Control valves are essential to a plant
The control valve was adequately controlling the process, but the actuator required more thrust than typical to move the valve back and forth. The OVD technology detected that hysteresis had quadrupled in one month and found that positioning accuracy was poor. It was only a matter of time before process integrity and the quality of the product being produced would be impacted.
The valve was flagged to be repaired during an upcoming minor
outage. At that time, the actuator was taken apart and technicians found that a
degraded O-ring on the piston had created residue that prevented the piston
from sliding smoothly within the piston chamber. The O-ring was replaced and
the valve returned to service. Operators immediately reported having more
robust control 2012-09-07
