Home / Standards / GB/T 12221-1989 GB/T 12221-1989 Abolished Metal valves for use in flanged pipe systems—Face-to -face and centre-to-face dimensions 法兰连接金属阀门 结构长度 Standard Type GBT ICS 23.060 CCS J16 Status 废止 Issue Date 1990-01-04 Implementation 1990-12-01 Responsible Dept N/A Drafting Unit N/A