2019HG/T 20545-2018 Technical specification for manufacturing pressure components of chemical industrial furnaces
1993HG 20545-1992 Technical Specification of Shop Fabrication for Pressure Parts of Chemical Furnace
HG 20545-1992 Technical Specification of Shop Fabrication for Pressure Parts of Chemical Furnace was changed to HG/T 20545-2018 Technical specification for manufacturing pressure components of chemical industrial furnaces.