CPV code 42511000 designates Heat-exchange units and machinery for liquefying air or other gases in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
42511000 sits under 42510000 (Heat-exchange units, air-conditioning and refrigerating equipment, and filtering machinery) and groups 2 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.