Are there any requirements regarding the type of flange and the sealing surface for pipelines carrying highly hazardous media?
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RT~ Recently, while reviewing documents on previous projects, I saw that the flange sealing surfaces for pipes in nitric acid media were of type FF. I remember thinking that this wasn’t allowed, right? Does anyone know if there are any requirements regarding the type of flange and the sealing surface for pipes carrying highly hazardous media or those at great heights? Which specific standard specifies it?
Chapter 13 of the \"Code for Design of Industrial Metal Piping\" GB50316 stipulates that for Class A1 fluids, flat welding (plate-type) flanges shall not be used, and the nominal pressure of the flanges shall not be lower than 2.0 MPa； When using soft gaskets, flanges with male and female surfaces or tenon and mortise surfaces should be selected ； For Class A2 fluids, flat (plate-type) flanges should not be used. For highly hazardous Class A2 fluids, when soft gaskets are employed, flanges with male and female faces or tenon and groove faces should be selected ； Some content is excerpted; you can check the specifications for details.
Yes, that’s it~ Thank you so much!
Is flat welding (plate type) PL or does it include SO as well?
Is there a conclusion available now, including for SO flanges?
HG/T 20580~20585 also have relevant requirements for highly hazardous media