I would like to ask everyone questions regarding edge misalignment and welding defects
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I have a question for everyone. We have a piece of equipment that lacks access holes and manholes. We carried out TIG welding with a root pass on the outer bevel after closing the seams, followed by manual welding for the finish layer. However, during the RT inspection, it was found that there was incomplete fusion inside. The analysis suggests that the misalignment between the cylinder and the head is quite significant; the outer sides aligned properly, but there was misalignment on the inside. I would like to ask for advice on how to handle such situations where there is excessive misalignment between the head and the cylinder, and where single-sided welding makes it difficult to ensure good welding quality Thank you all
Strictly control the roundness and inner diameter of both the cylinder body and the head; when assembling them, ensure that the assembly gap is around 2–3 mm, with the misalignment amount not exceeding 2 mm. Seek an expert for TIG root welding to ensure proper penetration without the formation of weld beads on the back side.
It’s likely that this filming won’t pass the standards, right? It’s difficult to get proper control when using padding
The welding process is certainly important, but it’s mainly the skill level of the welder that matters...
The last edit to this post was made by Pinocchio on 2017-12-5 at 08:56. For the butt welds of the boiler header shells, the inner wall is machined in order to ensure proper alignment; the amount of machining is generally not more than the negative deviation of the tube’s thickness, with a machining depth of 25–50 mm. For cylinders made of steel plates, the perimeter should be controlled before welding the longitudinal seams, and the cylinder should be aligned before welding the circumferential seams; during butt welding, assembly fixtures are used to control misalignment and gaps.
It’s not necessarily that the welding process itself is problematic; I think experienced welders should be assigned to carry out the work.
Here, the companies use gaskets, perform TIG welding for the root pass, and then SMAW welding. The pass rate for X-ray examinations is very high/
Well, I thought I could add a gasket and then weld it manually