Shape requirements of LSAW steel pipe

Before non-destructive testing (NDT), the welds of LSAW steel pipes must undergo a visual inspection to ensure they meet specific criteria. The general requirements for the appearance and surface quality of welded joints are as follows:

Weld Appearance:

The weld should have a uniform and aesthetically pleasing shape.

The width of the weld should appropriately overshadow each side of the groove edge by 2mm.

Fillet weld leg height should meet design specifications, and the shape should transition smoothly.

Welded Joint Surface Requirements:

- Surface Integrity:

Welds must be free of cracks, lack of fusion, pores, slag inclusions, and spatter.

- Undercut Tolerances:

For pipes with a design temperature below -29°C, stainless steel, and hardened alloy steel pipes, the weld surface should have no undercut.

For other materials, the undercut depth should not exceed 0.5mm. The continuous undercut length should be no more than 100mm, and the total length of undercuts on both sides of the weld should not exceed 10% of the entire weld length.

- Weld Reinforcement:

The weld surface should not be lower than the adjacent pipe surface.

Weld reinforcement should be no more than 3mm above the pipe surface.

- Misalignment:

The misalignment of the wall thickness at welded joints should be less than 10% of the pipe wall thickness and not exceed 2mm.

These standards ensure that the LSAW steel pipe welds meet the necessary quality and performance criteria, crucial for their application in various industries.