Abstract: A method of limiting control pressure provided to an actuator of a valve coupled to a valve positioner, a drive signal is provided to a pneumatic stage of the valve positioner. The pneumatic stage is arranged to control output pressure of the valve positioner in accordance with the drive signal. A pressure measurement from a pressure sensor communicatively coupled to the valve positioner is obtained, and an abnormal pressure is detected based on the pressure measurement. In response to detecting the abnormal pressure, the drive signal is controlled so as to limit the output pressure of the valve positioner, wherein the output pressure provides control pressure to the actuator.

Abstract: A method of limiting control pressure provided to an actuator of a valve coupled to a valve positioner, a drive signal is provided to a pneumatic stage of the valve positioner. The pneumatic stage is arranged to control output pressure of the valve positioner in accordance with the drive signal. A pressure measurement from a pressure sensor communicatively coupled to the valve positioner is obtained, and an abnormal pressure is detected based on the pressure measurement. In response to detecting the abnormal pressure, the drive signal is controlled so as to limit the output pressure of the valve positioner, wherein the output pressure provides control pressure to the actuator.

Abstract: A method of limiting control pressure provided to an actuator of a valve coupled to a valve positioner, a drive signal is provided to a pneumatic stage of the valve positioner. The pneumatic stage is arranged to control output pressure of the valve positioner in accordance with the drive signal. A pressure measurement from a pressure sensor communicatively coupled to the valve positioner is obtained, and an abnormal pressure is detected based on the pressure measurement. In response to detecting the abnormal pressure, the drive signal is controlled so as to limit the output pressure of the valve positioner, wherein the output pressure provides control pressure to the actuator.

Abstract: A method of limiting control pressure provided to an actuator of a valve coupled to a valve positioner, a drive signal is provided to a pneumatic stage of the valve positioner. The pneumatic stage is arranged to control output pressure of the valve positioner in accordance with the drive signal. A pressure measurement from a pressure sensor communicatively coupled to the valve positioner is obtained, and an abnormal pressure is detected based on the pressure measurement. In response to detecting the abnormal pressure, the drive signal is controlled so as to limit the output pressure of the valve positioner, wherein the output pressure provides control pressure to the actuator.

Abstract: Methods and apparatus for bypassing a positioner in an active control loop are described. An example actuator assembly includes a pneumatic actuator and a transfer station. The transfer station includes a body defining flow paths that enable fluid to flow between a supply pressure, a valve positioner, and the pneumatic actuator and between the supply pressure and the pneumatic actuator to bypass the valve positioner without disrupting a process loop including the valve positioner. The transfer station also includes a plurality of fluid flow control devices to control the fluid flow through the flow paths.

Abstract: The present invention comprises methods for testing the valve seating integrity of a valve. The valve components that determine valve seating integrity are typically a valve seat and a valve closing element that engages the valve seat to close the valve. Examples of the test method described herein respectively test valve seating integrity during opening of the valve and during closing of the valve, and do so in all instances without interrupting the operation of a process control system that includes the valve, without isolating the valve, and without relying on user analysis.

Abstract: Methods and apparatus for bypassing a positioner in an active control loop are described. An example actuator assembly includes a pneumatic actuator and a transfer station. The transfer station includes a body defining flow paths that enable fluid to flow between a supply pressure, a valve positioner, and the pneumatic actuator and between the supply pressure and the pneumatic actuator to bypass the valve positioner without disrupting a process loop including the valve positioner. The transfer station also includes a plurality of fluid flow control devices to control the fluid flow through the flow paths.

Abstract: A flow measurement module is adapted to operate in conjunction with a control valve assembly to measure a flow rate of a fluid though a flow passage regulated by the control valve assembly. The flow measurement module is communicatively coupled to an intelligent positioner within the control valve assembly to receive data pertaining to the position of the throttling element within the flow passage. The position of the throttling element is used to identify at least one associated valve sizing coefficient. The flow measurement module determines the flow rate of the fluid through the flow passage based on a sensed upstream pressure, a sensed downstream pressure and the valve sizing coefficient associated with the position of the throttling element within the flow passage.

Abstract: A flow measurement module is adapted to operate in conjunction with a control valve assembly to measure a flow rate of a fluid though a flow passage regulated by the control valve assembly. The flow measurement module is communicatively coupled to an intelligent positioner within the control valve assembly to receive data pertaining to the position of the throttling element within the flow passage. The position of the throttling element is used to identify at least one associated valve sizing coefficient. The flow measurement module determines the flow rate of the fluid through the flow passage based on a sensed upstream pressure, a sensed downstream pressure and the valve sizing coefficient associated with the position of the throttling element within the flow passage.