Process equipment validation
AssigneeRosemount Inc.
InventorsDale Perry, Mark Schumacher, Garrie Huisenga, Randy Longsdorf
Life of this patent
Estimating the term…
Abstract
A Safety Instrumented System for use with a process control system receives pressure of process fluid in the process piping. A valve positioner positions a valve which controls flow of process fluid through the process piping. The valve positioner is caused to perform a partial stroke of the valve or otherwise introduce a perturbation into the process. A resulting change in sensed pressure due to the perturbation is used to diagnose operation of the process.
Claims56
A Safety Instrumented System for use in diagnosing operation of a basic process control system (BPCS) connected by a process control loop, comprising:
- a pressure sensor coupled to process piping and the process control loop configured to measure a pressure of process fluid flows in the process piping;
- a valve positioner coupled to the process control loop position configured to control in response to a control signal from the process control loop a valve which controls flow of process fluid through process piping to there by control a process;
- and
- diagnostic circuitry applying a perturbation signal having a frequency relative to the control signal to cause the valve positioner to perform a partial stroke of the valve, the diagnostic circuitry configured to compare a change in pressure sensed by the pressure sensor due to the partial stroke with a stored pressure signature and responsively diagnose operation of the process control system based upon the comparison.
A diagnostic system in a Safety Instrument System (SIS) for diagnosing operation of a process control system having a process control loop, comprising:
- a pressure sensor coupled to process piping and the process control loop configured to measure a pressure of process fluid in the process piping;
- a valve positioner coupled to the process control loop responsive to a control signal from the process control loop configured to control position of a valve which controls flow of process fluid through the process piping;
- diagnostic circuitry configured to cause small variations at a frequency in the control signal during normal operation of the process control system, the diagnostic circuitry further configured to compare changes in pressure sensed by the pressure sensor due to the variations in the control signal with a stored pressure signature and responsively diagnose operation of the process control system.
A method in a Safety Instrumented System for use in diagnosing operation of a process control system housing a process control loop, comprising:
- sensing a pressure of a process fluid carried in process piping;
- controlling operation of the process by applying a control signal from the process control loop to a valve coupled to the process piping;
- causing the valve coupled to the process piping to perform a partial stroke by applying a perturbation signal at a frequency to the control signal;
- monitoring pressure changes of the process fluid following the partial stroke;
- and
- diagnosing operation of the process control system based upon the monitored pressure changes of the process fluid.
A method in a Safety Instruments System (SIS) of diagnosing operation of a process control system having a process control loop, comprising:
- introducing small variations at a frequency into a controlled position of a valve coupled to the process control loop and to the process piping;
- monitoring pressure of the process fluid following the introduction of small variations into the controlled positioned of the valve;
- diagnosing operation of the process control system based upon the monitored pressure of the process fluid.
Dependencies are inferred from the claim text.