seamless tubes

Savoy Piping Inc. supplies ASTM A213 T91 / ASME SA213 Grade T91 seamless tubes — the 9Cr-1Mo-V-Nb creep-strength-enhanced ferritic (CSEF) grade specified for modern high-pressure, high-temperature superheater and reheater service.

T91 is not “just another chrome moly tube.” Vanadium, niobium and controlled nitrogen create a tempered martensitic microstructure with strong creep resistance — which also means welding, PWHT and hardness control are non-negotiable. Soft or over-hard HAZs are a known risk if procedures slip.

What serious buyers ask for: heat chemistry within T91 limits, correct normalise-and-temper practice, hardness within specification, PMI, and complete EN 10204 documentation. For IBR-linked work, SA213 T91 with Form III-C may also be required.

Companion products: pipe grade ASTM A335 P91, plus conventional tube grades T22 and T11.

Also see: Alloy steel seamless hub · Chrome moly hub · Materials hub.

ASTM A213 T91 Alloy Steel Seamless Pipe Range

A213 T91 Alloy Steel Seamless Tubes Specification ASTM A213 / ASME SA213
A213 T91 Alloy Steel Seamless Tubes Grades ASTM A213 T5, ASTM A213 T9, ASTM A213 T11, ASTM A213 T22, ASTM A213 T91, ASME SA213 T5, ASME SA213 T9, ASME SA213 T11, ASME SA213 T22, ASME SA213 T91
A213 T91 Alloy Steel Seamless Tubes Type Seamless - Hot Rolled / Cold Drawn
A213 T91 Alloy Steel Seamless Tubes Outer Diameter Size A213 - 3/8" NB to 30" NB (Nominal Bore Size)
A213 T91 Alloy Steel Seamless Tubes Wall Thickness Schedule 20 to Schedule XXS (Heavier On Request) Up to 250 mm Thickness
A213 T91 Alloy Steel Seamless Tubes Length 5 to 7 Meters, 09 to 13 Meters, Single Random Length, Double Random Length And Customize Size.
A213 T91 Alloy Steel Seamless Tubes Pipe Ends Plain Ends / Beveled Ends / Coupling
A213 T91 Alloy Steel Seamless Tubes Delivery Conditions As Rolled, Cold Drawn, Normalizing Rolled, Thermomechanical Rolled / Formed, Normalizing Formed, Normalized and Tempered / Quenched and Tempered - BR / N / Q /T
A213 T91 Alloy Steel Seamless Tubes Coating Epoxy Coating / Colour Paint Coating / 3LPE Coating.
A213 T91 Alloy Steel Seamless Tubes Other Testing Tensile Test, Transverse Tension Tests, Flattening Test, Metal Structure and Etching Tests, Photomicrographs, Hardness Tests, etc.
A213 T91 Alloy Steel Seamless Tubes Dimension All Pipes Is Manufactured and Inspected / Tested to the Relevant standards including ASTM, ASME, API.
A213 T91 Alloy Steel Seamless Tubes Value Added Services Draw / Expansion / Machining / Sand Blasting / Shot Blasting / Galavanizing / Heat Treatment
A213 T91 Alloy Steel Seamless Tubes Packaging Loose / Bundle / Wooden Pallet / Wooden box-a / Plastic Cloth Wraps / Plastic End Caps / Beveled Protector
A213 T91 Alloy Steel Seamless Tubes Shipment & Transportation By Road - Truck / Train, By Sea - Break-bulk Conventional Vessel / FCL (Full Container Load) / LCL (Less Container Load) / 20 Feet Container / 40 Feet Container / 4 Feet Container / High Cube Container / Open Top Container, By Air - Freighter Civil Passenger and Cargo Planes
A213 T91 Alloy Steel Seamless Tubes Material Test Certificate Manufacturer Test Certificate As Per EN10204 3.1, 3.2 / Laboratory Test Certificate From NABL Approved Lab. / Under Third Party Inspection Agency Like SGS, TUV, DNV, LLOYDS, ABS ETC

What is ASTM A213 T91 tube?

ASTM A213 / ASME SA213 Grade T91 is seamless ferritic alloy-steel tubing often called modified 9Cr-1Mo. Typical chemistry includes roughly 8.00–9.50% Cr, 0.85–1.05% Mo, plus vanadium, niobium and nitrogen within specified ranges.

The grade delivers high creep rupture strength so designers can run higher steam temperatures/pressures — or reduce wall thickness versus older Cr-Mo tubes. Fabrication must follow CSEF best practice: controlled heat input, correct consumables, and carefully executed PWHT.

T91 is the tube counterpart to A335 P91 pipe. For even more demanding USC designs, some projects evaluate T92 / P92 families; confirm availability and approved class before substitution.

Typical applications of ASTM A213 T91 tube

  • Superheater and reheater tubes in supercritical / advanced thermal power plants
  • High-temperature boiler sections designed around CSEF 9Cr material
  • High-efficiency HRSG hot sections (project-dependent)
  • Critical heat-transfer tubing needing modified 9Cr creep strength
  • Matched CSEF systems with A335 P91 headers and piping

T91 vs T22 vs T9 — quick buyer guidance

T91 is the CSEF modified 9Cr tube for supercritical steam duty. T22 remains the conventional 2.25Cr-1Mo choice for many subcritical hot sections. Classic T9 is a traditional 9Cr-1Mo process/heater grade — not a drop-in for T91. Matching pipe: A335 P91.

