Patent Publication Number: US-2023159237-A1

Title: Pressure relief assemblies and methods

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/282,067, filed on Nov. 22, 2021, and entitled “PRESSURE RELIEF ASSEMBLIES AND METHODS,” the entire contents of which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF EMBODIMENTS OF THE DISCLOSURE 
     The present disclosure relates to lids or bases for containers with one or more pressure relief features to allow for venting and depressurization of the container. 
     BACKGROUND 
     Various types of containers or canisters are utilized to retain or hold contents that may be initially pressurized or may become pressurized over time. For example, aerosol canisters may be pressurized with an aerosol, and may retain this initial pressurization until a user causes aerosol to be released, thereby reducing the pressure within the aerosol canister. In some instances, a container may be pressurized, and may maintain the initial level of pressurization throughout the life cycle of the contents of the container. In still other instances, a container may become pressurized over time due to one or more factors that cause the container to become pressurized, such as a chemical reaction that occurs within the container. 
     In any of the aforementioned pressurization situations, one or more features may be built into or along one or more portions of the container, which may allow for venting of the container in the event that venting becomes necessary. In the scenario where pressure within the container increases after the container has been initially sealed, a venting feature may be included to prevent over-pressurization of the container, which could result in an uncontrolled release of contents from within the container. 
     While various venting features exist that provide for venting or depressurization of containers that include contents that become pressurized over time, improved devices and methods are needed that can allow for more controlled depressurization based on pre-determined factors associated with the contents of a particular container. 
     SUMMARY 
     Embodiments of the present disclosure generally relate to a venting system that includes a lid or base comprising a center wall that defines a central longitudinal axis, and a total radius that is measured from the longitudinal axis to an outermost surface of the lid or base, and a pressure relief feature that is disposed along the lid or base. The pressure relief feature includes at least a first venting feature defining a thinned region of the lid or base, a venting radius is measured from the longitudinal axis to an outermost extent of the first venting feature, and the venting radius is between about 5% and about 25% of the total radius of the lid or base, expressed as a percentage. 
     In some embodiments, the pressure relief feature further includes a second venting feature that also defines a thinned region of the lid or base. In some embodiments, the first venting feature and the second venting feature are concavely shaped with respect to the longitudinal axis. In some embodiments, the first venting feature and the second venting feature are convexly shaped with respect to the longitudinal axis. In some embodiments, the first venting feature is a mirror image of the second venting feature. In some embodiments, the first venting feature and the second venting feature define a v-shape. 
     In some embodiments, the venting system further includes a third venting feature that also defines a thinned region of the lid or base. In some embodiments, the first venting feature, the second venting feature, and the third venting feature define a v-shape. In some embodiments, the first venting feature consists of a circular notch that is disposed only on an underside of the lid or base. In some embodiments, the venting radius is between about 10% and about 22% of the total radius of the lid or base. 
     In some embodiments, a venting system includes a lid or base comprising a center wall that defines a central longitudinal axis, and a total radius that is measured from the longitudinal axis to an outermost periphery of the lid or base, and a pressure relief feature that is disposed along the lid or base. In some embodiments, the pressure relief feature includes at least a first venting feature defining a thinned region of the lid or base, a venting radius is measured from the longitudinal axis to an outermost extent of the first venting feature, the venting radius is less than about 40% of the total radius of the lid or base, expressed as a percentage, and the thinned region defines a region thickness that is less than about 40% of a maximum thickness of the central wall, expressed as a percentage. 
     In some embodiments, the pressure relief feature further includes a second venting feature that is spaced from the first venting feature. In some embodiments, the first venting feature and the second venting feature are mirror images of one another. In some embodiments, the first venting feature and the second venting feature define curved segments. In some embodiments, the first venting feature and the second venting feature define a v-shape. In some embodiments, the pressure relief feature further includes a third venting feature. In some embodiments, the thinned region extends through the central longitudinal axis. In some embodiments, the first venting feature defines an s-shape. In some embodiments, a minimum venting distance of the pressure relief feature is less than about 20% of the total radius of the lid or base. In some embodiments, a minimum venting distance of the pressure relief feature is less than about 50% of the total radius of the lid or base. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a bottom isometric view of a lid or base for a container, the lid or base having a first embodiment of a pressure relief feature; 
         FIG.  2    is a cross-sectional, side view of the lid or base taken through line  2 - 2  of  FIG.  1   ; 
         FIG.  3    is a bottom isometric view of a lid or base for a container, the lid or base having a second embodiment of a pressure relief feature; 
         FIG.  4    is a cross-sectional, side view of the lid or base taken through line  4 - 4  of  FIG.  3   ; 
         FIG.  5    is a bottom isometric view of a lid or base for a container, the lid or base having a third embodiment of a pressure relief feature; 
         FIG.  6    is a cross-sectional, side view of the lid or base taken through line  6 - 6  of  FIG.  5   ; 
         FIG.  7    is a bottom isometric view of a lid or base for a container, the lid or base having a fourth embodiment of a pressure relief feature; 
         FIG.  8    is a bottom plan view of a lid or base for a container similar to the lid or base for a container of  FIG.  7   ; 
         FIG.  9    is a cross-sectional, side view of the lid or base taken through line  9 - 9  of  FIG.  7   ; 
