Patent Publication Number: US-2021172778-A1

Title: Air duct assembly with field accessible ports

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a continuation in part of U.S. application Ser. No. 16/993,812, filed Aug. 14, 2020, which is a continuation of U.S. application Ser. No. 16/251,011, filed Jan. 17, 2019, which claims benefit of and priority to U.S. Provisional Application No. 62/618,142, filed Jan. 17, 2018, the entire disclosures of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     The present disclosure relates, in exemplary embodiments, to air duct airflow sensors. Air dampers are mechanical valves used to permit, block, and control the flow of air in air ducts. Typically, a pressure sensor is incorporated to detect and measure the air pressure in the air duct. Pressure measurement can be used to determine the desire amount of airflow and to actuate a damper to open or close, thus affecting airflow. 
     It would be desirable to have an airflow sensor that would not be dependent on airflow orientation so as to permit location of sensor closer to a bend in the air duct than conventional sensors can be positioned. It would be desirable to have an airflow sensor less susceptible to clogging. 
     SUMMARY 
     One implementation of the present disclosure is an air duct, according to some embodiments. The air duct includes a shell, a first annular chamber, a second annular chamber, a first pressure sensing coupler, a second pressure sensing coupler, a first field accessible coupler, and a second field accessible coupler. The first annular chamber is defined along a circumference of the shell and fluidly coupled with an inner volume that is defined by the shell through multiple first openings. The second annular chamber is defined along the circumference of the shell at a longitudinal position downstream of the first annular chamber, and is fluidly coupled with the inner volume of the shell through multiple second openings. The first pressure sensing coupler is fluidly coupled with the first annular chamber and the second pressure sensing coupler is fluidly coupled with the second annular chamber for pressure detection. The first field accessible coupler is fluidly coupled with the first annular chamber and the second field accessible coupler is fluidly coupled to the second annular chamber for providing pressurized air to the first annular chamber and the second annular chamber. 
     In some embodiments, the shell is a cylindrical hollow member. 
     In some embodiments, the second annular chamber is positioned at a throat of the shell, the throat defining a restricted cross-sectional flow area of the shell. 
     In some embodiments, the air duct further includes a first annular gasket and a second annular gasket. The first annular gasket is sealingly coupled with a radially outwards facing surface of the shell to define the first annular chamber between one or more interior surfaces of the first annular gasket and the radially outwards facing surface of the shell, according to some embodiments. The second annular gasket is sealingly coupled with the radially outwards facing surface of the shell to define the second annular chamber between one or more interior surfaces of the second annular gasket and the radially outwards facing surface of the shell, according to some embodiments. 
     In some embodiments, the first and second field accessible couplers are each open to and accessible from an exterior of the air duct. 
     In some embodiments, the first and second field accessible couplers are configured to fluidly couple with a pressure source configured to provide the pressurized air to flow through the first annular chamber and the multiple first openings to clear obstructions. In some embodiments, the pressure source is configured to provide the pressurized air to flow through the second annular chamber and the multiple second openings to clear obstructions. 
     In some embodiments, the first and second pressure sensing couplers are fluidly coupled with a pressure sensor of the air duct for detecting pressure values or a pressure differential between the first and second pressure sensing couplers. 
     In some embodiments, air flowing through the air duct flows through the multiple first openings, the first annular chamber, the second annular chamber, and the first and second pressure sensing couplers in a first direction for pressure detection. In some embodiments, the pressurized air flows through the multiple second openings, the first and second field accessible couplers, the first annular chamber, and the second annular chamber in a direction opposite the first direction for cleaning. 
     In some embodiments, the air duct further includes a damper and an actuator. In some embodiments, the actuator is configured to drive the damper to adjust a flow rate of air through the air duct. 
     Another implementation of the present disclosure is an air duct, according to some embodiments. In some embodiments, the air duct includes a shell, a first annular chamber, a second annular chamber, and a field accessible coupler. In some embodiments, the first annular chamber is defined along a circumference of the shell and is fluidly coupled with an inner volume of the shell through multiple first openings. In some embodiments, the second annular chamber is defined along the circumference of the shell at a longitudinal position that is downstream of the first annular chamber. In some embodiments, the second annular chamber is fluidly coupled with the inner volume of the shell through multiple second openings. In some embodiments, the field accessible coupler is fluidly coupled with the first annular chamber or the second annular chamber for providing pressurized air to the first annular chamber or the second annular chamber. In some embodiments, the second annular chamber is partially defined by an annular groove extending circumferentially along the shell, the annular groove extending inwards towards a longitudinal axis of the air duct. 
     In some embodiments, the second annular chamber is positioned at the annular groove of the shell. 
