Abstract: A method and apparatus for mounting components such as stems to other components such as plugs is provided. In accordance with one example embodiment of the present invention, a method of connecting and locking a stem within a component includes the step of disposing the stem in a first end of a passage formed in the component. The method continues by deforming an end portion of the stem to permanently non-rotationally lock the stem within the passage of the component. The step of deforming includes pressing a coining device into a second end of the passage to engage with an end portion of the stem and configure the stem for permanent non-rotational mounting within the component.

Abstract: An error correction and detection system for a dual-pulse output metering device is provided. The system detects errors in the dual-pulse output of the metering device by comparing the current phase difference it between the pulse streams to a desired or known phase difference and generating an error signal if the current phase difference is different from the desired phase difference. If an error signal is generated, the system additionally accounts for the error and provides a corrected pulse count output by either discarding the extra pulse, or calculating the number of missed pulses, and adding the missing number of pulses to the pulse count output.

Abstract: A magnet assembly is disclosed for use with a magnetic flux sensor to provide a position sensor adapted to detect a position of a moveable member. The magnet assembly comprises a magnet housing defining an inner surface. A magnet is provided that is sized for insertion into the magnet housing and adapted for movement with the moveable member, the magnet having a north pole and a south pole, wherein the magnet generates a magnetic flux. A centering ring is positioned between the magnet and the magnet housing, the centering ring including a biased wall acting to center the magnet in the magnet housing.

Abstract: A fluid control valve includes a valve body having a fluid passageway, a cage mounted in the fluid passageway and a valve plug assembly including a valve plug. The cage has a cage bore and defines one or more windows, a valve seat located below the windows and a flow control portion of the cage bore located between the valve seat and the windows. The flow control portion has an interior contour that varies in dimension as a function of distance from the valve seat. The flow control portion provides precise control in low flow conditions. The cage may further define a sealing lip located above the windows. The valve plug assembly may include a deformable sealing ring for engaging the sealing lip when the valve plug is in a closed position. The deformable sealing ring permits valve plug travel that is substantially free of sliding seal friction.

Abstract: Apparatus for determining fluid flow through a pressure regulator is disclosed. The pressure regulator is disposed in a fluid flow passage and has a throttling element moveable in the flow passage. A stem is attached to the throttling element. The apparatus includes a first pressure sensor for measuring pressure upstream of the throttling element, a second pressure sensor for measuring pressure downstream of the throttling element, and a travel sensor for detecting the position of the throttling element. A processor is provided which includes a stored algorithm for determining flow rate based on the measured pressure and travel values.

Abstract: A chemical sensor utilizing a substrate and a fluoropolymer coating is disclosed. Transducers may be connected to the substrate to generate an alternating potential across the substrate, which in turn causes the substrate to resonate due to the converse piezoelectric effect. The polymer coating absorbs the analyte, thus changing the mass of the sensor, and accordingly changing its resonant frequency. The transducers detect this change in resonant frequency to indicate to the operator that the analyte is present. The use of amorphous copolymers of 2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole (PDD), and tetrafluoroethylene (TFE) allows for improved sensitivity and responsiveness while also allowing for robust characteristics enabling the sensor to be used in a variety of environmental conditions.

Abstract: A fluid control valve includes a valve body having a fluid passageway, a cage mounted in the fluid passageway and a valve plug assembly including a valve plug. The cage has a cage bore and defines one or more windows, a valve seat located below the windows and a flow control portion of the cage bore located between the valve seat and the windows. The flow control portion has an interior contour that varies in dimension as a function of distance from the valve seat. The flow control portion provides precise control in low flow conditions. The cage may further define a sealing lip located above the windows. The valve plug assembly may include a deformable sealing ring for engaging the sealing lip when the valve plug is in a closed position. The deformable sealing ring permits valve plug travel that is substantially free of sliding seal friction.

Abstract: A method and apparatus statistically determines estimates of one or more process control loop parameters, such as bearing friction, seal friction, total friction, dead band, dead time, oscillation, shaft windup or backlash associated with a device or a control loop within a process control environment. The method and apparatus measures one or more signals within a process control loop when the process control loop is connected on-line within a process control environment, stores the measured signal as signal data and then performs one of a number of statistical analyses on the stored signal data to determine the desired parameter estimate.

Abstract: Apparatus for performing diagnostics through a regulator is disclosed. The pressure regulator is disposed in a fluid flow passage and has a throttling element moveable in the flow passage. A stem is attached to the throttling element. The apparatus includes a first pressure sensor for measuring pressure upstream of the throttling element, a second pressure sensor for measuring pressure downstream of the throttling element, and a travel sensor for detecting the position of the throttling element. A processor is provided which includes a stored algorithm for determining flow rate based on the measured pressure and travel values, and an alarm routine for generating logic alarms based on the measured operating parameters.

Abstract: A taper nut retention device mechanically fastens a plurality of pressure reduction disks. A cage end member at one end of the stacked disks has a series of counterbores, each aligned with respective mounting holes in each disk. A second cage end member at the other end of the stack has a series of inwardly converging, tapered bores with shallow taper angles, each aligned with respective mounting holes and a counterbore. A taper nut with a threaded interior and an outer tapered surface with a shallow taper angle matching the tapered bore is inserted into and engageably contacts the tapered bore. A threaded bolt is inserted into the counterbore and through the disk mounting holes to threadably engage the taper nut. Tightening of the bolt and nut mechanically secures the stacked disk assembly. A process for making the stacked disk assembly wherein each disk and the cage end members are plated with nickel and the components are fused together in a brazing oven.