         FIG.  10    is a bottom isometric view of a lid or base for a container, the lid or base having a fifth embodiment of a pressure relief feature; 
         FIG.  11    is a bottom plan view of a lid or base for a container similar to the lid or base for a container of  FIG.  9   ; 
         FIG.  12    is a cross-sectional, side view of the lid or base taken through line  12 - 12  of  FIG.  10   ; 
         FIG.  13    is a bottom isometric view of a lid or base for a container, the lid or base having a sixth embodiment of a pressure relief feature; 
         FIG.  14    is a bottom plan view of the lid or base for a container of  FIG.  13   ; 
         FIG.  15    is a bottom isometric view of a lid or base for a container, the lid or base having a seventh embodiment of a pressure relief feature; 
         FIG.  16    is a bottom plan view of the lid or base of  FIG.  15   ; 
         FIG.  17    is a bottom plan view of a lid or base for a container similar to the lid or base for a container of  FIGS.  15  and  16   ; 
         FIG.  18    is a bottom isometric view of a lid or base for a container, the lid or base having an eighth embodiment of a pressure relief feature; 
         FIG.  19    is a bottom plan view of the lid or base of  FIG.  18   ; 
         FIG.  20    is a bottom plan view of a lid or base for a container similar to the lid or base for a container of  FIGS.  18  and  19   ; 
         FIG.  21    is a bottom isometric view of a lid or base for a container, the lid or base having a ninth embodiment of a pressure relief feature; 
         FIG.  22    is a bottom plan view of the lid or base of  FIG.  21   ; 
         FIG.  23    is a bottom plan view of a lid or base for a container similar to the lid or base for a container of  FIGS.  20  and  21   ; 
         FIG.  24 A  is an isometric, cross-sectional view of a first profile of a pressure relief feature that may be applied to any of the lids or bases of  FIGS.  1 - 23   ; 
         FIG.  24 B  is an enlarged side view of the first profile of the pressure relief feature of  FIG.  24 A ; 
         FIG.  25 A  is an isometric, cross-sectional view of a second profile of a pressure relief feature that may be applied to any of the lids or bases of  FIGS.  1 - 23   ; 
         FIG.  25 B  is an enlarged side view of the second profile of the pressure relief feature of  FIG.  25 A ; 
         FIG.  26 A  is an isometric, cross-sectional view of a third profile of a pressure relief feature that may be applied to any of the lids or bases of  FIGS.  1 - 23   ; 
         FIG.  26 B  is an enlarged side view of the third profile of the pressure relief feature of  FIG.  26 A ; 
         FIG.  27 A  is an isometric, cross-sectional view of a fourth profile of a pressure relief feature that may be applied to any of the lids or bases of  FIGS.  1 - 23   ; and 
         FIG.  27 B  is an enlarged side view of the fourth profile of the pressure relief feature of  FIG.  27 A . 
     
    
    
     DETAILED DESCRIPTION 
     Before the embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Throughout the disclosure, the terms “about” and “approximately” mean plus or minus 5% of the number that each term precedes. 
     Embodiments of the present disclosure provide for a lid or base that is coupled with or forms a container. The lid or base may comprise a lid, plate, or another type of closure for enclosing contents within the container, the lid or base having one or more pressure relief or venting features that allow for controlled and targeted pressure relief when a maximum pressure threshold has been achieved within the container. Upon reaching a maximum pressure, the lid or base ruptures at one or more locations along the respective pressure relief feature(s) to allow for depressurization. The venting or pressure relief features described herein may be implemented in a wide variety of technologies, including applications related to aerosol containers, battery cell containers, capacitors, fuel storage reservoirs, and pressure vessels. In each of the aforementioned applications, pressure release may be required due to pressure build-up within the container, and the venting features disclosed herein may allow for depressurization or expulsion once a maximum pressure threshold has been reached. 
     Through finite element analyses (FEA) of various pressure relief feature configurations, certain configurations and orientations of pressure relief vents have been found to provide highly localized and targeted pressure relief once a maximum pressure threshold has been reached within the container. The present disclosure includes various configurations of pressure relief features on a circular lid or base that are configured to rupture once a maximum pressure threshold has been achieved. The maximum pressure threshold for the various configurations described herein may be different based upon the location, spacing, and number of the pressure relief features disposed along the lid or base. However, all of the pressure relief features disclosed herein are disposed entirely within a venting radius that is greater than 10% and less than 25% of a total radius of the lid or base, measured from a central longitudinal axis of the lid or base. By providing the venting features discussed hereinafter below, controlled and targeted pressure relief can be achieved at locations that are arranged spaced from a peripheral rim of the lid or base, and thus the container to which the lid or base is coupled. 
     Referring in particular to  FIGS.  1  and  2   , a lid or base  40  having a first embodiment of a pressure relief feature  42  is shown. The lid or base  40  includes a first or outer wall  44  that is configured for engagement with a container (not shown), a second or intermediate wall  46  that extends radially upward and inward from the outer wall  44 , and a third or central wall  48  that extends radially inward from the intermediate wall  46 . The pressure relief feature  42  is provided within or along the central wall  48 , and a central longitudinal axis  50  extends centrally through the central wall  48 . Referring to  FIG.  2   , the outer wall  44  includes a first or outermost portion  54 , a second or intermediate portion  56 , and a third or innermost portion  58 , the portions  54 ,  56 ,  58  of the outer wall  44  combining to define a U-shape in cross-section. The portions  54 ,  56 ,  58  are configured to be crimped or otherwise coupled with a container (not shown). The portions  54 ,  56 ,  58  are separated by corners or rounds  60  that define the various portions  54 ,  56 ,  58  of the outer wall  44 . The intermediate wall  46  also intersects with the outer wall  44  at one of the corners  60  and extends inward at a constant angle until the intermediate wall  46  intersects with the central wall  48 . The outermost portion  54  of the outer wall  44  also defines an outermost surface or rim that circumscribes a periphery of the lid or base  40 . 
