Abstract: Methods and apparatus for analyzing effects of friction on process control devices are disclosed herein. An example method includes determining a value corresponding to friction of an actuator and a process control device to be operated by the actuator, and determining a value indicative of an effect of the friction on operation of the process control device via the actuator based on the value corresponding to the friction and a predetermined value.

Abstract: Methods and apparatus for estimating useful life of a seal in a process control device are disclosed. An example method includes establishing a plurality of travel ranges of a stem or shaft of a process control device. Each travel range corresponds to different values corresponding to stresses experienced by the seal of the process control device during an operational cycle. The example further includes determining a count of operational cycles associated with each of the travel ranges and estimating a total amount of useful life of the seal consumed based on the counts.

Abstract: Methods and apparatus for estimating a condition of a seal of a rotary valve are disclosed. An example apparatus includes a housing and a processor positioned within the housing. The processor is to determine a seal wearing cycle of a flow control member of a rotary valve, the seal wearing cycle includes movement of the flow control member between a first position in contact with a seal and a second position. The processor is to determine a torque of an actuator operating the flow control member for the seal wearing cycle and estimate a condition of the seal based on the torque.

Abstract: Seal assemblies for use with fluid valves are described. An apparatus includes a cage, a plug having a seal gland and a seal assembly to be at least partially positioned in the seal gland. The seal assembly includes a back-up ring having a wedge-shaped protrusion and a seal defining a wedge-shaped groove to receive the protrusion. A pressure is to act on the back-up ring to urge the protrusion into the groove. An engagement between the protrusion and the groove is to urge the seal into sealing engagement with an inner surface of the cage.

Abstract: Methods and apparatus for estimating a condition of a seal of a rotary valve are disclosed. An example method includes determining a seal wearing cycle of a flow control member of a rotary valve. The seal wearing cycle includes movement of the flow control member between a first position in contact with a seal and a second position. The example method further includes determining a torque of an actuator operating the flow control member for the seal wearing cycle and estimating a condition of the seal based on the torque.

Abstract: Methods and apparatus for acoustic fluid valve calibration are disclosed herein. An example method involves rotating a closure member of a valve to a involves rotating a closure member of a valve to a plurality of positions along a valve stroke, obtaining acoustic emission signals generated by a fluid passing through the valve using a sensor when the closure member is in the positions, and identifying, using a processor, a zero position of the closure member based on the acoustic emission signals.

Abstract: Methods and apparatus for estimating a condition of a seal of a rotary valve are disclosed. An example method includes determining a seal wearing cycle of a flow control member of a rotary valve. The seal wearing cycle includes movement of the flow control member between a first position in contact with a seal and a second position. The example method further includes determining a torque of an actuator operating the flow control member for the seal wearing cycle and estimating a condition of the seal based on the torque.

Abstract: Methods and apparatus to use vibration data to determine a condition of a process control device are disclosed. An example method includes collecting first vibration data from a first sensor operatively coupled to a process control device during a calibration. The example method further includes calculating an operating threshold of the process control device based on the first vibration data, and determining a condition of the process control device if second vibration data associated with the process control device collected after the calibration exceeds the operating threshold.

Abstract: Methods and apparatus for analyzing effects of friction on process control devices are disclosed herein. An example method includes determining a value corresponding to friction of an actuator and a process control device to be operated by the actuator, and determining a value indicative of an effect of the friction on operation of the process control device via the actuator based on the value corresponding to the friction and a predetermined value.

Abstract: Methods and apparatus for estimating useful life of a seal in a process control device are disclosed. An example method includes establishing a plurality of travel ranges of a stem or shaft of a process control device. Each travel range corresponds to different values corresponding to stresses experienced by the seal of the process control device during an operational cycle. The example further includes determining a count of operational cycles associated with each of the travel ranges and estimating a total amount of useful life of the seal consumed based on the counts.