Hot gas draw welding
The hot gas welding (WZ) welding or Warmgasfächelschweißen (WF) welding is a welding method for joining pipes or slabs of partially crystalline (z. B. polyethylene , polypropylene , polyvinylidene fluoride ), or amorphous thermoplastic (z. B. polyvinyl chloride ). While hot gas draw welding is primarily used for plastic sheets, hot gas fan welding is used for plastic pipes. The procedure is defined in DVS 2207 Part 3.
Process description
DVS 2207-3 describes the exact workflow for the welding process. In the case of WZ and WF welding, welding consumables (e.g. round or profile rod) are used. The base material and the filler with warm gas is migrating (hot gas welding) or fanning (Warmgasfächelschweißen) movements (mostly hot air, rarely inert gas ) plasticized and joined together under pressure. These WZ and WF connections are assessed in accordance with the DVS 2202 Part 1, evaluation group I, II or III.
application areas
Hot gas drawing or hot gas fan welding is used in container, pipe and ventilation construction. In DVS 2212-1, further subgroups are distinguished:
- Subgroup I-1 WZ: Rigid polyvinyl chloride , sheets up to 5 mm thick, V-seam
- Sub-group I-2 WF: rigid polyvinyl chloride, pipes up to 110 mm × 5.3 mm, V-seam
- Subgroup I-3 WZ: Polypropylene , sheets up to 10 mm thick, X-seam
- Subgroup I-5 WZ: Polyethylene HD , sheets up to 10 mm thick, X-seam
- Subgroup I-7 WZ: polyvinylidene fluoride , sheets up to 4 mm, V-seam
Plastic welding license
As with all welding processes, there are different licenses:
- License according to DVS 2207-1 with the corresponding subgroup: Authorized to weld components according to the subgroup, but not in the public gas and water network. The extension test must be carried out after one or two years.
- License according to GW 330: Authorized to weld in the public gas and water network. The extension test must be carried out after one or three years.
literature
- DVS-Verlag (Hrsg.): Pocket book DVS guidelines and guidelines for joining plastics . 13th edition. 2010, ISBN 978-3-87155-220-5 .
Web links
- DVS 2202-1 regulations
- DVS 2207-3 set of rules
- DVS 2212-1 regulations
- Gerd Ahlers-Hestermann: Plastic Connection Technology Manual, page 207ff