     Referring in particular to  FIG.  2   , the outer wall  44  defines an outer wall thickness  64 , the intermediate wall  46  defines an intermediate wall thickness  66 , and the central wall  48  defines a central wall thickness  68 . In some embodiments, the central wall thickness  68 , the intermediate wall thickness  66 , and the outer wall thickness  64  may be the same or may be different. Still further, the portions  54 ,  56 ,  58  of the outer wall  44  may define the same thickness, or the thicknesses may be different. As discussed hereinafter below, a maximum thickness of the central wall thickness  68  is discussed below with respect to the various proportions of the pressure relief features  42  since all of the pressure relief features are disposed within the central wall  48 . Further, a first or inner surface  70  and a second or outer surface  72  of the lid or base  40  are further shown in  FIG.  2   , and each extend along all of the outer wall  44 , the intermediate wall  46 , and the central wall  48 . The outermost portion  54  of the outer wall  44  is also shown, which defines the outermost surface of the lid or base  40 . Still further, unless otherwise specified, the lid or base  40  of  FIGS.  1  and  2    is identical to the lid or base  40  of  FIGS.  3 - 23   . 
     Referring again to  FIG.  1   , the pressure relief feature  42  is shown in perspective, and includes a first venting feature or notch  76  and a second venting feature or notch  78 , which is a mirror image of the first venting feature  76 . The first venting feature  76  and the second venting feature  78  are both concavely curved with respect to the longitudinal axis  50 . The first venting feature  76  and the second venting feature  78  each radially extend about 90° around the central longitudinal axis  50 . In some embodiments, the first venting feature  76  and the second venting feature  78  may each extend around the central longitudinal axis  50  between about 30° and about 150°, or between about 60° and about 120°, or between about 75° and about 105° around the central longitudinal axis  50 . In some embodiments, the first venting feature  76  and the second venting feature  78  may each extend less than about 150°, or less than about 140°, or less than about 130°, or less than about 120°, or less than about 110°, or less than about 100°, or less than about 90°, or less than about 80°, or less than about 70°, or less than about 60°, or less than about 50°, or less than about 40°, or less than about 30°, or less than about 20°, or less than about 10° around the longitudinal axis  50 . 
     Referring to  FIG.  2   , the pressure relief feature  42  is shown in cross section and is generally located in or along the central wall  48  of the lid or base  40 . As noted above, the pressure relief feature  42  includes the first venting feature  76  and the second venting feature  78 , and defines thinned regions  80  between the inner surface  70  and the outer surface  72 , which are configured to rupture to release pressure from the lid or base  40 , if necessary. As discussed below and shown in detail in  FIGS.  24 A- 27 B , the thinned regions  80  each have a region thickness  82  that is less than about 20% of the maximum thickness of the central wall thickness  68 , and comprise one or more of the notch profiles discussed below. In some embodiments, the region thickness  82  may vary along one or both of the first venting feature  76  and the second venting feature  78 . In some embodiments, the region thickness  82  of the first venting feature  76  is larger than the region thickness  82  of the second venting feature  78 . In some embodiments, the region thickness  82  may increase between first and second ends of the first or second venting features  76 ,  78 . By varying the region thickness, the pressure relief feature  42  can be tuned or controlled for a programmable rupture. The characteristics of the region thickness  82  of  FIGS.  1  and  2    are applicable to all of the region thicknesses  82  of the pressure relief features  42  discussed below. 
     Still referring to  FIG.  2   , the central longitudinal axis  50  extends centrally through the central wall  48 , and in the present embodiment, the lid or base  40  is symmetric about the central longitudinal axis  50  in at least two directions. In some embodiments, the lid or base  40  is symmetric about the longitudinal axis  50  in at least three, or four, or five, or more directions. The central longitudinal axis  50  is shown extending centrally through the lid or base  40 , and a line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to an outermost surface  88  of the lid or base  40 . Further, a venting radius  90  is shown, being measured normal from the longitudinal axis  50  to an outermost location of the pressure relief features  42 . While the venting radius  90  is shown being less than about 18% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . The venting radius  90  may vary around the longitudinal axis  50 , or the venting radius  90  may be a constant radius. 
     Referring now to  FIGS.  3  and  4    the lid or base  40  is shown having a second embodiment of the pressure relief feature  42 . In a similar fashion as described above with respect to  FIGS.  1    and  2 , the pressure relief feature  42  includes the first venting feature  76  and the second venting feature  78 , which is a mirror image of the first venting feature  76 . The first venting feature  76  and the second venting feature  78  are both convexly curved with respect to the central longitudinal axis  50 . The first venting feature  76  and the second venting feature  78  each define an outwardly shaped curved arc, and each of the venting features radially extend about 90° around the longitudinal axis  50 . In some embodiments, the first venting feature  76  and the second venting feature  78  may each extend around the central longitudinal axis  50  between about 30° and about 150°, or between about 60° and about 120°, or between about 75° and about 105° around the longitudinal axis  50 . In some embodiments, the first venting feature  76  and the second venting feature  78  may each extend less than about 150°, or less than about 140°, or less than about 130°, or less than about 120°, or less than about 110°, or less than about 100°, or less than about 90°, or less than about 80°, or less than about 70°, or less than about 60°, or less than about 50°, or less than about 40°, or less than about 30°, or less than about 20°, or less than about 10° around the central longitudinal axis  50 . 
