During the ERW tube manufacturing process, welding creates a weld bead on both the outside and inside of the tube. While the outside bead can be removed by an external scarfing tool, the inside weld bead (internal burr) must also be removed for applications requiring a smooth inner surface.

AIS Machinery provides reliable Inner Scarfing Devices (Internal Burr Removal Devices) designed for ERW tube mills. We offer Mechanical Type and Hydraulic Type solutions to suit different production requirements, pipe sizes, and automation levels.

What Is an Inner Scarfing Device?

An Inner Scarfing Device, also called an Internal Burr Removal Device, is installed immediately after the high-frequency welding section of an ERW tube mill.

Its function is to remove the weld bead formed on the inner wall of the pipe, ensuring:

✅ Smooth internal surface
✅ Better pipe quality and appearance
✅ Improved fluid flow performance
✅ Compliance with higher product quality standards
✅ Easier downstream processing such as galvanizing, coating, bending, and threading

It is widely used for producing:

• Water pipes
• Structural tubes
• Furniture tubes
• Automotive tubes
• Precision steel pipes
• Mechanical tubes
• • 
  • 

Where Is It Used in an ERW Tube Mill?

The Inner Scarfing Device is installed immediately after the welding rolls and before the cooling section.

Typical ERW Tube Mill Process

Coil → Uncoiler → Strip Accumulator → Forming → HF Welding → Inner Scarfing Device → Cooling → Sizing → Straightening → Flying Saw → Run-out Table

How Does an Inner Scarfing Device Work? ⚙️

After the tube edges are welded together by the high-frequency welder, an internal weld bead is formed inside the pipe.

The Inner Scarfing Device inserts a specially designed scarfing tool (cutting tip) into the tube. As the welded tube continuously moves forward, the cutting edge precisely removes the excess weld bead without damaging the tube wall.

The removed burr exits together with the moving pipe or is guided away depending on the production setup.

The cutting depth and position can be adjusted to achieve stable and consistent burr removal.

Mechanical vs Hydraulic Inner Scarfing Device

AIS Machinery offers two types of Internal Burr Removal Devices.

Mechanical Type

✔ Simple structure

✔ Easy maintenance

✔ Cost-effective

✔ Suitable for stable production with fewer size changes

This type is widely selected by customers producing standard pipes with fixed specifications.

Hydraulic Type

✔ Hydraulic positioning

✔ More stable cutting force

✔ Better accuracy during high-speed production

✔ Suitable for larger pipe sizes and frequent specification changes

Hydraulic Inner Scarfing Devices are ideal for customers requiring higher productivity, automation, and consistent internal surface quality.

How to Choose the Right Inner Scarfing Device?

Choosing the correct model mainly depends on your production requirements.

Mechanical Type is recommended if:

• Production speed is moderate
• Pipe specifications change infrequently
• Budget is limited
• Standard internal surface quality is acceptable

Hydraulic Type is recommended if:

• High production speed is required
• Frequent size changes
• Larger diameter pipes
• Higher automation level
• Higher internal surface quality requirements

AIS Machinery can recommend the most suitable solution according to your tube specifications and production conditions.

Common Technical Parameters 📏

Typical application range (customized according to production requirements):

Parameters can be customized according to your ERW tube mill specifications.

Main Advantages ⭐

• High burr removal efficiency
• Smooth internal pipe surface
• Stable cutting performance
• Long service life
• Easy adjustment and maintenance
• Suitable for continuous production
• Compatible with various ERW tube mill sizes
• Available in mechanical and hydraulic versions
• Custom design for different pipe dimensions

Case Study 🌍

AIS Machinery has supplied Inner Scarfing Devices to customers in Russia and Southeast Asia, where the equipment has been operating reliably in production. Based on their positive experience, several customers have placed repeat orders for additional devices for different pipe sizes.

Each Inner Scarfing Device is custom-designed according to the customer's pipe diameter, wall thickness, and production requirements. Before manufacturing, our engineers provide detailed drawings for customer approval to ensure the device fits the ERW tube mill perfectly.

FAQ

1. What is the purpose of an Inner Scarfing Device?

It removes the internal weld bead produced during ERW welding, creating a smooth inner pipe surface and improving overall pipe quality.

2. What is the difference between mechanical and hydraulic types?

The mechanical type uses manual adjustment and is suitable for standard production. The hydraulic type uses hydraulic cylinders for faster, more accurate adjustment and is better for high-speed, automated production.

3. Can one device be used for different pipe sizes?

Yes. Within its designed production range, the device can be adjusted to accommodate different pipe diameters. The available range depends on the tube mill design.

4. Does removing the internal burr affect the pipe wall?

No. When properly adjusted, the scarfing tool removes only the weld bead without damaging the pipe wall.

5. Can the device be customized?

Yes. AIS Machinery can customize the Inner Scarfing Device according to your tube diameter, wall thickness, production speed, and ERW tube mill configuration.