Home / Standards / GB/T 25429-2019 GB/T 25429-2019 Active Petroleum drilling and production equipment—Drill string non-return valve 石油天然气钻采设备 钻具止回阀 Standard Type GBT ICS 75.180.10 CCS E92 Status 现行 Issue Date 2019-12-31 Implementation 2020-11-01 Responsible Dept 国家标准委 Drafting Unit N/A