How to choose the grade of flange forgings
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This post was last edited by Tianya Mingyue_EADL on 2021-9-19 at 17:04. Given a vertical vessel with benzene as the medium, a design pressure of 0.35 MPa, and a temperature of 100°C, which grade of forged flange should be selected—Grade II or Grade III? The design institute recommended choosing grade III forgings, while the company’s in-house quality assurance engineer believed that grade II forgings would be sufficient. . . .
We choose grade 3 forgings for media that are highly or extremely hazardous
Regarding the determination of the toxicity of benzene as a medium, the Solid Content Regulations refer to HG/T20660-2000, which classifies benzene as a medium that is not highly or extremely hazardous. However, in the newer version of HG/T20660, benzene has been classified as hazardous due to its carcinogenic properties. According to HG/T20581-2020, for media that are highly or extremely hazardous, grade III or IV forgings should be used. While I believe that grade II forgings can also be used according to the strict provisions of the Solid Content Regulations, it is still recommended to use grade III forgings