CPC Main Group F17C 3/00 Vessels not under pressure 3 direct subcodes Child Classifications Navigate with arrow keys, Enter to open F17C 3/005 F17C 3/02 with provision for thermal insulation (thermal insulation in general F16L59/00 ) F17C 3/12 with provision for protection against corrosion, e.g. due to gaseous acid (protection against corrosion in general C23F)