Home > Seamless Pipe > Alloy Steel Seamless Pipe
(Grades: ASTM A335 / ASME SA335 – P11, P22, P91 – Chrome-Moly Pipes)
Inox Steel India is a trusted manufacturer, supplier, stockist, and global exporter of Alloy Steel Seamless Pipes, supplying to critical industries across the GCC, Middle East, African Nations, Europe, and North & South America.
We specialize in Chrome-Moly alloy grades P11, P22 & P91, used for high temperature, high pressure, and creep-resistant applications in power plants, refineries, boilers, heat exchangers, petrochemical units, and HRSG systems.
As an ISO 9001, PED & IBR certified manufacturer, our Alloy Steel Seamless Pipes meet strict metallurgical, dimensional, and performance requirements as per ASTM A335, ASME SA335, EN, DIN, IBR & PED standards.
Industries rely on Inox Steel India for high integrity material, fast delivery, documentation accuracy, and export compliance.
An Alloy Steel Seamless Pipe is manufactured from steel containing specific percentages of chromium, molybdenum, vanadium, and niobium, designed to deliver superior strength, oxidation resistance, and thermal stability at elevated temperatures.
Unlike carbon steel, Chrome-Moly alloy pipes maintain structural integrity even under continuous cycle temperatures of 450–700 °C, making them critical for:
These pipes are seamless, meaning there is no welded joint, making them capable of withstanding:
Alloy Steel Seamless Pipes follow a precise production sequence:
P91 is the highest strength Chrome-Moly grade, ideal for extreme conditions (up to 650–700 °C).
✔ High-temperature resistance (450–700 °C)
✔ Exceptional creep strength
✔ Strong resistance to oxidation & scaling
✔ Better thermal fatigue performance
✔ Higher yield & tensile strength than carbon steel
✔ Superior dimensional stability
✔ Longer service life in boilers & superheaters
✔ Mandatory for power plant applications
Chrome-Moly pipes are the backbone of thermo-mechanical service lines where reliability is critical.
Below is our consolidated Alloy Steel Seamless Pipe Technical Datasheet comparing P11, P22 & P91.
ASTM A335 / ASME SA335 – P11, P22, P91 (Chrome-Moly)
| Parameter / Property | A335 P11 | A335 P22 | A335 P91 |
|---|---|---|---|
| Material Type | Chrome-Moly Alloy Steel | Chrome-Moly Alloy Steel | High Chrome – High Strength Alloy Steel |
| UNS Number | K11597 | K21590 | K91560 |
| Standard / Specification | ASTM A335 / ASME SA335 | ASTM A335 / ASME SA335 | ASTM A335 / ASME SA335 |
| Material Class | 1¼ Cr – ½ Mo | 2¼ Cr – 1 Mo | 9 Cr – 1 Mo – V – Nb |
| Temperature Service | High Temp (Up to 575 °C) | High Temp (Up to 600 °C) | Ultra High Temp (Up to 650–700 °C) |
| Tensile Strength (MPa) | 415 Min | 415 Min | 585 Min |
| Yield Strength (MPa) | 205 Min | 205 Min | 415 Min |
| Elongation (%) | 30% | 30% | 20% |
| Hardness (HBW) | 163 Max | 179 Max | 250 Max |
| Creep Resistance | Medium | High | Very High |
| Thermal Stability | Good | High | Excellent |
| Impact Toughness | Moderate | Good | High |
| Chemical Composition (%) | C ≤ 0.12, Cr 1–1.5, Mo 0.44–0.65 | C ≤ 0.15, Cr 1.9–2.6, Mo 0.87–1.13 | C 0.08–0.12, Cr 8–9.5, Mo 0.85–1.05, V, Nb |
| Heat Treatment | Normalized + Tempered | Normalized + Tempered | Normalized + Tempered |
| Manufacturing Method | Seamless | Seamless | Seamless |
| Equivalent EN / DIN Grades | 13CrMo44 | 10CrMo9-10 | X10CrMoVNb9-1 (P91) |
| Available Sizes (OD) | 12.7 – 660 mm | 12.7 – 660 mm | 21.3 – 660 mm |
| Schedules (Thickness) | SCH 20 – SCH XXS | SCH 20 – SCH XXS | SCH 20 – SCH XXS |
| Application Areas | Boiler Tubes, Superheaters, Heat Exchangers | Power Plants, Refineries, Petrochemicals | Ultra Supercritical Power Plants, HRSG, Steam Lines |
| End Finishes | Plain / Bevelled | Plain / Bevelled | Plain / Bevelled |
| Testing Requirements | Hydro, UT, Eddy Current, Hardness | Hydro, UT, Eddy Current | Hydro, UT, Hardness, Impact |
| HS Code / HSN Code | 7304.19.90 | 7304.19.90 | 7304.19.90 |
| Certifications | EN 10204 3.1/3.2, PED, IBR | EN 10204 3.1/3.2, PED, IBR | EN 10204 3.1/3.2, PED, IBR |
The table covers chemical composition, mechanical strength, heat treatment, temperature limits, hardness, creep strength, testing requirements, and dimensional availability — allowing engineers and procurement teams to select the correct grade for boilers, steam lines, and high-temperature service projects.
Maximum Operating Temperature
Choose P11 → P22 → P91 depending on heat load.
Stress Rupture Life & Creep Strength
Higher for P91 (required in supercritical plants).
Pressure Rating & Wall Thickness
Select appropriate Schedule: SCH 20, 40, 80, 120, 160, XXS.
Thermal Shock Conditions
P91 offers the best thermal fatigue performance.
Weldability Requirements
P11 & P22 are easier to weld; P91 requires PWHT.
Project Specification Compliance
EIL, NTPC, BHEL, ADNOC, ARAMCO, KNPC, SABIC, etc.
