The rapid development of large-scale coal chemical industry requires corresponding technical equipment support, especially coal-to-oil, methanol, synthetic ammonia, coal-to-olefin and other coal chemical industries require a large number of large-scale coal chemical valve equipment. Among them, coal-to-oil production (using coal liquefaction to make oil) is a new technology focused on development. The process conditions for direct coal liquefaction plant are very harsh, and the requirements imposed on the valve are very high. The characteristics of coal oil are flammable, high temperature and corrosion and wear, etc. The corresponding requirements for the valve will be high.