Cast steel gate valves are capable of connecting or cutting off media in pipelines, changing the flow direction of media and adjusting their pressure, so as to protect the normal operation of the pipeline equipment. With small fluid resistance and slight corrosion on sealing surfaces, this type of valve has a long service life. What's more, cast steel gate valves are widely applied to control the pipeline flow, pressure and temperature in various industrial automatic production and are used in environmental protection, energy management, fire protection system, petrochemical, light industry, water supply and drainage and other fields.