Control of the actuator on the valve

Abstract

The controller is configured to operate the flow control device. These configurations can operate an actuator that is part of an industrial valve. In one implementation, the controller can include a solenoid valve coupled to the actuator. The controller can utilize feedback from the valve, such as sensor data, to identify changes that the controller needs to make to the solenoid valve. These changes can direct the flow to different sides of the actuator.

Description

Technical Field

[0001] Flow control devices play a major role in many industrial facilities. For example, power plants and industrial processing facilities use different types of flow control devices to manage the flow of materials, typically fluids, throughout an extensive network of pipes, tanks, generators, and other equipment. These devices may include control valves that provide active control of the flow through the exchange of control signals with a central control network or a remote control station. In oil and gas pipelines and facilities, an operator may deploy a control valve having components that move (e.g., translate, rotate, etc.) to restrict or allow the flow of hydrocarbons such as natural gas. An actuator often accompanies the valve. This actuator uses an operating medium, e.g., natural gas from the network, to generate a force to move the components to an appropriate position. In many cases, feedback on the device, which is often a large mechanical linkage, is useful in assisting with position management.

Summary of the Invention

[0002] The subject matter of the present disclosure relates to improvements in the manufacture and construction of control valves. In one of the embodiments, a pneumatic / electric controller is provided for controlling a pneumatic actuator to position a closure member such as a ball or plug on the valve. The controller can incorporate a non-contact sensing unit such as a Hall effect sensor. This sensor provides feedback that the controller uses to operate a metering valve, for example, a solenoid valve. In this design, the pressure in the actuator is managed and then the position of the closure member is adjusted. This configuration is beneficial because it does not bleed any gas in the steady state, which means that the device only vents the working medium such as natural gas to the atmosphere in response to the movement of the control valve. The non-contact sensing unit provides a compact alternative to mechanical feedback that requires a "long stroke" movement to identify the position of the closure member, so this configuration also simplifies the assembly of the control valve itself. A fundamental advantage is that the external metering valve does not continuously "bleed" the working medium that pressurizes the actuator, so hydrocarbon emissions (e.g., methane emissions) are also reduced by the embodiments.

Brief Description of the Drawings

[0003] This specification refers to the following drawings.

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[0004] These drawings and any description in this specification represent examples that may disclose or illustrate the present invention. These examples include the best mode and enable the implementation of the present invention, including making and using any device or system by those skilled in the art and performing any incorporated method. The drawings are not to scale unless otherwise noted in the discussion. Elements in the examples may appear in one or more of several figures, or in combinations of several figures. The drawings may use like reference numerals to indicate identical or corresponding elements. The methods are merely illustrative and may be modified, for example, by reordering, adding, removing, and / or changing individual steps or stages. In this specification, such steps, as well as any part, component, element, or function, may be identified in the singular using the word "a" or "an", but this should not exclude the plural of such designation unless the specification explicitly states or describes such an exclusion. Similarly, any reference to "one embodiment" or "one implementation" should not exclude the existence of additional embodiments or implementations that incorporate the recited features.

Mode for Carrying Out the Invention

[0005] Next, the features of each example shown in the above drawings will be considered. These examples use a control device or "controller" to direct the movement or operation of a control valve. However, the proposed design is configured to reduce harmful emissions into the atmosphere because it does not continuously extract the working medium (such as natural gas) in the steady state. These configurations also simplify the assembly of certain flow control devices, such as control valves used in industrial applications, because the control logic does not require a large mechanical linkage mechanism for position feedback. The resulting device not only provides accurate position control, which is important for maintaining process parameters on the process line, but also reduces the potential escape gas emissions from the device. Other embodiments are within the scope of this disclosure.

[0006] FIG. 1 depicts a schematic view of one embodiment of a control unit 100. This embodiment is typically found in a distribution network 102 designed to convey a material 104 throughout a network of conduits 106. The control unit 100 may be part of a flow control device 108 having a valve body 110 connected in series with the conduit 106. The device may also have an actuator 112. A torque unit 114 may connect the actuator 112 to a closure member 116. In one implementation, the control unit 100 may have operating hardware 118 that connects to an appliance valve 120. A sensor 122 may provide feedback to the operating hardware 118.