     In some embodiments, the air duct further includes a first annular gasket, and a second annular gasket. In some embodiments, the first annular gasket is sealingly coupled with a radially outwards facing surface of the shell to define the first annular chamber between one or more interior surfaces of the first annular gasket and the radially outwards facing surface of the shell. In some embodiments, the second annular gasket is sealingly coupled with the radially outwards facing surface of the shell to define the second annular chamber between one or more interior surfaces of the second annular gasket and the radially outwards facing surface of the shell. 
     In some embodiments, the field accessible coupler is a first field accessible coupler fluidly coupled with the first annular chamber and the air duct further comprises a second field accessible coupler fluidly coupled with the second annular chamber, wherein the first field accessible coupler and the second field accessible coupler are configured to fluidly coupled with a pressure source. 
     In some embodiments, the pressure source is configured to provide the pressurized air to flow through the first annular chamber and the multiple first openings to clear obstructions. In some embodiments, the pressure source is also configured to provide the pressurized air to flow through the second annular chamber and the multiple second openings to clear obstructions. 
     In some embodiments, the air duct further includes first and second pressure sensing couplers that are independently fluidly coupled with the first annular chamber and the second annular chamber and a pressure sensor of the air duct for detecting pressure values or a pressure differential between the first annular chamber and the second annular chamber. 
     In some embodiments, the shell is a cylindrical hollow member including the annular groove. 
     In some embodiments, the annular groove defines a restricted cross-sectional flow area of the shell along the annular groove. 
     Another implementation of the present disclosure is a method for cleaning an air duct, according to some embodiments. In some embodiments, the method includes providing an air duct including an inner volume, first and second independent annular chambers that independently fluidly couple with the inner volume through a first set of openings and second set of openings, and first and second field accessible couplers. In some embodiments, the method includes fluidly coupling at least one of the first and second field accessible couplers with a pressure source. In some embodiments, the method further includes providing pressurized air through at least one of: (1) the first field accessible couplers, the first independent annular chamber, and the first set of openings, or (2) the second field accessible coupler, the second annular chamber, and the second set of openings. 
     In some embodiments, the air duct further includes first and second pressure sensing couplers. In some embodiments, the method further includes adjusting a position or configuration of the damper to control a flow rate of air through the air duct and detecting a pressure differential between longitudinal positions of the first and second annular chambers using the first and second pressure sensing couplers and a pressure sensor. 
     In some embodiments, the first and second pressure sensing couplers are independently fluidly coupled with the first and second annular chambers at a first radial position, and the first and second field accessible couplers are independently fluidly coupled with the first and second annular chambers at a second radial position. In some embodiments, air is configured to flow through the inner volume, the first set of openings and the second set of openings, the first and second independent annular chambers, and the first and second pressure sensing couplers in a first direction for pressure detection. In some embodiments, air is configured to flow through the first and second field accessible couplers, the first and second annular chambers, the first set of openings and the second set of openings, to the inner volume in a second direction that is opposite the first direction for clearing obstructions. 
     Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings disclose exemplary embodiments in which like reference characters designate the same or similar parts throughout the figures of which: 
         FIG. 1  is an isometric view of an air duct assembly, according to some embodiments. 
         FIG. 2  is a side cross-sectional view of an air duct airflow sensor assembly, according to some embodiments. 
         FIG. 3  is a side cutaway view of the air duct assembly of  FIG. 1 , according to some embodiments. 
         FIG. 4  is a top elevation view of the air duct assembly of  FIG. 1 , according to some embodiments. 
         FIG. 5  is an exploded perspective view of an air duct, ring and gasket components that can be utilized in the air duct assembly of  FIG. 1 , according to some embodiments. 
         FIG. 6  is another top view of the air duct assembly of  FIG. 1 , according to some embodiments. 
         FIG. 7  is a side cross-sectional view of the air duct assembly taken along the line B-B of  FIG. 6 , according to some embodiments. 
         FIG. 8  is a detail view C-C of the nipple, gasket and tube, according to some embodiments. 
         FIG. 9  is a detail view D-D of the gasket, according to some embodiments. 
         FIG. 10  is a side cross-sectional view of another air duct airflow sensor assembly, according to some embodiments. 
         FIG. 11  is a side cross-sectional view of another air duct airflow sensor assembly, according to some embodiments. 
         FIG. 12  is a perspective view of another air duct assembly, according to some embodiments. 
         FIG. 13  is a sectional view of a portion of the air duct assembly of  FIG. 12 , according to some embodiments. 
         FIG. 14  is a sectional view of another portion of the air duct assembly of  FIG. 12 , according to some embodiments. 
