Patent Publication Number: US-2020298035-A1

Title: Vented safety cabinet with thermally-actuated damper

Description:
TECHNOLOGICAL FIELD 
     The present disclosure pertains generally to a safety cabinet for the safe storage of flammable, combustible, or other hazardous materials, and more particularly to a safety cabinet with a vent system having a thermally-actuated damper. 
     BACKGROUND 
     A safety cabinet can be used for the onsite storage of flammable material at a manufacturing plant, for example. The safety cabinet can be provided to insulate flammable material stored within it from the direct effects of an external fire to help prevent (for at least some designated period of time) the contents of the safety cabinet from themselves igniting and adding to the deleterious effect of the original fire. 
     Venting a safety cabinet is typically not necessary for fire protection. However, a user of a safety cabinet may desire to vent the safety cabinet, as according to either an applicable law or an internal standard operating procedure. Venting the safety cabinet can help, in some instances, reduce the amount of odorous, ignitable vapor and/or hazardous vapor emitted by the materials stored within the safety cabinet. In such cases, it is desirable for the venting system to be installed so as to avoid adversely affecting the intended performance of the cabinet during a fire. In practice, however, venting a safety cabinet can be hard to do without compromising its specified fire performance rating. In fact, a vented cabinet could compromise the ability of the cabinet to protect its contents from a fire. During a fire, vapor from the contents stored in the safety cabinet can be emitted. If the ventilation system compromises the integrity of the safety cabinet, these ignitable vapors can combust to further contribute to the fire&#39;s destructive potential. 
     Previous safety cabinets have included a mechanism for closing the venting system that is thermally-activated. However, such conventional mechanisms can be very expensive. 
     There is a continued need in the art to provide additional solutions to enhance the venting of a safety cabinet. For example, there is a continued need for techniques for venting a safety cabinet using equipment that is economical and that can help maintain the performance of the safety cabinet in the event of a fire. 
     It will be appreciated that this background description has been created by the inventor to aid the reader, and is not to be taken as an indication that any of the indicated problems were themselves appreciated in the art. While the described principles can, in some aspects and embodiments, alleviate the problems inherent in other systems, it will be appreciated that the scope of the protected innovation is defined by the attached claims, and not by the ability of any disclosed feature to solve any specific problem noted herein. 
     SUMMARY 
     In one embodiment, a safety cabinet includes an enclosure, a door, and a vent system with a thermally-actuated damper. The enclosure defines an interior, an opening, and a vent port. The opening and the vent port are in communication with the interior of the enclosure. The door is rotatably mounted to the enclosure and is moveable over a range of travel between an open position and a closed position. The door, when in the closed position, is adapted to cover at least a portion of the opening of the enclosure. 
     The vent system includes a conduit having an internal passage and a thermally-actuated damper. The conduit is connected to the enclosure such that the internal passage of the conduit is in communication with the vent port of the enclosure. The thermally-actuated damper includes a body, a valve plate, and a pivot assembly. 
     The body extends along a longitudinal axis and has a first end and a second end. The ends are disposed in spaced relationship to each other along the longitudinal axis. The body defines an internal passage with a first opening disposed at the first end and a second opening disposed at the second end. The body comprises a portion of the conduit such that the first end of the body is in communication with the vent port of the enclosure. 
     The valve plate is disposed within the passage of the body such that the valve plate is intermediately disposed along the longitudinal axis between the first end and the second end of the body. The valve plate is movable between an open position and a closed position. The valve plate permits air flow between the openings of the passage of the body when the valve plate is in the open position, and the valve plate substantially occludes the passage of the body when the valve plate is in the closed position. 
     The pivot assembly includes a biasing system and a fusible link. The biasing system is mounted to the body such that it acts upon the valve plate and is adapted to bias the valve plate to the closed position. The fusible link is interconnected between the body and the biasing system to form an interconnection therebetween such that the valve plate is disposed in the open position. The fusible link constrains the valve plate from moving from the open position to the closed position via the interconnection of the fusible link between the body and the biasing system. The fusible link is configured to melt at a predetermined temperature to thereby disengage the interconnection of the fusible link between the biasing system and the body and to thereby allow the biasing system to move the valve plate to the closed position. 
     In another embodiment, a damper for a vent system of a safety cabinet is provided. The damper includes a body, a valve plate, and a pivot assembly. 
     The body extends along a longitudinal axis and has a first end and a second end. The ends are disposed in spaced relationship to each other along the longitudinal axis. The body defines a passage with a first opening disposed at the first end and a second opening disposed at the second end. 
     The valve plate is disposed within the passage of the body such that the valve plate is intermediately disposed along the longitudinal axis between the first end and the second end of the body. The valve plate is movable between an open position and a closed position. The valve plate permits air flow between the openings of the passage of the body when the valve plate is in the open position, and the valve plate substantially occludes the passage of the body when the valve plate is in the closed position. 
     The pivot assembly includes a valve support assembly, a biasing system, and a fusible link. The valve support assembly is mounted to the body and the valve plate. The valve support assembly is adapted to support the valve plate such that the valve plate is movable between the open position and the closed position. The biasing system is mounted to the body and at least one of the valve plate and the valve support assembly. The biasing system is adapted to bias the valve plate to the closed position. The fusible link is interconnected between the body and the biasing system to form an interconnection therebetween such that the valve plate is disposed in the open position. The fusible link constrains the valve plate from moving from the open position to the closed position via the interconnection of the fusible link between the body and the biasing system. The fusible link is configured to melt at a predetermined temperature to thereby disengage the interconnection of the fusible link between the biasing system and the body and to thereby allow the biasing system to move the valve plate to the closed position. 
