25/03/2025
What is Internal External Seam Welder Machine?
An Internal/External Seam Welder Machine is a specialized welding system used to produce continuous, high-quality longitudinal welds along the internal or external seams of cylindrical or tubular components—such as tanks, pipes, drums, vessels, or pressure cylinders. These machines are engineered for precise, consistent, and repeatable seam welding in industrial metal fabrication.
Technical Explanation
1. Function:
An Internal/External Seam Welder performs linear seam welding (as opposed to spot or arc welding) along the long axis (seam) of a workpiece, either from the inside (internal) or outside (external) surface, depending on part geometry and application.
2. Core Components:
| Component | Technical Description |
|---|---|
| Welding Head/Arm | Houses the torch, nozzles, and wire feed mechanisms. Can be MIG, TIG, or plasma. |
| Seam Tracking System | Uses sensors (e.g., laser, vision, or tactile) to automatically align with the seam during welding. |
| Clamping System | Pneumatic or hydraulic clamps hold the sheet or cylinder in perfect alignment to avoid gaps or misalignment. |
| Drive Mechanism | Linear motor or servo-driven system moves the welding torch or part in a precise linear path. |
| Cooling System | Cools the workpiece and torch during extended welds (especially for internal welding in closed vessels). |
| Control Unit (CNC or PLC) | Enables control of travel speed, current, arc length, voltage, oscillation, start/stop, and seam length. |
3. How It Works:
External Seam Welding:
- The workpiece (usually a shell or pipe) is mounted horizontally.
- The welding torch travels along the outer seam (top-down).
- Common welding processes: TIG, MIG/MAG, Plasma.
Internal Seam Welding:
- The welding arm or boom is inserted inside the cylinder.
- Torch travels along the inner seam, often requiring long reach tooling.
- Used for pressure vessels or sanitary tanks to avoid external surface distortion.
4. Key Technical Parameters:
| Parameter | Typical Range / Description |
|---|---|
| Weld Length | 500 mm – 6000+ mm |
| Material Thickness | 0.5 mm – 25 mm |
| Travel Speed | 100 – 2000 mm/min |
| Clamping Accuracy | ±0.1 mm |
| Torch Oscillation (Optional) | For wider welds or gap bridging |
| Seam Type | Butt, overlap, edge joint |
Welding Processes Used:
- GTAW (TIG): For thin stainless steel, aluminum—precision and cleanliness.
- GMAW (MIG/MAG): For faster welding on steel and thicker sections.
- PAW (Plasma Arc Welding): High-precision, low-distortion welds.
- Laser Seam Welding (in high-end systems)
Advantages:
- High Weld Quality – Uniform penetration, minimal distortion.
- Automation – Repeatable and consistent welds over long runs.
- Versatility – Suitable for both thin and thick wall components.
- Time-Saving – Reduces manual welding time significantly.
Applications:
- Pressure vessels
- Pipe manufacturing
- Food & pharma-grade tanks (sanitary welds)
- Heat exchangers
- Fuel tanks
- Cylindrical enclosures for electronics or aerospace