         FIG. 15  is a flow diagram of a process for operating and clearing an air duct, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Unless otherwise indicated, the drawings are intended to be read (for example, cross-hatching, arrangements of parts, proportion, degree, or the like) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, “upper” and “lower” as well as adjectival and adverbial derivatives thereof (for example, horizontally”, “upwardly”, or the like), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate. 
       FIG. 1  depicts an isometric view of a cylindrical air duct assembly  1 . As shown, the air duct assembly  1  includes a first end  2 , a second end  3 , and interior wall  4 , an exterior wall  5 , and a control assembly  100 . Air duct assembly  1  is further shown to include an air damper assembly  50  situated within the interior wall  4  to control the volume of air flowing through the cylindrical air duct assembly  1 . In some embodiments, the diameter of the interior wall  4  is approximately 10 inches. 
     Referring now to  FIGS. 2-9 , various views depicting the air duct airflow sensor assembly  10  are shown, according to some embodiments. Air may flow through the air duct airflow sensor assembly  10  in the direction indicated by arrow “A” as shown in  FIG. 2 . The air duct airflow sensor assembly  10  includes a low pressure detection device and a high pressure detection device. The low pressure detection device comprises a hollow ring  20  which is mounted to or otherwise associated with the interior wall  4 . In some embodiments, the outer diameter of the hollow ring  20  can range from 0.5 inches to 0.75 inches. In an exemplary embodiment, the outer diameter of the hollow ring  20  is 0.625 inches. The ring  20  has a plurality of apertures  22  defined in the inner periphery  23  of the ring (versus the outer periphery  24  which is proximate to the interior wall  4 ). In exemplary embodiments, the apertures  22  are disposed in the inner periphery of the ring  20  such that they are generally orthogonal to the orientation of airflow, so that air flows across the apertures  22 , rather than flowing into the apertures  22 . 
     A hollow connector nipple  28  is connected to an aperture defined in the ring  20  and an aperture defined in the duct  1 . A tube  32  is connected to the nipple  28 . Air flowing into the apertures  22  can flow through the ring  20 , into the nipple  28 , and through the tube  32 . The tube  32  is connected to a pressure sensor  34  such that the air flowing through the tube  32  is received and detected by the flow pressure sensor  34 . The ring  20  serves two purposes: as an air collection device, and as an airflow restriction obstacle, so as to create a measurable pressure differential. 
     The air duct  1  further includes multiple apertures  40  defined therein, the apertures  40  being arranged generally in a ring-shape around the interior wall  4 . A gasket  42  is associated with the exterior wall  5  and is located generally over the apertures  40 . The gasket  42  has a recessed area  43  such that when associated with the exterior wall  5  a chamber  43  is formed. Detail views of the apertures  40  and chamber  43  are specifically depicted in  FIGS. 8 and 9 . 
     A hollow connector nipple  44  is connected to the gasket  42 . In exemplary embodiments, a gasket guarding ring  45  may be used and is fitted over the gasket  42 . A tube  46  is connected to the nipple  44 . The tube  46  is connected to the pressure sensor  34 . In an alternative exemplary embodiment, a separate pressure sensor (not shown) can be connected to the tube  46 . The apertures  40 , gasket  42 , nipple  44 , tube  46  and pressure sensor  34  form a high pressure sensor detection device. 
     In exemplary embodiments, the pressure sensor  34  is part of a control assembly  6  that controls the opening and closing of a damper  50 . In one exemplary embodiment of a control assembly, specifically depicted in  FIG. 7 , a housing  100  is mounted to or otherwise associated with the air duct. A sensor  34 , processor  102 , actuator  104  and power supply  106  may be disposed within the housing  100 . A damper  50  is in operational communication with the actuator  104 . 
     In operation, air flowing through the duct  1  in the direction of arrow A first encounters the high pressure detection apertures  40 . A portion of the air enters the apertures  40  and flows into the chamber  43 . The air then moves into the tube  46  via the nipple  44 , and then into the pressure sensor  34 . The pressure detected is the “high” pressure in the duct  1 , i.e., the pressure upstream from the airflow restrictor which is the ring  20 . 
     Air flowing through the duct  1  next flows over the ring  20  and can enter the apertures  22  and travel through the nipple  28  and the tube  32 , and into the pressure sensor  34 . The pressure detected is the “low” pressure in the duct, i.e., the pressure at the point where airflow is restricted by the ring  20 . The differential between the high pressure measurement and the low pressure measurement is an indication of the air velocity through the duct, specifically a scaled square root of the measured pressure (i.e., an application of Bernoulli&#39;s principle). The sensor  34  can send a signal to the control assembly  6  that in turn can cause the damper  50  to rotate so as to open or close the air duct  1 . 