     Referring to  FIG.  4   , the pressure relief feature  42  is shown in cross section and is generally located in or along the central wall  48  of the lid or base  40 . The first venting feature  76  and the second venting feature  78  define thinned regions  80  between the inner surface  70  and the outer surface  72 , which are configured to rupture to release pressure from the lid or base  40 , if necessary. As shown in detail in  FIGS.  24 A- 27 B , the thinned regions  80  each have a region thickness  82  that is less than about 20% of the maximum thickness of the central wall thickness  68 . As noted above, the region thickness  82  may be adjusted based on a desired performance of the pressure relief feature  42 . 
     Still referring to  FIG.  4   , in the present embodiment, the lid or base  40  is symmetric about the central longitudinal axis  50  in at least two directions since the pressure relief features  42  are mirror images of one another. The longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, which in the present embodiment is measured normal from the longitudinal axis  50  to an innermost location of the pressure relief features  42 . In that sense, the venting radius  90  of the present embodiment is a minimum or inner venting radius, while the venting radius  90  of  FIGS.  1  and  2    is measured as a maximum or outer venting radius. In some embodiments, such as the embodiments of  FIGS.  5 - 12    discussed below, the venting radius  90  defines a constant radius around the longitudinal axis  50 . 
     While the venting radius  90  of  FIG.  4    is shown being less than about 16% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . The aforementioned distances are taken along the line segment or radius  86  in relation to the outermost surface  88  of the outer wall  44  taken along the particular line segment. In the present embodiment, the inner venting radius  90  varies around the longitudinal axis  50  since the first venting feature  76  and the second venting feature  78  are convexly disposed with respect to the central longitudinal axis  50 . 
     The concavely and convexly shaped first and second venting features  76 ,  78  of  FIGS.  1 - 4    are configured to allow for directional venting within a tight profile that extends in a direction of the central longitudinal axis  50 . A venting cone (not shown) may be produced by the contents within the container once rupture has occurred, and the concavely/convexly shaped venting features  76 ,  78  provide for a venting cone having a lower cone angle. For example, the venting features  76 ,  78  may provide for a cone angle, i.e., an angle between the longitudinal axis and a leg of the cone, that is less than about 30°, or less than about 25°, or less than about 20°, or less than about 15°, or less than about 10°, or less than about 5°. The venting cone may be defined as a cone that comprises at least 95% of particles that are dispersed from the container through one or both of the venting features  76 ,  78 . 
     Still further, the concavely and convexly shaped first and second venting features  76 ,  78  may be modified to allow for programmable, directional venting and may be configured for controlled venting in directions that are angled with respect to the central longitudinal axis  50 . In particular, the concavely shaped venting features  76 ,  78  of  FIGS.  1  and  2    allow for venting to occur via one or both of the venting features  76 ,  78  in a direction toward the longitudinal axis  50 , i.e., an inward direction. The convexly shaped venting features  76 ,  78  of  FIGS.  3  and  4    allow for venting to occur in a direction moving away from the central longitudinal axis  50 , i.e., an outward direction. However, the location and disposition of all of the venting features  76 ,  78  of  FIGS.  1 - 4    allow for a cone angle with a tight profile that allows for venting along the central longitudinal axis  50 , and the concavity or convexity of the venting features allows for more targeted venting. Still further, an evacuation time of the contents from within the container may be controlled based on the disposition, size, and curvature of the venting features  76 ,  78 . 
     Referring now to  FIGS.  5 - 12   , embodiments of the pressure relief feature  42  are shown applied to the lid or base  40 . The pressure relief feature  42  of  FIGS.  5 - 12    includes only the first venting feature  76 , which is circular. The first venting features  76  of  FIGS.  5 - 12    have centers that are collinear with the longitudinal axis  50 . The first venting features  76  include the thinned region  80  between the inner surface  70  and the outer surface  72 , the thinned region  80  being configured to rupture to release pressure from the lid or base  40 , if necessary. The central wall thickness  68  and the region thickness  82  are similar or identical to those described above with respect to  FIGS.  1  and  2    above. Referring in particular to  FIGS.  5 - 7 ,  9 ,  10 , and  12   , the pressure relief feature  42  is formed continuously around the central wall  48  of the lid or base  40 , i.e., 360° about the longitudinal axis  50 . In contrast, and referring to  FIGS.  8  and  11   , the pressure relief feature  42  is disposed about 275° around the longitudinal axis. In some embodiments, the pressure relief feature  42  may be disposed between about 150° and about 350°, or about  200  and about 325°, or about 250° and about 300°, or about 260° and about 290° about the central longitudinal axis  50 . In the present embodiment and referring to  FIGS.  24 A- 27 B , the thinned regions  80  each have a region thickness  82  that is less than about 20% of the maximum thickness of the central wall thickness  68 . The region thickness  82  may be adjusted based on a desired performance of the pressure relief feature  42 . 
