CPV code 42941000 designates Machinery for the heat treatment of gas in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
42941000 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 42940000 (Machinery for the heat treatment of materials).