Home > Welded Pipes > ASTM A671 / A672
Inox Steel India is a trusted manufacturer and exporter of ASTM A671 & ASTM A672 EFW (Electric Fusion Welded) Carbon Steel and Alloy Steel Pipes, widely used for high-pressure, high-temperature, and high-strength applications in refineries, power plants, chemical industries, and pipeline systems.
These pipes are produced by fusion welding carbon steel or alloy steel plates, followed by heat treatment, NDT testing, and mechanical testing depending on the required Class (12, 22, 32, 42). A671 & A672 pipes offer exceptional reliability for boiler piping, steam lines, fluid transmission, and structural pressure vessels.
Inox Steel India supplies A671/A672 EFW pipes in grades CC60, CC65, CC70, B60, B65, B70, customized for project-specific high-performance requirements.
A671 and A672 pipes are specialty Electric Fusion Welded (EFW) pipes manufactured from carbon steel or alloy steel plates. They are designed for:
| Standard | Material Type | Application |
|---|---|---|
| ASTM A671 | Carbon Steel / Alloy Steel | Low to high temperature service |
| ASTM A672 | Carbon Steel | High-pressure service with controlled weld quality |
Both are used in large-diameter piping systems requiring high integrity, toughness, and reliable weld performance.
Classes (Weld & Heat Treatment Requirements):
| Class | Weld Type | Testing | Heat Treatment |
|---|---|---|---|
| Class 12 | Double-welded | RT optional | As-welded |
| Class 22 | Double-welded | 100% Radiography | Normalized |
| Class 32 | Double-welded | 100% RT | Quenched & Tempered |
| Class 42 | Double-welded | UT / RT as per project | Normalized or Q&T |
Higher classes are used for core pressure-bearing applications.
Grades:
These grades define strength, mechanical properties and operating temperature.
1️⃣ Plate Selection
Carbon steel / alloy steel plates tested for chemical & mechanical properties.
2️⃣ Edge Beveling
Bevels prepared for uniform weld penetration.
3️⃣ Pipe Forming & Rolling
Plates rolled into cylindrical shape with high dimensional accuracy.
4️⃣ Electric Fusion Welding (EFW)
High-energy electrical fusion produces a strong, deep-penetration weld.
5️⃣ Weld Conditioning
Internal/external weld bead adjusted as per order.
6️⃣ Heat Treatment
Depending on class:
7️⃣ NDT Testing
RT / UT based on class and project requirement.
8️⃣ Hydrostatic Testing
Verification of pressure integrity.
9️⃣ Final Inspection & Marking
Grade, class, heat number, OD, WT, ASTM A671/A672 details.
Power Plants & Boilers
Used for high-temperature steam lines, HRSG units, boiler pipelines.
Oil & Gas Transmission
Long-distance, high-pressure fluid & gas transportation.
Refineries & Petrochemical Plants
Process piping for chemicals, hydrocarbons, and hot fluids.
Fertilizer & Chemical Industries
Pipelines requiring strong welds and high corrosion resistance.
Water & Desalination Projects
Used in intake/outlet pipes, large diameter municipal water supply.
Pressure Vessels & Structural Use
Heavy-wall pipes required for load-bearing structures.
ASTM A671 and A672 specify Electric Fusion Welded (EFW) large-diameter carbon steel and alloy steel pipes, used extensively in pressure pipelines, steam lines, boiler piping, refineries, petrochemical units, power plants, water transmission, and offshore projects.
They are manufactured from graded steel plates that undergo:
Inox Steel India supplies both A671 (CC series) and A672 (B series) grades in multiple classes (12/22/32/42), enabling engineers to choose the exact required weld quality and mechanical performance.
