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[MW:35697] PT inspection after Grinding a Weld Seam?

By Materials & Welding

Dear Members,

I have a question since I'm a beginner in this domain.


 After a weld inspection by PAUT, a crack was detected at a certain depth. I noticed that the welders grind down the weld surface until they reach the depth indicated by PAUT, and then apply a PT test.
My concern is: isn't there a risk that the grinding process may partially close or smear the crack surface, making it harder for the PT liquid to penetrate and properly reveal the defect?

If so, this could mean that PT might give a false result, and the crack would only be detected later when PAUT is reapplied after re-welding.

Am I misunderstanding the procedure? What is the best practice in this case?

Thanks,

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