Patent Publication Number: US-2022216566-A1

Title: Breathable overpressure assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Application Ser. No. 63/134,533, filed Jan. 6, 2021, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This disclosure relates generally to overpressure assemblies and, more particularly, to overpressure assemblies for sealed enclosures. 
     BACKGROUND 
     Many systems and vessels are sealed to prevent exposure of the contents stored therein, as well as to contain the discharge of chemical reactions that occur within the vessels. Example vessels include batteries such as lithium-ion batteries, which experience exothermic discharge reactions that produce heat within the sealed enclosures of the batteries. 
     Systems and vessels that are sealed may be subjected to internal pressure fluctuations. For example, changes in internal or external temperatures, altitude, humidity, and atmospheric pressure can cause the internal pressure of a sealed enclosure to increase or decrease. Breathable vents may be integrated into the design of a sealed enclosure to regulate the difference in pressure inside the enclosure relative to its immediate environment, while inhibiting contaminants and moisture from entering the sealed enclosure. 
     In some instances, the internal pressure of a sealed system or vessel may increase or decrease significantly, and sometimes in a very rapid manner such that the breathable vents are unable to equalize the pressure within the system. Thus, many sealed systems are provided with overpressure devices such as a rupture disc or explosion relief vent or panel. Example overpressure devices are described in U.S. Pat. Nos. 8,622,071, 8,733,383, 8,807,154, 9,677,391, and 10,228,069, the contents of which are incorporated by reference herein. 
     A rupture disc, also known as a pressure safety disc, burst disc, bursting disc, or burst diaphragm, is a non-reclosing pressure relief device that protects a sealed vessel, equipment, or piping system from over-pressurization or potentially damaging vacuum conditions. A rupture disc is a flat or shaped (e.g., domed) sheet of material and is designed to rupture at a predetermined pressure. 
     Rupture discs may be forward-acting (e.g., tension-loaded) or reverse-acting or reverse-buckling (e.g., compression-loaded). In forward-acting rupture discs, internal pressure loads are applied to the concave side of the rupture disc, thereby stretching the domed portion of the rupture disc until the tensile forces exceed the ultimate tensile stress of the material and the rupture disc bursts. Flat rupture discs may also be utilized as forward-acting rupture discs. In reverse-acting rupture disc, the internal pressure of the sealed enclosure pushes on the convex side of the rupture disc. When the pressure threshold is met, the dome of the rupture disc bursts. 
     Explosion relief vents or panels function similarly to rupture discs, and are typically used in larger sealed enclosures such as cargo containers and energy storage systems. Like rupture discs, explosion relief panels may be forward-acting (e.g., tension-loaded) or reverse-acting or reverse-buckling (e.g., compression-loaded). Explosion relief panels are often designed to achieve industry standards, such as National Fire Protection Agency (NFPA) 68, NFPA 885, and the ATEX directives. 
     In many sealed devices and systems, vents and rupture discs are externally-facing components that are exposed to ambient conditions. Many such devices and systems in which both vents and rupture discs are incorporated, such as batteries and similar devices and systems, include various internal components within a housing such as cathodes, anodes, electrolytes, separators, internal cells (e.g., cases or pouches), and associated wiring. Devices such as batteries often also include externally-facing components secured to the housing such as terminals (e.g., positive and negative terminals), dedicated vents or valves, and dedicated pressure relief devices. Due at least in part to these internal and externally-facing components, such devices and systems often have limited available packaging space or “footprint” for externally-facing components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of a breathable overpressure assembly showing a concave surface of a central rupture portion of a domed rupture disc member and vent openings having breathable membranes of the breathable overpressure assembly. 
         FIG. 2  is a rear perspective view of the breathable overpressure assembly showing a gasket extending about a convex surface of the central rupture portion of the domed rupture disc member, and shanks of fasteners extending through fastener openings of the breathable overpressure assembly. 
         FIG. 3  is a front elevation view of the breathable overpressure assembly showing breathable membranes covering vent openings of an outlet ring of the breathable overpressure assembly. 
         FIG. 4  is a rear elevation view of the breathable overpressure assembly showing the breathable membranes covering vent openings of a gasket of the breathable overpressure assembly. 
         FIG. 5  is an exploded view of the breathable overpressure assembly showing the breathable membranes between the gasket and a peripheral flange of the rupture disc member. 
         FIG. 6A  is an elevation view of the breathable membrane showing an annular adhesive layer on a membrane layer. 
         FIG. 6B  is cross-sectional view taken along line  6 B- 6 B of  FIG. 6A  showing the annular adhesive layer and an exposed membrane layer portion of the membrane layer. 
         FIG. 7  is a perspective view of a battery having the breathable overpressure assembly of  FIG. 1  secured to a side wall of a battery housing with the battery vented through the breathable membranes of the breathable overpressure assembly. 
         FIG. 8  is an outside view of the breathable overpressure assembly installed on the battery of  FIG. 7  showing the breathable membranes covering the vent openings of the outlet ring and the concave surface of the rupture disc member of the breathable overpressure assembly. 
         FIG. 9  is an inside view of the breathable overpressure assembly installed on the battery showing breathable membranes covering vent openings through the side wall of the battery housing. 
         FIG. 10A  is a cross-sectional view taken along line  10 - 10  of  FIG. 9  showing the fasteners received through fastener openings of the outlet ring. 
         FIG. 10B  is an enlarged view of the cross-section of  FIG. 10A  showing a conical head of a fastener received in a tapered fastener hole of the outlet ring. 
         FIG. 11A  is a cross-sectional view taken along line  11 A- 11 A of  FIG. 9  showing the breathable membranes aligned with vent openings of the side wall of the battery housing. 
         FIG. 11B  is an enlarged view of the cross-section of  FIG. 11A  schematically depicting a breathable membrane permitting the ingress and egress of gas through the side wall of the battery housing, and inhibiting the ingress of dust and other small particles into the interior of the battery. 
         FIG. 12  is a partially exploded view of a second breathable overpressure assembly having a breathable membrane disposed on an outer surface of a rupture disc member between the rupture disc member and the outlet ring. 
         FIG. 13  is an exploded view of a third breathable overpressure assembly having a single annular breathable membrane that covers all the vent openings of the rupture disc member, outlet ring, and gasket, and having fastener openings that are aligned with fastener openings of the rupture disc member, outlet ring, and gasket. 
         FIG. 14  is a front perspective view of a fourth breathable overpressure assembly showing vents extending through a central rupture portion of a rupture disc member. 
         FIG. 15  is a rear perspective view of the fourth breathable overpressure assembly of  FIG. 14  showing a breathable membrane covering the vents of the central rupture portion of the rupture disc member, and a mesh back plate that provides support for the central rupture portion. 
         FIG. 16  is a schematic exploded side elevation view of the fourth breathable overpressure assembly of  FIGS. 14 and 15  showing the outer mounting ring, rupture disc member, breathable membrane, mesh back plate, and inner gasket. 
         FIG. 17  is a front elevation view of a fifth breathable overpressure assembly having a generally planar, rectangular configuration and breathable membranes covering vent openings in a peripheral flange portion extending about a flat central rupture portion of a rupture panel member. 
         FIG. 18  is a front elevation view of a sixth breathable overpressure assembly having breathable membranes covering vent openings in a peripheral flange portion extending about a domed central rupture portion of a rupture member. 
         FIG. 19  is a side elevation view of the sixth breathable overpressure assembly of  FIG. 18  showing the domed central rupture portion. 
