Metcar Valves

Carbon graphite ball valve seats are utilized by many manufacturers in the most severe chemical environments, due to their high degree of chemical compatibility. Metcar’s carbon graphite ball valve seats are designed to handle hot liquids or gases ranging from approximately 350°F to over 800°F in oxidizing environments. They are also used for fire-safe ball valves in the petroleum industry, and must operate freely after a simulated fire test where the valve is heated to 1400-1800°F for at least thirty minutes. The ball valve seats are produced by shrink-fitting a carbon graphite ring into a metal retaining ring. After shrink-fitting, the carbon graphite is pre-stressed in compression and exhibits the same coefficient of thermal expansion as the metal retaining ring. The concave face of the carbon graphite ring is then polished to make a pressure-tight fit with the ball, and the back face of the carbon graphite is lapped flat to make a pressure-tight fit with the valve housing. Metcar’s technical staff can recommend the appropriate material for your application.