V-Port Ball Valves
Ball valves are a popular choice of control valve due to having various orifice geometries available upon order (e.g. Reduced ports, V-ports, Narrow slots, etc), which will provide different control characteristics. However, when throttling, all trim designs will direct abrasive flow into valve body and piping, eroding both.
Butterfly valves are typically selected for applications that have space constraints, as their body designs are among the narrowest in the industry. Despite their dimensional advantage, erosive slurry will be accelerated around both sides of the butterfly disc, significantly reducing the valve’s service life.
Pinch valves are a mining industry favorite; they work well in most applications and are relatively inexpensive. However, they do have their limitations. As the elastomer sleeve is ‘pinched’, abrasive flow is accelerated within the valve, with the highest velocities (and sleeve wear) occurring in the corners.
Knife Gate Valves
Knife gate valves are the least desirable valve for controlling abrasive slurry. When the gate modulates, acute angles are formed between the gate and valve body. These angles produce high fluid velocities, increasing the wear rate significantly. These valves are typically found in large diameter pipe, as they are economical by comparison.