         FIG. 20  is a front elevation view of a seventh breathable overpressure assembly having a circular score in a central rupture portion of a rupture disc member, and breathable membranes covering vent openings in a peripheral flange portion of the rupture disc member. 
         FIG. 21  is a schematic exploded side elevation view of the seventh breathable overpressure assembly of  FIG. 20  showing an outer domed rupture disc member, protective covers, a sealing membrane between the protective covers, and an inner metallic backing support member. 
         FIG. 22  is a front elevation view of an eighth breathable overpressure assembly having a radial scores in a central rupture portion, and breathable membranes covering vent openings in a peripheral flange portion. 
         FIG. 23  is a schematic exploded side elevation view of the eighth breathable overpressure assembly of  FIG. 22  showing a generally planar outer rupture disc member, protective covers, a sealing membrane between the protective covers, and an inner metallic backing support. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
     In one form, described herein is a breathable overpressure assembly or breathable rupture assembly for being mounted over an opening in a sealed container, sealed vessel, or other sealed enclosure. As used herein, a “sealed” enclosure keeps moisture, liquid, and dust or other small particles from entering an interior of the enclosure. A sealed enclosure may have an Ingress Protection (IP) rating, for example, of IP 64, IP 67, or IP 68. 
     The breathable overpressure assembly includes a rupture member having a central rupture portion and a peripheral flange that extends about the central rupture portion. The central rupture portion is sized to cover the opening in the sealed container and is configured to rupture at a predetermined pressure at an interior container side of the rupture member. The breathable overpressure assembly further includes at least one vent opening that extends through at least one of the central rupture portion and the peripheral flange. The breathable overpressure assembly further includes a breathable membrane that covers the vent opening for allowing the passage of gas through the at least one of the central rupture portion and the peripheral flange via the breathable membrane. 
     Also described herein is a breathable overpressure assembly that includes a rupture member, at least one breathable membrane, and a mounting ring. The rupture member includes a central rupture portion and a peripheral flange that extends about at least a portion of the central rupture portion. The peripheral flange includes a plurality of fastener openings and a plurality of vent openings that extend therethrough. The fastener openings and vent openings are formed in so as to alternate along the peripheral flange. The breathable membrane covers at least one vent opening of the rupture member. The mounting ring includes a plurality of fastener openings and a plurality of vent openings extending therethrough. The rupture member, breathable membrane, and mounting ring are arranged such that the plurality of fastener openings of the mounting ring are generally aligned with the plurality of fastener openings of the rupture member, and the plurality of vent openings of the mounting ring are generally aligned with the plurality of vent openings of the rupture member and the breathable membrane. 
     Also described herein is a sealed assembly that includes a housing and a breathable overpressure assembly secured to the housing. The breathable overpressure assembly includes a rupture member having a central rupture portion and a peripheral flange extending about at least a portion of a periphery of the central rupture portion. The peripheral flange is configured for being mounted to the housing. The peripheral flange includes at least one vent opening extending therethrough. The rupture member is configured to rupture at a predetermined rupture pressure at an interior container side of the rupture member. The breathable overpressure assembly further includes a breathable membrane that covers the vent opening. The breathable membrane is configured to regulate an internal pressure within an interior of the housing relative to an external pressure outside of the housing by allowing the passage of gas therethrough and keeping small particles outside of the housing from passing through the breathable member and entering the housing interior. 
     The breathable overpressure assembly is used as a pressure relief device for various vessels, conduit, and other sealed systems, and may be used in a variety of applications, such as in aerospace, agriculture, aviation, chemical, defense, food processing, medical, military, nuclear, oil field, petrochemical, pharmaceutical, and railroad applications. The breathable overpressure assembly may be used as a primary or secondary pressure relief device. 
     The breathable overpressure assemblies described herein may be referred to as integrated breathable overpressure assemblies in that they function to both provide constant pressure regulation (e.g., equalization) through the breathable membranes and instantaneous pressure relief (via rupture or bursting of the rupture member) in the event of sudden over- or under-pressurization. Such integrated breathable overpressure assemblies provide pressure regulation capabilities lacking in conventional rupture members, and provide instantaneous pressure relief lacking in conventional venting features. 
     The shape, size, quantity, and arrangement of the vent openings and breathable membranes described herein can be configured to achieve desired pressure regulations that may be necessitated, for example, due to changes in ambient or atmospheric conditions such as altitude, humidity, temperature, and atmospheric pressure. 
     The breathable overpressure assemblies described herein may be utilized in a variety of applications. For example, aircrafts may include sealed devices that are subject to internal pressure fluctuations during ascent and/or descent events. A battery installed in a fighter aircraft, for example, may experience a gradual internal pressure change during an ascent event, and may experience an extreme pressure change during a descent event (e.g., from approximately 50,000 feet to ground level in less than one minute). Furthermore, batteries within vehicles that operate in extreme weather conditions (e.g., temperatures ranging from approximately −40° C. to approximately 70° C.), such as many vehicles used by the military, may experience gradual or rapid internal pressure changes. As such, the breathable overpressure assemblies described herein are particularly suitable for use with batteries deployed in military aircraft and vehicles. The breathable membranes of the breathable overpressure assemblies described herein may provide constant gradual pressure regulation, while the rupture members of the breathable overpressure assemblies provide instantaneous pressure relief in the event of sudden over-pressurization. 
     The breathable overpressure assemblies described herein may also regulate pressure changes that occur due to chemical reactions within sealed batteries. For example, lithium-ion batteries include cells that generate heat during chemical reactions of the electrodes (e.g., cathodes and anodes) within the cells. This generation of heat increases the internal pressure of the battery. The breathable membranes of the breathable overpressure assembly permit gradual release of the internal pressure to equalize the internal and external pressures. 
     The breathable overpressure assemblies described herein may also account for degradation of a battery such as a lithium-ion battery. For example, when cells of a battery are exposed to excessive heat or overvoltage, a resulting pressure increase may cause off-gassing of one or more gases such as carbon monoxide, methane, ethane, ethylene, for example. The membranes of the breathable overpressure assembly permit release of such gases to deter further damage to the degrading cells. Continued exposure of the cells to excessive heat or overvoltage may result in a thermal runaway or “flameout” condition in which flammable gases may by ignited by the battery&#39;s high temperature, resulting in a fire. The rupture member of the breathable overpressure assembly is configured to rupture to permit controlled release of the ignited gases. For example, and as discussed in greater detail below, an exhaust hose may be connected to the battery at the breathable overpressure assembly over the membranes to provide controlled direction of vented and ignited gases away from the battery (e.g., to the outside atmosphere). 
     Referring now to  FIGS. 1-5 , a breathable overpressure assembly such as breathable rupture assembly  10  is shown. The breathable rupture assembly  10  includes a rupture diaphragm or disc  12  that is configured to rupture at a predetermine rupture pressure at an interior container side of the rupture disc  12 . The rupture disc  12  may be formed, for example, of stainless steel, hastelloy, Inconel, nickel, graphite, or other suitable material. The breathable rupture assembly  10  also includes one or more breathable membranes  14  that are secured to the rupture disc  12 , as discussed in greater detail below. 