     In exemplary embodiments, the pressure sensor  34  is a “dead-end” pressure sensor (versus a flow-through sensor); i.e., after the initial pressure is established no further airflow goes through the sensor. This can reduce the chance of the apertures  22  and  40  becoming clogged. 
     In one exemplary embodiment, for an air duct having a 10 inch diameter, a 0.5 inch diameter ring  20  was used. With such a construction measurements of 850 CFM (cubic feet per minute) down to 35 CFM were obtainable with a 0.1 in Wg duct static. In other embodiments, a 0.625 inch diameter ring  20  may be utilized. 
     A benefit of the presently described sensor assembly is that because of the ring  20  design having the apertures  22  orthogonal to the airflow orientation, air to be diverted into the ring  20  flows over the apertures  22 , rather than directly into the apertures  22 . This can reduce the likelihood of the apertures  22  becoming clogged by dust, dirt and debris that accompanies the airstream. 
     Another benefit is that the presently disclosed apparatus is not dependent on airflow orientation. Typically, conventional pressure sensor apparatus, such as variable air volume (“VAV”) boxes, are dependent on airflow orientation, and having a bend or other transition in the duct in the general area where the sensor can result in inaccurate measurement due to the airflow disruption that naturally occurs proximate to the bend. With the air detection means of the presently disclosed apparatus, which is not airflow orientation dependent, the sensor assembly can be located closer to a bend or other transition in the air duct without affecting pressure measurement. This provides the duct system designer with greater flexibility in designing the placement of the valve assembly. 
     Another benefit of the presently described sensor assembly is that it presents minimal obstruction to the airflow and thus allows for greater CFM velocity at lower duct statics. Additionally, in the event any of the apertures  22  become blocked, it is easy to carry out periodic maintenance by disconnecting the sensor  34  and introducing a blast of compressed air into the tube  32  or tube  46 . Any clogging debris will be blown out of the apertures  22  or  40 , respectively. 
     Another benefit of the presently described sensor assembly as part of an overall sensor/controller/damper design is that it can operate off of a 0-10V control signal to provide the desired airflow. This allows a designer or operator to set a required CFM with a linear control signal from a control system. 
     Referring now to  FIGS. 10 and 11 , alternate embodiments for airflow restriction used in the low pressure detection device are depicted. Specifically,  FIG. 10  depicts an airflow sensor assembly including a shroud component  60 . In some embodiments, the shroud component  60  can be ring-shaped, with an interior wall attachment portion  62 , an inclined portion  64 , and an aperture shielding portion  66 , although any suitable shroud configuration or geometry may be utilized. In some embodiments, the aperture shielding portion  66  extends from the interior wall  4  a distance ranging from 0.5 inches to 0.75 inches. 
     The aperture shielding portion  66  is situated proximate apertures  22  disposed within the air duct  1 . A gasket  48  is associated with the exterior wall  5  and is located generally over the apertures  22 . In some embodiments, one or more gasket guarding rings (not shown) may be used and fitted over the gaskets  42 ,  48 . The gasket  48  has a recessed area  49  such that when associated with the exterior wall  5  a chamber  49  is formed. Air flowing through the duct  1  flows over the interior wall attachment portion  62 , the inclined portion  64 , and the aperture shielding portion  66  of the shroud component  60  and can enter the apertures  22 . The air can then travel through the chamber  49  into the nipple  28 . Similar to the pressure measurement process described above with reference to  FIGS. 1-9 , after passing through the nipple  28 , the air can travel through a tube and into a pressure sensor for the purpose of controlling an air damper assembly. 
     Turning now to  FIG. 11 , an airflow sensor assembly including a channel feature  70  is depicted. Similar to the shroud component  60  described above with reference to  FIG. 10 , the channel feature  70  may be utilized as an air restriction feature in place of the hollow ring  20  described above with reference to  FIGS. 1-9 . The channel feature  70  can include multiple apertures  22  distributed about a periphery of the channel feature  70 . In some embodiments, the depth of the channel feature  70  can range from 0.5 inches to 0.75 inches. In an exemplary embodiment, the depth of the channel feature  70  is 0.625 inches. In other words, if the air duct  1  is nominally 10 inches in diameter, the diameter may expand to 11.25 inches in the region of the channel feature  70 . 
     A gasket  48  is associated with the exterior wall  5  and is located generally over the apertures  22 . In some embodiments, one or more gasket guarding rings (not shown) may be used and fitted over the gaskets  42 ,  48 . The gasket  48  has a recessed area  49  such that when associated with the exterior wall  5  a chamber  49  is formed. Air flowing through the duct  1  flows over the channel feature  70  and can enter the apertures  22 . The air can then travel through the chamber  49  into the nipple  28 . Similar to the pressure measurement process described above with reference to  FIGS. 1-9 , after passing through the nipple  28 , the air can travel through a tube and into a pressure sensor for the purpose of controlling an air damper assembly. 
