Abstract:
Embodiments of a bunghole cover are disclosed. The bunghole cover may have a main body with a lower portion, and the lower portion may be configured to engage a bunghole of a storage drum. The bunghole cover may also have a sealing portion configured to substantially conform around one or more tubes inserted within the bunghole The bunghole cover may also have at least one connection mechanism configured to connect a first portion of the main body to a second portion of the main body.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The subject matter described herein relates to storage drums, and more specifically to covers for the openings of chemical storage drums. 
         [0003]    2. Description of the Related Art 
         [0004]    Chemical feed systems are often used to extract chemicals from storage drums. Chemical feed systems may include a section of suction tubing, a chemical pump, and a section of discharge tubing. The suction tubing may be placed in the opening or bunghole of a storage drum in order for the chemical pump to draw the chemical out, and may include a check or foot valve to prevent backflow and/or a screen or filter on the bottom of the suction tubing in the drum. The diameter of the suction tubing is smaller than the diameter of the bunghole, thereby leaving at least a portion of the bunghole uncovered and allowing the suction tubing to move within the bunghole. 
         [0005]    If the bunghole is not at least partially covered, the contents of a storage drum may be exposed to the surrounding atmosphere or environment. For example, an uncovered bunghole increases the risk of splashing of the chemical (such as when the drum is moved or accidentally impacted). An uncovered bunghole also increases the possibility of chemical off-gassing which in turn may cause environmental contamination, odors, and in some cases an unpleasant or even dangerous workplace. Off-gassing may also reduce the shelf-life of a chemical stored in the storage drum if the product is volatile. An uncovered bunghole also increases the risk of contamination of the stored chemical itself because of the possibility that dirt, dust, other chemicals, vapors, etc. may enter the drum through the uncovered bunghole. 
         [0006]    Previous attempts to minimize these effects while still allowing a chemical feed system to be used include bunghole closures that secure the suction tubing and/or seal the bunghole. These bunghole closures, however, usually require the bunghole closure to be installed at the same time as the chemical feed system is installed, and cannot be installed once the suction tubing is already in place. If the suction tubing is already in place and the bunghole closure is to be installed, the suction tubing must first be removed, which may present a chemical hazard to the person removing the suction tubing or the surrounding surfaces. 
         [0007]    Also, some of these previous bunghole closures have threads or other features that are specific to one type of storage drum, and are thus not adaptable. Some only allow for a single section of suction tubing to be used to withdraw the stored chemical. Other bunghole closures have a separate portion of suction tubing used within the drum (i.e. one portion of suction tubing in the drum feeds into the bunghole closure, which feeds into a second portion of suction tubing, which feeds into the chemical pump) which increases the possibility of leaks, cracks, or other problems with the tubing sections. 
         [0008]    The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention as claimed is to be bound. 
       SUMMARY 
       [0009]    The various embodiments of a bunghole cover disclosed herein allow chemical storage drum bungs to be at least partially covered so as to reduce splashing, reduce off-gassing, increase the shelf life of the stored chemical, help prevent contamination, and so forth. The embodiments disclosed may be installed at the same time as a chemical feed system is installed or may also be placed on or in the bunghole after the chemical feed system is already in place. Furthermore, the flexibility of the disclosed embodiments allows for multiple lines of suction tubing to be used, and also allows a single bunghole cover to be used with several different types of bungholes. 
         [0010]    A first embodiment of a bunghole cover may include a vinyl main body with a skirt-like shape, an elastic cinch, a releasable closure strap at the top of the main body, and releasable strips along the sides and a portion of the bottom of the main body. A second embodiment of a bunghole cover may include two half-circle, cylindrical halves that taper from the top to the bottom. A third embodiment of a bunghole cover may include a disk-shaped injection-molded plastic main body with foam inserts and a flange extending downward to attach to the top of the bunghole. A fourth embodiment of a bunghole cover may include a sheet of nitrile with one or more release tabs. The sheet of nitrile may have adhesive along the borders of the sheet. In some instances, one or more of the embodiments may be used together. For example, the first and second embodiments may be used together to cover a bunghole. Or, the fourth embodiment may be used with any of the first, second, or third embodiments. Also, additional embodiments similar to the first, second, third, and fourth disclosed embodiments of a bunghole cover may be used. 
         [0011]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other features, details, utilities, and advantages of the present invention will be apparent from the following more particular written description of various embodiments of the invention as further illustrated in the accompanying drawings and defined in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1A  depicts a drum with two bungholes, a pump, and tubing coming out of one of the bungholes and into the pump. 
           [0013]      FIG. 1B  is a close-up of the bunghole and tubing of  FIG. 1A . 
           [0014]      FIG. 2A  is an isometric view of one embodiment of a bunghole cover, with the bunghole cover in a closed position. 
           [0015]      FIG. 2B  is a plan view of the bunghole cover of  FIG. 2A , with the bunghole cover open and laid flat. 
           [0016]      FIG. 2C  is an isometric view of the bunghole cover of  FIGS. 2A and 2B  placed on the bunghole of a drum. 
           [0017]      FIG. 3A  is an isometric view of a second embodiment of a bunghole cover. 
           [0018]      FIG. 3B  is a top plan view of the bunghole cover of  FIG. 3A . 