     The rupture disc  12  includes a central portion  20  that is configured to rupture (e.g., within milliseconds or microseconds) due to an increase or decrease in system pressure at an interior container side of the rupture disc  12 . The central portion  20  may include one or more preformed weaknesses or frangible portions, such as recesses, perforations, scores, or score lines, in a surface of the central portion  20  to form fault lines along which the central rupture portion  20  is intended to rupture or burst. For example, a cross-scored central portion (see  FIG. 22 ) forms petals that bend outwardly upon rupture of the central portion. A central portion having a circular score  16  (see  FIG. 20 ) extending about the central portion may form a circular tab that bends outwardly upon rupture of the central portion. The thickness and diameter of the material of the central portion  20  may be selected to achieve a desired rupture pressure threshold. A rupture pressure threshold may be, for example, approximately 4 pounds per square inch (psi), 5 psi, 15 psi, or 100 psi. 
     In one approach shown, the central rupture portion  20  is a central bulged or dome portion having a concave surface  22  and an opposing convex surface  24 . In this way, the rupture disc  12  may be a forward-acting (tension loaded) rupture disc or a reverse-acting (compression loaded) rupture disc. More particularly, when the breathable rupture assembly  10  is secured to a sealed vessel such that the concave surface  22  of the rupture disc  12  is exposed to the internal pressure of the vessel, the rupture disc  12  is a forward-acting rupture disc. An increase in internal pressure against the concave surface  22  causes the central portion  20  to stretch until the internal pressure reaches the rupture pressure threshold, at which time the tensile forces on the central portion  20  exceed the ultimate tensile stress of the material and the rupture disc  12  bursts along the score. When breathable rupture assembly  10  is secured to a sealed vessel such that the convex surface  24  of the rupture disc  12  is exposed to the internal pressure of the vessel, the rupture disc  12  is a reverse-acting rupture disc. An increase in internal pressure against the convex surface  24  causes the central portion  20  to compress until the internal pressure reaches the rupture pressure threshold, at which time the compressive forces on the central portion  20  causes the rupture disc  12  to collapse and burst along the score. In another approach, the central portion  20  is a flat central portion, and the rupture disc  12  may be a forward-acting rupture disc. 
     As shown in  FIG. 5 , the rupture disc  12  further includes a peripheral flange portion  30  that extends about a periphery  38  of the central bulged portion  20 . The peripheral flange portion  30  can be an annular flange that extends about the entire circumference of the central bulged portion  20  such that the peripheral flange portion  30  entirely surrounds the central bulged portion  20 . In another approach, the peripheral flange portion  30  extends about less than the entire circumference of central bulged portion  20 . In still another approach, the rupture disc  12  includes more than one annular flange that each extend about less than the entire circumference of central bulged portion  20 . 
     The peripheral flange portion  30  includes apertures or through openings that extend through the entire thickness of the peripheral flange portion  30  to open at both flat inner and outer surfaces  31 ,  33  thereof. More particularly, the peripheral flange portion  30  includes one or more vent openings  32  and one or more fastener openings  34 . The fastener openings  34  are sized to receive fasteners  36  therethrough, as discussed below. 
     The breathable membranes  14  are sized to cover the vent openings  32 , and may be shaped to correspond to the shape of the breathable membranes  14 . In the approach shown, the breathable membranes  14  are circular membranes, and the vent openings  32  are likewise circular openings with the breathable membranes  14  having a slightly larger diameter than the vent openings  32  so that a breathable membrane  14  can be secured over a corresponding vent opening  32  such that it entirely covers the vent opening  32 . In other approaches, the breathable membranes  14  and the vent openings  32  also have the same configuration but the configuration is other than circular, such as square, oval, or bean-shaped. 
     The breathable rupture assembly  10  of  FIGS. 1-5  includes four vent openings  32  and six fastener openings  34 . The vent openings  32  include a first pair of vent openings  32  at one half of the breathable rupture assembly  10  and a second pair of vent openings  32  at the other half of the breathable rupture assembly  10 . Each vent opening  32  is positioned between two fastener openings  34 . The number and size of the vent openings  32  may be selected to achieve desired venting. For increased venting, a breathable rupture assembly  10  having a larger total area of vent openings  32  may be provided by increasing the number and/or size of the vent openings  32 . For less venting, a breathable rupture assembly  10  having less total area of vent openings  32  may be provided by decreasing the number and/or size of the vent openings  32 . In one example, the peripheral flange portion  30  may have one, two, or three vent openings that are larger than the vent openings  32  shown. In another example, the peripheral flange portion  30  may have ten or more vent openings that are smaller than the illustrated vent openings  32 . 
     The breathable rupture assembly  10  may also include a mounting ring or outlet ring  40  that is secured to the rupture disc  12 , as can be seen in  FIGS. 1 and 3 . For example, the outlet ring  40  may be fixedly secured to the peripheral flange portion  30  at the externally-facing (outer) surface of the rupture disc  12  via welding (e.g., spot welding) the outlet ring  40  to the peripheral flange portion  30  about the radially-outward peripheral surfaces of each of the outlet ring  40  and the peripheral flange portion  30 . Additionally or alternatively, mechanical fasteners and/or adhesive may be used to be fixedly secure the outlet ring  40  to the peripheral flange portion  30 . The outlet ring  40  includes vent openings  42  and fastener openings  44  that are generally aligned with vent openings  32  and fastener openings  34 , respectively, of the rupture disc  12 . As used herein, features (such as openings and breathable membranes) are “generally aligned” when an axis extends through the features in the airflow direction corresponding to arrow  114  of  FIG. 11B . Generally aligned openings may be coaxial or may have central axes that are offset as long as portions of the openings overlap. As illustrated, the central axes  43 ,  45  of the vent and fastener openings  42 ,  44 , respectively, are coaxial. 
     The outlet ring  40  further includes a large central opening  46 . The outlet ring  40  may further include features that facilitate rupture of the central bulged portion  20 . For example, the outlet ring  40  may include one or more protrusions or teeth  47  that extend radially inwardly into the large central opening  46 . The radially inner ends  47 A of the teeth  47  may be generally aligned with the score  16  of the central bulged portion  20 , which may be arranged radially inwardly along the central bulged portion  20  from the juncture with the peripheral flange portion  30 , to help propagate the rupture of the rupture disc  12  along the score  16 . In another approach, the outlet ring  40  may have an inner annular edge that is aligned with the score  16 . In the illustrated form, the outlet ring  40  including the teeth  47  may include a generally smooth folding edge  48  that does not include teeth  47  and that is positioned adjacent a portion of the central bulged portion  20  that is not scored. About which an unscored region of the ruptured central bulged portion  20  bends when it ruptures. Upon rupture of the rupture disc  12 , one or more portions the central bulged portion  20  bend along the folding edge  48  and protrude through the central opening  46 . Due at least in part to the central bulged portion  20  not being scored adjacent the folding edge  48 , the central bulged portion  20  does not separate from the rest of the rupture disc  12  and is retained along the folding edge  48 . 
     The outlet ring  40  may facilitate attachment of the breathable rupture assembly  10  to a sealed vessel such as a battery (as discussed in greater detail with respect to  FIGS. 7-11B ). For example, the fastener openings  44  may include frustoconical or countersunk portions for receiving tapered head portions  37  of fasteners  36 . As shown in  FIG. 10B , for example, the fastener openings  44  may include a tapering wall  44 A that tapers from a first diameter at an outer surface  41 A of the outlet ring  40  to a second, smaller diameter at an inner surface  41 B of the outlet ring  40 . The tapered configuration of the fastener openings  44  receives and seats a tapered head portion  37  of a fastener  36 . In this manner, the clamping forces on the peripheral flange portion  30  are directly applied by the inner flat surface  41 B of the outlet ring  40  in engagement with the outer surface of the peripheral flange portion  30  to avoid having more localized clamping forces directly applied by the heads  37  of the fasteners  36 . 
