The ball valve seats are available in more than 150 proprietory grades and can be used in temperatures from approximately 350°F up to 800°F in oxidizing environments. They are also suitable for fire safe petroleum industry ball valves, which must operate freely after a simulated fire test in which the valve is heated to 1400-1800°F.
The ball valve seats are produced by shrink fitting a carbon-graphite ring into a metal retaining ring, which is available in Carpenter alloys, Hasteloy, Inconel, stainless steels, steel and titanium. 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 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
