【Beginner】Regarding flanges
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Experts, is HG/T20592-2009(B) the standard that is used for flanges in general? Also, when choosing the type of sealing surface, is it sufficient to consider PN? For PN25 and below, use RF; for PN16 and below, choose FF. For the rest, should TG or MFM be used? Is it sufficient to specify only DN for the flange size?
I never use the HG standards; I always use ASME and API instead.
Yes, the standard you mentioned is the European standard; there are both European and American standards, with the European standard being commonly used. You’re also correct regarding the type of flange sealing surface, but it is generally determined based on the requirements of the pipeline or equipment in question.
It is usually HG20592; I’ve also seen older companies use machine markings. When the pressure is higher, RJ surfaces are used. In addition to DN, there is also the material to consider~
Based on the process piping and equipment conditions? Could you be more specific?
Don’t we need to specify a few screw holes or something?
It is developed according to the owner’s specifications; I mainly use American standards and have never used Chinese standards.
The hole size corresponds to the pressure rating and nominal diameter; it’s specified in the standards