     The fastener openings  34  of the peripheral flange  30  of the rupture disc  12  may have a configuration different than the fastener openings  44  of the outlet ring  40 . For example, fastener openings  34  may have diameters that are smaller than the diameter of the fastener openings  44  at the outer surface  41 A of the outlet ring  40 . The diameter of a fastener opening  34  may be the same as the diameter of a fastener opening  44  at the inner surface  41 B of the outlet ring  40 . The fastener openings  34  may be generally cylindrical. 
     The breathable rupture assembly  10  may also include an annular gasket  50  that is disposed between the peripheral flange portion  30  at the inner side of the rupture disc  12  and an external surface of a sealed vessel such as the illustrated battery case  102  ( FIG. 7 ), discussed more fully hereinafter. The gasket  50  may be formed of a compressible, resilient material such as silicone. The gasket  50  forms a fluid-tight or substantially fluid-tight seal between the rupture disc  12  and the sealed vessel when the breathable rupture assembly  10  is installed on the sealed vessel. For example, as shown in  FIGS. 10A and 10B , when the breathable rupture assembly  10  is secured to a side wall  104  of a sealed vessel, fasteners  36  acts to compress the gasket  50  between the outlet ring  40  and the side wall  104 . Compression of the gasket  50  about the entire perimeter of the rupture disc  12  forms a seal with the vessel. 
     As also shown in  FIG. 10B , threaded fastener openings  104 A of the side wall  104  of the housing  102  have a diameter that is less than the diameter of the fastener openings  34 ,  44 , and  54  of the rupture disc  12 , outlet ring  40 , and gasket  50 , respectively, which, as discussed below, have a sufficient clearance to permit a threaded shank of a fastener  36  to pass therethrough. The threaded fastener openings  104 A of the side wall  104  are dimensioned to receive the threaded shank of a fastener  36  to threadingly engage the threaded shanks of fasteners  36 . 
     The gasket  50  includes one or more vent openings  52  and one or more fastener openings  54  that are aligned with vent openings  32  and fastener openings  34 , respectively, of the rupture disc  12  and of the outlet ring  40 . With reference to  FIGS. 11B and 12 , the vent openings  42  of the outlet ring  40 , the vent openings  32  of the rupture disc  12 , and the vent openings  52  of the gasket  50  may all have the same diameter. In this way, airflow through the vent openings  32 ,  42 ,  52  of passes through a constant diameter such that the airflow does not experience a change in cross-sectional area. The airflow therefore maintains a constant pressure as the airflow passes through the vent openings  32 ,  42 ,  52  of the breathable rupture assembly  10 . This configuration may allow for fine tuning of venting rates through the breathable membranes  14  at the vent openings  32 ,  42 ,  52 . 
     The gasket  50  further includes a large central opening  56  through which the central bulged portion  20  protrudes. In one approach, the gasket  50  is secured to the rupture disc  12  prior to the breathable rupture assembly  10  being installed on a sealed vessel. For example, the gasket  50  may have an adhesive (e.g., a pressure sensitive adhesive) applied at an outer rupture disc-facing surface  57  to adhere the gasket  50  to the rupture disc  12 . 
     Referring to  FIGS. 6A and 6B , the breathable membrane  14  is shown as a thin, circular membrane (although other shapes may be used). The breathable membrane  14  may include a membrane layer  60  and an adhesive layer  62  applied to the membrane layer  60  at an outer surface  60 ′ thereof. The membrane layer  60  is formed of an air-permeable material that allows for the ingress and egress of atmospheric gases therethrough, and regulates steady state pressure within a sealed enclosure. The membrane layer  60  may be formed, for example, of polytetrafluoroethylene (PTFE), polyethylene (PE), or ultra-high-molecular-weight polyethylene (UHMWPE, UHMW). The membrane layer  60  also has an Ingress Protection (IP) rating sufficient to inhibit passage of dust particles and moisture therethrough (e.g., IP 64, IP 67, or IP 68). The breathable membrane  14  may also have corrosion resistance properties (e.g., as described in ASTM B117-11). 
     The adhesive layer  62  may include a pressure-sensitive adhesive. The adhesive layer  62  is applied to less than the entire surface area of the membrane layer outer surface  60 ′ such that the membrane layer  60  includes an exposed membrane layer portion  60 ′ that is not coated by the adhesive layer  62 . For example, the adhesive layer  62  may be a ring-shaped adhesive layer  62  such that the exposed membrane layer portion  60 ′ is an inner circular exposed portion within the ring-shaped adhesive layer  62 . The ring-shaped adhesive layer  62  may have an inner diameter that is equal to or greater than a diameter of a vent opening  32  such that the exposed membrane layer portion  60 ′ has a diameter that is also equal to or greater than the diameter of the vent opening  32 . As such, the exposed membrane layer portion  60 ′ extends across and entirely covers the vent opening  32 . 
     In this way, the breathable membranes  14  may be secured to the rupture disc  12  such that the adhesive layers  62  adhere to an inner surface  31  of the peripheral flange portion  30  and the exposed membrane layer portions  60 ′ are situated to extend across and cover the corresponding vent openings  32 . As such, particles or moisture passing into vent openings  42  of the outlet ring  40  are inhibited from passing through the breathable membranes  14  at vent openings  32 , and are thus inhibited from passing into a sealed vessel to which the breathable rupture assembly  10  is secured. The breathable membranes  14  may be dimensioned such that they do not extend beyond an inner peripheral edge  35  or outer peripheral edge  39  of the peripheral flange portion  30 . For example, the diameter of the breathable membranes  14  may be less than a radial dimension of the peripheral flange portion  30 . 
     Referring now to  FIGS. 7-10, 11A, and 11B , a sealed device  100  such as a battery (e.g., a lithium-ion or lead-acid battery) may include various externally-facing components  101 . The externally-facing components  101  may include, for example, the breathable rupture assembly  10 , terminals (positive terminal  101 A and negative terminal  101 B), and other interfaces  101 C. The sealed device  100  also includes various internal components such as cathodes, anodes, electrolytes, separators, internal cells, and associated wiring. Such internal components are often compactly arranged within the sealed device, and can often limit the available “footprint” of the externally-facing components  101 . As described in greater detail below, the breathable rupture assembly  10  reduces the number of externally-facing components  101  by integrating a non-reclosing pressure relief device and a breathable vent, and therefore reducing the required total footprint or mounting area otherwise needed for the pressure relief device and the breathable vent on the sealed device. In certain applications, this reduction of externally-facing components  101  may simplify the arrangement of the internal components. 
     The breathable rupture assembly  10  may be secured to a side wall  104  of a casing or housing  102  of a sealed device  100 . In the installed configuration, fasteners  36  secure the breathable rupture assembly  10  proximate an outer surface  106  of the wall  104  where an opening  108  extends through the wall  104 . The concave surface  22  of the central bulged portion  20  is externally-exposed through the central opening  46  of the outlet ring  40  ( FIG. 8 ), and the convex surface  24  protrudes into the opening  108  in the wall  104  ( FIGS. 9-11B ). In this orientation, the breathable rupture assembly  10  is a reverse-acting rupture disc. 
