摘要 |
<p>A power-assisted valve is provided which is particularly effective for systems handling viscous materials, such as certain metering systems. The check valve operates effectively even with highly-filled viscous resins used in such systems. The valve includes a valve seat and a valve ball which can be urged toward the valve seat to a closed position by a fluid-powered cylinder and piston. The piston rod is separate from the valve ball so that the ball can rotate relative to the valve seat.</p> |