Ball Valves
Fisher ball valves with trunnions help maintain consistent flow rates for high capacity, heavy duty applications.
Fisher ball valves with trunnions help maintain consistent flow rates for high capacity, heavy duty applications.
A ball valve consists of a valve body with a rotatable ball to control flow. A ball valve as a throttling control device ideally uses a full port (full bore) or reduced port (reduced bore) mechanism. A port or bore is a cylindrical flow passage through the center of the ball, and when turned one-quarter of the way, the flow stops. The port of a full port or full bore ball valve equals the pipeline diameter and presents little or no restriction to flow to allow for pigging when not attenuated. The port of reduced port or reduced bore ball valve is smaller than the pipe to absorb a small amount of pressure drop.
Full port and reduced port ball valves are well suited for a variety of hydrocarbon and process industry applications, including pipeline, bypass, batch, monitor, and emergency shutoff service. Rangeability is typically 100:1.
Ball valves can be trunnion mounted to minimize friction for high pressure drops. A trunnion is a style of mounting the ball on the valve shaft or stub shaft with two diametrically opposed bearings.
Optional severe service attenuators for ball valves help control noise and vibration from high pressure drop liquids and gases. A trim for gas service can help reduce the noise effects that cause pipeline vibration. A trim designed for liquid service can help eliminate or reduce cavitation and associated noise and vibration.