     Referring to  FIGS. 11A and 11B , the wall  104  of the sealed device  100  includes one or more vent openings  112 , which may correspond in size, shape, and/or arrangement to one or more vent openings of the breathable rupture assembly  10 . For example, and referring to  FIG. 11B , in the installed configuration, the breathable rupture assembly  10  is arranged such that vent openings  42  of the outlet ring  40 , vent openings  32  of the rupture disc  12 , the breathable membranes  14 , and vent openings  52  of the gasket  50  are preferably aligned to be coaxial with the vent openings  112  of the wall  104 . The so installed breathable rupture assembly  10  permits air or other gases to flow into and out of the sealed device  100  (e.g., through vent openings  112  of the sealed device  100 ), as indicated at arrow  114 , to regulate the internal pressure within the housing  102  relative to an external pressure outside of the housing  102 . An increase in internal pressure of the sealed device  100  may be regulated through the breathable membranes  14  so that it approaches or reaches the external pressure. Furthermore, as discussed, the breathable membranes  14  are IP rated to inhibit passage of dust particles and moisture into the housing  102 , as indicated at arrow  116 . 
     Referring to  FIG. 11A , a vent opening  32  and an edge  20 A of the central rupture portion  20  of the rupture disc  12  may be spaced by a distance (D 1  to D 2 ) that is smaller than a diameter of the vent opening (D 2  to D 3 ). In one approach, the diameter of the vent opening  32  (D 3  less D 2 ) is less than the distance between the inner diameter of the vent opening and the radius of the central rupture portion  20  (D 2  less D 1 ). In another approach, the diameter of the vent opening  32  (D 3  less D 2 ) is greater than the distance between the inner diameter of the vent opening and the radius of the central rupture portion  20  (D 2  less D 1 ). In one example approach, D 1  is approximately 0.70″ from a central axis  12 A of the rupture disc  12 , D 2  is approximately 0.80″ from the central axis  12 A, D 3  is approximately 0.95″ from the central axis  12 A, and D 4  is approximately 1.13″ from the central axis  12 A. 
     Referring to  FIG. 12 , a breathable overpressure assembly such as breathable rupture assembly  10 ′ is provided that includes similar components as the breathable rupture assembly  10  shown in  FIGS. 1-5  wherein components of the breathable rupture assembly  10 ′ that are the same or similar to that of the previously-described breathable rupture assembly  10  will be provided with the same reference numeral. In the breathable rupture assembly  10 ′ of  FIG. 12 , the breathable membranes  14  are secured (e.g., adhered) to the peripheral flange portion  30  of the rupture disc  12  at the outer surface  33  of the peripheral flange portion  30  of the rupture disc  12  such that the breathable membranes  14  entirely cover vent openings of the rupture disc  12 , as discussed with respect to  FIGS. 1-5 . In this way, when the outlet ring  40  is fixedly secured to the outer surface  33  of the peripheral flange portion  30  at the concave side of the rupture disc  12  via welding (e.g., spot welding), mechanical fasteners, and/or adhesive, the breathable membranes  14  are locked in place between the outlet ring  40  and the rupture disc  12 . In this approach, the adhesive layer (e.g., adhesive layer  62  of  FIGS. 6A and 6B ) of the breathable membrane  14  acts to initially secure the breathable membrane  14  to the rupture disc  12 , and the compressive forces between the outlet ring  40  and the rupture disc  12  upon securement of the outlet ring  40  to the rupture disc  12  permanently secures the breathable membranes  14  in place across vent openings  32 ,  42  of the rupture disc  12  and the outlet ring  40 , respectively. 
     Similar to breathable rupture assembly  10 , the breathable rupture assembly  10 ′ permits air or other gases to flow into and out of a sealed device as indicated at arrow  114 ′ to regulate pressure in the sealed device, while also inhibiting passage of dust particles and moisture into the sealed device, as indicated at arrow  116 ′. In this way, any gradual increase of pressure differential between an internal pressure of a sealed device (e.g., sealed device  100 ) and an external pressure may be avoided through the breathable membranes  14  of the breathable rupture assembly  10 ′. 
     The central rupture portion  20  includes a score such as a generally circular score  16  that may be similar to score  206  of rupture disc member  222  discussed with respect to  FIGS. 20 and 21 . In the event of a sudden increase in pressure differential between internal and external pressures, the central rupture portion  20  of the rupture disc  12  is configured to rupture along score  16 . In this way, the internal and external pressures may be instantly equalized, thereby protecting internal components of the sealed device. 
     Referring to  FIG. 13 , a breathable overpressure assembly such as breathable rupture assembly  10 ″ is provided that includes similar components as the breathable rupture assembly  10  shown in  FIGS. 1-5  wherein components of the breathable rupture assembly  10 ″ that are the same or similar to that of the previously described breathable rupture assemblies  10 ,  10 ′ will be provided with the same reference numeral. The breathable rupture assembly  10 ″ of  FIG. 13  includes an annular breathable membrane  130  in place of (or in addition to) breathable membranes  14 . The material of the annular breathable membrane  130  may be the same as that of membrane layer  60  so that it may have properties similar to those discussed with respect to membrane layer  60  of  FIGS. 6A and 6B . In this regard, the annular breathable membrane  130  permits air or other gases to flow into and out of a sealed device to regulate pressure in the sealed device, while also inhibiting passage of dust and other small particles and moisture into the sealed device. The annular breathable membrane  130  includes fastener openings  134  that are aligned with fastener openings  34 ,  44 , and  54  of the rupture disc  12 , outlet ring  40 , and gasket  50 , respectively, and have sufficient clearance to permit threaded shanks of the fasteners  36  to pass therethrough. The annular breathable membrane  130  may include an adhesive layer (e.g., adhesive layer  62  of  FIGS. 6A and 6B ) for securing the annular breathable membrane  130  to the rupture disc  12 . In the approach shown, the annular breathable membrane  130  is secured between the rupture disc  12  and the gasket  50 . In another approach, the annular breathable membrane  130  is secured between the rupture disc  12  and the outlet ring  40 , similar to the breathable membrane  14  of  FIG. 12 . In still another approach, a first annular breathable membrane  130  is disposed between the rupture disc  12  and the gasket  50 , and a second annular breathable membrane  130  is secured between the rupture disc  12  and the outlet ring  40 . 
     Referring to  FIGS. 14-16 , a breathable overpressure device such as breathable rupture assembly  140  is provided that includes similar components as the breathable overpressure assemblies  10 ,  10 ′,  10 ″ described herein. The breathable rupture assembly  140  can be a generally circular assembly and includes a rupture disc  142  having a central rupture portion  142 A and a mounting ring  141 . The central rupture portion  142 A is configured to rupture at a predetermine rupture pressure at an interior container side of the breathable rupture assembly  140 . The mounting ring  141  is a metal ring and includes fastener openings  143  that are sized to receive fasteners  36  therethrough for securing the breathable rupture assembly  140  to a vessel, as previously discussed. 
     The breathable rupture assembly  140  also includes one or more vents  147 . The vents  147  are formed in the central rupture portion  142 A radially inward from the mounting ring  141 , and extend through the entire thickness of the rupture disc  142 . The vents  147  may be in the form of through openings or apertures  147 ′ and/or through slots  147 ″. In the approach shown, the rupture disc  142  includes arcuate through slots  147 ″ that each extend between a pair of through apertures  147 ′. 
     The vents  147  also function as preformed weaknesses or frangible portions of the central rupture portion  142 A along which the rupture disc  142  breaks or ruptures at the predetermined rupture pressure. For example, the through apertures  147 ′ and through slots  147 ″ may form frangible portions including fault regions and lines at which the rupture disc  142  is intended to rupture. A rupture pressure threshold may be, for example, approximately 4 psi, 5 psi, 15 psi, or 100 psi. The rupture disc  142  may also include a hinge portion  142 B about which the central rupture portion  142 A is intended to fold or bend during a rupture event. The hinge portion  142 B may be formed by providing a greater distance between adjacent vents  147  as compared to other adjacent vents  147  of the rupture disc  142 . Upon a rupture event, the central rupture portion  142 A becomes detached along the vents  147 , but remains connected at the hinge portion  142 B. 
