Welding Procedure Qualification: Key Positioning Weld Standards

Positioning weldis a key step before final welding. The quality of everypositioning weld affects the quality of the final weld. Because of this, GB50661 gives clear requirements for every positioning weld.

A positioning weldmust be made by a qualified Welder. The welder must hold the correct welding certificate. The welding materials should be the same as, or equal to, the materials used for the final weld.

The base metal near the positioning weld must meet the requirements of GB50661-7.1. A clean surface helps produce a better weld.

The thickness of a positioning weld should be at least 3 mm. If the final weld is thicker than 6 mm, the positioning weld should not be more than two-thirds of the final weld thickness.

The length of each positioning weld should be at least 40 mm. The distance between each positioning weld should be between 300 mm and 600 mm.

For steel backing joints, the positioning weld should be placed inside the groove. The preheating temperature should be 20°C to 50°C higher than the temperature used for the final welding. The positioning weld should follow the same welding procedure and quality requirements as the final weld.

If a positioning weld has cracks, porosity, slag inclusion, or other defects, the defects must be removed completely before the next welding step.

For structures that carry dynamic loads and require fatigue checking, a special positioning weld procedure should be prepared.

Why Positioning Weld Quality Matters

A positioning weld becomes part of the final weld. Because of this, poor positioning weld quality can cause defects in the finished joint. Good welding practice helps reduce repair work and improves production efficiency.

Qualified welders, correct welding materials, proper preheating, and careful inspection all help produce a strong positioning weld.

Morrow Welding Supports High-Quality Positioning Weld Applications

Morrow Welding Development Co., Ltd. specializes in the production and sales of welding power sources and welding equipment. Our products are widely used in steel construction, shipbuilding, oil and gas, metallurgy, and many other industries.

Our welding power sources provide stable arc performance, reliable welding quality, and high production efficiency. They help customers achieve consistent positioning weld quality and reliable final welding results.

Today, Morrow has stable markets in Europe, Asia, the Middle East, and many other regions. We continue to provide professional welding solutions for customers around the world.