|Valve technology, relies on materials science, structural science development. In recent years, China's synthetic materials, new alloy and development of new technologies, new materials, the use of metal, has made great progress, these are for valve technology development has added new content. The development of a metal such as titanium, since titanium has a high affinity for oxygen, to generate a solid oxide protective film, so that the number of strong corrosive media, in a passive state, exhibit excellent corrosion resistance in acid, alkali and widely used in organic, mixed organic acid in certain steel cutting only twelve weeks, while the long-term use titanium valves. Also, zirconium metal material, is another good corrosion resistance of the metal. Synthetic material is endless, such as polypropylene, polycarbonate, nylon and other materials, manufacture of valves have been used in the chemical industry. New ceramic valves are also being gradually promote the use. The new structure has also been introduced, such as the introduction of hard seal butterfly valve in the country over the past fifteen years to do. High pressure power station valve development, application and so on. New sealing materials; flexible graphite applications. It is immersed in the graphite lattice of a liquid, followed by forced evaporation, the lattice array direction of change, thus changing the soft graphite and become brittle material, he can do gasket and packing, as the high purity graphite, almost all capability chemical species, if the folder in which to increase the strength of nickel wire can be used for high temperature and pressure control valve packing, gaskets. Countries in the world in order to reduce costs, improve competitiveness, complete sets of equipment to large-scale development; currently the largest thermal power generating units is 1.3 million kilowatts (USA, Switzerland made) a 600,000-kilowatt generator set with three 200,000 kilowatts generator group, equipment unit power cost decreased by 10 to 20%, power plant construction costs, unit power, manufacturing hours, a 20% reduction in steel consumption 6,000,000 tons / year refinery and two 3 million tons / year refinery compared to only invest considerable in the latter 69%, 53% of steel consumption, covers an area of 54%, the production cost is 75%, while labor productivity has increased by 170% Foreign biggest oil refinery was 36.4 million tons / year, while 20 million t / year are more than 20. With the oil refining industry oil pipeline has also been rapid development. Has built the longest oil pipeline 4,830 kilometers (Iran). Longest gas pipeline 7,680 km (from Alaska through Canada to the United States) max diameter 1420mm and 1620mm. Maximum line pressure 9 ~ 12MPa these lines have strict requirements on power station valves, are used remote manipulation. Also with the increase of thermal units, in order to improve efficiency, it also will increase the operating parameters; specification subcritical pressure and temperature from the temperature of the critical temperature 566 ° C16.9MPa 583 ° C24.6MPa supercritical temperature of 650 & # 176 ; C35MPa summarized above, upsizing by the device on the valve material, structure, reliability of the more stringent requirements.