     As shown in  FIGS. 15 and 16 , the breathable rupture assembly  140  also includes a breathable membrane  144 . In the approach shown, the breathable membrane  144  is a disc-shaped membrane that extends across substantially the entire breathable rupture assembly  140  (e.g., across the mounting ring  141  and the rupture disc  142 ) adjacent to the rupture disc  142 . The breathable membrane  144  is formed of an air-permeable material that facilitates the ingress and egress of gases, and regulates steady state pressure within a sealed enclosure. The breathable membrane  144  may be formed, for example, of polytetrafluoroethylene (PTFE), polyethylene (PE), or ultra-high-molecular-weight polyethylene (UHMWPE, UHMW). The breathable membrane  144  also has an Ingress Protection (IP) rating sufficient to inhibit passage of dust and other small particles and moisture therethrough (e.g., IP 64, IP 67, or IP 68). The breathable membrane  144  may also have corrosion resistance properties (e.g., as described in ASTM B117-11). 
     The breathable membrane  144  covers the vents  147  including the through apertures  147 ′ and through slots  147 ″. In this way, when the breathable rupture assembly  140  is installed on a sealed enclosure, the breathable membrane  144  regulates the difference in pressure inside a sealed enclosure relative to its immediate environment, while inhibiting contaminants and moisture from entering the sealed enclosure through the vents  147 . 
     The breathable rupture assembly  140  also includes a back plate  145 . In the approach shown, the back plate  145  is a mesh back plate that extends across substantially the entire breathable rupture assembly  140 , and specifically across the mounting ring  141  and the rupture disc  142  including the central rupture portion  142 A thereof. The back plate  145  provides support for the central rupture portion  142 A to the central rupture portion  142 A from activating and rupturing in the reverse or “backward” direction which is in the direction opposite “INTERNAL PRESSURE” arrow in  FIG. 16 . For example, the back plate  145  provides vacuum support for the central rupture portion  142 A such that when the rupture disc  142  experiences a vacuum force from within a sealed enclosure, the back plate  145  keeps the rupture disc  142  from rupturing in the reverse direction. The back plate  145  also provides resistance against forces external to the sealed enclosure acting in the direction opposite “INTERNAL PRESSURE” arrow in  FIG. 16  that may otherwise cause the rupture disc  142  to activate in the reverse direction. 
     The breathable rupture assembly  140  may also include a gasket  146 . The gasket  146  may be formed of a compressible resilient material such as silicone. The gasket  146  forms a fluid-tight or substantially fluid-tight seal between the rupture disc  142  and a sealed enclosure (e.g., battery case  102  of  FIG. 7 ) when the breathable rupture assembly  140  is installed on the sealed enclosure. The gasket  146  may be an annular gasket that includes a large central opening  146 A so that it engages with a peripheral portion  145 A of the back plate  145  when the breathable rupture assembly  140  is fastened to the sealed enclosure. 
     In another approach, the breathable rupture assembly  140  includes through openings  148  in the mounting ring  141  and one or more breathable membranes  149  aligned with the vents or openings, similar to those discussed with respect to breathable overpressure assemblies  10 ,  10 ′,  10 ″. The openings  148  and breathable membranes  149  may be provided in addition to, or instead of, vents  147  and breathable membranes  144 . 
     Referring to  FIG. 17-23 , breathable overpressure assemblies such as breathable explosion vent assemblies  150 ,  150 ′,  150 ″ are shown. The breathable overpressure assemblies  150 ,  150 ′,  150 ″ may include similar components as the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140  described herein. For example, one or more of the breathable overpressure assemblies  150 ,  150 ′,  150 ″ may include a gasket that extends around a peripheral flange portion to form a fluid-tight or substantially fluid-tight seal between the assembly and a sealed vessel. 
     The breathable explosion vent assemblies  150 ,  150 ′,  150 ″ may be provided on sealed spaces that contain electrical devices that have the potential for an explosion. Explosions may be caused, for example, by an electric arc initiated by damage or failure of the device or circuitry. Example sealed spaces include power converters (e.g., direct current (DC) power converters), batteries (e.g., lithium-ion batteries), and other electrical boxes. During an explosion event, a rapid rise in pressure occurs in the containing structure. The breathable explosion vent assemblies  150 ,  150 ′,  150 ″ may provide controlled pressure release for sealed spaces where the possibility for explosion exists. The breathable explosion vent assemblies  150 ,  150 ′,  150 ″ may have a suitable shape (e.g., circular, rectangular, square), and may be flat or domed. 
     Referring to  FIG. 17 , a breathable explosion vent assembly  150  is provided that may include similar components as the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140  described herein. The illustrated breathable explosion vent assembly  150  is generally rectangular and includes a rupture member in the form of a rupture panel member  152  that is configured to rupture at a predetermined rupture pressure at an interior container side of the rupture panel member  152 . The rupture panel member  152  may be formed, for example, of stainless steel, hastelloy, Inconel, nickel, graphite, or other suitable material. In one approach, the rupture panel member  152  is a generally flat or planar configuration. In another approach, the rupture panel member  152  includes a bulged rupture region. The rupture panel member  152  may include a frangible portion or portions that are preformed weaknesses, such as scores, perforations, or cut lines  154 , in a surface of the rupture panel member  152  to form fault lines along which the rupture panel member  152  is intended to rupture. Cut lines  154  may be laser cut through the rupture panel member  152 . A rupture pressure threshold may be, for example, approximately 4 psi, 5 psi, 15 psi, or 100 psi. The rupture panel member  152  may also include a hinge portion  152 A about which a central portion  152 B of the rupture panel member  152  is intended to fold or bend during an explosion event. The hinge portion  152 A may be formed by providing a greater distance between adjacent cut lines  154  as compared to other adjacent cut lines  154  of the rupture panel member  152 . Upon an explosion event, the central portion  152 B of the rupture panel member  152  becomes detached along the cut lines  154 , but remains connected to the remained of the rupture panel member  152  at the hinge portion  152 A. 
     The breathable explosion vent assembly  150  also includes a rectangular peripheral flange portion  156  that has through openings that extend through the entire thickness of the peripheral flange portion  156 . More particularly, the peripheral flange portion  156  includes one or more vent openings  160  and one or more fastener openings  162 . The fastener openings  162  are sized to receive fasteners (e.g., fasteners  36  of  FIG. 5 ) therethrough, as previously discussed. The breathable explosion vent assembly  150  also includes one or more breathable membranes  164  that are secured to the peripheral flange portion  156  in like or similar fashion as discussed with respect to breathable overpressure assemblies  10 ,  10 ′,  10 ″. 
     The breathable explosion vent assembly  150  may also include a gasket  166 . The gasket  158  may be formed of a compressible resilient material such as silicone. Similar to gaskets  50 ,  146  discussed herein, the gasket  166  extends along the outer peripheral flange portion  156  and forms a fluid-tight or substantially fluid-tight seal between the outer peripheral flange portion  156  and the sealed enclosure when the breathable explosion vent assembly  150  is installed on the sealed enclosure. 
