11 FILTERS AND FILTER HOUSINGS FOR LIQUID AND GAS FILTRATION PLANTS; COMMERCIAL, INDUSTRIAL, MUNICIPAL AND RESIDENTIAL WATER FILTRATION PLANTS HEATING, COOLING AND VENTILATION SYSTEMS, COMPRISING PUMPS, FILTERS, BOILERS, FANS, NUCLEAR FUEL ELEMENTS OR HEAT EXCHANGERS FOR COMMERCIAL, INDUSTRIAL, MUNICIPAL AND RESIDENTIAL USE; DRINKING WATER FILTERS; CERAMIC ELEMENTS FOR THE CONDITIONING OF DRINKING WATER; FILTERS FOR FILTERING CHEMICALS, WASTE PRODUCTS, DRUGS, GASES, LIQUIDS, OIL POLYMERS, AND BEVERAGES; CERAMIC ELEMENTS FOR THE REMOVAL OF IMPURITIES FROM DRINKING WATER; NUCLEAR FUEL ELEMENT CANISTERS; CERAMIC CORES FOR COMPONENT CASTING; CERAMIC DIFFUSERS; HEATERS; PARTS FOR ALL THE AFORESAID GOODS