     Further and alternative aspects and features of the disclosed principles will be appreciated from the following detailed description and the accompanying drawings. As will be appreciated, the principles related to thermally-actuated dampers and safety cabinets disclosed herein are capable of being carried out in other and different embodiments, and capable of being modified in various respects. Accordingly, it is to be understood that the foregoing general description and the following detailed description is exemplary and explanatory only and does not restrict the scope of the disclosed principles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front elevational view of an embodiment of a safety cabinet constructed in accordance with principles of the present disclosure, illustrating a pair of doors in a closed position. 
         FIG. 2  is a top plan view of the safety cabinet of  FIG. 1  with a top panel thereof removed for illustrative purposes. 
         FIG. 3  is a perspective view of the safety cabinet of  FIG. 1 , illustrating the doors in an open position. 
         FIG. 4  is a perspective view of the safety cabinet of  FIG. 1 , illustrating a right door with an outer panel removed therefrom for illustrative purposes. 
         FIG. 5  is an enlarged detail view, taken from  FIG. 4  as indicated by Circle V. 
         FIG. 6  is an enlarged detail view, taken from  FIG. 1  as indicated by Circle VI, of an embodiment of a thermally-actuated damper constructed according to principles of the present disclosure. 
         FIG. 7  is a view as in  FIG. 6 , but in section. 
         FIG. 8  is a perspective view of an embodiment of a thermally-actuated damper constructed according to principles of the present disclosure. 
         FIG. 9  is an exploded view of the thermally-actuated damper of  FIG. 8 . 
         FIG. 10  is a perspective view of a valve plate of the thermally-actuated damper of  FIG. 8 . 
         FIG. 11  is a face view of the valve plate of  FIG. 10 . 
         FIG. 12  is a perspective view of a drive rod of the thermally-actuated damper of  FIG. 8 . 
         FIG. 13  is a side elevational view of the drive rod of  FIG. 12 . 
         FIG. 14  is an end elevational view of the drive rod of  FIG. 12 . 
         FIG. 15  is a perspective view of a pivot arm of the thermally-actuated damper of  FIG. 8 . 
         FIG. 16  is a side elevational view of the pivot arm of  FIG. 15 . 
         FIG. 17  is a first end elevational view of the thermally-actuated damper of  FIG. 8 , illustrating the thermally-actuated damper in an open position. 
         FIG. 18  is a first elevational view of the thermally-actuated damper of  FIG. 8 , illustrating the thermally-actuated damper in an open position. 
         FIG. 19  is a second end elevational view of the thermally-actuated damper of  FIG. 8 , illustrating the thermally-actuated damper in an open position. 
         FIG. 20  is a cross-sectional view, taken along line XX-XX in  FIG. 17 , of the thermally-actuated damper of  FIG. 8 . 
         FIG. 21  is a view as in  FIG. 17 , but illustrating the thermally-actuated damper in a closed position. 
         FIG. 22  is a view as in  FIG. 18 , but illustrating the thermally-actuated damper in a closed position. 
         FIG. 23  is a view as in  FIG. 19 , but illustrating the thermally-actuated damper in a closed position. 
         FIG. 24  is a cross-sectional view, taken along line XXIV-XXIV in  FIG. 21 , of the thermally-actuated damper of  FIG. 8 . 
         FIG. 25  is the cross-sectional view of  FIG. 23 , but in perspective. 
         FIG. 26  is the cross-sectional view of  FIG. 24 , but in perspective. 
     
    
    
     It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of this disclosure or which render other details difficult to perceive have been omitted. It should be understood that this disclosure is not limited to the particular embodiments illustrated herein. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The present disclosure is directed to embodiments of a safety cabinet with a vent system having at least one thermally-actuated damper that operates in response to increased ambient temperature to place the vent system of the safety cabinet in a closed position to further protect the contents stored in the interior of the safety cabinet from exposure to open flame and/or increased temperature as a result of a fire in the vicinity of the safety cabinet. To help ensure that a venting system of a safety cabinet mechanically closes in the event of a fire, the present disclosure is directed to embodiments of a thermally-actuated damper adapted to close the vent system of the safety cabinet in the event ambient thermal conditions exceed a threshold level. In embodiments, the thermally-actuated damper includes a thermally-actuated fusible link (e.g., one rated for 135° F. or 165° F.) to release and close a valve plate of the damper in the event of thermal conditions that cause the link to melt. When the fusible link melts, a spring can act to close the valve plate against a valve seat defined in a body of the damper. In embodiments, a simple, economical spring-loaded butterfly type valve plate is provided to act as the shutoff damper. 
     In embodiments following principles of the present disclosure, the thermally-actuated damper includes a body made from stainless steel for enhanced resistance to corrosion and frictional sparking. In embodiments, the damper can include brass bushings and washers at pivot locations to help reduce corrosion and friction caused by parts moving relative to each other. In embodiments, the mass of the body and its valve seat and the valve plate can help increase the thermal barrier that inhibits the heat produced in a fire created on the outside of the cabinet from migrating to the inside of the safety cabinet. 
