ASTM A335 P91 Alloy Seamless Pipes in seamless and welded to ASTM A 335. Get quotes from verified suppliers on MetalMitra.
- ASTM A335 P91 Alloy Seamless Pipes
- Grade 91
- Seamless
- ERW
- Welded
- EFW
- LSAW
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Specifications
| Dimensions | ASTM, ASME and API |
|---|---|
| Standard | ASTM A 335 / ASME SA 335 |
| Size | 1/2" NB to 36" NB |
| Schedule | SCH 40, SCH 80, SCH 160, SCH XS, SCH XXS, All Schedules, upto 12mm thk |
| Outer Diameter | 19.05mm – 114.3mm |
| Wall Thickness | 2.0mm – 14 mm |
| Type | Seamless |
| End | Plain End, Beveled End, Threaded |
| Form | Round, Square, Rectangular, Hydraulic Etc |
| Length | Single Random, Double Random & Required Length, Custom Size – 12 Meter lengths |
Grades & standards
- ASTM A335
Source ASTM A335 P91 Alloy Seamless Pipes from verified mills, manufacturers and stockists on MetalMitra. Options span seamless and welded, produced to ASTM A 335, and every order can ship with an EN 10204 3.1 certificate.
Choose seamless, ERW, welded or fabricated construction across a broad spread of diameters, wall thicknesses, schedules and lengths for process, pressure and structural lines.
Grade 91 is a 9Cr-1Mo-V creep-strength-enhanced ferritic steel used for high-temperature, high-pressure power plant service. Controlled additions of chromium, molybdenum, nickel or vanadium give alloy steel higher strength, deeper hardenability, better toughness and stronger performance at elevated temperature.
What you can source
- Seamless Pipes — The go-to choice for high-pressure and high-temperature lines.
- ERW Pipes — Economical welded pipe for utility and process piping.
- Welded / EFW Pipes — Fusion-welded construction for large-diameter runs.
- Tubes — Round, square and rectangular tubes, plus U-bends for heat exchangers.
Key properties
- High-Temperature Strength — Chrome-moly chemistry keeps its strength when temperatures climb.
- Creep Resistance — Proven in long-term, high-temperature pressure service.
- Hardenability — Heat-treats well to dial in strength and toughness.
- Durability — Performs reliably under heavy mechanical loads.
Pipes Tolerance – Grade 91
| NPS | OD Tolerance | NPS | WT Tolerance |
|---|---|---|---|
| 1/8" ≤ NPS ≤ 1 1/2" | +/- 0.4 | 1/8" ≤ NPS ≤ 2 1/2" , All T/D ratios | +20%, -12.5% |
| 1 1/2 < NPS ≤ 4" | +/- 0.79 | NPS ≥ 2 1/2" , T/D ≤ 5% | +22.5%, -12.5% |
| 4" < NPS ≤ 8" | +1.59, -0.79 | NPS ≥ 2 1/2" , T/D > 5% | +15%, -12.5% |
| 8" < NPS ≤ 12" | +2.38, -0.79 | (T= Specified Wall Thickness; D = Specified Outside Diameter) | — |
Applications & industries
- Power Plants
- Boilers
- Refineries
- Petrochemical
- Oil & Gas
- Heat Exchangers
- Automotive
- Engineering Components
- Pressure Vessels
- Heavy Machinery
- Fabrication
- General Engineering
Testing & documentation
Inspection and documentation for ASTM A335 P91 Alloy Seamless Pipes follow the applicable standard plus any extra requirements in your PO.
- Dimensional & visual inspection
- Grade verification against the order
- Chemical composition verification
- Mechanical property testing
- Flattening / flaring tests as applicable
- Hydrostatic testing as applicable
- Ultrasonic / eddy current testing as applicable
- EN 10204 3.1 Mill Test Certificate
- Third-party inspection (TPI) on request
Material properties
Chemical composition and mechanical properties are supplied to the limits of the governing material standard. Actual heat values are reported on the mill test certificate shared with each consignment.
Why source on MetalMitra
- Verified suppliers — Mills, manufacturers and stockists are reviewed by the MetalMitra team before they list.
- One RFQ, several quotes — Share size, grade and quantity once and compare offers side by side.
- Full traceability — Heat numbers, EN 10204 3.1 MTCs and third-party inspection on request.
- Delivered worldwide — Export-worthy packing and shipping to India, the Middle East, Africa, Europe and the Americas.
Request pricing
Post an RFQ for ASTM A335 P91 Alloy Seamless Pipes with your drawing or specification and receive quotes from verified suppliers.
Technical note: Values on this page are for reference. Always confirm against the governing standard, your purchase specification and the mill test certificate.
Applications & industries
- Power Plants
- Boilers
- Refineries
- Petrochemical
- Oil & Gas
- Heat Exchangers
- Automotive
- Engineering Components
- Pressure Vessels
- Heavy Machinery
- Fabrication
- General Engineering
- Oil & Gas
- Petrochemical & Refining
- Power Generation
- Chemical Processing
- Automotive
Testing & documents
Ask for the documents you need in your requirement — suppliers confirm them in their quotation:
- Mill test certificate to EN 10204 3.1, or 3.2 with third-party witness
- Third-party inspection (TPI) by SGS, Bureau Veritas, TÜV or your nominated agency
- Tests as the standard or your order requires: hydro, PMI, IGC, NDT, hardness or impact tests
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