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Inox Steel India is a leading supplier of ASTM A335 seamless alloy steel pipes for high-temperature and high-pressure service, used extensively in power plants, refineries, boilers, petrochemical units, chemical plants, and heater/reheater lines.
A335 P11, P22, and P91 are specially engineered to withstand:
These materials form the core of boiler & furnace piping systems, superheater & reheater coils, and high-pressure steam networks.
High-Temperature Service Pipes are used in systems where hot steam, hot gases, or high-temperature hydrocarbons flow at elevated pressure and temperature.
They must maintain:
And that’s exactly why industries use:
A335 P11 — The Versatile High-Temp Grade
A335 P91 — The Ultra-High-Temp Martensitic Grade
Used in main steam lines, hot reheat lines, high-pressure headers
A335 P22 — The Power Plant Workhorse
Raw Material Selection
High-quality alloy billets from vacuum-degassed steel.
Hot Piercing / Seamless Formation
Heat Treatment (Critical for P11/P22/P91)
Straightening & Dimensional Calibration
Mechanical & NDT Testing
Surface Treatment
Marking & Export Packaging
Grade • Heat No. • OD • WT • Standard • MTC attached.
| Property | P11 | P22 | P91 |
|---|---|---|---|
| High-Temp Strength | Medium | High | Very High |
| Creep Resistance | Medium | High | Extreme |
| Ideal Temperature (°C) | ~550°C | ~600°C | ~650–700°C |
| Weldability | Excellent | Good | Requires expertise |
| Cost | Lowest | Medium | Highest |
| Main Use | Steam & heater lines | Re-heaters, boilers | Supercritical power plants |
| Parameter / Property | A335 P11 | A335 P22 | A335 P91 |
|---|---|---|---|
| Material Type | Ferritic Alloy Steel | Ferritic Alloy Steel | Martensitic Alloy Steel |
| Main Alloying Elements | 1.25% Cr, 0.5% Mo | 2.25% Cr, 1% Mo | 9% Cr, 1% Mo-V-Nb |
| Temperature Capability | ~550°C | ~600°C | ~650–700°C |
| Delivery Condition | Normalized & Tempered | Normalized & Tempered | Normalized & Tempered |
| Min Yield Strength (MPa) | 205 | 275 | 415 |
| Min Tensile Strength (MPa) | 415 | 515 | 585 |
| Elongation (%) | 30 | 20 | 20 |
| Hardness (HB) | 163 Max | 179 Max | 250 Max |
| Creep Resistance | Medium | High | Very High |
| Fatigue Resistance | Moderate | High | Extreme |
| Pressure Capability | High | Higher | Highest |
| Pipe Type | Seamless | Seamless | Seamless |
| Available OD Range | ½” – 26″ | ½” – 26″ | ½” – 16″ |
| Wall Thickness Range | SCH 40 – XXS | SCH 40 – XXS | SCH 40 – XXS |
| Heat Treatment | N+T | N+T | N+T Mandatory |
| Equivalent Grades | EN 10216-2 13CrMo4-5 | EN 10216-2 10CrMo9-10 | EN 10216-2 X10CrMoVNb9-1 |
| Applicable Standards | ASTM A335 / ASME SA335 | ASTM A335 / SA335 | ASTM A335 / SA335 |
| HSN Code | 730419 | 730419 | 730419 |
Power Plants
Refineries
Petrochemical & Chemical Plants
Boiler OEMs & Fabricators
Fertilizer Plants
High-temperature service lines require materials that withstand heat, pressure, creep, thermal shock, oxidation, and fatigue. Below is the exact application and technical usage for each grade.