     In embodiments, a safety cabinet can include a pair of vent ports (such as, a low vent port and a high vent port, e.g.) which are in communication with the interior of the enclosure. The vent system can include conduit sections connected to the enclosure such that they are respectively in communication with the pair of vent ports. Each conduit section can have associated with it a thermally-actuated damper constructed according to principles of the present disclosure. In the event that a fire subjects the dampers of the safety cabinet to ambient temperatures that cause the respective fusible links to melt, the valve plate of each damper closes to stop the flow of air through the conduit sections either into or out of the enclosure of the safety cabinet. 
     In conventional vent systems, rigid metal conduit (such as, two-inch National Pipe Thread (NPT) pipe, for example) is used for the conduit sections. The rigid piping is typically used to help maintain the performance of a safety cabinet during a fire. In embodiments, a damper constructed according to principles of the present disclosure can be used in a way that eliminates the use of the rigid metal pipe of the vent system connected to the damper. In embodiments, the damper can include a coupling that is configured to be used with a plastic pipe (such as, a polyvinyl chloride (PVC) pipe, for example) while substantially maintaining the fire rating of the safety cabinet. In such situations, the mass of the body of the damper and the valve plate can act as a thermal barrier for the interior of the safety cabinet. In embodiments, alternate cabinet connections can be made to accommodate flexible tubing, duct work, etc. 
     Turning now to the Figures, an embodiment of a safety cabinet  30  constructed according to principles of the present disclosure is shown in  FIG. 1 . The safety cabinet  30  can be used to store flammable, combustible, or other hazardous materials. 
     In embodiments, the safety cabinet  30  includes an enclosure  30 , at least one door  40 , and a vent system  48  with at least one thermally-actuated damper  50  constructed according to principles of the present disclosure. Referring to  FIGS. 1 and 2 , in the illustrated embodiment, the safety cabinet  30  includes an enclosure  32 , a pair of doors  38 ,  40 , a retaining system  42  for retaining the doors  38 ,  40  in an open position ( FIG. 2 ), a closure system  44  for automatically closing the doors  38 ,  40  so that they move from an open position (see, e.g.,  FIG. 2 ) to the closed position (see, e.g.,  FIG. 1 ), a latch system  46  for latching the doors  38 ,  40  in the closed position to cover the opening of the enclosure  32  (see  FIGS. 3 and 4 , as well), and a vent system  48  with a pair of thermally-actuated dampers  50  that are both constructed according to principles of the present disclosure. The safety cabinet  30  has a double-walled construction. 
     Referring to  FIGS. 1 and 2 , the safety cabinet  30  includes an enclosure  32  having an outer shell  34  and an inner shell  36 , a left door  38 , and a right door  40 . The enclosure  32  includes the inner shell  36  to provide a double-walled construction, wherein each outer wall of the outer shell  34  has a corresponding inner wall of the inner shell  36 , with the corresponding inner and the outer walls separated by a predetermined distance to define an insulative air space. The left and right doors  38 ,  40  each have a double-walled construction similar to the enclosure  32 . 
     Referring to  FIG. 3 , the enclosure  32  also includes a top jamb  52 , a bottom jamb  53 , a left jamb  54 , and a right jamb  55 . The jambs  52 ,  53 ,  54 ,  55  of the enclosure  32  bound and define an opening  57  to an interior  59  defined by the enclosure  32 . The opening  59  is in communication with the interior  59  of the enclosure  32 . 
     Referring to  FIGS. 1-3 , in embodiments, the enclosure  32  defines at least one vent port  62  that is in communication with the interior  59  of the enclosure  32 . In the illustrated embodiment, the enclosure  32  defines a pair of vent ports  62 ,  64  that extend through both the outer shell  43  and the inner shell  36  such that the vent ports  62 ,  64  permit communication between the outside atmosphere adjacent the safety cabinet  30  and the interior  59  of the enclosure  32  through each vent port  62 ,  64 . In the illustrated embodiment, the lower vent port  62  on the left is configured to be an exhaust port that permits vapor from the bottom of the enclosure  32  to flow therefrom, and the upper vent port  64  on the right is configured to be a fresh air intake port that permits ambient air to enter the enclosure to make up for the exhaust stream flowing out of the enclosure  32  via the lower vent port  62 . 
     In embodiments, the safety cabinet can be provided with vent bungs  65  (with removable bung caps) constructed to be placed in the vent ports  62 ,  64  (see  FIG. 6 ) to facilitate the connection of the enclosure  32  to a respective conduit section  67  of the vent system  48 . In embodiments, a pipe  67  (such as, one having a two-inch NPT thread, for example) can be connected to each vent bung  65  to facilitate the attachment of the respective conduit section (which can also comprise suitable ducting as will be appreciated by one skilled in the art). 
     Referring to  FIG. 1 , in embodiments, the safety cabinet  30  includes at least one door  38 ,  40  that is adapted to cover at least a portion of the opening of the enclosure  32  when in the closed position. Each door  38 ,  40  can be rotatably mounted to the enclosure  32  so that it is moveable over a range of travel between an open position and a closed position. In the illustrated embodiment, the safety cabinet  30  includes a pair of doors  38 ,  40  configured to cooperate together to occlude the opening  57  to the interior  59  of the enclosure  32  of the cabinet  30 . In other embodiments, the safety cabinet  30  can include a single door that is configured to occlude the opening to the interior of the enclosure. 
