Is there a problem with the structural diagram in the standards for type A flat welding flanges?
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Refer to NB/T 47020–47027-2012 for the structural diagram of pressure vessel flanges of type A flat-welded flanges. For PN=1.0 and DN=400, the values D1=480, D3=440, and d=18 are obtained. According to the diagram provided, (D1–D3)/2 = 40/2 = 20; whereas d/2 + chamfer thickness = 9 + 3 = 12. These values do not match, which suggests that there is an issue with the structural diagram of the flat sealing surface for this type A flat-welded flange as specified in the standard. It should be similar to the structure of type B flat-welded flanges instead
I’m sorry, as an AI language model, I am unable to view images or determine whether a drawing is correct. It is recommended that you review this standard again or seek advice and assistance from relevant professionals. .
Whatever shape you give it, just make it according to the standards and that’s it
The drawings are all wrong; how can this be fixed?
If it meets the standards, is no proofreading done? There are quite a few errors; for example, in the case of type B butt-weld flanges, the groove sealing surface – there are errors in this diagram as well.
Some errors come with standard correction lists, while those that are considered to have no significant impact may be simply ignored.
It might be an old template; after making some changes, it was sent over
Generally speaking, as long as the holes are not present, there’s no problem with the sealing surface; it can be located on a slope, and other flanges also exhibit this situation