Use of the sealing surface on male and female flanges
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As the title suggests, is there any standard that requires the use of male and female flanges for toxic gases?
The ribbed flange is related to the pressure rating.
This post was last edited by Gan Dan Xiang Bo on 2017-8-25 at 16:01. According to GB 50316 clause 13.1.3.6 (3), if you want to use soft gaskets, you should use flanges with male-female surfaces or tenon-socket surfaces.
According to the tolerance specifications, to put it simply, it refers to necked butt-welded flanges
Let me complain about the ribbed flanges. I think this is just a stupid French standard. It offers no advantage in terms of leak prevention; on the contrary, it can make it difficult to clean the flange sealing surfaces, and problems with the gaskets are not visible from the outside. Or some people say that it can be beneficial to align the gaskets; what if there is a discrepancy between the diameter of the gasket and the diameter of the male and female surfaces? There are no raised and recessed face flanges in the American standard. I don’t know why it’s included in Chinese standards. It is recommended to abolish the standard for ribbed flanges.
Moreover, when resetting the pipeline after inspection and maintenance, it is necessary to align the convex and concave surfaces with absolute precision, not allowing the slightest error
When aligning flange welds, it is also necessary to distinguish between male and female fittings.
Perhaps only China has raised and recessed face flanges. It is particularly difficult to disassemble and assemble valves with uneven surfaces.
How can there be no uneven surfaces in American standards? Take a look for yourself at the mating surface of the flange standard B16.5 to see if any such unevenness exists
The American standard specifies a convex surface, rather than a concave-convex surface. Take another look.
How is it possible there are no uneven surfaces? Did you look carefully?