     As best seen in  FIGS. 1 and 2 , the left and right doors  38 ,  40  selectively cover the opening  57  of the enclosure  32  and are respectively moveable over a range of travel between a closed position and a range of open positions. The left and right doors  38 ,  40  are adapted to cover the opening  57  of the enclosure  32  when in the closed position. The doors  38 ,  40  of the safety cabinet  30 , which can have a double-walled construction to provide an insulative air space therebetween, can be placed in the closed position to help protect the contents stored therein from the harmful effects caused by an open flame and/or increased ambient temperature in the event of a fire. 
     Referring to  FIG. 1 , the left door  38  and the right door  40  are preferably rotatably mounted to the enclosure  32  by first and second hinges  68 ,  69 , respectively. The first hinge  68  is mounted to the left jamb  53  of the enclosure  32  and to the left door  38 . The second hinge  69  is mounted to the right jamb  54  of the enclosure  32  and to the right door  40 . The first and second hinges  68 ,  69  both extend substantially the full height of the left and right doors  38 ,  40 , respectively. 
     In some embodiments, the safety cabinet  30  can include means for automatically closing the doors. In embodiments, the safety cabinet  30  includes first and second actuators adapted to urge the first and second doors, respectively, to the closed position. Referring to  FIG. 2 , in the illustrated embodiment, first and second actuators in the form of air cylinders  71 ,  72  are attached to the left and right doors  38 ,  40 , respectively, and to the enclosure  32 . The air cylinders  71 ,  72  are adapted to bias the left and right doors  38 ,  40  to their closed positions. 
     While loading and unloading the safety cabinet  30 , however, it may be desirable that the doors  38 ,  40  remain in an open position. In some embodiments, the safety cabinet  30  can include means for selectively retaining the doors  38 ,  40  in an open position. In the illustrative embodiment, first and second door retention mechanisms  73 ,  74  are respectively provided to selectively retain the doors  38 ,  40  in the open position, as shown in  FIG. 2 . 
     In some embodiments, each door retention mechanism  73 ,  74  includes a retaining element  77 ,  78  which is adapted to be selectively connected to a fusible link  79 ,  80  to hold the doors  38 ,  40  in an open position. The door retention mechanisms  73 ,  74  are mounted to the enclosure  32  and are selectively connected to the left and right door  38 ,  40 , respectively. In some embodiments, the first and second retaining elements  77 ,  78  each has a detent feature that acts to selectively retain the respective door  38 ,  40 , in the open position. 
     The fusible links  79 ,  80  of the retaining system  42  can be constructed to fuse, i.e., melt, when the ambient temperature reaches a certain level. When the doors  38 ,  40  are held open by the door retention mechanisms  77 ,  78 , respectively, and the ambient temperature exceeds a threshold level, the links  79 ,  80  fuse, thereby releasing the doors  38 ,  40  and allowing the cylinders  71 ,  72  of the closure system  44  to move the doors  38 ,  40 , respectively toward the closed position. In some embodiments, the fusible links  79 ,  80  are configured to fuse when the ambient temperature exceeds about 165° F. 
     In embodiments, the left door  38  includes an inner sealing flange  82 , and the right door  40  includes an outer sealing flange  83 . The sealing flanges  82 ,  83  extend along substantially the entire height of the door  38 ,  40  to which it is attached. Each sealing flange  82 ,  83  is adapted to extend from the respective door  38 ,  40  to which it is attached to a position in which it is in overlapping relationship with the other door  40 ,  38 , respectively, when the doors  38 ,  40  are in the closed position. 
     In embodiments, to create a more effective seal, the inner and outer sealing flanges  82 ,  83  of the left and right doors  38 ,  40  are arranged such that the inner sealing flange  82  of the left door  38  is disposed in inward relationship to the right door  40 , and the outer sealing flange  83  of the right door  40  is disposed in outer relationship to the left door  38 . In embodiments, a suitable sequential door-closing system  90  can be provided that is adapted to coordinate the closure of the doors  38 ,  40  such that the left door  38  closes before the right door  40 . In embodiments, any suitable sequential door-closing system  90  can be used, such as the sequential door-closing system shown in  FIG. 2  and further described in U.S. Patent Application Publication No. US2013/0200767, for example. In other embodiments, a sequential door-closing system constructed according to principles described in U.S. Pat. No. 6,729,701 can be used. 
     When the doors  38 ,  40  are closed in a sequence wherein the left door  38  is in the closed position prior to the right door  40  being in a closed position, and, thereafter, the right door  40  moves to the closed position, the sealing flanges  82 ,  83  cooperate to form an effective seal between the doors  38 ,  40  to further protect the contents stored within the safety cabinet  30  from the outside environment. When sealed in this manner, flame and high temperature ambient air can be further inhibited from entering the enclosure  32  of safety cabinet  30 . 
     In embodiments, the safety cabinet  30  can include any suitable latch system  46  adapted to help retain the doors  38 ,  40  in the closed position. In embodiments, the latch system  46  can be a three-point latch system having various configurations, including a slam-latch style that need not be operated in order to permit the doors  38 ,  40  to move from an open position to the closed position. 
