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A335 / A312 Steam Line Pipe Supplier — Inox Steel India

Steam is the backbone of refineries, petrochemical plants, boilers, power plants, and chemical industries.
But not all steam is the same — superheated steam, saturated steam, clean steam, and condensate lines each require specific materials capable of handling:

  • High temperature
  • High pressure
  • Creep over long periods
  • Oxidation
  • Thermal shock
  • Water chemistry

Inox Steel India supplies A335 alloy steel and A312 stainless steel pipes engineered for the entire steam generation → distribution → return cycle.

Table of Contents

Why A335 + A312 Are the World Standards for Steam Lines

A335 (P11 / P22 / P91)

Ferritic alloy steels specifically designed to handle:

  • High-temperature operation (450–700°C)
  • High steam pressure
  • Creep resistance over decades
  • Oxidation from superheated steam
  • Thermal cycling near boilers/heaters

P11 → Medium HP steam
P22 → High HP steam
P91 → Ultra-supercritical steam

These grades are essential for:

  • Power plant steam circuits
  • Refinery boilers
  • Furnace heater coils
  • Superheater & reheater lines
  • HP steam headers

A312 (304 / 316L Stainless Steel)

Austenitic stainless steel is used where steam is:

  • Clean
  • Contamination-sensitive
  • Corrosive
  • Condensate-heavy
  • Low to medium pressure

Ideal for:

  • Condensate return lines
  • Utility steam distribution
  • Pharma & food-grade clean steam
  • Chemical plant steam tracing
  • Heat exchanger piping

316L provides superior resistance to:

  • Condensate corrosion
  • Chlorides
  • Organic chemicals

How Steam Behaves — And Why Material Selection Matters

Steam lines face unique engineering challenges:

✔ High Velocity: Steam travels at high speed, leading to erosion at bends & reducers.

✔ High Temperature: Superheated steam can reach 700°C in P91 lines.

✔ Pressure Fluctuations: Sudden changes cause fatigue failure if material is not creep-resistant.

✔ Water Hammer: Instant pressure spikes require seamless + strong alloy metals.

✔ Condensation: Condensate is corrosive → requiring stainless steel (A312).

✔ Oxidation: High temp steam oxidizes carbon steel; alloy steel resists this.

This is why EPC contractors globally use A335 + A312 for full steam circuits.

Where These Materials Are Used

  1. Boiler → Superheater → Furnace Lines Material: A335 P22 / P91
  2. Main HP Steam Lines → Turbines Material: A335 P91Medium Pressure Steam
  3. Distribution Material: A335 P11 / P22
  4. Clean Steam (Food/Pharma) Material: A312 TP316L
  5. Condensate Lines Material: A312 TP304/316L
  6. Chemical & Utility Steam Material: A312 + A106 combo

Master Technical Datasheet — A335 (P11 / P22 / P91) & A312 (Stainless Steel)

Parameter / Property A335 (P11 / P22 / P91) A312 (TP304 / TP316L)
Material Type Ferritic Alloy Steel Austenitic Stainless Steel
Temperature Range 450°C – 700°C Up to 650°C
Pressure Capability Very High Medium–High
Steam Suitability Superheated & HP Steam Clean Steam / Condensate
Corrosion Resistance Medium Very High
Oxidation Resistance High High
Creep Strength High → Ultra-High (P91) Medium
Manufacturing Type Seamless Seamless
Delivery Condition N+T (P11/P22), Q+T (P91) Annealed / Pickled
Common Grades P11, P22, P91 304, 304L, 316, 316L
Max OD Size ½” – 26” ½” – 24”
Schedule (WT) SCH 40 – XXS SCH 10 – SCH 80
Equivalent Standards EN 10216-2 EN 10216-5
Heat Treatment Mandatory Solution Annealed
Normal Use Cases HP steam, boiler lines, superheater Clean steam, condensate recovery
Magnetic Yes (Ferritic) No
Weldability Good (special for P91) Excellent
HSN Code 730419 730640
Certificates Supplied EN 10204 3.1 / 3.2 EN 10204 3.1

🌡 Where Each Grade Is Used in Steam Lines

A335 P11 / P22

  • HP steam lines (main steam up to ~560°C)
  • Superheater tubes
  • Reheater tubes
  • Heater & furnace coil steam lines
  • Boiler external piping

A335 P91

  • Ultra-high temperature (600°C–700°C)
  • Supercritical & ultra-supercritical steam
  • Main steam lines in power plants
  • HP header connections

A312 TP304 / TP316L

  • Clean steam lines
  • Condensate lines
  • Steam distribution in chemical & food industries
  • Heat exchangers & utility steam

🔥 Steam Line Selection Guide

Steam Type Recommended Material
High-pressure superheated steam (450–700°C) A335 P11 / P22 / P91
High-temperature steam for furnace/heater A335 P22
Ultra-superheated main steam A335 P91
Clean steam (pharma/food) A312 TP316L
Condensate return A312 TP304/316L
Medium-pressure steam (utility) A106 Gr C / A312

