Premium EFW (Electric Fusion Welded) Steel Pipe
High-performance Electric Fusion Welded (EFW) pipes engineered for high-pressure and high-temperature service. Manufactured by rolling steel plates and using a continuous longitudinal welding process, our EFW pipes offer superior structural integrity and reliability.
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Size Range: Outer Diameter (OD) up to 100 inches | Wall Thickness (WT) up to 2.5 inches.
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Standards: ASTM A671, ASTM A672, ASTM A691, ASTM A358.
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Classes: Various classes from Class 10 to Class 53 (covering different heat treatments and Radiographic Testing requirements).
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Key Features: Large diameter availability, precision longitudinal seams, and rigorous quality testing (RT, Hydrostatic).
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Applications: Petroleum, chemical industry, thermal power plants, and large-scale water conservancy projects.
Description
Product Overview
EFW Pipe refers to Electric Fusion Welding. It is a specialized manufacturing process for welded steel pipes characterized by continuous longitudinal welding. The pipe is formed by hot rolling a steel plate and welding the longitudinal seam. Our EFW pipes are primarily used in high-pressure and high-temperature environments where reliability is paramount.
Unlike standard ERW pipes, EFW pipes are typically produced in larger diameters and thicker walls, making them ideal for heavy-duty industrial transport systems and structural engineering.
Classes and Technical Requirements
The technical requirements for EFW pipes are categorized into various classes based on the heat treatment of the pipe and the intensity of Radiographic Testing (RT).
| Class | Heat Treatment of Pipe | Radiographic Examination |
|---|---|---|
| Class 10 | None | None |
| Class 11 | None | 9-degree Radiography (as per ASTM) |
| Class 12 | None | Full Radiography (100% RT) |
| Class 13 | None | Section 13 (ASTM Specific) |
| Class 20 | Stress Relieved | None |
| Class 21 | Stress Relieved | 9-degree Radiography |
| Class 22 | Stress Relieved | Full Radiography (100% RT) |
| Class 30, 31, 32 | Normalized | Varies by Class (None to Full RT) |
| Class 40, 41, 42 | Normalized and Tempered | Varies by Class (None to Full RT) |
| Class 50, 51, 52 | Quenched and Tempered | Varies by Class (None to Full RT) |
Size Range & Availability
| Specification | Range |
|---|---|
| Outside Diameter (O.D.) | 6″ – 100″ |
| Wall Thickness (W.T.) | 0.25″ – 2.50″ |
Manufacturing Process
Our EFW pipe manufacturing process utilizes fully automated and precisely controlled stages to ensure weld strength and pipe longevity.
EFW Pipe Production Flow Diagram
Standards & Material Grades
- ASTM A671: Specification for Electric-Fusion-Welded Steel Pipe for Atmospheric and Lower Temperatures. Grades: CA 55, CB 60, CB 65, CB 70, CC 60, CC 65, CC 70, CD 70, CD 80, CF 65, CF 70, etc.
- ASTM A672: Specification for Electric-Fusion-Welded Steel Pipe for High-Pressure Service at Moderate Temperatures. Grades: A 45, A 50, A 55, B 60, B 65, B 70, C 55, C 60, C 65, C 70, etc.
- ASTM A691: Carbon and Alloy Steel Pipe, Electric-Fusion-Welded for High-Pressure Service at High Temperatures.
- ASTM A358: Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless Steel Pipe for High-Temperature Service and General Applications.
Applications
Due to its high flexibility in diameter and wall thickness combinations, EFW pipe is widely used in:
- Energy: Transport of oil, natural gas, and thermal power plant steam pipelines.
- Chemical: Chemical industrial processing and smelting equipment.
- Infrastructure: Large-scale water conservancy projects, marine exploration, and environmental protection facilities.
- Structural: Civil architecture and mechanical equipment structural components.