1) American norms
ANSI, API, AWWA, MSS
Flange rating: 75lbs, 150lbs, 300lbs, 600lbs, 900lbs, 1500lbs, 2500lbs
2) European norms
DIN, EN1092-1, BS4504, UNI
Flange rating: PN6, PN10, PN16, PN25, PN40, PN63, PN64, PN100
3) Russian flanges
GOST 12820 and GOST 12821
Flange rating: PN0.6MPA, PN1.0MPA, PN1.6MPA, PN2.5MPA, PN4.0MPA.
4) Africa
SANS1123 or SABS1123
Flange rating: 600kpa, 1000kpa, 1600kpa, 2500kpa, 4000kpa
5) Chinese flanges
CCCP
Flange rating: PN6, PN10, PN16, PN25, PN40, PN63, PN64, PN100
6) British
BS10 TABLE D, BS10 TABLE E FLANGE, BS4504
Flange rating:
7) Australian
BS10 TABLE D, BS10 TABLE E FLANGE, BS4504
Flange rating:
8) Japanese
JIS B2220
Flange rating:
9) Korean
KS B1503
Flange rating: