metalworking machines and tools; gas supply equipment being part of a metalworking machine; gas automatic switching device (non-electric) for multiple gas containers for metalworking machines; gas purifier being part of a metalworking machine; heat treatment apparatus being part of a metalworking machine; apparatus for producing gas and powder mixtures; apparatus for the compression of gas; apparatus for the condensing of solvent gases; gas purifier being part of a 3D printer; heat treatment apparatus being part of a 3D printer; washing apparatus; washing apparatus for 3D printers