The 6-inch, W-K-M, Model 310, Full-Port, DynaSeal Ball Valve with chromium-oxide coated ball and seats (METC SOA Test Valve No. A-7) completed 465 cycles with clean gas in the Valve Static Test Unit and 3,258 cycles with limestone solids in the Valve Dyname Test Unit. Inspection of the valve after static testing revealed chipping of the chromium oxide coating in noncritical areas around the stem slot and ball lips. In dynamic testing the valve exhibited excessive leakage with the 1/4-inch x 100-mesh limestone test medium. The minus 100-mesh limestone test medium accumulated between the ball and valve body, which led to increased friction. The actuator exerted increasingly higher torques on the valve stem and eventually deformed the valve stem. Several modifications would be necessary to overcome the problems Test Valve No. A-7 experienced in dynamic testing. The chromium-oxide coating showed relatively little wear indicating that this type of trim is suitable for solids-handling lockhopper service. A similar W-K-M, Model 310 Ball Valve was rebuilt by METC using ceramic aluminum-oxide ball and seats. The initial leakage was high due to surface irregularities remaining from the manufacturing process. After relatively few cycles in a clean gas, extensive chipping of the ball was discovered. It was concluded that the use of solid ceramic components requires a valve design that accommodates their specific physical properties.