     Referring in particular to  FIGS.  5  and  6   , the lid or base  40  and the pressure relief feature  42  are radially symmetric about the longitudinal axis  50  since the pressure relief feature  42  extends entirely around the longitudinal axis  50 . The longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, being measured normal from the longitudinal axis  50  to a location of the pressure relief feature  42 . Since the pressure relief feature  42  defines a circle, the venting radius  90  is constant around the entire longitudinal axis  50 . While the venting radius  90  is shown being less than about 11% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . In the present embodiment, the venting radius  90  is constant around the longitudinal axis  50  since the first venting feature  76  defines the shape of a circle. 
     Referring now to  FIGS.  7  and  9   , the lid or base  40  and the pressure relief feature  42  are also radially symmetric about the longitudinal axis  50  since the pressure relief feature  42  extends entirely around the longitudinal axis  50 . The longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, being measured normal from the longitudinal axis  50  to a location of the pressure relief feature  42 . Since the pressure relief feature  42  defines a circle, the venting radius  90  is constant around the entire longitudinal axis  50 . While the venting radius  90  is shown being less than about 18% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . In the present embodiment, the venting radius  90  is constant around the longitudinal axis  50  since the first venting feature  76  defines the shape of a circle. 
     Referring to  FIG.  8   , the lid or base  40  and the pressure relief feature  42  are similar to the lid or base  40  and pressure relief feature  42  of  FIGS.  7  and  9    but differ in that the pressure relief feature  42  does not extend entirely around the central longitudinal axis  50 . As noted above, the pressure relief feature  42  of  FIG.  8    is disposed about 275° around the longitudinal axis. In some embodiments, the pressure relief feature  42  may be disposed between about 150° and about 350°, or about 200 and about 325°, or about 250° and about 300°, or about 260° and about 290° about the central longitudinal axis  50 . Still referring to  FIG.  8   , venting ramps  92  are disposed at the beginning and end points of the pressure relief feature  42 , which are shown in the form of gradual tapered portions at distal ends of the pressure relief feature  42 . The venting ramps  92  are generally trapezoidal in shape when viewed from below, but the venting ramps  92  may define other shapes such as triangles, squares, rectangles, or another polygonal shape. The venting ramps  92  may be formed through a manufacturing process, and may define various different taper angles depending upon the notch depth and configuration of the pressure relief feature  42 . 
     Referring now to  FIGS.  10  and  12   , the lid or base  40  and the pressure relief feature  42  are radially symmetric about the central longitudinal axis  50  since the pressure relief feature  42  extends entirely around the longitudinal axis  50 . The longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, being measured normal from the longitudinal axis  50  to an outermost location of the pressure relief feature  42 . Since the pressure relief feature  42  defines a circle, the venting radius  90  is constant around the entire central longitudinal axis  50 . While the venting radius  90  is shown being less than about 22% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . In the present embodiment, the venting radius  90  is constant around the central longitudinal axis  50  since the first venting feature  76  defines the shape of a circle. 
     Referring to  FIG.  11   , the lid or base  40  and the pressure relief feature  42  are similar to the lid or base  40  and pressure relief feature  42  of  FIGS.  10  and  12    but differ in that the pressure relief feature  42  does not extend entirely around the central longitudinal axis  50 . As noted above, the pressure relief feature  42  of  FIG.  11    is disposed about 275° around the longitudinal axis. In some embodiments, the pressure relief feature  42  may be disposed between about 150° and about 350°, or about 200 and about 325°, or about 250° and about 300°, or about 260° and about 290° about the central longitudinal axis  50 . Still referring to  FIG.  11   , the venting ramps  92  are disposed at the beginning and end points of the pressure relief feature  42 , which are shown in the form of gradual tapered portions at distal ends of the pressure relief feature  42 . The venting ramps  92  are generally trapezoidal in shape when viewed from below, but the venting ramps  92  may define other shapes such as triangles, squares, rectangles, or another polygonal shape. The venting ramps  92  may be formed through a manufacturing process and may define various different taper angles depending upon the notch depth and configuration of the pressure relief feature  42 . 
     Referring to  FIGS.  13  and  14   , another embodiment of the pressure relief feature  42  is shown. The pressure relief feature  42  includes the first venting feature  76 . The first venting feature  76  of the present embodiment is an s-shaped venting feature and includes a first or lower portion  94  and a second or upper portion  96  that intersect at an inflection point. The first portion  94  and the second portion  96  define lower and upper lobes of the s-shape, i.e., a spline-shaped and continuous segment. In the present embodiment, the central longitudinal axis  50  extends through the inflection point between the first portion  94  and the second portion  96 . However, in other embodiments, the inflection point of the first venting feature  76  may be offset from the central longitudinal axis  50 . In some embodiments, the first portion  94  and the second portion  96  may be of different sizes, may define different radii of curvature, or may extend varying distances around the longitudinal axis  50 . Referring to  FIG.  14   , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . In the present embodiment, the venting radius  90  extends through points along first venting feature  76  that are farthest from the central longitudinal axis  50 , which are spaced from distal ends of the first venting feature  76 . 