     Referring to  FIGS. 3-5 , in embodiments, the latch system  46  includes a bullet slam latch  102 , first and second latch rod assemblies  104 ,  105 , and a paddle handle  107  (see also,  FIG. 1 ). In the illustrated embodiment, the first and second latch rod assemblies  104 ,  105  each includes a distal bullet slam latch  108 ,  109  as described in U.S. Pat. No. 9,630,036. The paddle handle  107  is adapted to selectively actuate the latch system  46  to move the distal ends  108 ,  109  of the latch rod assemblies  104 ,  105  and the bullet slam latch  102  from an extended position to a retracted position in which the doors  38 ,  40  can be moved from the closed position to one of a range of open positions. 
     Actuating the paddle handle  107  moves the latch rod assemblies  104 ,  105  toward each other in opposing latch rod retracting directions which in turn moves the distal bullet slam latches  108 ,  109  to retracted positions. Actuating the paddle handle  107  also moves the bullet slam latch  102  in a slam latch retracting direction to a retracted position. The bullet slam latch  102  and the first and second latch rod assemblies  104 ,  105  are adapted to bias the latch members to extended positions but also to permit the latch members to move from the extended positions to respective retracted positions in response to the door  40  moving from an open position to the closed position (in other words, when it is “slammed” closed). 
     Referring to  FIGS. 3 and 4 , for ready access to the latch system  46  for maintenance, for example, the inner panel of the right door  40  includes an access hole  135  covered by a removable cover plate  137 . The access hole  135  is disposed such that the paddle handle  107 , the proximal ends of the latch rod assemblies  104 ,  105 , and the bullet slam latch  102  are readily accessible through the hole  135 . The latch system  46 , including the bullet slam latch  102  and the latch rod assemblies  104 ,  105 , for example, can be similar in construction, operation, and other respects to one described in U.S. Pat. No. 9,630,036, which is incorporated herein by this reference. In other embodiments, the latch system  46  can have a different arrangement, as will be appreciated by one skilled in the art. For example, in other embodiments, the latch system  46  can have a construction according to principles shown and described in U.S. Pat. No. 6,729,701, which is incorporated herein by this reference. 
     Referring to  FIG. 1 , in the illustrated embodiment, the safety cabinet  30  includes the vent system  48  which is vented to the outdoors in such a manner that the ability of the safety cabinet  30  to meet the ten-minute fire test performance rating using the standard time-temperature curve as set forth in Standard Methods of Fire Tests of Building Construction and Materials, NFPA 251-1969, which is incorporated by reference, as specified in § 1910.106 is not adversely affected. In embodiments, the vent system  48  can be used to adhere to the requirements in some jurisdictions that the safety cabinet  30  be vented to prevent vapor accumulation in the cabinet and to expel toxic or noxious fumes emitted from the contents stored within the safety cabinet  30 . 
     In embodiments, the vent system  48  is mounted to the enclosure  32  such that the vent system  48  is in communication with at least one vent port  62 ,  64  of the enclosure  32 . In embodiments, the vent system  48  includes a conduit  145  having an internal passage  147  and a thermally-actuated damper  50 . The conduit  145  is connected to the enclosure  32  such that the internal passage  147  of the conduit  145  is in communication with the vent port  62  of the enclosure  32 . 
     In the illustrated embodiment, the vent system  48  includes a first conduit  145  in communication with the lower vent port  62 , a second conduit  148  in communication with the upper vent port  64 , the first and second dampers  50  associated with the first and second conduits  145 ,  148 , respectively, and an exhaust fan  149  in communication with the first conduit  145 . In embodiments, each vent port  62 ,  64  can be equipped with a suitable flash arrestor screen as are known to those skilled in the art. In the illustrated embodiment, the lower vent port  62  acts as an exhaust outlet through which air inside the interior of the enclosure  32  is drawn, and the upper vent port  64  acts as a fresh air inlet through which ambient air outside the safety cabinet  30  is delivered into the enclosure  32  of the safety cabinet  30 . 
     In embodiments, the exhaust fan  149  can be any suitable fan adapted to draw air from the interior of the enclosure  32  of the safety cabinet  30  through the first conduit  145 . In embodiments, the exhaust fan  149  includes a non-sparking fan blade and a non-sparking shroud. In embodiments, the exhaust fan  149  is arranged so that air from the interior of the safety cabinet  30  is exhausted directly outside of the structure within which the safety cabinet  30  is disposed. 
     In the illustrated embodiment, the thermally-actuated dampers  50  have substantially the same construction and operate in a similar manner. Each damper  50  is disposed within a respective conduit  145 ,  148  to form part of the internal passage  147  (see  FIG. 7 ). 
     Each thermally-actuated damper  50  is adapted to be in an open position (see  FIG. 20 ) under normal ambient temperature conditions to permit the vent system  48  to act to draw air from the interior of the enclosure out through the first conduit  145  and to convey fresh intake air into the enclosure  32  through the second conduit. Each thermally-actuated damper  50  is adapted to move to a closed position (see  FIG. 24 ) when the temperature to which it is subjected exceeds a predetermined threshold such that the conduit within which the thermally-actuated damper  50  is occluded, thereby substantially preventing airflow from or into the enclosure  32  via the vent ports  62 ,  64 . 
