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A335 / A106 Heavy Schedule High-Pressure Pipe Supplier — Inox Steel India

Inox Steel India is a trusted supplier of High-Pressure seamless pipes in ASTM A335 (P-Grades) and ASTM A106 (CS) with Heavy Schedules (SCH 80, SCH 160 & SCH XXS).

These pipes are specially engineered to handle:

  • Extremely high internal pressure
  • High-temperature steam/hydrocarbon flow
  • Rapid temperature fluctuations
  • Erosion & corrosion under stress
  • Long-term creep & fatigue loading
  • Severe refinery & power plant conditions

Heavy wall thickness is mandatory for pressure integrity, especially in boiler circuits, steam networks, reformer coils, heater lines, and power plant high-pressure headers.

Inox Steel India supplies these pipes fully certified and inspection-ready for Boiler, Power Plant & Refinery EPC requirements.

Table of Contents

Understanding High-Pressure Service — Why Heavy SCH Is Mandatory

High-Pressure Service is defined as operation where:

  • Internal pressure is beyond standard design limits
  • Temperature exceeds 400°C–700°C
  • Steam velocity and density increase stress on pipe walls
  • Hydrocarbon feed lines run under high operating pressure
  • Pressure surges, pulses & fatigue loads are common

Standard thickness pipes cannot survive these conditions.
Therefore Heavy-Schedule Pipes are used:

✔ SCH 80
✔ SCH 160
✔ SCH XXS (Extra Extra Strong)

These ensure:

  • Higher allowable working pressure
  • Delayed creep deformation
  • Better thermal fatigue life
  • Increased corrosion allowance
  • Stronger weld joints
  • Longer operational lifespan in severe duty

Why A335 (P-Grades) + A106 Are Used Together

High-pressure networks often require dual-material sections:

System Area Recommended Material Why
High-Temperature Main Steam A335 P91 / P22 Superior creep + heat resistance
Superheater / Reheater Piping A335 P22 / P91 Handles 550–700°C
High-Pressure Hydrocarbon Lines A106 Gr C Strong + good weldability
Furnace/Heater Piping A335 P11 / P22 Chrome-Moly heat resistance
Power Plant HP Header Lines A335 P91 Maximum strength & creep life
Refinery HP Process Lines A106 Gr B / C (Heavy SCH) High pressure stability

A335 provides temperature endurance,
while A106 provides pressure resistance inside refineries.

Manufacturing Process — Precision for High-Pressure Durability

Steel Billet Selection

  • Vacuum-degassed alloy steel (A335)
  • High-carbon billets (A106)

Seamless Pipe Formation

  • Hot piercing
  • Plug / mandrel mill rolling
  • Stretch reduction

Heavy Wall Sizing

  • Heavy-SCH sizing mills
  • Outer/inner diameter calibration

Heat Treatment

A335:

  • Normalized + Tempered (P11/P22)
  • Austenitize → Quench → Temper (P91)

A106:

  • Hot finished
  • Normalized (if requested)

Critical Testing (Mandatory for HP Pipes)

  • Hydrostatic test at high pressure
  • Ultrasonic (UT) / Eddy Current
  • Hardness test
  • Creep property validation (A335)
  • Microstructure test (P91)

Finishing

  • Beveled ends for welding
  • Surface varnish / black oil
  • Marking: Grade + SCH + Heat No.

Engineering Comparison — A335 vs A106 for High-Pressure Use

Property A335 (P11/P22/P91) A106 (Gr B/C)
Temperature Capability Very High (500–700°C) Up to 425°C
Pressure Capability Extreme (Heavy SCH) High (Heavy SCH)
Creep Resistance High to Ultra High Medium
Weldability Good → Requires expertise for P91 Excellent
Best Use Steam / Boiler / Header Lines HP Refinery & Hydrocarbon Lines
Cost Medium–High Low–Medium

Master Technical Datasheet — A335 / A106 (HEAVY SCH)

