Compensating for orientation of a valve positioner on a valve assembly

A valve positioner for use on a process control valve or “valve assembly.” The process control valve may include a pneumatic actuator and a valve having a closure member coupled with the pneumatic actuator and moveable relative to a seat. The valve positioner may couple to the pneumatic actuator to provide a pneumatic signal to set a position of the closure member relative to the seat. An accelerometer may couple with the valve positioner. The accelerometer may generate data in response to orientation of the valve positioner. In one implementation, the configurations can use this data to ensure proper visualization of data on a display. The data also permits the device to properly manage operating modes, like tight shut-off or fully-opened mode, that may prevail due to orientation issues that cause defects in a measured position for a closure member that regulates flow of material through the valve assembly.

BACKGROUND

Process control valves are a type of process device that finds use to automate industrial processes. These devices may include a controller, or “valve positioner,” that maintains operation of other components to regulate flow of materials on a process line. Problems with one or more control valves may disrupt processes or prevent the process line, in whole or in part, from operating in accordance with necessary process parameters. These disruptions can lower yields and reduce quality. In large, industrial operations, failures in the process line may lead to significant expense due to downtime necessary to troubleshoot and repair the problematic device(s).

SUMMARY

The subject matter of this disclosure relates to improvements to avoid operating defects that may result from maintenance on process devices. Of particular interest herein are embodiments that can generate data that measures orientation of the valve positioner relative to other parts of the valve assembly. These embodiments may use this data to ensure that information displays to an end user independent of the orientation, as well as to expedite maintenance tasks to repair or upgrade existing hardware, or integrate new hardware, onto the valve assembly without the need to recalibrate or otherwise engage in lengthy commissioning procedures.

Where applicable, like reference characters designate identical or corresponding components and units throughout the several views, which are not to scale unless otherwise indicated. The embodiments disclosed herein may include elements that appear in one or more of the several views or in combinations of the several views. Moreover, methods are exemplary only and may be modified by, for example, reordering, adding, removing, and/or altering the individual stages.

DETAILED DESCRIPTION

The discussion below describes embodiments of process control devices. These embodiments illustrate certain improvements in valve assemblies, like those found in industrial process systems to regulate flow of materials on process lines. Other embodiments are within the scope of the subject matter herein.

FIG. 1depicts a schematic diagram of an exemplary embodiment of a valve positioner100. This embodiment is shown as part of a valve assembly, identified generally by the numeral102. The valve assembly102may include an actuator104that couples with a valve106, typically by way of a valve stem108that connects to a closure member110. The actuator104modulates movement of the closure member110relative to a seat112. In practice, the valve positioner100may have operating hardware114that includes a display unit116. The operating hardware114may also include a position sensor118to identify proximity of the closure member110to hardstop limits120(shown here as a lower limit L1and an upper limit L2). As also shown, the operating hardware114may further include a measurement unit122that couples with the valve components, for example, the valve stem108.

At a high level, the valve positioner100may be configured to generate data that describes its orientation. These configurations may have functionality to utilize this data to correct for differences in orientation that can frustrate some operations on the device. This functionality may ensure that data properly displays on the display unit116found on the valve positioner100. As an added benefit, the functionality may also permit the valve positioner100to more accurately initiate operating modes that trigger in response to the closure member110at or near the hardstop limits120.

The valve assembly102may be configured for use on process lines that serve a variety of industries. These configurations may integrate into conduits, like pipes and pipelines, as part of a process line or lines that transfer materials around chemical facilities, refineries, oil & gas recovery systems, and the like. In one implementation, the valve positioner100connects to a control network (or “distributed control system” or “DCS,”) which maintains operation of all devices on the process line to ensure that materials flow in accordance with a process. The DCS may include a controller that generates a control signal with operating parameters for the valve assembly102for this purpose. These operating parameters define a commanded position for the closure member110relative to the seat112.

The actuator104may be configured to generate a load that works against pressure of material to set the commanded position of the closure member110. These configurations may employ pneumatic devices, although electrical or electronic devices (e.g., motors) may work as well. Pneumatic devices may have a diaphragm internal to a housing. In operation, the valve positioner100may deliver gas, or “instrument air,” as a pneumatic signal that changes pressure that acts against the diaphragm inside of the housing. Parameters for the pneumatic signal depend in large part on the commanded position for the closure member110.

