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EN 10204 3.1 / 3.2, IBR
3rd-party inspection on every heat
1/8″ – 48″ NPS
SCH 10 to SCH XXS, ex-stock
Hot Finished Seamless
Cold drawn seamless on request
P91 • UNS K91560
9Cr-1Mo-V modified Chrome Moly steel
Up to 600–650°C
Highest creep strength in the P-series
ASTM A335 / ASME SA335
Dual code, every heat MTC-backed
Mill-Direct Pricing
Stockist rates, no broker markup
IBR + Third-Party Ready
SGS, Bureau Veritas, TUV, Lloyd’s witnessed
24–48 Hr Quotation
P91 pricing confirmed within 2 working days
Cut, Bevel & PWHT
Value-added shop services in-house
Direct Export Lanes
FCL/LCL to GCC, Africa & the Americas
Every Heat PMI-Tested
Positive Material Identification on 100% of stock
📌 Table of Contents
Aesteiron Steels LLP stocks and supplies ASTM A335 P91 Pipe a 9Cr-1Mo-V modified Chrome Moly grade built to handle the hottest highest-pressure sections of a power plant including superheater headers main steam lines and HRSG piping. Where ordinary P11 or P22 can no longer hold design margin above 600 degrees Celsius P91 becomes the specification engineers rely on.
Each length supplied under ASME SA335 P91 UNS K91560 goes through normalizing tempering and PMI verification before leaving our yard backed by dual ASTM and ASME certification along with EN 10204 3.1 and 3.2 test certificates while IBR Form III-C stays available on request.
Whether the order calls for a single test coupon or a full container load we move SA335P91 Boiler Steel Pipe ex-stock to EPCs boiler fabricators and piping stockists across the Middle East Africa and the Americas with documentation ready well before the pipe ships.
Core specification snapshot for buyers comparing mills and stockists.
Trusted ASTM A335 P91 Pipe Stockist in Mumbai holding ready stock across multiple pipe types to suit varied project needs.
Our Regular Export Destinations
Full ex-stock size band, ready to cut to drawing length.
1/8″ – 2″ NB, SCH 40 to XXS
2.5″ – 12″ NB, SCH 40 to SCH 160
14″ – 48″ NB, heavy wall on request
Send your OD and pressure rating – we'll match it against the SA335 P91 weight and schedule chart.
Indicative OD, wall thickness and unit weight for commonly ordered sizes.
| NPS | OD (mm) | Schedule | Wall Thk (mm) | Approx Wt (kg/m) |
|---|---|---|---|---|
| 4″ | 114.3 | SCH 80 | 8.56 | 22.32 |
| 1/2″ | 21.3 | SCH 160 | 5.08 | 2.03 |
| 16″ | 406.4 | SCH 40 | 12.70 | 123.31 |
| 1″ | 33.4 | SCH 20 | 3.38 | 2.50 |
| 6″ | 168.3 | SCH 20 | 7.11 | 28.26 |
| 20″ | 508.0 | SCH 10 | 3.68 | 45.79 |
| 3/4″ | 26.7 | SCH 80 | 3.91 | 2.20 |
| 10″ | 273.1 | SCH 40 | 9.27 | 60.31 |
| 2″ | 60.3 | SCH 10 | 2.29 | 3.28 |
| 24″ | 609.6 | SCH 20 | 17.78 | 259.40 |
| 1 1/4″ | 42.2 | SCH 40 | 3.56 | 3.39 |
| 12″ | 323.9 | SCH 80 | 12.70 | 97.50 |
| 3″ | 88.9 | SCH 40 | 5.49 | 11.29 |
ASTM A335 P91 pipe pressure rating is calculated per ASME B31.1/B31.3, varying by size, schedule, and design temperature.
Suitable for continuous operation up to 600–650°C, well beyond the limits of P11 or P22.
Its higher hot allowable stress compared to P22 allows a thinner wall for the same pressure rating, reducing overall weight.
We can calculate the exact allowable pressure for your specific NPS, schedule, and design temperature.
Chemical composition is based on ladle analysis, in accordance with ASTM A335 / ASME SA335 requirements.
| Element | Cr | C | Mo | Mn | V | Si | Nb | Ni | N | P | Al | S |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wt % | 8.00–9.50 | 0.08–0.12 | 0.85–1.05 | 0.30–0.60 | 0.18–0.25 | 0.20–0.50 | 0.06–0.10 | ≤0.40 | 0.030–0.070 | ≤0.020 | ≤0.040 | ≤0.010 |
Minimum room-temperature mechanical requirements, normalized & tempered condition.
The same alloy is recognized worldwide under these regional designations.
Reliable ASTM A335 P91 Pipe Stockist in Mumbai holding normalized and tempered stock ready for supply.
Post-weld heat treatment recommended at 750–770°C for field joints
730–800°C, minimum 1 hour, restores toughness while retaining strength
1040–1080°C, air cooled to develop full martensitic transformation
Quick side-by-side to help select the right grade for design temperature and pressure.
| Parameter | ASTM A335 P91 Pipe | ASTM A335 P11 Pipe | ASTM A335 P22 Pipe |
|---|---|---|---|
| Tensile Strength | 585 MPa min | 415 MPa min | 415 MPa min |
| Molybdenum | ~1% | ~0.5% | ~1% |
| Max Design Temp | 600–650°C | ~540°C | ~580°C |
| Chromium | ~9% | ~1.25% | ~2.25% |
HS codes may vary by destination; we confirm the exact code on your shipping invoice.
Final pricing depends on a combination of size, testing, quantity, and prevailing alloy costs.
Cr/Mo/V index
MOQ vs bulk
OD & wall
3.1 vs 3.2 vs IBR
Established ASTM A335 P91 Pipe Supplier in India issuing EN 10204 3.1/3.2 certification for every batch.
Radiography
100% Tested
EN 10204 3.2
Ultrasonic
Form III-C
EN 10204 3.1
Every heat is Positive Material Identification tested and backed by a traceable Mill Test Certificate before it leaves the shop.
Recognized ASTM A335 P91 Pipe Supplier in India holding wall thickness tolerance within specified limits.
Trusted ASTM A335 P91 Pipe Exporter in India supplying pipe in black and varnish-coated finish.
Dependable ASTM A335 P91 Pipe Supplier in India supplying pipe for boiler headers and HRSG piping.
Fertilizer & Petrochemical Plants
Main Steam & Hot Reheat Lines
Nuclear & Fossil Power Plant Piping
Refinery High-Temp Process Lines
HRSG Piping, Combined Cycle Plants
Superheater & Reheater Headers
Waste-to-Energy Boiler Systems
Steam Generator Interconnecting Piping
Correct preheat, interpass control, and post-weld treatment are essential to avoid cracked joints.
750–770°C post-weld heat treatment, no exceptions on P91 joints
Controlled below 400°C to avoid untempered martensite
ER90S-B9 (GTAW root) / E9015-B9 (SMAW fill), matching 9Cr-1Mo-V chemistry
200–300°C minimum, held through welding & interpass
Dependable ASTM A335 P91 Pipe Stockist in Mumbai preparing export-ready packing for prompt dispatch.
VCI-wrapped, end-capped and heat-number stenciled export packing keeps your pipe corrosion-free in transit.
Recognized ASTM A335 P91 Pipe Exporter in India sourcing only from approved global mill brands.
Vallourec
Tenaris
Salzgitter Mannesmann
Nippon Steel
Jindal SAW
ISMT
Maharashtra Seamless
TPCO
Aesteiron maintains and distributes Vallourec, Tenaris, Jindal SAW, ISMT, Salzgitter Mannesmann and TPCO origin ASTM A335 P91 Pipe across regional stock points in the Middle East, Africa and the Americas, as one of India's active P91 Pipe Stocking Distributors ensuring consistent stock availability.
Stockholder for Jindal SAW & ISMT P91 Pipe Stockholder
Stockist of Jindal SAW & MSL P91 Pipe Stockist
Distributor for TPCO & Sumitomo P91 Pipe Distributor
Supplier of Vallourec & ISMT P91 Pipe Supplier
Authorised Stockist of Jindal SAW & ISMT P91 Pipe Stockist
Supplier of TPCO & MSL Alloy P91 Pipe Supplier
Stocking Distributor for Tenaris & Vallourec P91 Pipe Distributor
Supplier of Vallourec & ISMT High Alloy P91 Pipe Supplier
Stockist of Vallourec & Sumitomo P91 Pipe Stockist
Stockholder for Tenaris & Salzgitter Mannesmann P91 Pipe Stockholder
Distributor for Tenaris & Vallourec P91 Pipe Distributor
Stocking Distributor for Salzgitter Mannesmann P91 Pipe Distributor
Stockholder for ISMT & Jindal SAW P91 Pipe Stockholder
Supplier of Vallourec & TPCO Seamless P91 Pipe Supplier
Stocking Distributor for ISMT & Jindal SAW P91 Pipe Distributor
Stockist of Vallourec & Tenaris P91 Pipe Stockist
Share size, schedule & quantity – we quote CIF/FOB with MTC in 48 hours.
Recent P91 Pipe orders executed for EPCs, IPPs and boiler fabricators across the Middle East, Africa and USA.
4″ SCH 80, normalized & tempered, PMI & hydro-tested, EN 10204 3.1 MTC.
Refinery EPC Contractor, Saudi Arabia
JUBAIL INDUSTRIAL CITY, KSA6″ SCH 120, seamless, PWHT at 760°C, third-party witnessed.
Combined Cycle Power Plant, USA
HOUSTON, USA8″ SCH 80, ASME SA335 P91, IBR Form III-C, EN 10204 3.2 MTC.
Independent Power Producer, Nigeria
LAGOS, NIGERIA3″ SCH 160, beveled ends, PMI verified, SGS inspected.
Gas Processing Facility, Egypt
CAIRO, EGYPT10″ SCH 80, PWHT & PMI certified, EN 10204 3.2 MTC.
Thermal Power Station, South Africa
JOHANNESBURG, SOUTH AFRICA12″ SCH 100, hot-bending & PWHT, third-party witnessed.
EPC Contractor, Ethiopia
ADDIS ABABA, ETHIOPIASuperheater/reheater headers, main steam lines and HRSG piping in high-temperature service up to 650°C.
UNS K91560, a 9Cr-1Mo-V alloy steel.
P91 has ~9% Chromium plus Vanadium for higher creep strength; P22 has ~2.25% Chromium with no Vanadium.
Yes, IBR Form III-C is available on request, along with EN 10204 3.1/3.2 MTCs.
Normalizing at 1040–1080°C, followed by tempering at 730–800°C.
Why Aesteiron?
Tools & Downloads
Conclusion
ASTM A335 P91 Pipe, UNS K91560, is the modified Chrome Moly grade to specify wherever design temperature or creep life pushes past what P11 or P22 can deliver. Buyers across India, the Middle East, Africa and the Americas trust Aesteiron Steels LLP as a responsive P91 Pipe stockist for quick, certified quotes.
Quick form – quote in 2 hours.
