The Eddy Current Testing Machine is an advanced non-destructive testing (NDT) equipment designed for online inspection of welded steel pipes and tubes. It is widely used in ERW tube mills to detect weld seam defects and surface flaws without damaging the pipe.
By using electromagnetic induction technology, this machine ensures stable, high-speed, and reliable quality inspection during continuous pipe production.


Main Applications
The Eddy Current Testing Machine is mainly used for:
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🔹Weld seam inspection of ERW steel pipes
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🔹Detection of surface and near-surface defects
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🔹Online quality control during high-speed tube production
Typical defects detected include:
It is suitable for carbon steel pipes, structural tubes, and precision ERW pipes.
Position in ERW Tube Mill
In an ERW Tube Mill, the eddy current testing machine is installed:
This position allows real-time monitoring of weld quality and helps prevent defective pipes from entering the finishing process.
Working Principle
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📍The probe generates a high-frequency alternating magnetic field
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📍Eddy currents are induced on the pipe surface
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📍Any defect causes a change in the eddy current signal
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📍The system analyzes the signal and triggers alarms or markings
This method is non-contact, fast, and highly sensitive, making it ideal for continuous online inspection.
Key Features
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Online inspection for ERW tube mills
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High sensitivity for weld seam detection
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Stable digital signal processing
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Non-contact testing, no damage to pipes
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Suitable for round, square, and rectangular tubes
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Optional marking and alarm system
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Easy operation and low maintenance

Typical Technical Parameters
(Parameters can be customized according to pipe size and inspection standard)
| Item |
Specification |
| Pipe Outer Diameter |
Ø10 – Ø219 mm |
| Wall Thickness |
0.5 – 8.0 mm |
| Inspection Speed |
Up to 120 m/min |
| Detection Type |
Weld seam & surface defects |
| Probe Type |
Encircling / Segment probe |
| Frequency Range |
Single or multi-frequency |
| Alarm System |
Audio & visual alarm |
| Marking Output |
Optional ink marking |
| Control System |
Digital processing system |
Related Equipment
The Eddy Current Testing Machine usually works together with:
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HF Welder
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Impeder
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Cooling System
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Sizing Machine
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Flying Saw / Cold Saw
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Pipe Marking Machine
Together, they form a complete ERW pipe quality control system.
Why Choose Eddy Current Testing?
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✔Improves weld seam quality control
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✔Reduces rejection rate and rework cost
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✔Meets international inspection standards
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✔Enhances automation level of ERW tube mills
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✔Essential equipment for export-oriented pipe production
Eddy Current Testing Machine – FAQ🔍
Q1: What is an eddy current testing machine used for?
A: It is used for non-destructive testing of metal pipes to detect weld seam and surface defects during production, especially in ERW tube mills.
Q2: Can this machine inspect weld seams online?
A: Yes. The eddy current testing machine is designed for online inspection and can continuously monitor weld seam quality during high-speed pipe production.
Q3: Where is it installed in an ERW tube mill?
A: It is typically installed after HF welding and cooling, before or after the sizing section, to ensure weld quality before further processing.
Q4: What types of defects can be detected?
A: Common detectable defects include cracks, pinholes, incomplete welding, and surface flaws near the weld seam.
Q5: Is the testing process harmful to the pipe?
A: No. Eddy current testing is a non-contact and non-destructive inspection method and does not damage the pipe surface.
Q6: What pipe sizes can be inspected?
A: The machine supports a wide range of pipe diameters and wall thicknesses. Specifications can be customized according to production requirements.
Q7: Can it work with other ERW tube mill equipment?
A: Yes. It can be integrated with HF welders, sizing machines, flying saws, and marking systems to form a complete quality control line.
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- 1. Coil car and Storage
- 2.Single And Double Heads Un-coiler & Hydraulic And Pneumatic Un-coiler
- 3.Peeler and hold down roll arm
- 4.Flattening Machine
- 5.Automatic and Semi Auto Shearer & Butt Welder
- 6.Vertical Cage Accumulator & Horizontal Loop Accumulator & Landing Horizontal Spiral Loop Accumulator


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- 1. Eddy current machine
- 2. Seam annealing machine
- 3. Straightener machine
- 4. Chamfer and end facer machine
- 5. Hydro Tester machine
- 6. Threading machine
- 7. Painting and oil machine
- 8. Automatic bundle and package machine


Spare Parts and Consumble Parts
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- 1. Rollers, Moulds, Dies, D2,D3 material to choose
- 2. Ferrite, Impeder, Fiberglass tube
- 3. HSS saw blades, TCT Saw blades, Friction saw blades
- 4. OD burr remove inserts, ID burr remover inserts
- 5. HF welder Induction Coil and other HF welder spare parts
- 6. Copper tube for induction Coil, PTFE pipe for Induction Coil
- 7. Mosfet, Boards
- 8. Steel pipe Strapping machine
- 9. Zinc Spray Machine, Zinc wire, Zinc spray gun


- Why Choose Us?
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1.Leading Technology, Reliable Quality, Excellent Service! Optimized Design, High quality material select! Heat treatment process guarantee!
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2.Spiral bevel gear, drum gear coupling and carburization. Gear teeth quenching. Driven system stable, efficient and wearable with lower noise.
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3.High precision wear resisting and Long life of toolings. All the machine Lathes, Key Grooves are positioned and Milled by CNC.
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4.Quality department make sure the material of the raw materials quality, and ensure the machine running perfect.

After-sales service
- 1.Machine test running videos will supply to customer before shipment.
- 2.Online techenical support WHOLE LIFT FREE.
- 3.Professional engineers team to install the machine, train your employee well.
- 4.One year warranty and life-long technical support.
- 5 .24 hours for engineer response.
- 6.Your business relationship with us will be confidential to any third party.
- 7. We welcome customers to visit our factory anytime.
