DVS 1502-1-1982 Manual arc welding at pipes of ductile cast iron for pipelines of the public gas and water supply; principles of welding engineering
DVS 1502-2-1982 Manual arc welding at pipes of ductile cast iron for pipelines of the public gas and water supply; welding of parts of ductile cast iron or steel
DVS 1148-1995 history
1995DVS 1148-1995 Examination of welders - Manual arc welding at pipes of ductile cast iron
1982DVS 1148-1982 Examination of welders; manual arc welding at pipes of ductile cast iron for pipelines of the public gas and water supply