Home / Standards / GB/T 12777-2019 GB/T 12777-2019 Active General 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 2019-05-10 Implementation 2019-12-01 Responsible Dept 国家标准委 Drafting Unit N/A