The valve106may be configured to fix flow parameters for materials that flow into the process line. These configurations often include hardware that couples with the pipes or pipelines. Manufacture of this hardware often comports with properties of the materials, including its composition and “phase,” for example, solid, fluid, or solid-fluid mix. The closure member110may embody a plug, ball, butterfly valve, or like implement that can contact the seat112to prevent flow. Location of the closure member110relative to the seat112, in turn, permits more or less flow of material to satisfy the process parameters.

The operating hardware114may be configured to process and generate signals. These configurations may employ electrical and computing components (e.g., processors, memory, executable instructions, etc.). These components may also include electro-pneumatic devices that operate on incoming instrument air. The display unit116may include devices to convey information about operation of the valve assembly102. These devices may have a “default” display orientation that coincides with a preferred reading orientation for an end user. The position sensor118may leverage non-contact modalities (e.g., magnetics) to generate data that defines a measured position of the closure member110. These modalities are useful to allow the valve positioner100to easily separate from (and install onto) the valve assembly102. This feature simplifies maintenance and, in some applications, allows technicians to remove and replace the valve positioner100as part of tasks to repair, upgrade, or maintain the device. In operation, the operating hardware114may process the control signal from the DCS and the positioner sensor118to set the pneumatic signal that operates the actuator104to locate the closure member110at the commanded position to achieve flow of material through the valve106to meet process parameters.

The hardstop limits120may be configured as values to manage travel of the closure member110. These values may correspond to a maximum “travel” and a minimum “travel” for the closure member110relative to the seat112. The operating hardware114may compare the measured position for the closure member110against these values to initiate one or more operating “modes.” A “fully-opened” mode will cause the closure member110to reaches it farthest position from the seat112in proximity to the upper limit L2. In “tight shut-off” mode, the operating hardware114may locate the closure member110in its closed position (in contact with the seat112) in response to commanded positions below the “lower” hardstop limit L1. For example, if the lower limit L1is 10%, then the operating hardware114adjusts the pneumatic signal so that the closure member110contacts the seat112at commanded positions below 10% and operate as normal for commanded positions above 10%. The tight shut-off mode is useful to prevent operating conditions that arise with the closure member110in close proximity to the seat112. These operating conditions cause the working fluid to flow at high flow rates or velocity that can cause wear and damage that can degrade performance and life span of the valve assembly102.

The measurement unit122may be configured to provide data to the operating hardware114. These configurations may embody sensors that generate signals in response to orientation of the valve positioner100. The sensors may include devices that can generate data that describes (or measures) slope or angle of objects. The operating hardware114may use this data to account for changes in orientation that might be detrimental to operation of the valve assembly102. For example, the operating hardware114may maintain the preferred reading orientation on the display unit120independent of the orientation of the valve positioner100. This feature can prevent text or other visualizations from appearing “upside” down to the end user. The operating hardware114may account for orientation to ensure that the device operates in appropriate operating modes at the hardstop limits120. This feature can prevent use of the tight shut-off mode either to “early” (at commanded positions that are above the actual lower limit116) or to “late” (at commanded positions that are below the actual lower limit116).

FIG. 2depicts a schematic diagram of an example of the valve positioner100ofFIG. 1. The display unit116may include a display124, like an LCD, that provides a visualization126, typically alpha-numeric characters, icons, or the like. The measurement unit122may include an accelerometer128that can generate data that defines an angle130for the valve positioner100relative to a reference132, typically a vertical or horizontal plane. Other devices (e.g., inclinomoteters or tilt sensors) may suffice as well. Values for the angle130may describe orientation for the valve positioner100on the valve assembly102. Preferably, the value for the angle130is approximately zero degrees (0°). This value coincides with a “default” orientation, often a result of assembly of the valve positioner100onto the valve assembly102at a factory. However, the angle130may assume other values that are greater than or less than zero degrees (0°). Practically, these values are in a range of from 1° to 5°; however, this disclose contemplates that the orientation of the valve positioner100may deviate from the default orientation by more or less as well.

FIGS. 3 and 4depict schematic diagrams of examples of the valve positioner100that are angularly offset from the default orientation.FIG. 3shows the valve positioner100in an offset orientation that is 180°, or essentially “upside-down,” relative to the default orientation ofFIG. 2. This orientation may occur in the field, for example, as necessary to properly fit the valve positioner100on the valve assembly102at a point of installation on the process line. Notably, the operating hardware114can use orientation data (from the accelerometer128) to make appropriate adjustments that maintains the “default” display orientation for information on the display124.

