What is the wind tower welding process?

The welding process for wind tower construction is critical for ensuring the structural integrity and longevity of the towers. Here is an overview of the main steps involved in the wind tower welding process.

Wind tower welding process

Material Preparation

Cutting: The steel plates used for wind towers are cut to size using methods like plasma cutting, laser cutting, or oxy-fuel cutting.

Edge Preparation: The edges of the steel plates are beveled to prepare them for welding. This helps ensure strong and consistent welds.

Plate Rolling

Rolling: The cut and prepared steel plates are rolled into cylindrical or conical sections. Rolling is done using plate rolling machines to achieve the desired curvature and diameter.

Tack Welding

Alignment: The rolled plates are aligned and held in place using fixtures.

Tack Welding: Small welds are made at intervals to hold the sections together temporarily before the final welding. Tack welds ensure that the plates remain properly aligned.

Root Pass Welding

Root Pass: The first pass, or root pass, is performed to join the plates from the inside. This pass is crucial as it forms the foundation of the weld. It is usually done using a welding process like Gas Tungsten Arc Welding (GTAW) or Shielded Metal Arc Welding (SMAW).

Fill and Cap Pass Welding

Filling: Subsequent passes are made to fill the groove created by the beveled edges. Multiple passes are required to fill the joint completely.

Capping: The final pass, known as the cap pass, is done to create a smooth and even surface on the weld. This pass also enhances the weld's appearance and ensures it meets quality standards.

Non-Destructive Testing (NDT)

Inspection: After welding, non-destructive testing methods such as ultrasonic testing (UT), radiographic testing (RT), and magnetic particle testing (MPT) are used to inspect the welds for defects. Any identified defects are repaired and re-tested to ensure quality.

Assembly of Sections

Joining Sections: The cylindrical or conical sections are joined together to form longer sections or the entire tower. This is typically done using submerged arc welding (SAW) due to its high deposition rate and quality welds.

Flange Welding: Flanges are welded to the ends of the sections to allow them to be bolted together during tower assembly.

Post-Weld Treatment

Stress Relieving: Heat treatment processes are used to relieve residual stresses in the welded sections.

Surface Treatment: The welded sections are cleaned, and surface treatments such as sandblasting and coating (e.g., painting or galvanizing) are applied to protect against corrosion.

Final Inspection and Quality Control

Dimensional Check: The final assembly is checked for dimensional accuracy.

Load Testing: Load tests may be conducted to ensure the structural integrity of the tower.

Transportation and Installation

Transport: The completed sections are transported to the installation site.

Erection: The sections are lifted and bolted together on-site to form the complete wind tower.

The welding process for wind towers requires precision and adherence to strict quality standards to ensure the towers can withstand harsh environmental conditions and operational stresses.