[0007] Generally, the controller 100 may be configured to regulate the flow of a fluid, typically a gas. These configurations can include a device that can receive instructions to adjust the flow of material through the flow control device. The device can compare the instructions to feedback regarding components within the flow control device. This mechanism can indicate whether the flow is appropriate. If not, the device can modify the flow control device to adjust the flow to meet the process or other flow parameters, for example, in connection with the application of the device in a process line.

[0008] The distribution system 102 may be configured to deliver or move resources on or as part of a process line. These configurations can embody an extensive infrastructure. The material 104 can include gases, liquids, solids, or mixtures. The conduits 106 can often include pipes or pipelines connected to pumps, boilers, compressors, etc. The pipes may also connect to tanks or reservoirs. In many facilities, this equipment forms a complex network.

[0009] The flow control device 108 can be configured to regulate the flow of the material 104 through the conduit 106 in this complex network. These configurations can include control valves and similar devices. The valve body 110 within such a device is often made of cast, forged, or machined metal. This structure can form flanges at the openings I, O. The adjacent pipes 106 can be connected to these flanges. The actuator 112 may use pressurized natural gas and may generate a load together with a piston, spring (or springs), or flexible diaphragm. The torque unit 114 can convert the load (from the actuator 112) into rotational motion. This feature can change the position of the closure member 116, typically a ball, plug, or disk.

[0010] The operating hardware 118 can be configured to manage this position. These configurations can embody devices capable of processing data. These devices can include computing components such as a processor or memory that can execute specific algorithms or method steps using firmware, software, or other executable instructions. These algorithms can, for example, process an input and then generate an operating signal to change the state of the appliance valve 120 (often a solenoid valve). This state can control the pneumatic signal S1 that pressurizes the actuator 112 to move the closure member 116 to its defined position.

[0011] The sensor 122 may be configured to define the measured position of the closure member 116. These configurations can include devices that utilize a non-contact modality to generate data corresponding to the measured position. For example, devices using magnetism can be prevalent. In one implementation, a Hall effect sensor can be present in proximity to one or more magnets that rotate simultaneously with the torque unit 114.

[0012] Figure 2 depicts a perspective view of an exemplary structure of the controller of FIG. 1. Sensor 122 may be present in enclosure 124, preferably an "explosion-proof" housing, or a housing having a structure that prevents or delays ignition of internal gas. Enclosure 124 can have a window 126 for a technician to view the inside of this housing. In one implementation, an electronic display screen may alternatively replace or accompany window 126 as needed. Port 128 may also provide access to the interior of enclosure 124. Port 128 can include a control port 130 shown here at the top of enclosure 124. Control port 130 may enable a control cable to connect to operation hardware 118. This cable can carry control signals from a central control network or a remote control station in the form of a 4 - 20 mA signal. A 12 or 24 volt power signal would be similarly useful. As also shown, port 132 may enable a wire or cable to extend from operation hardware 118 to a portion of instrumentation valve system 134. These wires may extend through conduit 136 and connect to instrumentation valve 120. In one implementation, instrumentation valve 120 can embody a solenoid valve that couples to actuator 112. The solenoid valve can change state to control the flow of pressurized actuating medium entering and leaving actuator 112. A double-acting or single-acting solenoid may be useful for this purpose.

[0013] The structure of the actuator 112 can be adapted for use with the controller 100. This structure can include a mount 138 that receives the enclosure 124. The mount 138 can be coupled to the base 140 by a fastener F such as a screw or bolt. The base 140 can support the valve body 110. Also as shown, the base 140 can support a load generator 142 that can include a spring cartridge 144 and a pneumatic cylinder 146. Other components such as the moving scale 148 can also be fixed to the base 140. In one implementation, the wired conduit 136 can enable a signal to be transmitted from the operating hardware 118. This signal can open and close a portion of the solenoid valve 120. This feature enables the working medium to be pressurized or vented from different sides of the pneumatic cylinder 146. These pressure changes adjust the position of the closure member 116 within the valve body 110.