Abstract: A fluid pressure reduction device for use with a fluid valve control member movable through the device. The pressure reduction device is formed of a plurality of stacked disks having an outer perimeter and an inner perimeter defined by a hollow center aligned along a longitudinal axis. The disks are formed in a cage assembly for receiving the fluid valve control member within the hollow center along the inner perimeter. The stacked disks include a plurality of longitudinal channels formed in the disk around the inner perimeter. Guide members formed of a metal harder or at least with greater wear resistant characteristics than the disks are provided in each of the longitudinal channels. The guide members are adapted to the inner perimeter for guiding the fluid valve control member in movements through the hollow center for reducing wear on the inner perimeter. It is preferred that the guide members comprise longitudinal rods inserted within each channel.

Abstract: A method for providing an indication and alarm of a possible failure in a fluid control valve stem, plug or seat in a process control system having a microprocessor based valve positioner. The drive pressure, drive signal and valve position feedback are monitored. If greater than a predetermined change in the drive pressure or the valve position feedback is detected, then a second series of detection steps is initiated. In the second detection steps the present set point to process value relationship, such as flow rate or other process variable is compared to a stored test cycle derived set point to process value relationship for the same set point. If there is a process value change, then the operator is alerted as this change may indicate there is a damaged valve stem, plug, or seat problem which needs to be inspected.

Abstract: A maintenance interface device for use in a digital, loop-powered process control network includes an interface to either a two-wire input/output port of a field device or to a two-wire communication media, a control logic for determining a simple status of the field device or communication loop, and a display for displaying the simple status. The maintenance interface device may be used for fault analysis to detect whether a field device or a communication loop is operational or nonoperational, powered or unpowered, and generating a valid communication signal or generating an invalid communication signal. The maintenance interface device is adapted to perform simple functionality tests on a plurality of devices in a process control network including a loop controller, a digital control system, an operator console, a workstation, a personal computer, and a bridge to thereby detect the functionality of those devices on a communication wire.

Abstract: An electro-mechanical actuator for operating a fluid control valve and controlling the operation of one or more field instruments, including other valve actuators. An electro-mechanical actuator has a drive unit and an electric motor driving the drive unit to open and close a fluid control valve to the fully opened and fully closed states under the control of monitoring limit open and limit closed sensors. Auxiliary control output lines connected to other field instruments from the electro-mechanical actuator drive associated fluid control valves to fully open and fully closed states. Limit open sensors and limit closed sensors monitor the valve open and closed state of the other respective field instruments and through a respective pair of auxiliary travel input lines to the electro-mechanical control the field instrument.

Abstract: A control valve assembly including a no-bleed pilot valve is disclosed. The pilot valve includes a pressure responsive valve adapted to move in connection with a control parameter, such as downstream fluid pressure. The pressure responsive valve selectively connects certain ports with upper and lower chambers of a control valve actuator so that the upstream and downstream fluid pressures may be used to operate the actuator.

Abstract: A system and method for collecting data relating to emissions from an emissions source is disclosed. The system comprises an accumulator adapted to receive emissions from the emissions source, a sensor in flow communication with an outlet of the accumulator for generating a signal indicative of a physical property of the emissions, and a sensor interface circuit receiving the signal and generating data relating to the emissions from the emissions source. A system and method for reducing emissions from an emissions source is also disclosed, including a microcontroller receiving data relating to the emissions from the emissions source and generating control signals for reducing the emissions.

Abstract: A taper nut retention device mechanically fastens a plurality of pressure reduction disks. A cage end member at one end of the stacked disks has a series of counterbores, each aligned with respective mounting holes in each disk. A second cage end member at the other end of the stack has a series of inwardly converging, tapered bores with shallow taper angles, each aligned with respective mounting holes and a counterbore. A taper nut with a threaded interior and an outer tapered surface with a shallow taper angle matching the tapered bore is inserted into and engageably contacts the tapered bore. A threaded bolt is inserted into the counterbore and through the disk mounting holes to threadably engage the taper nut. Tightening of the bolt and nut mechanically secures the stacked disk assembly. A process for making the stacked disk assembly wherein each disk and the cage end members are plated with nickel and the components are fused together in a brazing oven.

Abstract: The present invention is directed to a method of and a device for monitoring, from a central location, the current operating conditions (such as values of process parameters) in a process control network having distributed control functions. In one embodiment, the method and device of the present invention use scheduled periodic communications to send signals containing, for example, measured values of process parameters developed by field devices to a centralized viewing device. The viewing device receives the signals and stores at least one value of the process parameters, and maybe more values if necessary to monitor and control the process. To retrieve the stored process parameters for viewing, the viewing device processes messages from human interface devices requesting the stored values of one or more of the stored parameters and then transmits response messages containing the stored values.

Abstract: A control system for positioning a control valve is disclosed. The control system employs first and second control loops, and a plug and seat valve assembly. The first control loop monitors a position or variable of the valve or device being controlled and compares it to a provided setpoint to generate a setpoint for the plug and seat valve. The second control loop compares the measured position of the plug and seat valve to the second setpoint to generate a correction signal to accurately position the plug and seat valve. By employing first and second control loops, the accuracy and responsiveness to which the control valve is positioned is improved.