11 BLAST FURNACES AND PARTS THEREFOR, FOR THE PRODUCTION OF HOT METAL AND OXYGEN BLOWN STEEL; HEATING VESSELS OF BOILER PLATE AND SPECIAL STEEL FOR THE CHEMICAL AND MINERAL OIL INDUSTRIES; CHEMICAL REACTORS; MACHINERY FOR AMMONIA SYNTHESIS, NAMELY, GAS COOLERS, GAS INLETS, OXIDIZERS, SHIFT CONVERTERS, AND AIR SEPARATORS; AND NUCLEAR REACTOR PRIMARY LOOPS, AND PARTS THEREFOR