     Referring now to  FIGS. 12-13 , another air duct assembly, shown as valve  200  can be configured to include one or more field accessible ports  222 , according to another embodiment. The valve  200  can be the same as or similar the air duct assembly  1  as described in greater detail above with reference to  FIGS. 1-11  and may include any of the features, geometry, components, etc., of the air duct assembly  1 . For example, the valve  200  can include a damper  214  that is the same as or similar to the damper  50  of the air duct assembly  1 . The valve  200  can also include a housing within which an actuator  204  is positioned, similar to the housing  100  and the actuator  104 . The valve  200  can also include any of the pressure sensor  34 , the processor  102 , and the power supply  106 . 
     The valve  200  can include a shell, a body, a tubular member, a duct wall, etc., shown as shell  202 . The shell  202  may define a radially inwards facing surface and a radially outwards facing surface and may have a thickness. The shell  202  can also define an inner volume  221  of the valve  200  through which air or a fluid can flow. The valve  200  can include an inlet opening  218  and an outlet opening  220  such that air or fluid flowing through the inner volume  221  of the valve  200  enters the valve  200  through the inlet opening  218 , flows through the inner volume  221  of the shell  202  and exits the valve  200  through the outlet opening  220 . The valve  200  or the shell  202  may define a longitudinal axis  210 , thereby defining a longitudinal direction. The longitudinal axis  210  may extend through a cross-sectional center of the valve  200  or the shell  202 . 
     The actuator  204  can be configured to drive a shaft  205  to rotate about an axis  207 . The axis  207  can extend in a radial direction through the longitudinal axis  210 . The shaft  205  can be rotatably coupled with the shell  202  of the valve  200  on either radial side of the shell  202 . The damper  214  can be fixedly coupled with the shaft  205  such that rotation of the shaft  205  drives rotation of the damper  214 . The damper  214  can include a plurality of fingers  216  or sealing member that are configured to seal with the radially inwards facing surface of the shell  202  when the damper  214  is driven to an extremum rotational position. In this way, the damper  214  can be operated to substantially seal or close off the inner volume  221  of the shell  202  so that air or another fluid is limited from flowing therethrough. The damper  214  can also be configured to partially engage the radially inwards facing surface of the shell  202  to provide a limited or a reduced flow area through which the air or fluid flowing through the inner volume  221  of the shell  202  passes. 
     The valve  200  also includes a housing  206  within which a pressure sensor (e.g., pressure sensor  34 ) is positioned. The valve  200  can be configured to measure pressure or a pressure differential between two different positions along the longitudinal axis  208  as described in greater detail above with reference to the pressure sensor  34 . 
     The valve  200  also includes the field accessible ports  222 . The field accessible ports  222  can be positioned proximate the inlet opening  218  of the duct assembly  200 . In an exemplary embodiment, the field accessible ports  222  are positioned at a longitudinal position along the longitudinal axis  208  that matches with longitudinal positions of gaskets (e.g., the gaskets  42  and  48  or gaskets  240  and  242  as described in greater detail below with reference to  FIG. 13 ) or of one or more connectors for pressure. 
     The field accessible ports  222  may include a high pressure port  224  (e.g., a nipple connector or coupler) and a low pressure port  226  (e.g., a nipple connector or coupler). In some embodiments, the high pressure port  224  is positioned upstream of the low pressure port  226 . The high pressure port  224  and the low pressure port  226  can be fluidly coupled with a pressure source  232  (e.g., a compressor, a tank of compressed air, a pump, a fan, a blower, etc.) through corresponding tubular members  228  and  230 , respectively. The high pressure port  224  and the low pressure port  226  can each be configured to fluidly or sealingly couple with a corresponding inner volume (e.g., an inner chamber) that is defined within an annular member  238 . The housing  206  and the pressure sensor therewithin is positioned at or near the annular member  238 , and the field accessible ports  222  are also positioned at the annular member  238 . The annular member  238  may facilitate defining independent high and low pressure inner volumes or chambers with the radially outwards facing surface (e.g., an exterior surface) of the shell  202 . The independent high and low pressure chambers can each be fluidly coupled with an inner volume of the valve  200  (e.g., the inner volume through which the air or fluid flows). 
     Referring now to  FIG. 13 , the field accessible ports  222  are shown in greater detail, according to an exemplary embodiment. The high pressure port  224  is configured to fluidly couple with a high pressure chamber  244  that is defined by a first gasket  240  and the shell  202 . The low pressure port  226  is configured to fluidly couple with a low pressure chamber  246  that is defined by a second gasket  242  and the shell  202 . The first gasket  240  can be the same as or similar to the gasket  42  of the air duct assembly  1  as described in detail above. The second gasket  242  can be the same as or similar to the gasket  48  of the air duct assembly  1  as described in greater detail above. 