[0014] Figure 3 depicts an elevation view of the structure of another example of the valve system 134. In this example, the wiring can extend from the enclosure 124 into a junction box 150 that surrounds the valve operating hardware 152. The junction box 150 may employ certain safety features such as an explosion-proof design so that the device complies with hazardous conditions. The operating hardware 152 can include a harmonic seal H that separates a pair of terminal strips T. The harmonic seal H can prevent gas flow between the terminal strips T and thus operates as another safety measure to avoid ignition of residual gas in proximity to the flow control device 108. The terminal strips T can be coupled to a pair of single-acting solenoid valves 120. However, the present disclosure also contemplates the use of one double-acting solenoid valve 120. In one implementation, the position of the closure member 116 within the valve body 110 can be adjusted by opening and closing the solenoid valve 120.

[0015] Figure 4 depicts the structure of FIG. 2 with the panel removed from the base 140. In one implementation, the torque assembly 154 can be coupled to the load generator 142. The torque assembly 154 may include a shaft 156 having one end that is located outside the base 140 proximate to the enclosure 124 of the controller 100. This end may similarly extend into the enclosure 124. The shaft 156 may have a second end that is fixed to the closure member 116 of the flow control device 108. This configuration of the torque assembly 154 can couple the sensor 122 to the closure member 116. In this way, the controller 100 can monitor the position of the closure member 116.

[0016] Figure 5 depicts a schematic view of an example of the controller 100. The sensor 122 can embody a magnetic flux sensor 158, although the present disclosure contemplates the use of other device technologies such as ultrasonic, piezoelectric, or optical sensing. The magnetic flux sensor 158 can be integrated as a component of, or as part of, the operating hardware 118. The end of the shaft 152 can be located proximate to the magnetic flux sensor 158. In one example, the end may carry a pair of magnets 160. This pair may be annularly offset from each other, for example, by 180°. In use, the magnets 160 assume positions associated with the angular orientation of the shaft 152, which itself reflects the position of the closure member 116 (e.g., relative to the seat 114). The magnetic flux sensor 158 is located proximate to the shaft 152 such that data corresponds to changes in polarity from the rotating magnets 160. The operating hardware 118 can correlate these changes to identify the position of the closure member 116. In one implementation, the magnetic flux sensor 158 can assume a first position, shown here to be on or aligned with the center of rotation (C) of the shaft 152. This first position often corresponds to the default orientation of the valve positioner 100 on the flow control device 108.

[0017] FIG. 6 depicts a flowchart of a method 200 for operating the controller 100 of FIG. 1. These steps of the method may correspond to executable instructions, such as a computer or software program, that configure the system controller 100 for a particular operation. The instructions may, for example, process data to reach a value that defines the operation of the flow control 108. These operations can identify the position of the closure member 114 and then adjust this position as needed for the flow control device 108 to operate within the process line. In one implementation, method 200 may include receiving data from one or more sources at step 202. This data may originate, for example, from the sensor 122 as information regarding the position of the closure member 114. The data may be transmitted from an RTU. This data can instruct the controller 100 regarding the actual process position of the closure member 114. At step 204, method 200 may include comparing the sensor data from the sensor 122 with data from a remote terminal unit (“RTU”). This may include determining, at step 206, whether the signals are within each other's tolerance ranges. If within the tolerance range, method 200 may continue to receive data (at step 202). If not within the tolerance range, method 200 may continue to determine the relationship between the sensor data and the RTU data at step 208. This relationship can indicate whether the closure member 114 has opened or closed too far from its commanded position. If it has closed too far, method 200 may continue to generate a signal at step 210 that changes the state of the solenoid to allow gas to pressurize the first side of the pneumatic cylinder 146 (and vent from the second side), thereby changing the position of the closure member 114 and opening the flow control device 108. On the other hand, if the valve has opened too far, method 200 may continue to generate a signal at step 212 that changes the state of the solenoid to allow gas to pressurize the second side of the pneumatic cylinder 146 (and vent from the first side), thereby changing the position of the closure member 114 and closing the flow control device 108.