| Parameter / Property | ASTM A671 (CS / Alloy Steel) | ASTM A672 (CS / Alloy Steel) | Standard Requirements – A671 / A672 |
|---|---|---|---|
| Material Type | Carbon Steel / Alloy Steel | Carbon Steel / Alloy Steel | EFW Pipes for high-pressure service |
| Manufacturing Standard | ASTM A671 | ASTM A672 | Electric Fusion Welded Pipes |
| Manufacturing Process | Plate welded (EFW) | Plate welded (EFW) | Mandatory EFW fusion welding |
| Grades Available | CC60, CC65, CC70 | B60, B65, B70 | Carbon Steel & Alloy Steel Grades |
| Heat Treatment | Normalized / Quenched & Tempered | Normalized / Quenched & Tempered | Depends on class & grade |
| Classes Available | Class 12, 22, 32, 42 | Class 12, 22, 32, 42 | Defines weld RT requirement & heat treatment |
| Weld Testing | RT / UT as per class | RT / UT as per class | Mandatory NDT |
| Mechanical Strength (TS) | As per grade (415–520 MPa approx.) | As per grade (415–520 MPa approx.) | ASTM defined |
| Yield Strength (YS) | 240–260 MPa approx. | 240–260 MPa approx. | ASTM defined |
| Impact Testing | Optional / As per order | Optional / As per order | Required for low temp service |
| OD Range | 16” – 60” (custom up to 80”) | 16” – 60” (custom up to 80”) | Large-bore EFW pipes |
| Wall Thickness | SCH 20 – SCH 160 / Custom | SCH 20 – SCH 160 / Custom | Heavy-wall available |
| End Types | Bevelled / Plain Ends | Bevelled / Plain Ends | API / ASME prep |
| Applications | High pressure, boilers, pipelines | High pressure, pipelines, refineries | Critical service |
| Coatings Available | Black, Painted, Epoxy, 3LPE | Black, Painted, Epoxy, 3LPE | Project-specific |
| Testing Documentation | MTC 3.1, RT Films, UT Reports | MTC 3.1, RT Films, UT Reports | Required |
| HSN Code | 7305 / 7306 | 7305 / 7306 | Large-diameter CS welded pipes |
ASTM A671 (Carbon Steel / Alloy Steel)
ASTM A672 (Carbon Steel)
| Standard | Best For | Key Advantage |
|---|---|---|
| A671 | Broader temperature range | Available in multiple alloy steel variations |
| A672 | High-pressure pipelines | Strict weld testing requirements |
| Class | Heat Treatment | Testing Requirement | Typical Application |
|---|---|---|---|
| Class 12 | As Welded | RT Optional | Water lines, non-critical use |
| Class 22 | Normalized | 100% RT | High-pressure steam & petrochemical |
| Class 32 | Quenched & Tempered | 100% RT | Severe service conditions |
| Class 42 | Normalized / Q&T | UT / RT per order | Special engineered piping |
| Parameter | Capability |
|---|---|
| Outside Diameter (OD) | 16” – 60” (Custom up to 80”) |
| Wall Thickness | SCH 20 – SCH 160 / Custom Heavy Wall |
| Length | 6 m / 12 m / Custom |
| Weld Type | EFW (Electric Fusion Welded) |
| Ends | Bevelled / Plain |
| Form | Round |
| Coating Options | Black, Painted, Epoxy, 3LPE/3LPP |
| Grade / Class | Price (INR/kg) | Price (USD/kg) |
|---|---|---|
| A671 CC60 / A672 B60 | ₹ 72 – ₹ 105 | $ 1.10 – $ 1.45 |
| A671 CC65 / A672 B65 | ₹ 78 – ₹ 115 | $ 1.15 – $ 1.55 |
| A671 CC70 / A672 B70 | ₹ 95 – ₹ 135 | $ 1.35 – $ 1.85 |
| Heat-Treated (Q&T / Normalized) | +₹ 10 – ₹ 25 | +$ 0.15 – $0.35 |
| 3LPE/3LPP Coated Pipes | +₹ 18 – ₹ 40 | +$ 0.25 – $ 0.55 |
Prices vary depending on class, OD, WT, weld testing (RT/UT), and coating type.
7305 / 7306 — Large Diameter Carbon Steel Welded Pipes
✔ Mandatory Tests (As per ASTM A671 / A672)
✔ Mechanical Tests
✔ Additional Tests (On Request)
✔ Documentation Provided
✔ TPI Inspection Available
SGS • BV • DNV • TÜV • Lloyd’s Register
Inox Steel India supplies A671/A672 EFW pipes to:
Middle East:
Africa:
Europe:
Americas:
Asia Pacific:
Widely used in:
High-pressure piping demands precision welding, stringent testing, and consistent metallurgy. Inox Steel India is known globally for delivering reliable, certified, and fully traceable ASTM A671 & A672 EFW pipes that meet the toughest engineering requirements.
✔ Reasons Engineers & EPC Contractors Prefer Us:
Inox Steel India ensures consistency, mechanical reliability, and premium quality for every high-pressure pipeline requirement.
Power Plants & HRSG Units
Oil & Gas (Onshore & Offshore)
Refineries & Petrochemical Complexes
Water & Desalination Projects
Chemical & Fertilizer Industries
Structural & Heavy Engineering
A671/A672 pipes are chosen where safety, strength, and weld reliability cannot be compromised.
Large-diameter, heavy-duty EFW pipes require secure packaging and proper loading.
✔ Standard Packing
✔ Heavy Industrial Packing
✔ Export Grade Packing
✔ Ports of Dispatch
JNPT • Mundra • Hazira • Chennai • Vizag
Looking for ASTM A671 / ASTM A672 EFW Carbon & Alloy Steel Pipes for refineries, power plants, boilers, HRSG units, petrochemical projects, or high-pressure transmission lines?
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
alloy@inoxsteelindia.in
+91 9930796690
Inox Steel India
Email
Phone
→ Class 22 (Normalized + 100% RT) is the most demanded
→ Class 32 (Q&T + 100% RT) used for severe service
→ Yes — 3LPE, 3LPP, FBE coatings available on request.
→ Standard up to 60”, custom up to 80”.
→ Yes — complete documentation is provided with every order.
→ Yes — depending on grade and class, especially CC70 / B70 and Class 22/32.
We provide certified pipes with RT/UT reports, heat charts, MTC 3.1/3.2 & global delivery.