     The first gasket  240  can be configured to sealingly couple with the radially outwards facing surface of the shell  202  in a circumferential direction. The second gasket  242  can be similarly configured to sealingly couple with the radially outwards facing surface of the shell  202  in the circumferential direction. The first gasket  240  (e.g., a radially inwards facing surface of the first gasket  240 ) and the radially outwards facing surface of the shell  202  may define the high pressure chamber  244 . The high pressure chamber  244  may have a circumferential or annular shape and may be a void or an open space that extends along the radially outwards facing surface or the exterior surface of the shell  202 . The low pressure chamber  246  can be positioned downstream from the high pressure chamber  244  and may have a similar shape or form as the high pressure chamber  244 . For example, the low pressure chamber  246  may be defined by the radially outwards facing surface or the exterior surface of the shell  202  and the second gasket  242  (e.g., a radially inwards facing surface of the second gasket  242 ). The low pressure chamber  246  can also have a circumferential or annular shape and may be a void or an open space that extends along the radially outwards facing surface or the exterior surface of the shell  202 . The first gasket  240  includes a channel or hole  258  through which the high pressure port  224  fluidly couples with the high pressure chamber  244 . The second gasket  242  similarly includes a channel or hole  259  through which the low pressure port  226  fluidly couples with the low pressure chamber  246 . 
     The low pressure chamber  246  can have a larger size (e.g., a larger area, a larger volume, etc.) compared to the high pressure chamber  244 . The second gasket  242  that defines the low pressure chamber  246  is positioned over an annular groove  266  (e.g., a curved groove, a radially inwards extending portion of the shell  202 , a parabolic portion of the shell  202 , a curved portion of the shell  202 , a concave curvature of the shell  202 , a throat of the shell  202 , a restriction, a restrictive portion of the shell  202 , etc.). The annular groove  266  is a portion of that shell  202  that, along the longitudinal axis  210 , curves inwards over a first longitudinal distance to an apex, and then curves outwards over a second longitudinal distance from the apex. The annular groove  266  extends circumferentially about the shell  202 . In this way, the first gasket  240  can be positioned over a cylindrically shaped portion of the shell  202 , while the second gasket  242  is positioned over a curvature of the shell  202  (e.g., the annular groove  246 ), thereby resulting in the high pressure chamber  244  having a smaller volume than the low pressure chamber  246 . The annular groove  266  can also function as a restriction (e.g., to provide a venturi effect) to adjust the pressure of the air flowing through the inner volume  221  of the valve  200 . 
     In some embodiments, the shell  202  includes a first set of radially spaced openings  234  (e.g., angularly spaced in a circumferential direction about the longitudinal axis  210 ) and a second set of radially spaced openings  236 . The first set of radially spaced openings  234  and the second set of radially spaced openings  236  may be apertures, holes, windows, bore, through-holes, etc., that extend from the corresponding one of the high pressure chamber  244  or the low pressure chamber  246 , through the shell  202  to the inner volume  221 . In this way, the first set of radially spaced openings  234  can be longitudinally positioned along the longitudinal axis  210  such that the first set of radially spaced openings  234  align with any of the first gasket  240 , the high pressure chamber  244 , the high pressure port  224 , or the tubular member  228 . Similarly, the second set of radially spaced openings  236  can be longitudinally positioned along the longitudinal axis  210  such that the second set of radially spaced openings  236  align with any of the second gasket  242 , the low pressure chamber  246 , the low pressure port  226 , or the tubular member  230 . The first set of radially spaced openings  234  are positioned longitudinally upstream from the second set of radially spaced openings  236 . Each opening or hole of the first set of radially spaced openings  234  and the second set of radially spaced openings  236  may be angularly offset from each other a specific angular amount. The first set of radially spaced openings  234  and the second set of radially spaced openings  236  can be uniformly spaced about a circumference of the shell  202  (e.g., so that adjacent openings of the first set of radially spaced openings  234  or adjacent openings of the second set of radially spaced openings  236  are angularly offset a same amount as another adjacent opening), or may be non-uniformly spaced about the circumference of the shell  202 . 
     Referring now to  FIG. 14 , the valve  200  may include a pair of pressure ports for pressure sensing. The pressure ports include a high pressure port  248  and a low pressure port  250 . The high pressure port  248  and the low pressure port  250  are positioned at a different radial position along the circumference of the shell  202  relative to the pair of field accessible ports  222 . The high pressure port  248  is configured to fluidly couple with the high pressure chamber  244  though the gasket  240 . The first gasket  240  includes a channel or hole  262  through which the high pressure port  248  fluidly couples with the high pressure chamber  244 . The second gasket  242  includes a channel or hole  264  through which the low pressure port  250  fluidly couples with the low pressure chamber  246 . 
