Thought question 18: What are the minimum diameters for non-destructive testing?
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Thought question 18: What are the minimum diameters for non-destructive testing? What is the minimum diameter for RT detection? What is the minimum diameter for UT testing? What is the minimum diameter for MT testing? What is the minimum diameter for PT testing?
There shouldn’t be any limit on the minimum diameter for RT testing, right?
Why does GB150.4 specifically mention that for all non-destructive testing, the butt welds of the nozzles with a diameter of ≥250 should be inspected in conjunction with the shell.
For steel small-diameter tubes, the minimum size can be φ5×2
DN250 should be the boundary diameter considering it as the main pressure-bearing element, and it has nothing to do with whether non-destructive testing is possible.
When the nominal diameter is less than 250, penetrant testing is generally chosen, as magnetic particle testing is no longer suitable
It’s a different thing from what RT can detect as the minimum diameter; considering your level, you’re quite experienced in this field – how can you still not understand this concept?
UT is affected by the probe contact surface and is highly dependent on the radius of the workpiece being inspected. .
In my understanding, since the DN250 pipe is used as the main pressure-bearing component and is treated in the same way as the cylinder, the butt joint B seam also requires the same type of flaw detection as the cylinder’s B seam. If the tube is too small, the unevenness in thickness as detected by radiography will increase. There are standards specifying what size tube to use and how many images to take.