ASTM A213 T91 Alloy Steel Seamless Tubes chemical compositions

Composition, %
Grade UNS Designation Carbon Manganese Phosporus Sulphur Silicon Nickel Chromium Molybdenum Vanadium Niobium Aluminium Other Elements
T5 K4154 0.15 0.30-0.60 0.025 0.025 0.50 … 4.00-6.00 0.4-0.65 …
T9 K90941 0.15 max 0.30-0.60 0.025 0.025 0.25-1.00 … 8.00-10.00 0.90-1.10 …
T11 K11597 0.05-0.15 0.30-0.60 0.025 0.025 0.50-1.00 … 1.00-1.50 0.44-0.65 …
T22 K2159 0.05-0.15 0.30-0.60 0.025 0.025 0.50 … 1.9-2.60 0.87-1.13 …
T91 K991 0.07-0.14 0.30-0.60 0.02 0.010 0.20-0.50 0.4 8.0-9.5 0.85-1.05 0.18-0.25 0.06-0.10 0.02 Ti 0.01 ZR 0.01

ASTM A213 T91 Seamless Tubes Permissible Variation in Wall Thickness

Hot rolled Outside Diameter, mm Tolerance, %
OD≤101.6, WT≤2.4 +40/-0
OD≤101.6, 2.4＜WT≤3.8 +35/-0
OD≤101.6, 3.8＜WT≤4.6 +33/-0
OD≤101.6, WT>4.6 +28/-0
OD>101.6, 2.4＜WT≤3.8 +35/-0
OD>101.6, 3.8＜WT≤4.6 +33/-0
OD>101.6, WT>4.6 +28/-0
Cold Drawn Outside Diameter, mm Tolerance, %
OD≤38.1 +20/-0
OD>38.1 +22/-0

ASTM A213 T91 Tubes Permissible Variations in Outside Diameter

Hot rolled Outside Diameter, mm Tolerance, mm
OD≤101.6 +0.4/-0.8
101.6＜OD≤19.5 +0.4/-1.2
19.5＜OD≤228.6 +0.4/-1.6
Cold Drawn Outside Diameter, mm Tolerance, mm
OD＜25.4 ±0.10
25.4≤OD≤38.1 ±0.15
38.1＜OD＜50.8 ±0.20
50.8≤OD＜63.5 ±0.25
63.5≤OD＜76.2 ±0.30
76.2≤OD≤101.6 ±0.38
101.6＜OD≤19.5 +0.38/-0.64
19.5＜OD≤228.6 +0.38/-1.14

SUPPLEMENTARY REQUIREMENT for ASTM A213 T91 Seamless Tubes

S1. STRESS-RELIVED ANNEALED Tubes
S2. STABILIZING HEAT TREATMENT
S3. UNSTRAIGHTENED Tubes
S4. INTERNGRANULAR CORROSION TEST

Frequently asked questions — ASTM A213 T91

What is ASTM A213 T91 used for?

ASTM A213 T91 is used for high-temperature, high-pressure boiler tubing — especially superheater and reheater tubes in supercritical power plants — where creep strength of modified 9Cr-1Mo is required.

What is the difference between T91 and T22?

T22 is conventional 2.25Cr-1Mo chrome moly. T91 is a vanadium-niobium modified 9Cr CSEF steel with much higher creep strength for advanced steam temperatures. They are not interchangeable without design review.

Why is hardness control important for T91?

Incorrect welding or PWHT can leave soft or overly hard zones that hurt creep life or toughness. Projects usually require documented hardness surveys after heat treatment for T91 tubing and attachment welds.

Can Savoy Piping supply T91 with 3.1 / 3.2 certificates?

Yes. We supply ASTM A213 / ASME SA213 T91 seamless tubes with EN 10204 3.1 or 3.2 MTCs, and can support third-party inspection and IBR documentation when required.

Supplying ASTM A213 T91 Alloy Steel Seamless Tubes to Countries -

We Export ASTM A213 T91 Alloy Steel Tubes to Saudi Arabia, Iran, Iraq, United Arab Emirates, Qatar, Bahrain, Oman, Kuwait, Turkey, Egypt, Yemen, Syria, Israel, Jordan, Cyprus, Singapore, Malaysia, Indonesia, Thailand, Vietnam, South Korea, Japan, Sri Lanka, Maldives, Bangladesh, Myanmar, Taiwan, Cambodia, Argentina, Bolivia, Brazil, Chile, Venezuela, Colombia, Ecuador, Guyana, Paraguay, Uruguay, United States of America, Canada, Mexico, Panama, Costa Rica, Puerto Rico, Trinidad And Tobago, Jamaica, Bahamas, Denmark, Russia, Norway, Germany, France, Italy, United Kingdom, Spain, Ukraine, Netherlands, Belgium, Greece, Czech Republic, Portugal, Hungary, Albania, Austria, Switzerland, Slovakia, Finland, Ireland, Croatia, Slovenia, Malta, Nigeria, Algeria, Angola, South Africa, Libya, Egypt, Sudan, Equatorial Guinea, The Republic Of Congo, Gabon, Europe, Africa, Asia, North America, South America, Middle East, Far East.etc

Savoy Piping Inc. is a well known worldwide Exporter of ASTM A213 T91 Alloy Steel Seamless Tubes, Savoy Piping Inc. is committed to provide each and every customer with the highest standard of customer service. We deal in A213 T91 Alloy Steel Seamless Tubes in India and Overseas, offering a wide range of ASTM A213 T91 Alloy Steel Seamless Tubes