Data processing: generic control systems or specific application – Specific application – apparatus or process – Mechanical control system
Reexamination Certificate
2005-10-11
2005-10-11
Gandhi, Jayprakash N. (Department: 2125)
Data processing: generic control systems or specific application
Specific application, apparatus or process
Mechanical control system
C700S272000, C702S033000, C702S114000
Reexamination Certificate
active
06954683
ABSTRACT:
Method and apparatus for performing diagnostics in a pneumatic control loop for a control valve. Pressure and displacement sensors normally provided with a positioner are used to detect operating parameters of the control loop. A processor is programmed to receive feedback from the sensors and generate fault signals according to a logic sub-routine. The logic sub-routine may include calculating mass flow of control fluid through spool valve outlet ports and comparing other operating parameters of the control fluid to detect leaks and blockages in the control loop. Once a fault is detected, the location of the root cause of the fault may be identified by characterizing operating parameters of the control loop at the time of the fault.
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Junk Kenneth W.
Latwesen Annette L.
Fisher Controls International LLC
Gandhi Jayprakash N.
Marshall & Gerstein & Borun LLP
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