     Referring now to  FIGS.  15  and  16   , another embodiment of the pressure relief feature  42  is shown. The pressure relief feature  42  includes the first venting feature  76 . The first venting feature  76  of the present embodiment is a v-shaped venting feature, and includes a first or left portion  94 , a second or intermediate portion  96 , and a third or right portion  98 . The left portion  94  is a mirror image of the right portion  98  of the v-shaped venting feature, and the left portion  94  is connected with the right portion  98  via the intermediate portion  96 . A first plane or line  100  extends through the left portion  94  and the longitudinal axis  50 , and a second plane or line  102  extends through the right portion  98  and the longitudinal axis  50 . The first plane  100  and the second plane  102  intersect at the longitudinal axis  50 . In the present embodiment, the first plane  100  extends along an entire length of the first portion  94 , and the second plane  102  extends along an entire length of the third portion  98 . In some embodiments, a third venting feature  104  (see  FIG.  21   ) may also be provided on either side of the first and second venting features  76 ,  78 . 
     Still referring to  FIGS.  15  and  16   , the longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, being measured normal from the longitudinal axis  50  to an outermost location of the pressure relief feature  42  taken along the first line  100  or the second line  102 . In the present embodiment, the venting radius  90  extends to a radially outermost location of the first venting feature  76 . Thus, the venting radius  90  in the present embodiment extends to a farthest extent of the first portion  94  or the third portion  98 . While the venting radius  90  is shown being less than about 22% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . 
     Still further, a minimum venting distance  106  is shown in  FIG.  16   , which defines the closest distance between the longitudinal axis  50  and the pressure relief feature  42 . The minimum venting distance  106  may be less than about 50% of the venting radius  90 , less than about 40% of the venting radius  90 , less than about 30% of the venting radius  90 , less than about 20% of the venting radius  90 , or less than about 15% of the venting radius  90 , or less than about 10% of the venting radius  90 , or less than about 7% of the venting radius  90 , or less than about 5% of the venting radius  90 . Still further, the minimum venting distance  106  may be less than about 10% of the total radius  86 , or less than about 8% of the total radius  86 , or less than about 6% of the total radius  86 , or less than about 4% of the total radius  86 , or less than about 2% of the total radius  86 . The minimum venting distance  106  may also be greater than about 1% of the venting radius  90 , or greater than about 1% of the total radius  86 . 
     Referring to  FIG.  17   , a pressure relief feature  42  is depicted that is similar to the pressure relief feature  42  of  FIGS.  15  and  16   , but defines a larger minimum venting distance  106 , and a larger angle ⊖ between the first line  100  and the second line  102 . The angle ⊖ of  FIG.  17    is about 122°, and the angle ⊖ of  FIG.  16    is about 46°. In some embodiments, the angle ⊖ may be between about 20° and about 160°, or between about 30° and 150°, or between about 40° and about 140°, or between about 50° and 130°, or between about 60° and 120°. Further, the minimum venting distance  106  of  FIG.  17    is about 70% of the venting radius  90 , while the minimum venting distance  106  of  FIG.  16    is about 20% of the venting radius  90 . In some embodiments, the minimum venting distance is greater than about 10%, or about 20%, or about 30%, or about 40% or about 50%, or about 60%, or about 70% of the venting radius  90 , expressed as a percentage. The first plane or line  100  extends through the first portion  94 , and the second plane or line  102  extends through the right portion  98 , but neither of the lines  100 ,  102  extend through the longitudinal axis  50 . 
     Referring now to  FIGS.  18  and  19   , another embodiment of the pressure relief feature  42  is shown. The pressure relief feature  42  includes the first venting feature  76  and a second venting feature  78  that is a mirror image of the first venting feature  76 . Both the first and second venting features  76 ,  78  include the first or left portion  94 , the second or intermediate portion, and the third or right portion  98 . The left portion  94  is a mirror image of the right portion  98  of the first and second venting features  76 ,  78 , and the left portion  94  is connected with the right portion  98  via the intermediate portion  96 . The first plane or line  100  extends through both of the left portions  94  and the longitudinal axis  50 , and the second plane or line  102  extends through both of the right portions  98  and the longitudinal axis  50 . The first plane  100  and the second plane  102  intersect at the longitudinal axis  50 . In the present embodiment, the first plane  100  extends along an entire length of the first portions  94 , and the second plane  102  extends along an entire length of the third portions  98 . The first plane  100  also extends through the first venting feature  76  and the second venting feature  78 , and the second plane  102  extends through the first venting feature  76  and the second venting feature  78 . 
     Still referring to  FIGS.  18  and  19   , the longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, being measured normal from the longitudinal axis  50  to an outermost location of the pressure relief feature  42 . In the present embodiment, the venting radius  90  extends to a radially outermost location of the first venting feature  76 . Thus, the venting radius  90  in the present embodiment extends to a farthest extent of the first portion  94  or the third portion  98  of the venting features  76 ,  78 . While the venting radius  90  is shown being less than about 22% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . 
     Still further, the minimum venting distance  106  is shown in  FIG.  19   , which defines the closest distance between the longitudinal axis  50  and the pressure relief feature  42 . The minimum venting distance  106  may be less than about 20% of the venting radius  90 , or less than about 15% of the venting radius  90 , or less than about 10% of the venting radius  90 , or less than about 7% of the venting radius  90 , or less than about 5% of the venting radius  90 . Still further, the minimum venting distance  106  may be less than about 10% of the total radius  86 , or less than about 8% of the total radius  86 , or less than about 6% of the total radius  86 , or less than about 4% of the total radius  86 , or less than about 2% of the total radius  86 . The minimum venting distance  106  may also be greater than about 1% of the venting radius  90 , or greater than about 1% of the total radius  86 . 
