Dresser, Inc.

Peter S Levesque

Henry William Boger

Larry Gene Schoonover

Harold Randall Smart

James Albert Stares

Mark Chester

Denis Auguste Vital

Alex J Legere

Christopher Colwell

Chunhe Zhou

Raymond Villier

Mark V Chester

Systems and processes may provide improved performance for a pneumatic positioner during a safety override. In certain implementations, a system and process may include may include the ability to receive an input control signal, power control circuitry of the pneumatic positioner using the input control signal, and generate a control signal for a signal-to-pressure converter with the control circuitry based at least partially on the input control signal. The system and process may also include the ability to detect an unsafe operating condition for the pneumatic positioner based on an input signal and modify the control signal in response to detecting the unsafe operating condition, to cause the converter to transition to a safe state. The system and process may additionally include the ability to allow the control circuitry to continue being powered by the input control signal while the converter is in the safe state.

Safety override circuit for pneumatic positioner and method of use thereof

Systems and processes may provide improved performance for a pneumatic positioner during a safety override. In certain implementations, a system and process may include the ability to receive an input control signal, power control circuitry of the pneumatic positioner using the input control signal, and generate a control signal for a signal-to-pressure converter with the control circuitry based at least partially on the input control signal. The system and process may also include the ability to detect an unsafe operating condition for the pneumatic positioner based on an input signal and modify the control signal in response to detecting the unsafe operating condition, to cause the converter to transition to a safe state. The system and process may additionally include the ability to allow the control circuitry to continue being powered by the input control signal while the converter is in the safe state.

Controlling fluid regulation may provide increased efficiency and reliability. In one general aspect, a system and process for fluid regulation may include the ability to receive a command signal, generate a control signal based on the command signal, and move a magnetizable element relative to a wire coil in accordance with the control signal, the movement affecting a pressure in a pressure cavity. The system and process may also include the ability to sense the pressure in the pressure cavity due to the position of the magnetizable element and adjust the control signal based on the sensed pressure and the command signal. The system and process may further include the ability to sense a second parameter of the fluid regulation system and adjust the command signal based on the second parameter.

Fluid regulation control

Effective power regulation may be achieved for a field instrument that derives power from a communication signal. In particular aspects, a system and process for power regulation include the ability to receive a communication signal and adjust the voltage supplied to a power converter based on the current of the communication signal. The system and method also include the ability to convert power of the communication signal with the power converter.

Power regulation for field instruments

A valve positioner system that includes one or more unique control methods and devices, including several routines to facilitate the continuous maintenance, calibration and adjustment requirements of the valve. The positioner system may utilize pressure and position feedback signals to monitor the valve. The positioner system may utilize an external controller for various diagnostic and other routines. The positioner system can provide automatic positioning and can operate in a manual operating mode or an automatic operating mode. The positioner system can diagnose the valve while the valve process is running or during a maintenance operation. The positioner system can provide nonlinear control of the valve position. The positioner system can self-tune and self-characterize the valve to assure uniform position control. The positioner system can provide valve control through pressure feedback when a position feedback fails or other diagnosed problems. The positioner system can provide constraints to prevent slope reversal or slope changes in the valve characterization that would produce undesirable valve gain.

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Norwood, MA, United States of America

Peter S Levesque