Regarding the issue of hardness difference between ring-groove face flanges and ring gaskets
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Generally, when metal ring gaskets are used with ring-grooved flanges, standards specify requirements regarding the difference in hardness; for example, clause 7.4.7 of SH/T3059-2012 states that \"the hardness of the metal ring gasket material should be 30~40 HB lower than that of the flange material.\" For flanges and gaskets made of the same material, such as face flanges with grooves and octagonal gaskets both made of 304 material, how can this requirement be met?
The standards indeed require this, but in practice all of these materials are the same
I’m asking how this requirement is met during manufacturing? I want to know the principle and process!
Reduce the hardness by heat treating the metal gasket.
Could you please tell me how to do it specifically?
Thank you to the original poster for providing such important information on the source of the difference in hardness between the metal ring gasket and the flange!