Carbon-graphite ball valve seats for hot liquids or gases

Metallized Carbon Corporation has introduced a range of carbon-graphite ball valve seats for valves thathandle hot liquids or hot gases. The seats are available in more than 150 grades of Metcar’s proprietary carbon/graphite material and are suitable for use at temperatures from approximately 350°F, at which point plastic ball valve seats begin to soften. They can be used in fire safe petroleum industry ball valves, which must operate freely after a simulated fire test at elevated temperatures.

03/11/2011 11:52:20

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.