       FIGS. 8-26  show one of the thermally-actuated dampers  50  (or a component thereof) of the safety cabinet  30  of  FIG. 1 . It should be understood that the description of this thermally-actuated damper  50  is applicable to the other thermally-actuated dampers  50 , as well. Referring to  FIGS. 8 and 9 , in embodiments, the thermally-actuated damper  50  includes a body  150 , a valve plate  152 , and a pivot assembly  154 . In the illustrated embodiment, the thermally-actuated damper  50  includes the body  150 , the valve plate  152 , the pivot assembly  154  having a fusible link  157 , and a coupling  159 . 
     In embodiments, any suitable technique can be used to fabricate the components of the damper  50 , as will be appreciated by one skilled in the art. In embodiments, the components of the damper  50  can be produced using known machining techniques, including Computer Numerical Control (CNC) machining, or using a combination of castings and machined parts. In embodiments, other than positioning the valve plate  152  on the valve seat of the body  150 , assembly of the damper  50  can be performed from the outside of the housing body  150 . 
     Referring to  FIG. 9 , the body  150  extends along a longitudinal axis LA and has a first end  171  and a second end  172 . The ends  171 ,  172  are disposed in spaced relationship to each other along the longitudinal axis LA. The body  150  defines an internal passage  173  with a first opening  174  disposed at the first end  171  and a second opening  175  disposed at the second end  172  (see also,  FIG. 20 ). Referring to  FIG. 7 , the body  150  comprises a portion of the conduit  148  such that the opening  174  of the first end  171  of the body  150  is in communication with the upper vent port  64  of the enclosure  32 . 
     Referring to  FIGS. 7 and 20 , in embodiments, at least one of the first and second ends  171 ,  172  of the body  150  each includes a threaded surface  178  which is configured to threadingly mate with a suitable pipe section, such as a coupling  159 , for example. In the illustrated embodiment, both the first and second ends  171 ,  172  of the body  150  include a threaded surface  177 ,  178 , which in the illustrated embodiment both comprise an external threaded surface. In other embodiments, the body  150  can include at least one internal threaded surface disposed adjacent at least one of its first and second ends  171 ,  172 . 
     Referring to  FIG. 23 , the body  150  of the damper includes an exterior surface  181  and an interior surface  182 . The interior surface  182  is generally cylindrical and defines the passage  173  thereof. The exterior surface  181  is in outer radial circumscribing relationship to the interior surface  182 . 
     In embodiments, the body  150  defines a suitable valve seat  183  for sealing engagement with the valve plate  152 . In the illustrated embodiment, the interior surface  182  has a first projection  184  and a second projection  185  that define the valve seat  183 . The first and second projections  184 ,  185  are in opposing relationship to each other such that they extend radially inward toward each other. The first projection  184  is disposed adjacent the first end  171  of the body  150  and includes a first valve seat surface  187  extending radially inwardly and facing the second end  172  of the body  150 , and the second projection  185  includes a second valve seat surface  188  extending radially inwardly and facing the first end  171  of the body  150 . The first and second projections  184 ,  185  are similar in shape and size and comprise arcuate segments (see, e.g.,  FIG. 9 ). 
     Referring to  FIG. 24 , the valve seat  183  comprises the first and second valve seat surface  187 ,  188 . In the illustrated embodiment, the first and second valve seat surface are disposed in offset relationship to each other along the longitudinal axis LA in an amount substantially equal to the thickness of the valve plate  152 . 
     Referring to  FIG. 9 , in embodiments, the body  150  defines a cross bore  191  that extends radially from the exterior surface  181  to the interior surface  182 . The cross bore  191  can be configured to accommodate the access of the pivot assembly  154  to the valve plate  152 . In the illustrated embodiment, the body  150  defines a pair of cross bores  191 ,  192 . The cross bores  191 ,  192  are in opposing relationship to each other and both extend radially from the exterior surface  181  to the interior surface  182 . 
     In the illustrated embodiment, the body  150  includes a link anchor post  194  configured to secure the fusible link  157  thereto. The link anchor post  194  projects outwardly from the body  150 . 
     Referring to  FIGS. 9-11 , the valve plate  152  comprises a substantially flat circular disc configured to selectively occlude the passage  137  of the body  150 . The valve plate  152  includes a central rib  201  that defines first and second threaded bores  203 ,  205  therein that are configured to threadingly engage portions of the pivot assembly  154  to facilitate the rotational movement of the valve plate  152  between an open position and a closed position. The valve plate includes a drive member engagement portion  207  coinciding with the first threaded bore  203 . The engagement portion  207  is configured to be rotatively coupled with a drive member  210  of the pivot assembly  154  to permit the pivot assembly  154  to selectively rotate the valve plate  152  with respect to the body  150 . 
     Referring to  FIGS. 20 and 24 , the valve plate  152  is disposed within the passage  173  of the body  150  such that the valve plate  152  is intermediately disposed along the longitudinal axis LA between the first end  171  and the second end  172  of the body  150 . The valve plate  152  is movable between an open position (as shown in  FIG. 20 ) and a closed position (as shown in  FIG. 24 ). The valve plate  152  permits air flow between the openings  174 ,  175  of the passage  173  of the body  150  when the valve plate  152  is in the open position, and the valve plate  152  substantially occludes the passage  173  of the body  150  when the valve plate  152  is in the closed position to substantially prevent air flow between the openings  174 ,  175  of the passage. 
