Material related problems of A105 blind plate BL flange

For the same standard flange, different materials have different withstand voltage at different temperatures. The relationship among temperature, material and withstand voltage in Hg 20604-97 standard. As there are many kinds of steel in the world, the commonly used steel grades in the literature are grouped according to their characteristics. The nominal pressure grade belongs to the flange of European system, and the material group number is 1.0-14. 0 (11 grades in total); nominal pressure class belongs to American system flange, material group number is 1. 02.4 (12 grades in total). The same standard number at the same temperature. If the number of material groups is different, the pressure resistance (high impact pressure) of flange is also different.