Parameter / Property A335 (P11 / P22 / P91) A106 (Gr A / B / C)
Material Type Ferritic Alloy Steel High-Temperature Carbon Steel
Pressure Rating Very High High
Temperature Range 500–700°C Up to 425°C
Pipe Type Seamless Seamless
Heavy Schedules Available SCH 80 • SCH 160 • SCH XXS SCH 80 • SCH 160 • SCH XXS
Yield Strength 205–415 MPa 240–275 MPa
Tensile Strength 415–620 MPa 415–550 MPa
Creep Resistance High–Ultra High Medium
Main Alloy Elements Cr-Mo / Cr-Mo-V-Nb Carbon/Manganese
Delivery Condition N+T / Q+T Hot Finished / Normalized
Manufacturing Type Seamless (SMLS) Only Seamless (SMLS) Only
OD Range ½” – 26” ½” – 36”
WT Range SCH 40–XXS / Heavy Wall SCH 20–XXS / Heavy Wall
Used For HP Steam, Boiler, Reheater, Furnace HP Hydrocarbon, Steam, Refinery Process
Equivalent Standards EN 10216-2 EN 10216-1
HSN Code 730419 730419
Certificates Provided EN 10204 3.1 / 3.2 EN 10204 3.1 / 3.2

Industry Usage & Market Deployment

Power Plants (Thermal, Supercritical & Ultra-Supercritical)

  • Main steam lines
  • Hot reheat lines
  • High-pressure headers
  • Water-wall piping
  • Superheater/reheater coils

Refineries & Petrochemical

  • Furnace feed lines
  • High-pressure hydrocarbon lines
  • Boiler circuits
  • Hydrogen & reformer piping
  • Steam cracking furnaces

Chemical & Fertilizer Plants

  • High-pressure ammonia synthesis lines
  • Reactor feed lines
  • Steam circuits

Boiler OEMs & Pressure Equipment Fabricators

  • Coil manufacturing
  • HP heater tubes
  • Boiler tubes & bends

Why Choose Inox Steel India for High-Pressure Pipes?

  • Specialization in Heavy-SCH Seamless Pipes (SCH 80/160/XXS)
  • A335 P11/P22/P91 & A106 Gr B/C always in stock
  • Strict microstructure check for P91
  • TPI: SGS • TUV • DNV • BV • Lloyds
  • Global export capability
  • EPC project-ready documentation
  • Custom cut lengths, bends & fabrication support

Applications — Grade & Schedule Selection Guide

High-pressure pipelines require a combination of temperature resistance, internal-pressure strength, and creep resistance. Below is the engineering-approved usage for each material & schedule.

A335 P11 / P22 / P91 — For High-Temperature High-Pressure Systems

Typical Applications

  • Main steam lines
  • Hot reheat lines
  • High-pressure headers
  • Superheater & reheater coils
  • HP boiler circuits
  • Furnace & heater piping
  • Steam reforming units
  • HRSG piping

Schedule Recommendation

  • SCH 80 — General HP steam lines
  • SCH 160 — High-temp/high-pressure headers
  • SCH XXS — Ultra-high pressure & supercritical lines (mainly P91)

Industries

Power Plants • Boilers • Petrochemical • Fertilizer • Refinery

A106 Gr B / Gr C — For High-Pressure Hydrocarbon & Steam Lines

Typical Applications

  • High-pressure hydrocarbon feed lines
  • Furnace/Heater lines
  • Refinery process piping
  • High-pressure steam lines (≤ 425°C)
  • Crude & fuel oil heating lines
  • Hydrogen service (with PWHT)

Schedule Recommendation

  • SCH 80 — Standard refinery HP lines
  • SCH 160 — Hydrogen & high-pressure units
  • SCH XXS — Severe refinery HP services

Industries

Refinery • Petrochemical • Chemical • Gas Processing • Boiler Plants

A335 / A106 Heavy Schedule Pipe — Dimensional Chart

Nominal Bore Size (NB) | OD (mm) | WT (mm)

