Issues related to the classification of pressure vessel flanges and technical requirements
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Recently, while studying the classification and technical requirements for pressure vessel flanges 47020, I noticed that the selection of materials for flanges, gaskets, and studs/nuts is based on Table 2 in the standard. What is the purpose of Table 3, which lists the available materials for studs, in this standard? It doesn’t seem to be explained anywhere in the standard; I would appreciate some guidance from those who know more about this. Thank you
Screws made of different materials have varying temperature ranges suitable for use. The appropriate screw material should be selected based on the type of flange and the type of gasket used
Screws made of different materials have varying temperature ranges suitable for use. The appropriate screw material should be selected based on the type of flange and the type of gasket used
Then I just need to choose according to Table 2, right? Isn’t Table 2 the table that shows the material matches for flanges, gaskets, and bolts and nuts?
Tables 3, 4, and 5 provide details on the selection of studs under corresponding pressure and nominal diameter conditions; for example, the 35 steel studs listed in Table 3 can be used at 0.25 MPa for diameters of 2800 and 3000. Table 2 is a matching table for flanges, gaskets, studs, and nuts. For type B and long-neck flanges, the specific studs to be used are specified in Tables 3 to 5. I hope I have made this clear
I basically understand what you mean. I have designed a heat exchanger and need to use type A flanges. Can I simply select steel grade 35 according to Table 2 for the studs? Thank you
For Type A flanges, select according to Table 2; 35 is suitable, and nuts of size 20 or 25 can be used
Table 2 contains a column with three types of stud materials, and further selection is required using Table 3. Please refer to the explanations in Column 1 of Table 2.
Table 2 is the matching table, and Table 3 is the selection table. First, select the stud material according to Table 3, and then determine the material compatibility of the flange, nut, and gasket using the matching table.