A335 P11 — Moderate High-Temperature Alloy Steel Pipe
Typical Applications
Service Characteristics
Industries
Refinery | Chemical | Petrochemical | OEM Boilers | Fertilizer
Sizes Available
A335 P22 — High Creep & High-Pressure Boiler Grade
Typical Applications
Service Characteristics
Industries
Power | Refinery | Petrochemical | Fertilizer | Thermal Energy
Sizes Available
A335 P91 — Ultra High-Temperature Martensitic Alloy Steel Pipe
Typical Applications
Service Characteristics
Industries
Supercritical thermal plants | Refinery heaters | Petrochemical | Boiler OEMs
Sizes Available
| NB Size | OD (mm) | SCH 40 WT (mm) | SCH 80 WT (mm) | SCH 160 WT (mm) |
|---|---|---|---|---|
| ½” | 21.3 | 2.77 | 3.73 | 4.78 |
| 1″ | 33.4 | 3.38 | 4.55 | 6.35 |
| 2″ | 60.3 | 3.91 | 5.54 | 8.74 |
| 3″ | 88.9 | 5.49 | 7.62 | 11.13 |
| 4″ | 114.3 | 6.02 | 8.56 | 13.49 |
| 6″ | 168.3 | 7.11 | 10.97 | 18.26 |
| 8″ | 219.1 | 8.18 | 12.70 | 23.01 |
| 10″ | 273.0 | 9.27 | 15.09 | 28.58 |
| 12″ | 323.9 | 9.53 | 17.48 | 33.32 |
| 16″ | 406.4 | 12.70 | 23.01 | 41.28 |
A335 P11 — Alloy Steel Seamless Pipe
| Type | INR/kg | USD/kg |
|---|---|---|
| P11 SCH 40 | ₹ 230 – ₹ 300 | $3.00 – $3.95 |
| P11 SCH 80 / 160 | ₹ 250 – ₹ 340 | $3.30 – $4.40 |
A335 P22 — High-Temp Alloy Steel Pipe
| Type | INR/kg | USD/kg |
|---|---|---|
| P22 SCH 40 | ₹ 260 – ₹ 340 | $3.50 – $4.50 |
| P22 SCH 80 / 160 | ₹ 280 – ₹ 380 | $3.80 – $5.10 |
A335 P91 — Ultra High-Temp Pipe
| Type | INR/kg | USD/kg |
|---|---|---|
| P91 SCH 40 | ₹ 450 – ₹ 600 | $6.00 – $8.00 |
| P91 SCH 80 / XXS | ₹ 500 – ₹ 700 | $6.50 – $9.30 |
✔ 730419 — Alloy Steel Seamless Pipes
✔ 730451 / 730459 — High-temperature alloy grades
A335 high-temp pipes require strict QA/QC because they operate in extreme temperature & pressure systems.
Mechanical Testing
Non-Destructive Testing (NDT)
Pressure Tests
Chemical & Metallurgical Tests
Documentation Provided
High-temperature systems require pipes that can withstand extreme heat, pressure, creep, oxidation, and thermal fatigue. Inox Steel India is a trusted supplier of A335 P11, P22, and P91 for Power Plants, Refineries, Chemical Plants, Petrochemical Units, and Boiler Manufacturers.
We specialize in heat-treated alloy steel pipes, especially P91, where metallurgical accuracy is critical.
Top Reasons to Choose Inox Steel India
🔥 Power Plants (Thermal / Supercritical / Ultra-Supercritical)
P91 / P22 are mandatory for these lines.
🛢 Refineries (Heater, Reformer, Steam Systems)
P11 / P22 widely used.
🏭 Petrochemical & Chemical Plants
🏗 Boiler OEMs & EPC Contractors
We support large OEMs with cut lengths, U-bending & fabrication.
Since P11, P22 & P91 are high-value alloy steel pipes, packaging is done with care.
✔ Export Packaging Includes:
🌍 Major Export Destinations
UAE • Saudi Arabia • Qatar • Oman • Kuwait • Bahrain
South Africa • Kenya • Nigeria • Egypt
Thailand • Malaysia • Vietnam • Indonesia
Italy • Poland • Netherlands • Spain
If you need high-temperature alloy steel pipes near Alankar Cinema (Mumbai), Inox Steel India supplies:
We dispatch same-day across Mumbai, Navi Mumbai, Thane & globally.
We support:
✔ Material selection (P11 vs P22 vs P91)
✔ Heat treatment & microstructure validation
✔ Boiler/steam line applications
✔ Shutdown & expansion projects
✔ Global export documentation
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
alloy@inoxsteelindia.in, steel@inoxsteelindia.in
+91 9930796690
P91 is mandatory for main steam & hot reheat lines in supercritical plants.
Because its martensitic structure must be formed correctly for creep strength.
Yes — SGS, BV, TUV, DNV, Lloyds can inspect material before dispatch.
Yes — bulk shipments to GCC, Europe, Africa & Southeast Asia.
SCH 80, SCH 160 & XXS for high-pressure lines.
Inox Steel India supplies high-quality, heat-treated, and project-approved A335 P11, P22 & P91 pipes for refineries, power plants, boilers, petrochemical units & global EPC contractors.