2005DVS 2207-4-2005 "Welding of thermoplastic - Extrusion welding of pipes, piping parts and panels - Processes and requirements"
1981DVS 2209-1-1981 "Welding of thermoplastics; extrusion welding; procedures, characteristics"
DVS 2209-1-1981 "Welding of thermoplastics; extrusion welding; procedures, characteristics" was changed to DVS 2207-4-2005 "Welding of thermoplastic - Extrusion welding of pipes, piping parts and panels - Processes and requirements".