scope:

This guideline applies to the welding of lining membranes made of polymer materials in large sealing systems in the fi eld of geotechnical and hydraulic engineering. Part 1 covers and replaces the former part 1 of the DVS 2225 series of guidelines. Guideline DVS 2225, Part 3 applies to the welding of lining membranes in systems in accordance with the German Water Resources Act (WHG) in geotechnical and hydraulic engineering, Guideline DVS 2225, Part 4 applies to the welding of lining membranes of polyethylene (PE) for protecting groundwater in landfi ll and contaminated sites, Guideline DVS 2225 Part 5 applies to the welding of lining membranes in tunnel construction.

This guideline is intended to provide the responsible authorities, clients, companies performing the work, and quality management with instructions for the performance of welding work and weld inspections on the site.

In particular, the guideline incorporates the stringent requirements these applications impose on the quality of the welded joint, and therefore its execution in an expert manner appropriate to the material used.

The work may only be performed by specialist companies, by welders who have received expert instruction and training in the further processing of semi-fi nished products.

Moreover, it provides instructions for the installation of lining membranes, and the structural design of welded joints between the lining membranes and components