We profinession flange manufacture10 year more , everyone flange as stadrad as
GB-9112-2000
GB/T13402-1992
GB/T13403-1992
SH3406-1996
HG20592-20635-97
JB/T 74-90-94
JB/ T 4700-4707-2000
ASTM/ANSI B16.5
ASTM/ANSI B16.28
ASTM/ANSI B16.36
ASTM/ANSI B16.47
ASTM/ANSI B16.48
AP1605
JIS
DIN
ISO