India:
GCC & Middle East:
Africa:
Europe & Americas:
Inox Steel India ensures fast export dispatch from JNPT, Mundra, Hazira, meeting all global documentation requirements.
Alloy Steel Seamless Pipes (Chrome-Moly) are engineered for high temperature, high pressure, and long-term creep resistance, making them essential in power plants, refineries, boilers, and petrochemical units.
Each grade—P11, P22, P91—is suitable for a specific temperature range and stress level.
ASTM A335 P11 – Medium Temperature Chrome-Moly Pipe
Temperature Range: up to 575 °C
Chromium-Moly Composition: 1¼ Cr – ½ Mo
Industries: Refinery, Petrochemical, Fertilizer, Mechanical
Applications:
Why P11?
ASTM A335 P22 – High Temperature Chrome-Moly Pipe
Temperature Range: up to 600 °C
Chromium-Moly Composition: 2¼ Cr – 1 Mo
Industries: Power Plants, Chemical Plants, Oil & Gas
Applications:
Why P22?
ASTM A335 P91 – Ultra High-Temperature Alloy Pipe
Temperature Range: 650–700 °C
Composition: 9 Cr – 1 Mo – V – Nb (martensitic alloy)
Industries: Ultra-Supercritical Power Plants, HRSG Systems
Applications:
Why P91?
| NPS (Inch) | OD (mm) | Wall (SCH 40) | Weight (kg/m) |
|---|---|---|---|
| ½″ | 21.3 | 2.77 | 1.27 |
| 1″ | 33.4 | 3.38 | 2.48 |
| 2″ | 60.3 | 3.91 | 5.44 |
| 4″ | 114.3 | 6.02 | 14.90 |
| 6″ | 168.3 | 7.11 | 28.26 |
| 8″ | 219.1 | 8.18 | 43.40 |
| 10″ | 273.1 | 9.27 | 63.20 |
| 12″ | 323.9 | 9.53 | 84.25 |
Prices vary by grade, heat treatment, thickness, and project requirements.
| Grade / Standard | Size Range (OD) | INR/kg (F.O.B Mumbai) | USD/kg (F.O.B India) | Common Use |
|---|---|---|---|---|
| A335 P11 | 12.7 – 660 mm | ₹ 220 – ₹ 290 | $ 2.65 – $ 3.50 | Boilers, Heat Exchangers |
| A335 P22 | 12.7 – 660 mm | ₹ 260 – ₹ 330 | $ 3.10 – $ 4.00 | Superheater / Reheater |
| A335 P91 | 21.3 – 660 mm | ₹ 380 – ₹ 520 | $ 4.60 – $ 6.30 | Main Steam / HRSG Lines |
✔ 7304.19.90
Applicable globally for Alloy Steel Seamless Pipes (Chrome-Moly / High Temp Service) used in power, refinery, boiler, and chemical industries.
Each Alloy Steel Seamless Pipe undergoes comprehensive QA/QC as per ASTM A335 & customer specification:
Every dispatch includes:
📄 MTC EN 10204 3.1 / 3.2
📄 IBR Approval (if applicable)
📄 PED CE Compliance
📄 Heat Number Traceability
If you are searching for a “Alloy Steel Seamless Pipe Supplier near Alankar Cinema, Mumbai”, Inox Steel India is one of the most trusted stockists and manufacturers of ASTM A335 P11, P22, and P91 Chrome-Moly pipes.
We supply across India and export regularly to the UAE, Saudi Arabia, Oman, Qatar, Kuwait, Nigeria, South Africa, Germany, Italy, USA, Brazil, Chile, Mexico, and more than 65+ countries.
With a strong inventory ranging from NPS ½″ to 26″ in multiple wall thicknesses (SCH 20 to XXS), we support EPC contractors, boiler manufacturers, turbine suppliers, refinery operators, and power plant developers with fast delivery, MTC documentation, and international certification support.
Your Trusted Source for Chrome-Moly Alloy Steel Seamless Pipes
| Industry | Application | Preferred Grade |
|---|---|---|
| Thermal Power Plants | Main Steam Lines • Reheat Lines | P22 / P91 |
| Oil & Gas Refineries | High Temp Process Piping | P11 / P22 |
| Petrochemical Units | Reactor Systems • Header Lines | P22 / P91 |
| Boilers & Heat Exchangers | Tubes • Superheaters | P11 / P22 |
| HRSG / CCPP Plants | Ultra High Temp Steam Lines | P91 |
| Chemical Plants | Steam Piping • Heater Tubes | P11 |
| Fertilizer Units | Utility Lines | P11 / P22 |
We follow globally accepted packaging methods:
Regular Export Destinations:
UAE · Oman · Saudi Arabia · Kuwait · Qatar · Bahrain · Nigeria · Kenya · Egypt · South Africa · Germany · UK · Italy · USA · Brazil · Mexico · Peru · Chile.
Our technical sales team responds within 24 hours with grade recommendation, price and lead time.
Whether you require P11 for boilers, P22 for high temperature service, or P91 for supercritical power plants, Inox Steel India supplies certified, tested, export-ready materials with complete documentation.
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
alloy@inoxsteelindia.in
+91 9930796690
7304.19.90 (Global classification for alloy steel seamless pipes).
Approx:
Yes — IBR-form certified P11, P22, and P91 pipes are available.
Yes — they require controlled welding conditions and mandatory PWHT.
Yes — regular exports to UAE, Oman, Saudi, Nigeria, Kenya, South Africa.
Whether you require P11 for boilers, P22 for high temperature service, or P91 for supercritical power plants, Inox Steel India supplies certified, tested, export-ready materials with complete documentation.
ISO Certified • IBR Approved • PED CE Marked • Trusted in 65+ Countries