Non-destructive testing for the surface of LSAW steel pipes: for ferromagnetic steel pipes, should use magnetic particle testing; for non-ferromagnetic steel pipes, should use penetration testing. The application of surface non-destructive testing is carried out in accordance with the requirements of the standard. The detection objects and applications are generally as follows:

(1) Quality inspection of the outer surface of pipe.

(2) Detection of surface defects of important butt welds.

(3) Detection of surface defects of important fillet welds.

(4) Detection of surface defects in the welding joints of important socket welding and jumper tee branch pipes.

(5) Surface defect detection after pipe bending.

(6) Groove detection of welded joints with larger material quenching tendency.

(7) Detection of grooves for non-austenitic stainless steel pipes whose design temperature is lower than or equal to -29 degrees Celsius.

(8) Double-sided weldments are inspected after root cleaning

(9) When using oxyacetylene flame to cut welding fixtures on alloy pipes with a tendency to harden, detect the defects in the grinding parts.