What is the basic requirements for weld appearance of L290 LSAW pipe?

Before the non-destructive testing of L290 LSAW pipes, the weld appearance inspection should meet the requirements. The general requirements for the appearance of the welded seam of the longitudinal steel pipe and the surface quality of the welded joint are as follows:

The welding appearance of L290 LSAW pipe should be well formed, and the width should be 2mm on each side covering the edge of the groove. The height of the foot of the fillet weld should meet the design requirements, and the shape should transition smoothly.

Welded joint surface

(1) Cracks, lack of fusion, pores, slag inclusions, and splashes are not allowed.

(2) The weld surface of pipelines whose design temperature is lower than -29 degrees, stainless steel and alloy steel pipelines with a greater tendency to harden hardening shall not have undercuts. The undercut of the weld of other materials should be greater than 0.5mm, the length of the continuous undercut should not be greater than 100mm, and the total length of the undercut on both sides of the weld should not be greater than 10% of the full length of the weld.

(3) The weld surface shall not be lower than the pipe surface. The remaining height of the weld is not more than 3mm, (the large width of the back groove of the welded joint assembly).

(4) The staggered side of the welded joint should be no more than 10% of the wall thickness and no more than 2mm.