FIG. 4shows the valve positioner100only slightly askew relative to the default orientation ofFIG. 2. This orientation may correspond with a “re-installed” orientation for the valve positioner100on the valve assembly102. The re-installed orientation may follow maintenance to remove (and replace) the valve positioner100on the valve assembly102. This process may require that the valve positioner100is separate from the valve assembly102on the process line, for example, to update hardware (or software). The process may reuse the “original” valve assembly with these updates. However, in some cases, the process replaces the “original” valve positioner100(or “first valve positioner”) with a “new” valve positioner100(or “second valve positioner”). This process may coincide with operations that effectively upload data from the first valve positioner onto the second valve positioner, also known as “cloning.” Notably, the improvements herein are effective to avoid defects in operation of the second valve positioner that makes use of “cloned” data from the first valve positioner. These defects may occur in data that defines the measured position of the closure member110, which in turn can frustrate use of either the fully-opened mode or the tight shut-off mode.

FIG. 5depicts a schematic diagram of exemplary structure for the position sensor118for use on valve positioner100ofFIG. 1. This structure may include a magnetic flux sensor134, although this disclosure contemplates use of other device technology, like ultrasonic, piezoelectric, or optically sensitive, as well. The magnetic flux sensor134may integrate as a component of the operating hardware114that resides in the valve positioner100. When the valve positioner100is on the valve assembly102, this component is proximate a position transfer unit136that conveys movement on the valve106to the valve positioner100. Components for the position transfer unit136are independent from the valve positioner100. This feature permits the valve positioner100to separate from (and replace onto) the valve assembly102for maintenance noted herein. In one implementation, the position transfer unit136may include a linkage138(or other mechanism that can transfer movement) that couples the valve stem108with a rotatable unit140inside of the valve positioner100. The rotatable unit140may include an annular drum142that supports a pair of magnets142that are annularly offset from one another, e.g., by 180°. In use, the linkage138causes the annular drum142to rotate concomitantly with the valve stem108. The magnetic flux sensor130resides proximate the annular drum138so that data corresponds with changes in polarity from the rotating magnets132. The operating hardware114may correlate these changes to identify the position for the closure member110. In one implementation, the magnetic flux sensor134may assume a first position, shown here to align the magnetic flux sensor130on or with the center of rotation (C) for the annular drum138. This first position often corresponds with the default orientation for the valve positioner100on the valve assembly102.

FIG. 6depicts a schematic diagram of the valve positioner100that is offset from its default orientation inFIG. 5. The magnetic flux sensor134assumes a second position that is offset from the first position by an angular offset146. Examples of the angular offset146may be consistent with the angle130because the magnetic flux sensor134mounts or affixes in the valve positioner100(as part of the operating hardware114). In use, the angular offset146changes the relationship between the magnetic flux sensor134and the center of rotation (C) on the annular drum140. Notably, the operating hardware114can account for the angular offset146in calculations to determine whether to implement the fully-opened mode or the tight-shut off mode with the closure member110proximate the hardstop limits120.

FIG. 7depicts a schematic diagram of topology for the valve positioner100ofFIG. 1. The operating hardware114may include a processing unit148that has computing components like a processor150that couples with memory152. Executable instructions154may reside on one or both of the computing components150,152. Data from the accelerometer128and flux sensor134may reside on the memory152as well. The executable instructions154may code one or more of these stages as a computer program, like software or firmware. The computer program may configure the processor150for functionality that can improve performance of the valve positioner100to identify and correct for the angle130of the valve positioner100on the valve assembly102.

FIG. 8depicts a flow diagram for an exemplary method200with stages to account for orientation of the valve positioner100ofFIG. 1following maintenance. These stages may correlate to one or more executable instructions154. In one implementation, the method200may include, at stage202, retrieving data corresponding with a value for an offset angle from the accelerometer for a replacement valve positioner. This replacement valve positioner may be “new” hardware or “updated” hardware, particularly as relates to cloning procedures noted here. The method200may also include and, at stage204, comparing this value to a base angle value that describes an offset angle for the previously-installed valve positioner. At stage206, the method200may include stages to determine whether actions are necessary to correct for the orientation of the replacement valve positioner. For example, if the values are the same or within some threshold, then no action is required (at stage208). If the value is different, the method200may include, at stage210, calculating an offset value, for example, the value that reflects a relationship between the offset angle and the base angle value. The method200may also include, at stage212, correcting functionality on the valve positioner100, which may include, at stage214, applying the offset value to values for the upper hardstop limit and the lower hardstop limit or, at stage216, updating the orientation of the visualization on the display.

