Tips for Detecting Weld Seam Issues After Scarfing in 2026

In welded tube production, quality issues rarely appear at the end of the line. They often begin with the strip material upstream, or after welding at the scarfing station.

A welding process issue, inconsistent bead removal, or minor scarfing setup problems can introduce surface and near-surface defects or material integrity further down the line. Left unchecked, these issues damage equipment, create additional scrap, and increase the probability that a defective tube reaches the customer.

In previous posts, we have examined the differences between welded and seamless tubes and shown how a unified eddy current testing platform can improve mill uptime. What becomes clear when those ideas are applied on the production floor is that inspection effectiveness is directly correlated to process placement. Detecting defects only after multiple downstream steps limits the ability to correct the root cause.

Inspection after welding and scarfing changes that dynamic. This is where excess material is removed, where weld inconsistencies may first appear on the surface, and where process drift can be identified before it affects the rest of the line.

The PRÜFTECHNIK NDT EDDYCHEK 6 series by FOERSTER is designed to operate anywhere along the line, including this critical point.  It delivers fast, stable eddy current inspection directly after welding, giving tube producers immediate visibility into surface and weld-related defects as they occur. Problems are identified early, process adjustments can be made quickly, and downstream operations remain protected.

As welded tube applications expand and specifications tighten, real-time feedback at the point of defect creation has become a baseline requirement for consistent tube quality.

Why It Matters

Scarfing quality directly influences more than surface appearance. It affects equipment life, production efficiency, and customer risk. When tube scarfing performance degrades, the impact is felt across the entire mill:

• Surface and near-surface defects propagate downstream.
  Residual weld beads, tearing, grinder marks, or heat-affected zone irregularities can pass through sizing and straightening, becoming harder to correct.
• Downstream equipment is exposed to unnecessary wear and tear.
  Undetected surface defects accelerate damage to rolls, guides, and cutting tools. It can also damage probes or coils, resulting in increased maintenance and unplanned downtime.
  Defects become more expensive to address over time.
  Issues found after cutting or bundling often result in scrap, rework, or missed deliveries rather than simple process adjustments.
• Weld integrity risks increase.
  Conditions such as lack of fusion, cold welds, or edge misalignment may only become apparent after scarfing exposes the weld area.
• Process knowledge gaps grow.
  With fewer experienced operators on the line, mills need objective, automated inspection to ensure consistency across shifts and product changes.

Inspection post scarfing is one of the few opportunities to connect weld quality, surface condition, and process stability in real time. Without it, mills lose visibility at a moment when defects are still correctable.

By identifying issues after scarfing, manufacturers can protect downstream operations, reduce scrap, and maintain control over tube quality before problems escalate.

How We Help

The PRÜFTECHNIK NDT EDDYCHEK 6 series by FOERSTER is a fully digital, multi-channel eddy current architecture. Each testing channel operates with its own dedicated oscillator and patented digital demodulator, eliminating multiplexing and preserving signal integrity even at high production speeds. This design is particularly important in post-scarfing applications, where small surface changes and residual weld conditions must be detected reliably and repeatably.

Built for High-Speed Tube Production

The EDDYCHEK 6 series is designed for continuous, in-line operation on welded tube mills:

• Supports multichannel, multifrequency testing, enabling simultaneous monitoring of weld seams and adjacent surface area.
• Capable of operating at line speeds up to 20 m/s in welded tube applications, with encoder or light-barrier speed tracking to maintain accurate defect positioning.
• Modular system architecture allows expansion as inspection requirements evolve, from standard configurations to advanced multi-sensor setups.

For more complex applications requiring multiple sensors or rotating systems, the EDDYCHEK 610 extends these capabilities with support for up to 10 channels across 6 test positions, making it the ideal solution for demanding weld and surface inspection tasks on high-performance tube lines.

Targeted Detection Where Welding and Scarfing Matters Most

Post-welding inspection demands sensitivity without instability. The EDDYCHEK 6 series addresses this through advanced signal processing and evaluation tools:

• High-resolution XY and real-time signal displays allow operators to see changes in surface and weld behavior as they occur.
• Flexible masking and alarm thresholds enable classification of defects by type, density, and severity, supporting clear pass/fail decisions without subjective interpretation.
• End-signal suppression prevents false indications at cut lengths, improving evaluation stability in continuous production environments.

This combination allows the EDDYCHEK to reliably identify weld-related conditions such as residual weld beads, laminations, seams, surface defects, and scarfing chatter, while maintaining consistent performance across shifts and operators.

Documentation, Traceability, and Process Insight

Beyond detection, the EDDYCHEK 6 series provides the data needed for modern quality requirements:

• Archiving of test parameters and results for repeatability and audit readiness.
• Integration with EDDYTREND II software for trend analysis, helping identify gradual process drift such as scarfing tool wear or weld instability over time.
• Export of inspection data in structured formats to support quality reporting and root cause analysis.

Installed after welding and scarfing, the EDDYCHEK gives manufacturers the insight needed to protect downstream operations, reduce scrap, and maintain consistent tube quality at full production speed.

Conclusion & Key Takeaways

In welded tube production, quality issues rarely originate at the end of the line. They begin earlier, often at welding and scarfing, where small process variations can introduce defects that grow more costly as they travel downstream.

The PRÜFTECHNIK NDT FOERSTER’s EDDYCHEK 6 series by FOERSTER enables tube producers to move inspection upstream and transform it into a real-time process control tool.

What This Means for Tube Producers

• Earlier detection of weld and scarfing-related defects
• Reduced scrap, rework, and downstream tooling damage
• Stable, high-speed inspection that keeps pace with production
• More consistent quality, regardless of operator experience
• Documented inspection results that support audits and customer requirements

Operator Checklist: Is the EDDYCHEK 6 Series a Good Fit for Your Line?

The EDDYCHEK 6 series may be the right solution if you are seeing any of the following:

• Scarfing chatter issues or variable weld bead removal
• Surface or weld defects discovered after cutting or bundling
• Unexpected wear or damage to downstream equipment
• Weld-related defects that are difficult to diagnose once production moves on
• Inspection results that vary by shift or operator
• Difficulty maintaining quality at higher line speeds
• Limited inspection data for traceability, audits, or root cause analysis

If several of these apply, inspection is likely happening too late in the process. Moving eddy current testing directly after welding and scarfing can significantly reduce production risk. Learn more about the EDDYCHEK 6 series and how it helps tube producers protect throughput, improve consistency, and deliver reliable tube quality at full production speed.