Home / Standards / GB/T 21539-2008 GB/T 21539-2008 Active Cement-purpose PU piston 混凝土泵用聚氨酯活塞 Standard Type GBT ICS 83.140.99 CCS G47 Status 现行 Issue Date 2008-04-07 Implementation 2008-10-01 Responsible Dept 中国石油和化学工业联合会 Drafting Unit N/A