The Valve for Abrasive and Slurry On/Off and Control Applications: The Ball Sector Valve

Ball Sector Valve

The Ball Sector Valve is intended to perform well in harsh environments such as slurries, dry media, fluids containing suspended solids, or liquids containing fibers. When combined with pneumatic and electric actuators, it is the best choice for exact control in various process industries such as mining, pulp and paper, and the chemical industry. 

The ball sector valve comprises a hemispherical shell - the ball sector - that is securely held in place in the valve body by two large bearing stems.

Ball sector valves deliver exceptional performance in demanding applications. When conventional butterfly and ball segment valves are closed, their critical sealing components are subjected to the most wear in the valve. Because of the unique design of the ball sector, the seal seals through a surface part that is less prone to wear. The ball sector valve facilitates sealing through less exposed areas of the ball sector to avoid abrasion-caused leakage. The sealing surface is not exposed to high flow velocities significantly extends the service life of ball sector valves. A self-adjusting PTFE packing with an integrated spring element seals the shaft and protects the bearing from media particles. This innovative seal design, combined with a variety of materials and finishes for the ball sector and valve seat, significantly extends the valve's life compared to other valve technologies. As a result, it is particularly suited to abrasive, high viscosity, or fiber-containing media. 

The modified equal-percentage operating characteristic (difference pressure increases as the valve closes) combined with the outstanding rangeability of 300:1 means that the valve can be used for most control tasks. The valve body's special connection ensures that the differential pressure on the valve has little effect on the actuating torque. 

Other technologies, such as a segmented ball or rotary globe valves, employ an excentric shaft, causing the ball or plug to lift up from the valve seat when the valve begins to open. As a result, sealing areas are immediately subjected to permanent wear. Particulate can become lodged between the seal ring and the ball/plug. The ball sector valve has centric and robust trunnions that allow the ball sector to maintain constant contact with the valve seat, preventing media contamination. Changes in differential pressure have no effect on the permanent actuation torque.

For more information about Schubert & Salzer products, contact Miller Energy by calling 800-631-5454, or visit https://millerenergy.com.