     In the illustrated embodiment, the valve plate  152  is in contacting engagement with the first projection  184  and the second projection  185  when the valve plate  152  is in the closed position. The pivot assembly  154  is operable to pivot the valve plate  152  about a pivot axis PA in a closing direction  214  from the open position in  FIG. 20  to the closed position in  FIG. 24 . The valve plate  152  includes a first face  211  and a second face  212  in opposing relationship to the first face  211  (see also  FIG. 10 ). The first and second faces  211 ,  212  are both circular and are substantially the same size. The first and second valve seat surfaces  187 ,  188  are configured to interferingly engage the first and second faces  211 ,  212  of the valve plate  152 , respectively, to prevent the valve plate  152  from rotating further about the pivot axis PA in the closing direction  214 . 
     Referring to  FIG. 9 , the pivot assembly  154  is adapted to selectively move the valve plate  152  from the open position to the closed position in the event that the ambient thermal conditions of the damper  50  exceed a threshold level. The pivot assembly  154  can be connected to the body  150  and the valve plate  152 . The illustrated pivot assembly  154  includes a valve support assembly  221 , a biasing system  223 , and the fusible link  157 . 
     In embodiments, the valve support assembly  221  is adapted to support the valve plate  152  such that the valve plate  152  is movable between the open position and the closed position. In the illustrated embodiment, the valve support assembly  221  is adapted to support the valve plate  152  such that the valve plate  152  is rotatably movable about the pivot axis PA between the open position and the closed position. In embodiments, the valve support assembly  221  is mounted to the body  150  and the valve plate  152 . 
     In the illustrated embodiment, the valve support assembly  221  includes a pair of bushings  231 ,  232 , a pair of trunnion members  234 ,  235 , a pair of washers  237 ,  238 , and a support sleeve  239 . The bushings are respectively disposed at least partially within the cross bores of the body  150 . In embodiments, the bushings  231 ,  232  can be made from any suitable material. For example, in embodiments, the bushings  231 ,  232  can be made from a material that inhibits the production of electrical sparks from friction caused by relatively moving parts. In embodiments, the bushings  231 ,  232  are made from a suitable brass. 
     Referring to  FIGS. 17 and 21 , the trunnion members  234 ,  235  are connected to the valve plate  152  such that the trunnion members  234 ,  235  extend, respectively, from the valve plate  152  into the cross bores  191 ,  192  of the body  150 . The trunnion members  234 ,  235  and the valve plate  152  are pivotable about the pivot axis PA with respect to the body  150 . The trunnion members  234 ,  235  each include a distal end  241 ,  242 . The trunnion members  234 ,  235  extend, respectively, from the valve plate  152  into the bushings  231 ,  232  such that the distal ends  241 ,  242  of the trunnion members  231 ,  232  are disposed laterally outward of the bushings  231 ,  232  with a respective one of the washers  237 ,  28  interposed therebetween. The trunnion members  234 ,  235  extend through the bushings  231 ,  232 , respectively, such that the distal end  241 ,  242  of each trunnion member  234 ,  235  is disposed in outer relationship to the respective bushing  231 ,  232  such that the distal ends  241 ,  242  of the trunnion members  231 ,  232  provide a captured connection between the valve plate  152  and the body  150 . 
     In the illustrated embodiment, the valve support assembly  221  is adapted to support the valve plate  152  such that the valve plate  152  is rotatably movable about the pivot axis PA between the open position and the closed position. The valve plate  152  rotates about the pivot axis PA in the closing direction  214  when moving from the open position to the closed position. In embodiments, at least one of the first and second projections  184 ,  185  of the body  150  is configured such that said at least one of the first and second projections  184 ,  185  defines the location of the closed position by being configured to interferingly engage the valve plate  152  to prevent the valve plate  152  from rotating from the open position further about the pivot axis PA in the closing direction  214  (see also,  FIGS. 25 and 26 ). 
     Referring to  FIG. 8 , the biasing system  223  is adapted to bias the valve plate  152  to the closed position. In embodiments, the biasing system  223  is mounted to the body  150  such that it acts upon the valve plate  152  and is adapted to bias the valve plate  152  to the closed position. In embodiments, the biasing system  223  is mounted to the body  150  and at least one of the valve plate  152  and the valve support assembly  221 . 
     Referring to  FIG. 9 , in the illustrated embodiment, the biasing system  223  includes the drive member  210  and a spring  251 . Referring to  FIGS. 19 and 23 , the drive member  210  defines the pivot axis PA. The drive member  210  extends through the first cross bore  191  of the body  150  (see also,  FIG. 9 ). The drive member  210  is coupled to the valve plate  152  such that rotational movement of the drive member  210  about the pivot axis PA correspondingly rotates the valve plate  152 . The spring  251  is mounted to the body  150  and to the drive member  210  such that the spring  251  exerts a spring force against the drive member  210  configured to rotate the drive member  210  about the pivot axis PA in the closing direction  214  when the fusible link  157  melts to move the valve plate  152  from the open position to the closed position (see also,  FIGS. 18 and 22 ). 
