Pneumatic unloading gray ball valve in the oil, gas, coal and ore mining, refining processing and pipeline transport systems; kinds of chemical products, pharmaceutical and food production; hydropower, thermal power and nuclear power's electricity production system; urban and industrial enterprises to drainage, heating, and air supply system; farmland irrigation and drainage systems; in metallurgical production systems to a wide range of applications, is a production and construction, national defense construction and people's lives, an important mechanical products. Valve closed species used in all types of piping systems truncated or connected media stream, the medium in accordance with a predetermined program delivered to the designated point. Nominal diameter: DN15-500mm; nominal pressure:-2.5mpa PN1.6; Suitable medium: water, gas, oil, natural gas and acid corrosion, oxidation, urea and other media; Applicable temperature: -20-150 - 300 ° C; Drive mode: manual, pneumatic, electric, etc.; Body material: carbon steel, cast steel, 304,316,316 L stainless steel;