Industry Usage & Market Deployment

Industrial Fabrication

  • Equipment frames
  • Machine stands
  • CNC bases
  • Conveyor structures
  • Truss systems

Refineries & Petrochemical Plants

  • Structural supports
  • Pipe racks
  • Platforms & walkways
  • Access structures

Construction & Civil Engineering

  • Steel buildings / warehouses
  • PEB structures
  • Staircase frames
  • Roof trusses

Infrastructure

  • Bridges
  • Cantilever structures
  • Crane/hoist beams

Mechanical & Engineering Projects

  • Boom structures
  • Lifting frames
  • Offshore modules
  • Rig structures

Why Inox Steel India Is a Trusted Steam-Line Supplier

  • Full range of A335 P11 / P22 / P91
  • Full range of A312 304 / 316 / 316L
  • Seamless only — no ERW
  • Heavy-SCH availability for high pressure
  • TPI: SGS • TUV • DNV • BV • Lloyds
  • Heat treatment charts for P91
  • Condensate-resistant SS pipes for utility steam
  • Bulk availability for refinery/power shutdowns
  • Ready stock near Alankar Cinema, Mumbai
  • Global export experience

Technical Usage & Applications — Grade-Wise

Superheated / Main HP Steam (450–700°C)

Recommended Material:

✔ A335 P22 (up to ~560°C)
✔ A335 P91 (600–700°C)

Applications

  • Main steam lines
  • Hot reheat lines
  • Superheater & reheater coils
  • Furnace/Heater steam piping
  • High-pressure boiler piping
  • HRSG hot steam circuits

Medium Pressure Steam (~350–450°C)

Recommended Material:

✔ A335 P11 / P22
✔ Sometimes A106 Grade C

Common Uses

  • Utility steam
  • Distribution steam networks
  • Process heating in chemical plants
  • Steam supply to reactors

Clean Steam Lines (Food / Pharma)

Recommended Material:

✔ A312 TP316L

Common Uses

  • Autoclaves
  • Sterilization lines
  • Pure steam generator output
  • Elevator & pharma-grade steam lines

Condensate Return Lines

Recommended Material:

✔ A312 TP304 / TP316L
Because condensate is corrosive, stainless steel ensures life-long performance.

Dimensional Chart — A335 (P11/P22/P91) for Steam Lines

NB OD (mm) SCH 40 WT SCH 80 WT SCH 160 WT SCH XXS
1″ 33.4 3.38 4.55 6.35 9.09
2″ 60.3 3.91 5.54 8.74 15.09
3″ 88.9 5.49 7.62 11.13 18.26
4″ 114.3 6.02 8.56 13.49 21.95
6″ 168.3 7.11 10.97 18.26 28.58
8″ 219.1 8.18 12.70 23.01 33.32
10″ 273.0 9.27 15.09 28.58 38.10

These sizes cover 95% of all steam-line applications.

Dimensional Chart — A312 (304/316L)

Size OD (mm) SCH 10S WT SCH 40S WT SCH 80S WT
1″ 33.4 2.77 3.38 4.55
2″ 60.3 2.77 3.91 5.54
3″ 88.9 3.05 5.49 7.62
4″ 114.3 3.05 6.02 8.56
6″ 168.3 4.19 7.11 10.97

316L SCH 40 is the most used condensate & clean-steam size.

Indicative Pricing (INR + USD)

A335 Steam-Line Alloy Steel (P-Grades)

Grade Schedule INR/kg USD/kg
P11 SCH 40 / 80 ₹ 240 – ₹ 320 $3.10 – $4.20
P22 SCH 40 / 80 ₹ 260 – ₹ 350 $3.50 – $4.60
P91 SCH 160 / XXS ₹ 450 – ₹ 700 $6.00 – $9.30

P91 cost depends heavily on heat treatment compliance.

A312 Stainless Steel Steam-Line Pipes

Grade Schedule INR/kg USD/kg
TP304 / 304L SCH 10 / 40 ₹ 260 – ₹ 340 $3.40 – $4.30
TP316 / 316L SCH 10 / 40 ₹ 310 – ₹ 390 $4.10 – $5.20

316L is preferred for clean steam.

HSN Codes

  • A335: 730419
  • A312: 730640

Testing & QA for Steam-Line Materials

Steam-line pipes must resist creep, oxidation, corrosion and thermal cycling.
So we follow strict QA:

Mechanical Tests

  • Tensile
  • Yield
  • Elongation
  • Hardness
  • Creep-rupture (mandatory for P91)

Corrosion & Oxidation Resistance

  • Intergranular corrosion test (for SS)
  • PMI for stainless & alloy steel

NDT

  • UT / Eddy Current
  • MPI
  • Visual & Dimensional Test

Hydro Test

High-pressure hydro testing for all A335 & A312 pipes.

