Valve sealing is a very important parameter in valve design. Valve seals have an impact on the main functions of valves, which are to control flow and prevent leakage. Valve seals are critical in preventing the escape of the liquid or gaseous media in the valve such as the fugitive emissions of volatile compounds, release of hazardous or toxic media (gases or liquids), or leak of corrosive compounds into the environment.
There are two commonly sealing way for industry valves, soft sealing and hard sealing(metal sealing). They are used in different working conditions.