NB OD SCH 80 WT SCH 160 WT SCH XXS WT
½” 21.3 3.73 4.78 7.47
1″ 33.4 4.55 6.35 9.09
2″ 60.3 5.54 8.74 15.09
3″ 88.9 7.62 11.13 18.26
4″ 114.3 8.56 13.49 21.95
6″ 168.3 10.97 18.26 28.58
8″ 219.1 12.70 23.01 33.32
10″ 273.0 15.09 28.58 38.10
12″ 323.9 17.48 33.32 44.45
14″ 355.6 19.05 35.71 47.63
16″ 406.4 21.44 40.49 50.80
Full Heavy-SCH Chart (PDF) can be provided

High-Pressure Pipe – Price List (Indicative 2025)

A106 Heavy-SCH Seamless Pipes

Grade Schedule INR/kg USD/kg
A106 Gr B SCH 80 ₹ 120 – ₹ 160 $1.60 – $2.15
A106 Gr B SCH 160 ₹ 130 – ₹ 180 $1.70 – $2.40
A106 Gr C SCH XXS ₹ 150 – ₹ 200 $2.00 – $2.70

A335 Heavy-SCH Alloy Steel Pipes

Grade Schedule INR/kg USD/kg
P11 SCH 80 / 160 ₹ 240 – ₹ 320 $3.10 – $4.20
P22 SCH 80 / 160 ₹ 260 – ₹ 350 $3.50 – $4.60
P91 SCH 160 ₹ 450 – ₹ 600 $6.00 – $8.00
P91 SCH XXS ₹ 500 – ₹ 700 $6.50 – $9.30
Complete price list (PDF) available

HSN Codes

✔ 730419 — Seamless alloy & carbon steel pipes (heavy-SCH)
✔ 730429 — For special heavy-wall alloy steels

Testing & Quality Assurance — High-Pressure Pipes

High-Pressure pipes undergo stringent testing due to severe service conditions.

Mechanical Tests

  • Tensile
  • Yield
  • Elongation
  • Hardness
  • Creep-rupture (A335)

Mandatory NDT

  • Ultrasonic Testing (UT)
  • Eddy Current
  • Magnetic Particle Inspection (MPI)
  • Radiography (for bends/fabrication)

Pressure Tests

  • High-pressure hydro test
  • Pneumatic leak test (optional)

Metallurgical Tests

(Critical for A335 P91)

  • Microstructure analysis
  • Grain size
  • Carbide distribution
  • Tempering validation

Documentation Supplied

  • EN 10204 3.1 MTC
  • Heat Treatment Charts (mandatory for P91)
  • PMI Test
  • Hydro / NDT reports
  • TPI certificates (SGS, TUV, BV, DNV)
  • Packing list, invoice, COO

Special Fabrication Support

Inox Steel India provides services for heavy-SCH high-pressure pipes:

  • Precision cut lengths
  • Beveling
  • Sandblasting
  • Bending
  • PWHT support
  • Custom fabrication for power plants & refineries

Why Choose Inox Steel India for Heavy-SCH High-Pressure Pipes?

High-pressure steam and hydrocarbon systems demand materials that can withstand elevated temperature, extreme internal pressure, fatigue, and creep over long operational cycles.
Inox Steel India supplies fully certified A335 & A106 Heavy Schedule (SCH 80/160/XXS) seamless pipes for the world’s most demanding applications.

Top Reasons Inox Steel India Is the Right Choice

  1. Specialist in Heavy-SCH Pipes for Boilers, Steam & Furnace Duty: SCH 80, SCH 160, and SCH XXS available across A335 & A106.
  2. Full Range of A335 P-Grades: P11 → P22 → P91 (Supercritical grade) always in stock.
  3. High-Pressure Carbon Steel (A106 Gr B/C): Perfect for refinery HP hydrocarbon and steam lines.
  4. TPI Tested & Approved Material: SGS | TUV | BV | DNV | Lloyds.
  5. P91 Microstructure Expertise: We ensure correct austenitizing, quenching, tempering & hardness.
  6. Bulk Export Capability: Ships to GCC, Africa, Europe, Southeast Asia & US markets.
  7. Complete QA/QC: Hydro, NDT, PMI, chemical analysis, heat treatment charts.
  8. Shutdown & Emergency Supply Specialist: Same-day dispatch for urgent refinery & power plant shutdowns.