     Referring to  FIGS. 18 and 19 , a breathable explosion vent assembly  150 ′ is provided that includes similar components as the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150  described herein. The breathable explosion vent assembly  150 ′ has a generally square configuration and includes a rupture member in the form of a rupture panel member  172  that is configured to rupture at a predetermine rupture pressure at an interior container side of the rupture panel member  172 . As shown in  FIG. 19 , the breathable explosion vent assembly  150 ′ may have a bulged or domed rupturable portion  174  that extends outwardly relative to a sealed enclosure. As shown by the “INTERNAL PRESSURE” arrow, increases in pressure within the sealed enclosure act on the concave wall  174 A of the domed rupturable portion  174 . In this way, the breathable explosion vent assembly  150 ′ may be a forward-acting (tension loaded) rupture assembly. 
     Similar to the previously discussed breathable overpressure assemblies, breathable explosion vent assembly  150 ′ includes a square peripheral flange portion  176  extending about the central domed rupturable portion  174  that has through openings that extend through the entire thickness of the peripheral flange  176 . More particularly, the peripheral flange  176  includes one or more vent openings  180  and one or more fastener openings  182 . The fastener openings  182  are sized to receive fasteners (e.g., fasteners  36 ) therethrough, as previously discussed. The breathable explosion vent assembly  150 ′ also includes one or more breathable membranes  184  that are secured to the peripheral flange  176  to extend over and cover the vent openings  180  in like or similar fashion as discussed with respect to the breathable overpressure assemblies previously described herein. 
     Referring to  FIGS. 20 and 21 , a breathable overpressure assembly such as breathable explosion vent assembly  150 ″ is provided that includes similar components as the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′ described herein. As shown in  FIG. 20 , the breathable explosion vent assembly  150 ″ has a generally circular configuration. As shown in  FIG. 21 , the breathable explosion vent assembly  150 ″ may have a bulged or domed rupturable portion  204  that extends outwardly relative to a sealed container. In this way, the breathable explosion vent assembly  150 ″ may be a forward-acting (tension loaded) rupture assembly. 
     Similar to the previously discussed breathable overpressure assemblies, breathable explosion vent assembly  150 ″ includes a peripheral flange portion  208  that has through openings that extend through the entire thickness of the peripheral flange portion  208 . More particularly, the through openings of the peripheral flange portion  208  can include one or more vent openings  210  and one or more fastener openings  212 . The vent openings  210  and fastener openings  212  may alternate about the circumference of the peripheral flange portion  208 . The fastener openings  212  are sized to receive fasteners (e.g., fasteners  36 ) therethrough, as previously discussed. The breathable explosion vent assembly  150 ″ also includes one or more breathable membranes  214  that are secured to the peripheral flange portion  208  to cover the vent openings  210  in like or similar fashion as discussed with respect to the breathable overpressure assemblies previously described herein. 
     As shown in  FIG. 21 , the breathable explosion vent assembly  150 ″ may be a composite assembly that includes a stack of layers, as described below. The layers cooperate to form the domed rupturable portion  204  and the peripheral flange portion  208 . 
     The layers of the breathable explosion vent assembly  150 ″ include an outer domed rupture disc member  222  that has a peripheral flange portion  208 A and a central rupture portion  222 A that is configured to rupture at a predetermined rupture pressure at an interior container side of the rupture disc member  222 , as previously discussed. The rupture disc member  222  may be formed, for example, of 316 stainless steel. The rupture disc member  222  may include a frangible portion such as score  206  in the central rupture portion  222 A to form a fault line along which the rupture disc member  222  is intended to rupture. Score  206  may be laser cut all the way through the rupture disc member  222 . In the illustrated approach, the score  206  is a generally circular score  206  that is disposed inwardly and spaced from the edge of the peripheral flange portion  208 A. The score  206  does not extend entirely around the central rupture portion  222 A such that where the score  206  is not formed in the rupture disc member  222 , the central rupture portion  222 A forms a hinge portion  222 B about which an inner portion  222 C of the central rupture portion  222 A is intended to fold during a rupture event. 
     The score  206  may include a plurality of arcuate score segments  206 A that each extend between score ends  206 B,  206 C and form unscored segments  222 D of the central rupture portion  222 A between respective pairs of score ends  206 B,  206 C. A predetermined rupture pressure may be a controlled by varying the distance between score ends  206 B,  206 C. For example, a rupture disc member  222  having a shorter distance between score ends  206 B,  206 C, and thus shorter unscored segments  222 D, may have a lower predetermined rupture pressure than a rupture disc member  222  having a longer distance between score ends  206 B,  206 C and having longer unscored segments  222 D. A predetermined rupture pressure may also be controlled by increasing or decreasing the thickness of the material of the rupture disc member  222 , and more particularly, the thickness of the central rupture portion  222 A. A predetermined rupture pressure may also be controlled by increasing or decreasing the distance between score ends  206 B,  206 C adjacent the hinge portion  222 B. Upon a rupture event, the inner portion  222 C of the central rupture portion  222 A becomes detached at the unscored segments  222 D and folds about the hinge portion  222 B, but remains connected to the central rupture portion  222 A at the hinge portion  222 B. 
     The breathable explosion vent assembly  150 ″ further includes an inner metallic backing support member  226  that may be formed of 316 stainless steel. The backing support member  226  includes a frangible portion such as score  207 A, which may be laser cut all the way through the backing support member  226 . Score  207 A has generally the same configuration as the score  206  of the rupture member  222  (e.g., generally circular) and is aligned with score  206  in the assembled form of the breathable explosion vent assembly  150 ″. Whereas score  206  may include unscored segments  222 D, score  207 A may be cut all the way from one end of the hinge around the backing support member  226  to the other end of the hinge so that it extends in an uninterrupted fashion except for the hinge  222 B. The backing support member  226  may also have scores  207 B that are not aligned with scores  206  (e.g., that extend across a face of the domed rupturable portion  204 ). 
     The backing support member  226  may further include clips  209  that are secured to an inner concave wall surface  226 A of the backing support member  226 . The clips  209  are welded or otherwise secured to the concave wall surface  226 A such that each clip  209  extends across the score  207 A. In the illustrated approach, the clips  209  are spot-welded  209 A, as indicated at  209 A, in alternating fashion. For example, a first clip  209  may be spot-welded  209 A to the concave wall surface  226 A at a radially inner side of the score  207 A, and an adjacent second clip  209  may be spot-welded  209 A to the concave wall surface  226 A at a radially outer side of the score  207 A. The illustrated clips  209  have a hexagonal configuration, although other configurations such as rectangular are possible. 
     The clips  209  cause the composite breathable explosion vent assembly  150 ″ to operate in a forward-acting direction such that the breathable explosion vent assembly  150 ″ ruptures in the direction indicated by the “INTERNAL PRESSURE” arrow in  FIG. 21 , but resists forces that would tend to cause the breathable explosion vent assembly  150 ″ to rupture in the reverse direction. More particularly, the clips  209  cause the backing support member  226  to resist vacuum forces against the concave side of the domed rupturable portion  204  and to resist compressive forces (e.g., external forces) against the convex side of the domed rupturable portion  204 , but allow the backing support member  226  to rupture in the direction indicated by the “INTERNAL PRESSURE” arrow when the pressure differential between internal and external pressures of the sealed container reaches a predetermined bursting pressure. 
     The breathable explosion vent assembly  150 ″ further includes a sealing membrane  224  positioned between the rupture disc member  222  and the backing support  226 . The sealing membrane  224  may be formed, for example, of Teflon or PTFE. The sealing membrane  224  protects against pressure losses through scores  206 ,  207 A of the rupture member  222  and the backing support member  226 , thereby sealing the opening  108  of the housing  102 . 
