Ventilation valve used in chemical industry, building materials, power plants, glass and other industries in ventilation, dust cold or hot gas pipeline environmental projects, as a medium to regulate the flow of gas or cut pipe controls. Ventilation valve structural characteristics: 1, no rod, bolts, etc., reliable, long service life. You can multi-site installation, the flow of influence from the media. 2, using the new form of the middle and short style dish plate welded structural steel fabrication design, compact structure, light weight, easy to install, low flow resistance, high turnover, avoid high temperature expansion effects, easy operation. The main parameters: Nominal pressure (MPa) 0.05MPa medium temperature -30 ℃ ~ -350 ℃ strength test 0.1MPa Suitable medium hot and cold air, flue gas medium velocity 25m / s leak rate of 1-3%, the main part material: Name body parts valve plate valve shaft material carbon steel, carbon steel, stainless steel