     The high pressure port  248  and the low pressure port  250  are configured to fluidly couple with a pressure sensor  252  through a corresponding tubular member  254  and a tubular member  256 . The high pressure port  248  and the low pressure port  250  are configured to fluidly couple with the inner volume  221  similarly to the high pressure port  224  and the low pressure port  226  through the first set of radially spaced openings  234  and the second set of radially spaced openings  236 . In this way, the high pressure port  224  and the high pressure port  248  both fluidly couple with the high pressure chamber  244 , and the low pressure port  226  and the low pressure port  250  both fluidly couple with the low pressure chamber  246 . 
     It should be understood that while  FIG. 13  shows the pressure source  232  fluidly coupled with both the high pressure chamber  244  and the low pressure chamber  246  simultaneously, the pressure source  232  may be coupled to only one of the high pressure chamber  244  and the low pressure chamber  246  at a time, according to some embodiments. For example, a technician may fluidly couple the pressure source  232  with the high pressure chamber  244  (without fluidly coupling the pressure source  232  with the low pressure chamber  246 ) through the high pressure port  224 , and operate the pressure source  232  to perform cleaning of the high pressure chamber  244  and the first set of radially spaced openings  234 . The technician may subsequently de-couple the pressure source  232  from the high pressure chamber  244  and proceed with fluidly coupling the pressure source  232  with the low pressure chamber  246  for cleaning the low pressure chamber  246  and the second set of radially spaced openings  236 . In this way, the technician may either use the pressure source  232  to clean both the high pressure chamber  244  and the low pressure chamber  246  simultaneously, or may clean the high pressure chamber  244  and the low pressure chamber  246  individually. 
     Referring to  FIGS. 13-14 , the pressure ports are configured to receive air from the inner volume  221  to determine a pressure measurement of air flowing through the valve  200 . For example, the air may flow through the first set of radially spaced openings  234  and the second set of radially spaced openings  236  into the high pressure chamber  244  and the low pressure chamber  246 , respectively. The air may flow through the hole  262  of the first gasket  240 , through the high pressure port  248  and the tubular member  254 , and into the pressure sensor  252  to obtain a high pressure reading, and simultaneously flow through the hole  264  of the second gasket  242 , through the low pressure port  250  and the tubular member  256  and into the pressure sensor  252  to obtain a low pressure reading. In this way, the pressure sensor  252  can detect a high pressure value and a low pressure value (or a pressure differential therebetween) of the air flowing through the valve  200  at different longitudinal positions along the valve  200 . The pressure ports can be the same as or similar to the nipple  44  and the nipple  28  as described in greater detail above. 
     The field accessible ports  222  can be one way valves (e.g., to permit flow only into the high and low pressure chambers) or may be removably fluidly coupled with the pressure source  232  through the tubular members  228  and  230 . The pressure source  232  is configured to provide a pressurized air or fluid to the high pressure port  224  and the low pressure port  226  through the first tubular member  228  and the second tubular member  230 . The pressurized air then enters the high pressure chamber  244  and the low pressure chamber  246  through the high pressure port  224  and the low pressure port  226 , respectively. The pressurized air can then flow through the first set of radially spaced openings  234  and the second set of radially spaced openings  236  from the high pressure chamber  244  and the low pressure chamber  246 , respectively, and enter the inner volume  221  of the valve  200 . The pressurized air can be used to clean or clear the first set of radially spaced openings  234  and the second set of radially spaced openings  236  by blowing air through the high pressure chamber  244  and the low pressure chamber  246  and the first set of radially spaced openings  234  and the second set of radially spaced openings  236 . In this way, air can flow out of the inner volume  221  into the high pressure chamber  244  and the low pressure chamber  246  through the first set of radially spaced openings  234  and the second set of radially spaced openings  236 , respectively, for pressure sensing purposes and can be injected in an opposite direction (e.g., into the high pressure chamber  244  and the low pressure chamber  245  and through the first set of radially spaced openings  234  and the second set of radially spaced openings  236  into the inner volume  221 ) for cleaning or clearing purposes (e.g., to remove obstructions or build-up at any of the first set of radially spaced openings  234 , the second set of radially spaced openings  236 , the high pressure chamber  244 , or the low pressure chamber  246 ). 