     Referring to  FIG. 9 , in the illustrated embodiment, the drive member  210  of the damper  50  comprises a drive sleeve  253  and a pivot arm  255 . The drive sleeve  253  extends along the pivot axis PA through one of the cross bores  191  of the body  150 . Referring to  FIGS. 9 and 12-14 , the drive sleeve  253  includes an inner end  257  and an outer end  258 . The inner end  257  of the drive sleeve  253  is coupled to the valve plate  152  such that rotational movement of the drive member  210  about the pivot axis PA correspondingly rotates the valve plate  152 . In the illustrated embodiment, the inner end  257  comprises a valve plate socket that is configured to engagingly receive the engagement portion  207  of the valve plate  152 . The outer end  258  of the drive sleeve  253  is disposed in outer relationship to the exterior surface  181  of the body  150 . 
     Referring to  FIGS. 15 and 16 , the pivot arm  255  includes a proximal end  260  that defines a generally square-shaped opening  261  that is configured to engagingly receive the outer end  258  of the drive sleeve  253  therein. The pivot arm  255  includes a distal end  263  that defines a mounting hole  265  therethrough that is configured to threadingly receive a link fastener  267  therein (see also,  FIG. 9 ) to help secure the link  157  to the biasing system  223 . The pivot arm  255  also defines a spring mounting hole  269  therein that is configured to retain therein an end of the spring  251 . In the illustrated embodiment, the spring mounting hole has a chamfered (or frustoconical) shape to help facilitate the insertion of the end of the spring  251  therein. Referring to  FIGS. 18 and 21 , the pivot arm  255  is mounted to the drive sleeve  253  adjacent the outer end  258  thereof such that the distal end  263  of the pivot arm  255  projects from the drive sleeve  253 . 
     Referring to  FIG. 21 , the spring  251  is connected to the pivot arm  255  via the spring mounting hole defined through the pivot arm  255 . Referring to  FIG. 22 , in the illustrated embodiment, the body  150  defines a second spring mounting  271  hole therein to retentively receive therein the other end of the spring  251 . In embodiments, the spring  251  is mounted to the body  150  and to the pivot arm  255  such that the spring  251  exerts a spring force against the drive sleeve  253  configured to rotate the drive member  210  about the pivot axis PA in the closing direction  214  to move the valve plate  152  from the open position to the closed position. 
     Referring to  FIGS. 17 and 18 , the fusible link  157  is interconnected between the body  150  and the biasing system  223  to form an interconnection therebetween such that the valve plate  152  is disposed in the open position. In embodiments, the fusible link  157  is retentively connected to the drive member  210  to constrain the rotational movement of the drive member  210  about the pivot axis PA such that the valve plate  152  is disposed in the open position. In the illustrated embodiment, the fusible link  157  is retentively connected to the body  150  and to the pivot arm  255  to constrain the rotational movement of the drive member  210  about the pivot axis PA such that the valve plate  152  is disposed in the open position. 
     The fusible link  157  constrains the valve plate  152  from moving from the open position to the closed position via the interconnection of the fusible link  157  between the body  150  and the biasing system  223 . The fusible link  157  is configured to melt at a predetermined temperature to thereby disengage the interconnection of the fusible link  157  between the biasing system  223  and the body  150  and to thereby allow the biasing system  223  to move the valve plate  152  to the closed position. 
     In the illustrated embodiment, the fusible link  157  of the damper includes a first link end  274  and a second link end  275 . The first link end  274  of the fusible link  157  is mounted to the link anchor post  194  via a fastener  267 , and the second link end  275  of the fusible link  157  is mounted to the distal end  263  of the pivot arm  255  via a second fastener  267 . Referring to  FIG. 9 , a pair of washers  277  can be associated with each link fastener  267  to help permit each end  274 ,  275  to be relatively rotatable with respect to the component to which it is connected. The washers  277  can be disposed on both sides of the link  157  such that the link is interposed between the pairs of washers  277 . 
     Referring to  FIGS. 9 and 20 , the coupling  159  includes a mating threaded surface  280  that is configured to threadingly engage at least one of the threaded surfaces  178  of the first and second ends  171 ,  172  of the body  150  such that the coupling  159  is substantially aligned with the body  150  along the longitudinal axis LA thereof. Referring to  FIG. 7 , in embodiments, the coupling  159  comprises a portion of the conduit  148 . In embodiments, the conduit  148  includes pipe sections  282  that are coupled to the coupling  159  of the damper  50 . In embodiments, the pipe sections  282  can be made from a suitable plastic, such as PVC, for example. In embodiments, the pipe section  282  can be made from plastic rather than metal to provide a cost savings and to help facilitate the installation of the conduit  148 . 
     The safety cabinet  30  can be similar in construction and functionality in other respects to a safety cabinet as shown and described in U.S. Pat. No. 6,729,701, which is incorporated in its entirety herein by this reference. For example, the other components of the latch system  46 , the retaining system  42 , and the closure system  44  can be similar to those shown and described in U.S. Pat. No. 6,729,701. In embodiments, the safety cabinet  30  can be similar in construction and functionality in other respects to a safety cabinet as shown and described in any of U.S. Pat. Nos. 8,172,344 and/or 9,630,036 and/or U.S. Patent Application Publication No. US2008/0106174 and/or US2013/0200767, which are all incorporated in their entireties herein by this reference. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the present disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the present disclosure and does not pose a limitation on the scope of the present disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the present disclosure. 
     Preferred embodiments of this present disclosure are described herein, including the best mode known to the inventors for carrying out the present disclosure. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the present disclosure to be practiced otherwise than as specifically described herein. Accordingly, this present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.