Regarding Type A flanges and Type B flanges
Thread Content
What to do if the dimensions of Type A flanges as specified in NB/T47021 are not suitable, given that a Type B flange structure would be inappropriate? The design pressure is 0.375 MPa, the diameter is 2000, and the medium is herbicides
Then design a custom flange by yourself; as long as the calculations are correct, that’s enough
The problem is that the reviewers believe that if something isn’t specified in NB/T47021, then it shouldn’t be used, as they are the authorities in this field. If it’s possible to exceed the specified limits, then there’s no need for any regulatory restrictions in that standard
How to refute it? Is there any literature explaining it?
Since the standard cannot be met, one has to design their own.
That’s a good idea; I really don’t understand how someone like him could become an auditor. With his way of thinking, too many chemical plants would be unable to continue operating.
The criteria for choosing standard flanges are, first, cost-effectiveness, and second, the absence of the need for drawing preparation; however, if such standards are not available, one must carry out the calculations themselves and create the drawings. Complies with the requirements of GB/150.3-2011
This post was last edited by wanlirn on 2019-6-25 14:29. Herbicides? It depends on the degree of hazard. For substances like paraquat, I need to conduct a review; high-neck flanges are required, and the manufacturing standards are very strict – this isn’t something to take lightly
Design it as a Type B flange; the diameter is too large.
When selecting a standard flange, it is necessary to meet all the conditions specified by the standard; those that do not meet these conditions require a custom design.