     Referring to  FIG.  20   , a pressure relief feature  42  is depicted that is similar to the pressure relief feature  42  of  FIGS.  18  and  19   , but defines a larger minimum venting distance  106 , and a larger angle ⊖ between the first line  100  and the second line  102 . The angle ⊖ of  FIG.  20    is about 122°, and the angle ⊖ of  FIG.  19    is about 46°. In some embodiments, the angle ⊖ may be between about 20° and about 160°, or between about 30° and 150°, or between about 40° and about 140°, or between about 50° and 130°, or between about 60° and 120°. Further, the minimum venting distance  106  of  FIG.  17    is about 70% of the venting radius  90 , while the minimum venting distance  106  of  FIG.  16    is about 20% of the venting radius  90 . In some embodiments, the minimum venting distance is greater than about 10%, or about 20%, or about 30%, or about 40% or about 50%, or about 60%, or about 70% of the venting radius  90 , expressed as a percentage. The first plane or line  100  extends through the first portion  94 , and the second plane or line  102  extends through the right portion  98 , but neither of the lines  100 ,  102  extend through the longitudinal axis  50 . Further, neither of the lines  100 ,  102  extend through both the first venting feature  76  and the second venting feature  78 . 
     Referring now to  FIGS.  21  and  22   , another embodiment of the pressure relief feature  42  is shown. The pressure relief feature  42  includes the first venting feature  76 , the second venting feature  78 , and the third venting feature  104 . The venting features  76 ,  78 ,  104  include the first or left portion  94 , the second or intermediate portion  96 , and the third or right portion  98 . The left portions  94  are each a mirror image of the right portions  98  of the venting features  76 ,  78 ,  104 , and the left portions  94  are connected with the right portions  98  via the intermediate portion  96 . The first plane or line  100  extends through the left portion  94  of the first venting feature  76  and the longitudinal axis  50 , and the second plane or line  102  extends through the right portion  98  of the first venting feature  76  and the longitudinal axis  50 . The first plane  100  and the second plane  102  intersect at the longitudinal axis  50 . In the present embodiment, the first plane  100  extends along an entire length of the first portion  94 , and the second plane  102  extends along an entire length of the third portion  98 . Further, the first plane  100  and the second plane  102  only extend through the left portion  94  and the right portion  98  of the first venting feature  76 , but do not extend through the respective portions of the second venting feature  78  or the third venting feature  104 . 
     Still referring to  FIGS.  21  and  22   , the longitudinal axis  50  is shown extending centrally through the lid or base  40 , and the line segment or total radius  86  of the lid or base  40  is shown, being measured normal from the longitudinal axis  50  to the outermost surface  88  of the lid or base  40 . Further, the venting radius  90  is shown, being measured normal from the longitudinal axis  50  to a location of the pressure relief feature  42 . In the present embodiment, the venting radius  90  extends to a radially outermost location of the first venting feature  76 . Thus, the venting radius  90  in the present embodiment extends to a farthest extent of the first portion  94  or the third portion  98 . While the venting radius  90  is shown being less than about 22% of the total radius  86  from the longitudinal axis  50 , the venting radius  90  may be less than about 25% of the total radius  86  from the longitudinal axis  50 , or less than about 20% of the total radius  86  from the longitudinal axis  50 , or less than about 15% of the total radius  86  from the longitudinal axis  50 , or less than about 10% of the total radius  86  from the longitudinal axis  50 . The embodiment of  FIGS.  21  and  22    may also include the minimum venting distance  106  as described above, which may have parameters that are similar to those described above with respect to  FIGS.  15  and  16   , and  FIGS.  18  and  19   . 
     Referring to  FIG.  23   , a pressure relief feature  42  is depicted that is similar to the pressure relief feature  42  of  FIGS.  21  and  22   , but defines a larger minimum venting distance  106 , and a larger angle ⊖ between the first line  100  and the second line  102 . The angle ⊖ of  FIG.  20    is about 122°, and the angle ⊖ of  FIG.  19    is about 46°. In some embodiments, the angle ⊖ may be between about 20° and about 160°, or between about 30° and 150°, or between about 40° and about 140°, or between about 50° and 130°, or between about 60° and 120°. Further, the minimum venting distance  106  of  FIG.  17    is about 70% of the venting radius  90 , while the minimum venting distance  106  of  FIG.  16    is about 20% of the venting radius  90 . In some embodiments, the minimum venting distance is greater than about 10%, or about 20%, or about 30%, or about 40% or about 50%, or about 60%, or about 70% of the venting radius  90 , expressed as a percentage. The first plane or line  100  extends through the first portion  94 , and the second plane or line  102  extends through the right portion  98 , but neither of the lines  100 ,  102  extend through the longitudinal axis  50 . Further, the first line  100  extends only through the first venting feature  76  and the second venting feature  78 , while the second line  102  extends only through the first venting feature  76  and the third venting feature  104 . 
