Basic requirements for weld appearance of LSAW steel pipe:
 
Before nondestructive testing of straight seam steel pipe, the appearance inspection of weld should meet the requirements. The General requirements for weld appearance and surface quality of welded joints of straight seam steel pipes are as follows:
Welding should look good, with 2 mm edge width of each groove covered properly. The height of fillet weld should meet the design requirements, and the shape should be smooth transition.


Surface requirements of welded joints:
(1) No cracks, lack of fusion, pore, slag and spatter are allowed.
(2) For pipes with design temperature below - 29 degrees, stainless steel and hardened alloy pipes are usually large welded surfaces without undercutting. The bottom cutting depth of other material pipeline weld should be more than 0.5 mm, the length of continuous bottom cutting should not exceed 100 mm, and the total length of both sides of bottom cutting should reach 10% of the whole length of weld.
(3) It shall not be lower than the surface of the welded surface of the pipeline. The weld reinforcement shall not exceed 3 mm (maximum width of weld after groove).
(4) The wall thickness of the wrong side of the welded joint should be less than 10% and less than 2 mm.