     The breathable explosion vent assembly  150 ″ may also include one or more internal protective covers  220 . The protective covers  220  may be formed, for example, of Teflon, PTFE, or aluminum, and may be in the form of slit-slot covers. The protective covers  220  are arranged on one or both of the inner and outer surfaces of the sealing membrane  224 . For example, an inner protective cover  220  may be arranged between the metal backing support  226  and the sealing membrane  224 , and an outer protective cover  220  may be arranged between the rupture disc member  222  and the sealing membrane  224 . In this way, the protective covers  220  prevent the sealing membrane  224  from being damaged by burrs or sharp edges of the metal backing support  226  and the rupture disc member  222  such as caused by formation of the score  206  in the rupture disc member  222 . The protective covers  220  may also include cut lines or scores, as discussed in greater detail below. 
     In one approach, the sealing membrane  224  and the metal backing support  226  have a predetermined forward-acting bursting pressure that is less than the predetermined bursting pressure of the rupture disc member  222 . For example, the rupture disc member  222  may have a predetermined bursting pressure of approximately 6 psi, and rupture disc member  222 , and the sealing membrane  224  and the metal backing support  226  may each have a bursting pressure less than 4 psi. 
     Referring to  FIGS. 22 and 23 , a breathable overpressure assembly such as breathable explosion vent assembly  150 ′″ is provided that includes similar components as the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ′, and  150 ″ described herein. As shown in  FIG. 22 , the breathable explosion vent assembly  150 ′″ has a generally circular configuration. As shown in  FIG. 23 , the breathable explosion vent assembly  150 ′″ may be generally planar. 
     Similar to the previously discussed breathable overpressure assemblies, breathable explosion vent assembly  150 ′″ includes a peripheral flange portion  258  that has through openings that extend through the entire thickness of the peripheral flange portion  258 . More particularly, the peripheral flange portion  258  includes one or more vent openings  260  and one or more fastener openings  262 . The vent openings  260  and fastener openings  262  may alternate about the circumference of the peripheral flange portion  258 . The fastener openings  262  are sized to receive fasteners (e.g., fasteners  36 ) therethrough, as previously discussed. The breathable explosion vent assembly  150 ′″ also includes one or more breathable membranes  264  that are secured to the peripheral flange portion  258  to cover the vent openings  260  in like or similar fashion as discussed with respect to the breathable overpressure assemblies previously described herein. 
     As shown in  FIG. 23 , the breathable explosion vent assembly  150 ′″ may include a stack of layers that cooperate to form a central rupture portion  252  and the peripheral portion  258 . The layers of the breathable explosion vent assembly  150 ′″ may be the same materials as discussed with respect to the layers of breathable explosion vent assembly  150 ″; for example, a rupture disc member  272 , an inner metallic backing support  276 , a sealing membrane  274 , and one or more protective covers  270 . 
     In the illustrated approach, the rupture disc member  272  may include one or more frangible portions, such as scores  256 , in a central rupture portion  272 A of the rupture disc member  272  to form fault lines along which the rupture disc member  272  is intended to rupture. Scores  256  may be laser cut through the entire rupture disc member  272 . The scores  256  may be radially extending scores that extend between the peripheral portion  258  and the center  272 B of the central rupture portion  272 A without passing through the center  272 B. A predetermined rupture pressure at which the disc member  272  is rated to rupture may be adjusted by increasing or decreasing the distance between radially inner ends  256 A,  256 B of the scores  256  at the center  272 B of the central rupture portion  272 A. For example, a greater rupture pressure may be achieved by increasing the distance between opposing radially inner ends  256 A,  256 B of the scores  256 , and a lesser rupture pressure may be achieved by decreasing the distance between opposing radially inner ends  256 A,  256 B of the scores  256 . The scores  256  facilitate rupturing of the central rupture portion  272 A such that upon rupture, the central rupture portion  272 A forms generally triangular-shaped petal portions  272 C having edges predetermined by the scores  256 . The petal portions  272 C are retained by the rupture disc member  272  at hinge portions  272 D radially inward of the peripheral flange portion  258 . 
     The protective covers  270  may also include cut lines or scores  270 A. The scores  270 A may extend across the center  272 B of the central rupture portion  272 A of the rupture disc member  272 . The scores  270 A may be angularly offset (“clocked”) relative to the scores  256  of the rupture disc member  272 . In this way, petals  270 B formed between adjacent scores  270 A are arranged between the scores  256  and the sealing membrane  274  to protect the sealing membrane  274  from any sharp edges formed by the scores  256  in the rupture disc member  272 . 
     As described, the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′,  150 ″,  150 ′″ provide both ventilation and pressure relief for sealed vessels or systems in a compact, integrated manner. The breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′,  150 ″,  150 ′″ also allow for customization of the shape, size, quantity, and arrangement of the vent openings and breathable membranes to address various ventilation needs. The integration of the ventilation and pressure relief capabilities also provides several advantages. For example, the integrated breathable overpressure assemblies  10 ,  10 ′,  10 ′,  140 ,  150 ,  150 ′,  150 ″,  150 ′″ may reduce installation time as compared to installation time required to install separate rupture discs and vents on a sealed assembly. Furthermore, the integrated breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′,  150 ″,  150 ′″ may provide a weight reduction for a sealed assembly as compared to a sealed assembly having both a rupture disc and standalone vent. Still further, the breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′,  150 ″,  150 ′″ allow for the elimination of a dedicated vent and therefore increase available packaging space for other components of the sealed vessels. Elimination of a dedicated vent may also reduce the height or width of a sealed vessel. 
     Furthermore, in many applications, exhaust hoses are connected to a sealed vessel at egresses (e.g., vents and rupture discs) of the sealed vessel to direct gases released through the egresses to a desired location. For example, a sealed battery such as a lithium-ion battery may be installed in a vehicle or aircraft. An exhaust hose may be connected to the battery at the vent to direct vented gases to the outside atmosphere. Similarly, an exhaust hose may be connected to the battery at the rupture disc to direct gases expelled during a rupture event to the outside atmosphere. In this way, the exhaust hoses prevent potentially harmful exhaust gases expelled from the battery from reaching the cabin of the vehicle. A sealed vessel that has a rupture disc and a standalone vent has two potential egresses for gases to escape from the sealed vessel. As such, to simultaneously control and disperse gases from the two egresses, two exhaust hoses or similar devices may be required. 
     In contrast, the integrated breathable overpressure assemblies  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′,  150 ″,  150 ′″ discussed herein provide one general location for vented or rupturing gases to escape. In this way, as shown in  FIG. 7  a single exhaust hose  300  may be used to control and disperse gases from a single egress, thereby reducing installation time and simplifying ventilation systems. For example, the exhaust hose  300  may have a fitting  302 , which includes mounting a flange, and an opening  304  that are sized to fit over both the central rupture portion  20  and the vent openings  32 ,  42 ,  52  of an integrated breathable overpressure assembly  10 ,  10 ′,  10 ″,  140 ,  150 ,  150 ′,  150 ″,  150 ′″. The exhaust hose  300  is therefore able to receive both rupture gases through the central rupture portion  20  and vented gases through the vent openings  32 ,  42 ,  52  and breathable membranes  14  and can direct the gases from the interior of the housing to an exterior of an enclosure (such as an aircraft or vehicle) in which the housing is disposed. 
     While there have been illustrated and described particular embodiments of the present invention, those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above-described embodiments without departing from the scope of the invention, and it is intended for the present invention to cover all those changes and modifications which fall within the scope of the appended claims.