FIG. 9depicts a perspective view of exemplary structure for the valve positioner100in exploded form. The valve positioner100may include a manifold156having a manifold body158, typically machined or formed metal, plastic or composite. The manifold body158may include flow features160(e.g., openings, flow paths, etc.) to direct fluid among the components of the manifold156. Standoff devices162may operate to mount a converter unit164, like a current-to-pressure converter, and relay166to the manifold body158. The units164,166work together to deliver the pneumatic signal to the actuator104. As also shown, the valve positioner100may also have an enclosure, shown as covers (e.g., a first cover168and a second cover170). The covers168,170may secure with the manifold body158to protect the control components from conditions that prevail in the environment surrounding the valve assembly102. The second cover170may incorporate the display124, as well as a pushbutton input device172may operate as the primary local user interface to allow an end user (e.g., technician) to interact with the valve positioner100. This feature may be important for regular maintenance, configuration, and setup, for example, to allow the end user to exit from valve operating mode and step through a menu structure to manually perform functions such as calibration, configuration, and monitoring. In one implementation, the valve positioner100may further include one or more gauges (e.g., a first gauge174and a second gauge176) that can provide an indication of the flow conditions (e.g., pressure, flow rate, etc.) of the fluid that the valve positioner100uses to operate the valve106in the valve assembly102.

FIG. 10depicts a perspective view of exemplary structure for the valve assembly102. This structure may be useful to regulate process fluids in industrial process lines typical of industries that focus on chemical production, refining production, and resource extraction. As shown, the valve106may include a fluid coupling178that forms a flow path180with flanged, open ends182. Valve components like the closure member110and the seat112may reside inside of the fluid coupling178(and, thus, are hidden in the present view). The actuator104may include a bulbous housing184, typically with two pieces that clamp about the edges to entrap a diaphragm (not shown) round the periphery. As noted herein, the actuator often turns pressurized air into mechanical load that modulates movement of the closure member110to move relative to the seat112between, for example, an open position, a partially-open position, and a closed position. The valve positioner100may fasten to a bracket186that is part of the valve assembly102. Fasteners such as bolts are useful for this purpose. When mounted, the rotatable unit136(FIG. 6) extends into the back of the manifold156(FIG. 9).

In view of the foregoing discussion, the embodiments herein incorporate devices to measure orientation, or angle, of the valve positioner on the bracket186. These embodiments ensure data displays independent of the orientation, essentially to ensure that the end user can readily access and read numbers, letters, or other indicators on the display. As also noted, the embodiments can also ensure use of certain operating modes or functions occurs at the correct time. This feature may prevent damage to the device that might occur with the closure member in very close proximity to the seat. A technical effect of the proposed embodiments is to afford the device with improved functionality that can serve to facilitate maintenance and repair, particularly as part of “cloning” procedures.

Topology for circuitry herein may leverage various hardware or electronic components. This hardware may employ substrates, preferably one or more printed circuit boards (PCB) with interconnects of varying designs, although flexible printed circuit boards, flexible circuits, ceramic-based substrates, and silicon-based substrates may also suffice. A collection of discrete electrical components may be disposed on the substrate, effectively forming circuits or circuitry to process and generate signals and data. Examples of discrete electrical components include transistors, resistors, and capacitors, as well as more complex analog and digital processing components (e.g., processors, storage memory, converters, etc.). This disclosure does not, however, foreclose use of solid-state devices and semiconductor devices, as well as full-function chips or chip-on-chip, chip-on-board, system-on chip, and like designs. Examples of a processor include microprocessors and other logic devices such as field programmable gate arrays (“FPGAs”) and application specific integrated circuits (“ASICs”). Memory includes volatile and non-volatile memory and can store executable instructions in the form of and/or including software (or firmware) instructions and configuration settings. Although all of the discrete elements, circuits, and devices function individually in a manner that is generally understood by those artisans that have ordinary skill in the electrical arts, it is their combination and integration into functional electrical groups and circuits that generally provide for the concepts that are disclosed and described herein.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. An element or function recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or functions, unless such exclusion is explicitly recited. References to “one embodiment” of the claimed invention should not be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, the claims are but some examples that define the patentable scope of the invention. This scope may include and contemplate other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Examples appear below that include certain elements or clauses one or more of which may be combined with other elements and clauses describe embodiments contemplated within the scope and spirit of this disclosure.