A Real Time Analysis of Control Valve Stiction and Quantification in Petroleum Process

Stiction is a common problem in spring diaphragm or piston operated control valves in process industries. A method is proposed by fitting an ellipse to the controlled variable (PV) and controller output (OP) plot and the maximum width of the ellipse is the apparent stiction .The mathematical modeling of the work is done with reference to the M. A. A shouktat choudhury valve stiction model. In this paper for real time analysis the significant points (SIPO) is defined as the width of the ellipse by plotting controlled variable (PV) and controller output (OP) data.