     While the aforementioned embodiments of  FIGS.  1 - 23    depict the pressure relief feature  42  disposed along the central wall  48  of the lid or base  40 , it is contemplated that the pressure relief feature  42  may be provided along the intermediate wall  46  or the outer wall  44  in alternative embodiments. While the lid or base  40  is described and shown in the various figures as having bottom and top surfaces or sides  70 ,  72 , it should be understood that the lid or base  40  may be disposed with either of its top side  72  and bottom side  70  in an upward-facing or downward-facing configuration and need not be limited to the orientations depicted within the figures. The lid or base  40  disclosed herein may be adapted to be connected to the upper end of the sidewall of a canister or container, as described above. Further the minimum or inner venting radius  90  of any of the pressure relief features  42  of  FIGS.  1 - 16    may be greater than about 5% of the total radius  86  from the longitudinal axis  50 , or greater than about 10% of the total radius  86  from the longitudinal axis  50 , or greater than about 15% of the total radius  86  from the longitudinal axis  50 , or greater than about 20% of the total radius  86  from the longitudinal axis  50 . 
     Referring to  FIGS.  24 A- 27 B , any of the thinned regions  80  discussed above may have a region thickness  82  that is less than about 10% of the central wall thickness  68 , or a region thickness  82  that is less than about 15% of the central wall thickness  68 , or a region thickness  82  that is less than about 25% of the central wall thickness  68 , or a region thickness  82  that is less than about 30% of the central wall thickness  68 , or a region thickness  82  that is less than about 35% of the central wall thickness  68 , or a region thickness  82  that is less than about 40% of the central wall thickness  68 . The region thickness  82  may be adjusted based on a desired performance of the pressure relief feature  42 . 
     Still referring to  FIGS.  24 A- 27 B , various profiles of the pressure relief features  42  are shown, which are configured to provide for varying, controlled, and targeted pressure relief when a maximum pressure threshold has been achieved within a container or canister to which the lid or base  40  has been applied. More particularly, the various profiles of the pressure relief feature  42  define notches that have been cut out or otherwise removed from the central wall  48 . A first or trapezoidal profile  110  is shown in  FIGS.  17 A and  17 B , a second or triangular profile  112  is shown in  FIGS.  18 A and  18 B , a third or rectangular profile  114  is shown in  FIGS.  19 A and  19 B , and a fourth or rounded profile  116  is shown in  FIGS.  20 A and  20 B . Referring to  FIGS.  17 A and  17 B , the trapezoidal profile  110  is shown, which includes a first leg or segment  120 , a second leg or segment  122 , and a third leg or segment  124  that combine to define the trapezoidal profile  110 . The thinned region  80  is also shown in more detail and is disposed between the inner surface  70  and the outer surface  72  of the central wall  48 . The thinned region  80  creates a membrane or rupture wall that is configured to rupture at a particular pressure threshold. 
     Referring now to  FIGS.  18 A and  18 B , a second or triangular profile  112  is shown, which includes the first leg or segment  120  and the second leg or segment  122 , which intersect at a vertex  128 . The thinned region  80  of the second profile  112  is defined between the outer surface  72  of the central wall  48  and the vertex  128 . Referring to  FIGS.  19 A and  19 B , the third or rectangular profile  114  is shown, which includes the first leg or segment  120 , the second leg or segment  122 , and the third leg or segment  124 . The first segment  120  and the third segment  124  intersect to define a right angle, and the second segment  122  and the third segment  124  intersect to define a right angle. The thinned region  80  of the third profile  114  is defined between the outer surface  72  of the central wall  48  and the third segment  124 . Referring to  FIGS.  20 A and  20 B , the fourth or rounded profile  116  is shown, which includes the first segment  120 , the second segment  122 , and the third segment  124 . The first segment  120  and the second segment  122  are generally straight, while the third segment  124  is generally rounded or semi-circular. The thinned region  80  further comprises a width  130 . The thinned region  80  defines a constant thickness along the width  130  of the third profile  114 , but the thickness of the thinned region  80  of the first profile  110 , the second profile  112 , and the fourth profile  116  varies along the widths  130  thereof due to the geometry of the various profiles. 
     While the lid or base  40  of the present disclosure is configured for attachment to a cylindrical container, it is contemplated that the lid or base  40  may take varying forms, and may have a cross-section that is prismatic, rectangular, or cubic. To that end, the line segment  86  as disclosed herein may reference the distance from the longitudinal axis  50  of the lid or base  40  to the outermost surface  88  of the outer wall  44  of the lid or base  40 . In embodiments that include a prismatic, rectangular, or cubic cross-section, the length of the line segment  86  may vary about the longitudinal axis  50 , while in the present embodiment, the radius  86  is identical about the longitudinal axis  50  since the lid or base  40  defines a circular cross section. While the lid or base  40  of the present embodiment is radially symmetric, prismatic, rectangular, or cubic containers may be symmetric about one, two, three, four, or more planes that intersect the longitudinal axis  50 . 
     While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front and the like may be used to describe embodiments of the present disclosure, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like. Variations and modifications of the foregoing are within the scope of the present disclosure. It is understood that the embodiments disclosed and defined herein extend to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present disclosure. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. 
     It will be appreciated by those skilled in the art that while the embodiments of the present disclosure have been described in connection with particular embodiments and examples, the disclosure is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples, and uses are intended to be encompassed by the claims attached hereto. Various features and advantages of the invention are set forth in the following claims.