[0018] Taking the above into consideration, the improvements herein utilize designs that can reduce costs and eliminate fugitive emissions. Embodiments herein, in one example, utilize Hall effect sensors to provide feedback representative of the position (e.g., opening percentage) of a control valve. The use of this sensor eliminates the need for mechanical feedback, which often requires long travel to record the same position on these types of valves. The device may also utilize a solenoid valve to control the pressure within a pneumatic actuator. By using this valve, for example, fugitive emissions of natural gas or similar operating media that pressurize these types of valves used in air actuators can be eliminated.

[0019] The following examples include specific elements or sections for explaining embodiments contemplated within the scope of this specification. These elements may also be combined with other elements and sections to explain embodiments as well. This specification includes and contemplates other examples conceivable by those skilled in the art. These other examples fall within the scope of the claims if, for example, they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that have little difference from the literal language of the claims.

Claims

1. A valve assembly comprising: an actuator having a pneumatic cylinder; a shaft connected to the actuator; a valve connected to the shaft; an actuator control system comprising a non-contact sensor proximate to an end of the shaft and a solenoid valve coupled to the pneumatic cylinder.

2. The valve assembly according to claim 1, wherein the solenoid valve comprises a double-acting solenoid.

3. The valve assembly according to claim 1, wherein the solenoid valve comprises a single-acting solenoid.

4. The valve assembly according to claim 1, further comprising a magnet disposed at an end of the shaft proximate to the non-contact sensor.

5. The valve assembly according to claim 1, wherein the non-contact sensor comprises a Hall effect sensor.

6. The valve assembly according to claim 1, further comprising a torque unit connected to the pneumatic cylinder and the shaft.

7. The valve assembly according to claim 1, further comprising an explosion-proof housing, wherein the non-contact sensor is disposed within the explosion-proof housing.

8. The valve assembly according to claim 1, further comprising an explosion-proof housing, wherein the non-contact sensor is disposed within the explosion-proof housing and the solenoid valve is disposed outside the explosion-proof housing.

9. The valve assembly according to claim 1, wherein the non-contact sensor is configured to generate a signal corresponding to a % open position of the valve.

10. The valve assembly according to claim 1, wherein the signal corresponds to an increase in pressure on one side of the pneumatic cylinder.

11. A valve assembly comprising: a pneumatic cylinder; a solenoid valve connected to the pneumatic cylinder; a controller coupled to the solenoid valve and comprising a Hall effect sensor; wherein the controller is configured to change a state of the solenoid valve in response to a signal from the Hall effect sensor.

12. The valve assembly according to claim 11, wherein the controller comprises an explosion-proof housing.

13. The valve assembly according to claim 11, further comprising an explosion-proof housing connected to the controller and the solenoid valve.

14. An explosion-proof housing connected to the controller and the solenoid valve, The valve assembly according to claim 11, further comprising a terminal circuit within the explosion-proof housing that connects the controller and the solenoid valve.

15. The valve assembly according to claim 11, wherein the state of the solenoid valve corresponds to an increase or decrease in pressure within the pneumatic cylinder.

16. A valve, comprising: a pneumatic actuator; a torque unit coupled to the pneumatic actuator; a shaft coupled to the torque unit; a Hall effect sensor proximate a first end of the shaft; control hardware coupled to the Hall effect sensor; and a solenoid valve coupled to the control hardware, wherein the control hardware changes the state of the solenoid valve in response to a signal from the Hall effect sensor.

17. The valve according to claim 16, further comprising a magnet disposed at the first end of the shaft.

18. The valve according to claim 16, further comprising a closure member coupled to a second end of the shaft, wherein the signal corresponds to the position of the closure member.

19. The valve according to claim 16, wherein the signal corresponds to the pressure within the pneumatic cylinder.

20. The valve according to claim 16, wherein the signal corresponds to an increase in pressure on a first side of the pneumatic cylinder.

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