Heat Treatment Documentation (P91)

  • Austenitizing chart
  • Quenching record
  • Tempering curve
  • Hardness range check (190–250 HB as per spec)

Documents Provided

  • EN 10204 3.1 / 3.2
  • NDT Reports
  • Chemical Analysis
  • Mechanical test
  • Heat treatment charts
  • Packing list + Invoice + COO

Value-Added Services

  • Cut-to-length
  • Beveling
  • Spool fabrication
  • PWHT support (A335)
  • Pipe bending for steam tracing
  • Export packaging

Why Choose Inox Steel India for Steam-Line Piping?

Steam lines — especially high-pressure and high-temperature circuits — are among the most critical pipelines in any refinery, boiler house, petrochemical unit, or power plant.
They run at 450°C–700°C with heavy thermal cycling and demand absolute metallurgical integrity.

Inox Steel India supplies fully certified, seamless, creep-resistant steam-line pipes in A335 & A312 that ensure reliable long-term service.

Top Reasons EPC, Boiler OEMs & Refineries Prefer Us

  1. Expert in A335 P11 / P22 / P91 Steam Grades: For superheated, reheater, furnace, and HP boiler lines.
  2. Complete Range of A312 (304/316L) for Clean Steam & Condensate
    Perfect corrosion resistance and thermal stability.
  3. TPI-Approved Materials: With inspection by SGS, TUV, DNV, BV, Lloyds.
  4. Strict Creep & Heat-Treatment Control for P91: We supply only correctly tempered, code-compliant P91—no brittle pipe risk.
  5. Large Stock Near Alankar Cinema, Mumbai: Ready for shutdown jobs, emergency replacements, & new projects.
  6. Export Specialists for Boiler & Steam-Line Packages: Covering GCC, Africa, Europe, Southeast Asia & USA.
  7. Cut-to-Length, Spool Fabrication & PWHT Support: End-to-end steam-system supply capability.

Industries & Steam Applications We Serve

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

  • Main steam line
  • Hot reheat
  • HRSG steam circuits
  • Boiler outlet lines
  • Turbine steam inlet

🛢 Refineries

  • Steam cracking furnaces
  • Reformer steam lines
  • Boiler house steam distribution
  • Heater steam coils

🏭 Petrochemical & Chemical

  • Steam tracing
  • Reactor steam jackets
  • Process heating steam
  • Utility steam grids

🧪 Pharmaceutical / Food

  • Clean steam (316L)
  • Sterilization/Autoclave lines
  • Pure steam generator systems

⚙️ Industrial Manufacturing

  • Textile plant boilers
  • Paper & pulp steam heaters
  • Rubber & tyre heating lines

Inox Steel India is trusted by EPC contractors, boiler manufacturers, steam system integrators, and refinery shutdown teams.

Export Packaging for Steam-Line Pipes

Steam-line materials must maintain metallurgical stability, so we pack them with maximum protection.

✔ Export Packaging Includes:

  • HDPE + VCI wrapping
  • Painted/oiled protection
  • Bevelled-end protectors
  • Steel-strapped bundles
  • Wooden boxes for SS small sizes
  • Heat No. / Grade / Size marking
  • MTC & QA documents inside bundle

🌍 Export Destinations

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

Steam-Line Pipe Supplier Near Alankar Cinema, Mumbai — Inox Steel India

Looking for Steam-Line Pipes (A335/A312) near Alankar Cinema, Mumbai?

Inox Steel India supplies:

  • A335 P11 / P22 / P91 Seamless
  • A312 TP304 / TP316L Seamless
  • SCH 40 / SCH 80 / SCH 160 / XXS
  • Clean steam & condensate return lines
  • Boiler & HRSG steam piping supply

Fast delivery to Mumbai • Navi Mumbai • Thane and export-ready shipments worldwide.

Talk to Our Steam-Line Experts

We assist with:
✔ Steam-grade selection (P11/P22/P91 vs 304/316L)
✔ Line temperature/pressure guidance
✔ Spool fabrication & PWHT support
✔ Shutdown/emergency material supply
✔ EPC documentation & TPI inspection

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)

Condensate is corrosive → stainless steel prevents pitting & corrosion.

Yes — due to its ultra-high creep strength and temperature capability.

Yes — TP316L is the global standard for clean steam.

Yes — mandatory to ensure metallurgical integrity.

  • A335: SCH 40 / SCH 80 / SCH 160
  • A312: SCH 40S

Yes — HEAT NO. based steam line sets + fittings + flanges + valves.

Order A335 / A312 Steam-Line Pipes Today

Inox Steel India supplies premium-quality seamless steam-line pipes for boilers, turbines, refineries, chemical plants, and clean-steam applications.

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