     It should be understood that as used in the present disclosure, the terms “port” or “coupler” may include or be any opening, fitting, hollow member, aperture, grooves, press-fit openings, etc., configured to selectively fluidly couple an exterior of the valve  200  (e.g., the pressure source  232  and/or the pressure sensor  252 ) with an interior of the valve  200  (e.g., the high pressure chamber  244  and/or the low pressure chamber  246 ). The high pressure port  224 , the low pressure port  226 , the high pressure port  248 , or the low pressure port  250  may be any component, opening, fitting, hollow member, aperture, groove, etc., that is integral with or separate from the first gasket  240  and/or the second gasket  242 . 
     Referring now to  FIG. 15 , a flow diagram of a process  1500  for operating and cleaning an air duct is shown, according to some embodiments. The process  1500  can be performed using the valve  200 . The process  1500  can include steps  1502 - 1510 . 
     The process  1500  includes providing an air duct or a valve including an inner volume, a pair of independent annular chambers that fluidly couple with the inner volume through one or more openings, a first pair of coupler, a second pair of couplers, and a damper (step  1502 ), according to some embodiments. The air duct may be the same as or similar to the valve  200  as described in greater detail above with reference to  FIGS. 12-14 . For example, the inner volume may be the inner volume  221 , the pair of independent annular chambers may be the high pressure chamber  244  and the low pressure chamber  246 , the openings may be the first set of radially spaced openings  234  and the second set of radially spaced openings  236 , the first pair of couplers may be the pressure ports, the second pair of couplers may be the field accessible ports  222 , and the damper may be the damper  214 . 
     The process  1500  also includes operating the damper to control a flow rate of air through the air duct (step  1504 ), according to some embodiments. In some embodiments, the damper is operated to adjust (e.g., increase or decrease) a cross-sectional area of the air duct to change air flow, flow rate, or pressure across the valve. Step  1504  can be achieved by operating the actuator  204  to rotate the damper  214  about the axis  207 . The damper  214  includes fingers  216  that can engage a radially inwards facing surface of the shell  202 , thereby adjusting a cross-sectional flow area of the air duct. 
     The process  1500  also includes detecting a first and a second pressure at different longitudinal positions along the duct using the first pair of couplers and a pressure sensor (step  1506 ), according to some embodiments. The first pair of couplers can be configured to sample air at an upstream and a downstream position to detect a pressure at the upstream and the downstream position. The first pair of couplers can each be fluidly coupled with a corresponding one of the pair of independent annular chambers, which are fluidly coupled with the inner volume of the air duct through different sets of the one or more openings. In this way, air flowing through the inner volume of the air duct can be directed through the one or more openings, the pair of independent annular chambers, and the first pair of couplers, which may direct the air from the upstream and downstream position through tubular members to a pressure sensor. 
     The process  1500  includes fluidly coupling the second pair of couplers with a pressure source (step  1508 ), according to some embodiments. For example, the second pair of couplers can also fluidly couple with the pair of independent annular chambers and the pressure source. Step  1508  can be performed by a field technician when the air duct should be cleaned or cleared of obstructions. The second pair of couplers can be the field accessible ports  222  and can be accessed from an exterior of the air duct. It should be understood that step  1508  does not need to be performed when the air duct is operating for pressure detection. For example, step  1508  can be performed when the air duct is not powered (when steps  1504 - 1506  are not being performed), or even when the air duct is not installed in a building. In this way, step  1508  can be performed at any time. 
     The process  1500  includes providing pressurized air through the second pair of couplers, the pair of independent annular chambers, and the one or more openings, to the inner volume of the duct (step  1510 ), according to some embodiments. Step  1510  can be performed by operating the pressure source (e.g., the pressure source  232 ) to provide the pressurized air to the second pair of couplers. Step  1510  can be performed to clear any of the second pair of couplers, the pair of independent annular chambers, the one or more openings, the inner volume of the duct, or the first pair of couplers. 
     As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. 
     “Optional’ or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not. 
     Throughout the description and claims of this specification, the word “comprise” and variations of the word, such as “comprising’ and “comprises,” means “including but not limited to,” and is not intended to exclude, for example, other additives, components, integers or steps. “Exemplar” means “an example of” and is not intended to convey an indication of a preferred or ideal embodiment. “Such as” is not used in a restrictive sense, bur for explanatory purposes. 
     Disclosed are components that can be used to perform the disclosed methods, equipment and systems. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc., of these components are disclosed that while specific reference of each various individual and collective combination and permutation of these may not be explicitly disclosed, each is specifically contemplated and described herein, for all methods, equipment and systems. This applies to all aspects of this application including, but not limited to, steps in disclosed methods. Thus, if there ae a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific embodiment or combination of embodiments of the disclosed methods. 
     It should further be noted that any patents, applications and publications referred to herein are incorporated by reference in their entirety.