Home / Standards / GB/T 12777 GB/T 12777 Active General Technical Specification for Metal Bellows Expansion Joints 金属波纹管膨胀节通用技术条件 Standard Type GBT ICS 47.020.30 CCS U50 Status 现行 Issue Date 2022-12-28 Implementation 2019-12-01 Responsible Dept N/A Drafting Unit N/A