Q647F / H / Y API6D pneumatic fixed ball in the exploitation of oil, gas, coal and ore, refining, processing and pipeline systems; in chemical products, pharmaceutical and food production species; hydropower, thermal power and nuclear power production system; In the cities and industrial enterprises to drainage, heating, and gas supply systems; in farmland irrigation and drainage systems; and to be widely used in metallurgy production system it is a production construction, national defense and people's lives important mechanical products. Valve closed piping system in various types of seed used to cut off or connected media stream, the medium in accordance with a predetermined program delivery to each designated point.