2012DL/T 272-2012 Technical specification of 220 kV-750 kV oil immersed power transformer
1970SD 326-1989 Technical specifications for imported 220-500 kV power transformers
SD 326-1989 Technical specifications for imported 220-500 kV power transformers was changed to DL/T 272-2012 Technical specification of 220 kV-750 kV oil immersed power transformer.