Method and apparatus for qualifying performance of a conventional control valve
US9429938B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2011 |
| Grant date | Aug 30, 2016 |
| Priority date | — |
| Expiry date | Oct 27, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B19/0428
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method of qualifying performance of a conventional control valve in a process plant, the valve being controlled by a controller, the method comprising a processor obtaining data samples from a database stored on a server of the process plant, each data sample comprising a process variable, a set-point, and a manipulated variable; the processor computing a non-linearity index from the data samples and determining if the non-linearity index is greater than a threshold value; if the non-linearity index is greater than the threshold value, the processor charting a plot of the process variable against the manipulated variable and determining if the plot has an elliptical or rectangular fit; and if the plot has an elliptical fit, the processor determining if a percentage of the total number of data samples lying within a theoretical ellipse encompassed within the elliptical fit is less than or equal to a preset percentage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.