metal safety valves and metal safety or relief non-return valves, all manually operated; metal manually operated industrial valve fittings, in particular, special valve fittings being parts of pipes for use in the biological, food, cosmetic, or chemical industries; metal manually operated safety or relief non-return valves being parts of pipes and boiler tanks for use in energy power production (steam production) and petrochemical industries; metal manually operated safety valves being parts ...