CPV code 44162500 designates Drinking-water piping in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
44162500 is a leaf code — the most specific level of its branch — so it can be used directly as the main CPV code of a contract notice. If it does not quite fit, check the neighbouring codes under 44162000 (Piping).