Ball valve design with simple compact in structure, small overall dimensions, fast in switching, less in flow resistance, convenient for pneumatic and electric control, non-directional installation, thus it has been widely used under the high temperature and high pressure working conditions such as daily chemicals, fine chemicals, biochemical & biotechnology, pharmaceutical, shipbuilding, paper making, printing and dyeing, coating, environmental protection, refrigeration, oils & fats, greases, brewing, food and beverage, water treatment, urban construction and etc.