Industries & High-Pressure Applications We Serve

🔥 Power Plants (Thermal, Supercritical, Ultra-Supercritical)

  • Main steam line (A335 P91)
  • Hot reheat line
  • HP headers (XXS)
  • Superheater/reheater coils
  • Boiler water-wall piping

🛢 Refineries

  • Furnace/Heater high-pressure lines
  • Hydrocarbon feed lines
  • Hydrogen service (A106 Gr C + PWHT)
  • Steam cracking furnaces

🏭 Petrochemical & Chemical Plants

  • Reformer piping
  • High-pressure process lines
  • HP reactors & boiler circuits
  • Steam reformers & heat recovery

🧪 Fertilizer Plants

  • Ammonia high-pressure synthesis lines
  • Steam & process piping

🏗 Boiler OEMs / Fabricators

  • Superheater coils
  • Reheater coils
  • High-pressure tube bundles
  • HP bends & headers

Inox Steel India supports EPC contractors with reliable, heavy-duty high-pressure materials.

Export Packaging — For High-Pressure & Heavy-SCH Pipes

Because heavy-SCH pipes often have thick walls & critical metallurgy, we ship with maximum protection.

✔ Export Packaging Includes:

  • HDPE wrapping + VCI protection
  • Beveled-end protectors
  • Steel-strapped bundles
  • Varnished/oiled surface
  • Wooden crates for small OD tubes
  • Heat No. + Grade + Schedule + Standard marking
  • Impact-protected ends (foam or plastic)

🌍 Major Export Destinations

UAE • Saudi Arabia • Qatar • Oman • Kuwait • Bahrain
South Africa • Nigeria • Kenya • Egypt
Malaysia • Indonesia • Vietnam • Thailand
Italy • Poland • Spain • Netherlands • UK

A335 / A106 Heavy-SCH Pipe Supplier Near Alankar Cinema, Mumbai

Looking for High-Pressure Pipes near Alankar Cinema, Mumbai?

Inox Steel India supplies:

  • A335 P11 / P22 / P91
  • A106 Gr B / Gr C
  • SCH 80 / SCH 160 / SCH XXS
  • Seamless heavy-wall high-pressure pipes
  • Ready stock + same-day dispatch

Trusted by Refineries, Boilers, Power Plants, Petrochemicals & EPC contractors across Mumbai, Navi Mumbai & Thane.

Talk to Our High-Pressure Alloy Steel Experts

We support:
✔ Material selection (P11 vs P22 vs P91)
✔ Heat treatment & microstructure validation
✔ Boiler/steam line applications
✔ Shutdown & expansion projects
✔ Global export documentation

Inox Steel India

52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004

Email

alloy@inoxsteelindia.in, steel@inoxsteelindia.in

Phone

+91 9930796690

Frequently Asked Questions (FAQs)

Because it handles 650–700°C, offers extremely high creep strength & fatigue resistance.

It offers superior strength at high pressure and is ideal for furnace & process piping.

Yes — mandatory for verifying correct metallurgical structure.

Yes — A106 Gr B/C & P11/P22 in SCH 80–160 usually in stock; P91 available on request.

Yes — bends, cut lengths, PWHT, headers & coil fabrication.

Yes — Europe, Middle East, Africa, SE Asia & the USA.

Order High-Pressure Heavy-SCH Pipes Today

Inox Steel India supplies A335 P-Grades & A106 Heavy-SCH Seamless Pipes for extreme high-pressure and high-temperature service in power plants, refineries & petrochemical projects.

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