CPV code 50531500 designates Repair and maintenance services of derricks in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
50531500 sits under 50531000 (Repair and maintenance services for non-electrical machinery) and groups 1 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.