Home / Standards / GB/T 23681-2009 GB/T 23681-2009 Active Refrigerating systems and heat pumps - System flow diagrams and piping instrument diagrams - Layout and symbols 制冷系统和热泵 系统流程图和管路仪表图 绘图与符号 Standard Type GBT ICS 27.200 CCS J73 Status 现行 Issue Date 2009-04-17 Implementation 2009-11-01 Responsible Dept 中国轻工业联合会 Drafting Unit N/A