Abstract: Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a non-volatile memory to be operatively coupled to a field device of a process control system; and a radio-frequency identification tag to be operatively coupled to the non-volatile memory. The non-volatile memory is to store data received from at least one of the field device or a radio-frequency identification writer via the radio-frequency identification tag. The radio-frequency identification tag is to wirelessly transmit the data to a radio-frequency identification reader. The data includes at least one of maintenance information, diagnostic information, or configuration information associated with the field device. The non-volatile memory and the radio-frequency identification tag to be physically coupled to the field device.

Abstract: Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a non-volatile memory to be operatively coupled to a field device of a process control system; and a radio-frequency identification tag to be operatively coupled to the non-volatile memory. The non-volatile memory is to store data received from at least one of the field device or a radio-frequency identification writer via the radio-frequency identification tag. The radio-frequency identification tag is to wirelessly transmit the data to a radio-frequency identification reader. The data includes at least one of maintenance information, diagnostic information, or configuration information associated with the field device. The non-volatile memory and the radio-frequency identification tag to be physically coupled to the field device.

Abstract: Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a radio-frequency identification (RFID) device to be communicatively coupled to a field device of a process control system via a wired connection. The RFID device includes an RFID tag to be powered via the wired connection based on power provided to the field device. The power is provided to the field device along with a control signal.

Abstract: Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a radio-frequency identification (RFID) device to be communicatively coupled to a field device of a process control system via a wired connection. The RFID device includes an RFID tag to be powered via the wired connection based on power provided to the field device. The power is provided to the field device along with a control signal.

Abstract: Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a radio-frequency identification tag operatively coupled to a field device of a process control system. The radio-frequency identification tag has a processor, an onboard memory, and an antenna. The onboard memory stores data received from the field device to be communicated to a radio frequency identification reader. Power for the processor and the onboard memory is to be drawn from control system power provided to the field device.

Abstract: Method and apparatus for mounting RFID devices to process control devices are disclosed. An example apparatus includes a mount to couple a radio-frequency identification tag to a field device. The mount is rotatable relative to the field device to adjust the radio-frequency identification tag to be oriented relative to a radio-frequency identification reader. The mount includes a first portion to be coupled to the field device and a second portion to receive the radio-frequency identification tag.

Abstract: Methods and apparatus for evaluating vibration resistance of a component of a fluid control valve are disclosed herein. An example method disclosed herein includes selecting a component of a fluid control valve and positioning a sensor relative to the selected component. The method also includes mechanically exciting the selected component, determining a resonant frequency of the selected component, and taking corrective action based on the resonant frequency of the selected component.

Abstract: Methods and apparatus for RFID communications in a process control system are disclosed. An example apparatus includes a radio-frequency identification tag operatively coupled to a field device of a process control system. The radio-frequency identification tag has a processor, an onboard memory, and an antenna. The onboard memory stores data received from the field device to be communicated to a radio frequency identification reader. Power for the processor and the onboard memory is to be drawn from control system power provided to the field device.

Abstract: Method and apparatus for mounting RFID devices to process control devices are disclosed. An example apparatus includes a mount to couple a radio-frequency identification tag to a field device. The mount is rotatable relative to the field device to adjust the radio-frequency identification tag to be oriented relative to a radio-frequency identification reader. The mount includes a first portion to be coupled to the field device and a second portion to receive the radio-frequency identification tag.

Abstract: Apparatus to control a fluid flow are disclosed. An example fluid flow control apparatus described herein includes a signal stage comprising a signal stage relay having a supply plug being operatively connected to a valve seat at a first end and an exhaust seat at a second end and a seal operatively coupled to the supply plug such that the seal provides a feedback area to apply a fluid pressure feedback force to the exhaust seat.

Abstract: A valve packing assembly for a control valve includes a seal assembly, a loading assembly, and a packing retainer. The seal assembly has a seal component to provide a fluid seal around a valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem. The loading assembly is configured to advantageously provide a predetermined packing stress to the seal assembly that is in the same direction as a process stress applied to the seal assembly by a process fluid, thereby substantially reducing packing friction and packing wear in the control valve assembly.

Abstract: A system and method for accurately measuring supply gas consumed by a particular process control component within a process control system is disclosed. Enhanced measurement accuracy is derived from measuring the consumption of the process control component in a normal operating mode of the process control system. The amount of fluid expended by one process control component is separated by a fluid control system from the amount of supply gas expended in actuating other process control components. The amount of fluid expended by each component may be determined by measuring a decrease in a fluid within a vessel having a known quantity that independently supplies supply gas to each component during its operation.

Abstract: Methods and apparatus for evaluating vibration resistance of a component of a fluid control valve are disclosed herein. An example method disclosed herein includes selecting a component of a fluid control valve and positioning a sensor relative to the selected component. The method also includes mechanically exciting the selected component, determining a resonant frequency of the selected component, and taking corrective action based on the resonant frequency of the selected component.

Abstract: A valve packing assembly for a control valve includes a seal assembly, a loading assembly, and a packing retainer. The seal assembly has a seal component to provide a fluid seal around a valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem. The loading assembly is configured to advantageously provide a predetermined packing stress to the seal assembly that is in the same direction as a process stress applied to the seal assembly by a process fluid, thereby substantially reducing packing friction and packing wear in the control valve assembly.

Abstract: A valve packing assembly for a control valve includes a seal assembly, a loading assembly, and a packing retainer. The seal assembly has a seal component to provide a fluid seal around a valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem. The loading assembly is configured to advantageously provide a predetermined packing stress to the seal assembly that is in the same direction as a process stress applied to the seal assembly by a process fluid, thereby substantially reducing packing friction and packing wear in the control valve assembly.

Abstract: Apparatus to control a fluid flow are disclosed. An example fluid flow control apparatus described herein includes a signal stage comprising a signal stage relay having a supply plug being operatively connected to a valve seat at a first end and an exhaust seat at a second end and a seal operatively coupled to the supply plug such that the seal provides a feedback area to apply a fluid pressure feedback force to the exhaust seat.

Abstract: Apparatus to determine the position of a movable member of an actuator operating a valve assembly are disclosed. The movable member of the actuator displaces an actuation arm of a position sensor such that relative displacement occurs between a magnetic flux source and a magnetic flux sensor of the position sensor.

Abstract: Apparatus to determine the position of a movable member of an actuator operating a valve assembly are disclosed. The movable member of the actuator displaces an actuation arm of a position sensor such that relative displacement occurs between a magnetic flux source and a magnetic flux sensor of the position sensor.

Abstract: A valve travel indicator is described. An indicator portion indicates a location on a valve indicator scale. A retaining portion is fixedly coupled to the indicator portion and movably coupled to a valve stem. The retaining portion fixedly couples the indicator portion to the valve stem during movement of the valve stem and movably couples the indicator portion to the valve stem in response to a predetermined force level exerted upon the indicator portion.

Abstract: A valve travel indicator is described. An indicator portion indicates a location on a valve indicator scale. A retaining portion is fixedly coupled to the indicator portion and movably coupled to a valve stem. The retaining portion fixedly couples the indicator portion to the valve stem during movement of the valve stem and movably couples the indicator portion to the valve stem in response to a predetermined force level exerted upon the indicator portion.