2006DVS 2212-1-2006 "Qualification testing of plastics welders - Qualification test groups I and II - Hot gas welding with the torch separate from the filler rod (WF), high-speed hot gas welding (WZ), heated toolbutt welding (HS), sleeve welding with an incorporated electric
1994DVS 2212-1-1994 "Examination of plastic welders examination - Group I - Hot gas welding with torch separate from filler rod (WF), hot gas string-bead welding (WZ), heated tool butt welding (HS)"