Corrosion resistance of Material of the flanges 1

[tranmylinh]

Dear Sirs,
When I read standard JIS B 2220:2004 that required:
Materials of the flanges shall be the ones given in table 5 or those at least equivalent to them in both the mechanical properties and corrosion resistance. (Table 5 : please see attached file)
I don't now what "at least equivalent to corrosion resistance" means. Please show me. Thanks so much.

 

[0707]

In my point of view corrosion resistance is determined by the material´s group number refered on the table 5.

good luck

luis