Home / Standards / GB 20904-2007 GB 20904-2007 Active Horizontal directional drilling - Safety operation rules 水平定向钻机 安全操作规程 Standard Type GB ICS 53.100 CCS P97 Status 现行 Issue Date 2007-03-26 Implementation 2007-10-01 Responsible Dept 工业和信息化部 Drafting Unit N/A