Nuclear valves, although in the nuclear power plant equipment as an attachment, but essential. Valves for nuclear power than conventional large-scale thermal power station to use its technical characteristics and requirements of the valve is higher. Valves generally have gate valves, globe valves, check valves, butterfly valves, safety valves, main steam isolation valves,Lug butterfly valve, ball valves, diaphragm valves, pressure reducing valves and control valves, etc.; a representative of the highest technical parameters of the valve: The largest diameter DN1200mm (nuclear three butterfly), DN800mm (core 2 of the main steam isolation valve), DN350mm (nuclear one of the main circuit gate); maximum pressure: about CL1500; maximum temperature: about 350