           [0019]      FIG. 3C  is a cross-section view of the bunghole cover of  FIGS. 3A and 3B  viewed along line  3 C- 3 C of  FIG. 3B . 
           [0020]      FIG. 3D  is an isometric view of the bunghole cover of  FIGS. 3A ,  3 B, and  3 C placed in the bunghole of a drum. 
           [0021]      FIG. 4A  is an isometric view of a third embodiment of a bunghole cover. 
           [0022]      FIG. 4B  is an isometric view of the bunghole cover of  FIG. 4A  in an open position. 
           [0023]      FIG. 4C  is a top plan view of the bunghole cover of  FIG. 4A . 
           [0024]      FIG. 4D  is a cross-section view of the bunghole cover of  FIGS. 4A through 4C  viewed along line  4 D- 4 D of  FIG. 4C . 
           [0025]      FIG. 4E  is an isometric view of the bunghole cover of  FIGS. 4A , through  4 D, placed on the bunghole of a drum. 
           [0026]      FIG. 5A  is a bottom plan view of a fourth embodiment of a bunghole cover. 
           [0027]      FIG. 5   b  is an isometric view of the bunghole cover of  FIG. 5A  placed on the bunghole of a drum. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]      FIG. 1A  shows a chemical feed system  100  that includes a storage drum  150  with two bungholes  152 ,  154 , a portion of suction tubing  156 , a chemical pump  158 , and a portion of discharge tubing  160 . The storage drum  150  may be made of polyethylene, some other type of plastic, metal, or any type of material suitable for storage of a chemical. Note also that the drum  150  may be used to store materials other than chemicals, such as water. The storage drum  150  may be any size, such as a 5-gallon, 15-gallon, 30-gallon, or 55-gallon drum. In still other embodiments, a larger (e.g., 250-375 gallon) chemical tote may be used. The suction  156  and discharge  160  tubing may also be made of polyethylene or any other type of chemically-resistant material. The suction tubing  156  may include a check valve or a foot valve connected at a distal end, and may also include a screen or filter (not shown in  FIG. 1A ). The suction tubing  156  may extend down to the bottom of the drum  150  so as to enable the pump  158  to draw all of the stored chemical out of the drum  150 . The chemical pump  158  may be manual or electric, and may include a meter, an adjustable pump speed, and so forth. The chemical pump  158  may be placed on a nearby table or other supporting structure  170 , as shown in  FIG. 1 . 
         [0029]      FIG. 1B  is a close-up view of the bunghole  152  and tubing  156  shown in  FIG. 1A . The bungholes  152 ,  154  are defined by a circumferential lip or rim  162  that extends above the top surface of the drum  150 . The rim  162  may be threaded to receive threaded caps that seal the bungholes  152 ,  156  during storage or transportation. In some embodiments, the outer surface of the bunghole rim  162  may be threaded (as shown in  FIG. 1A ), while in other embodiments the inner surface of the bunghole rim  162  may be threaded. In other embodiments, the inner surface of the bunghole rim  162  may be threaded, and the outer surface of the bunghole rim may have a single thread-type protrusion. Because the bunghole  152  of  FIG. 1B  is not covered, splashing, off-gassing, and so forth may occur. 
         [0030]      FIG. 2A  is an isometric view of a first embodiment of a bunghole cover  210 . The bunghole cover  210  shown in  FIG. 2A  includes a vinyl body  212 , an elastic cinch  214 , a hook and loop (e.g. Velcro™) closure strap at the top  216 , and opposing hook and loop strips  218  on the sides and on a portion of the bottom. It also includes a hook and loop pull tab  220  that protrudes from the bottom of the bunghole cover  210 . The body  212  of the bung cover  210  may have a skirt-like shape; specifically, the body  212  may have an arc-shaped top  222  and bottom  224 , with the bottom  224  being wider than the top  222 , and straight sides.  FIG. 2B  is a plan view of the bunghole cover  210  of  FIG. 1  laid flat, and illustrates the skirt-like shape, as just described. The bunghole cover  210  of  FIGS. 2A and 2B  may also have an elastic cinch  214 . The cinch  214  may in some embodiments be formed by attaching an elastic strap to the bottom of the body  212 , such as by sewing. The hook and loop closure strap  216  at the top of the bunghole cover  210  may be attached to the back side of the bunghole cover  210  (again, for example, by sewing), and may have loops on one side and hooks on the other so that when wrapped around, it attaches to itself. The hook and loop closure strap  216  may be provided in several different colors so as to allow a user to color-code chemical storage bins. The bunghole cover  210  may also have various configurations of hook and loop straps  218 . As shown in  FIGS. 2A and 2B , some embodiments of a bunghole cover  210  may include a portion of hooks  218  on the right, rear side of the body, and a portion of loops  218  on the left, front side of the body  212  or vice versa. The hooks  218  and loops  218  may be placed along the left and right sides of the body  212 , and may also extend along the bottom of the body  212  for further attachment. 
         [0031]      FIG. 2C  shows the first embodiment of a bunghole cover  210  placed on the bunghole  252  of a chemical storage drum  250 . In  FIG. 2C , the body  212  of the bunghole cover  210  has been wrapped around the rim  262  of the bunghole  252 , with tubing  256  extending from it and with the cinch  214  at the bottom of the bunghole cover  210  engaging the sidewalls of the bunghole  252 . The hooks  218  on the right rear side engage the loops  218  on the left front side of the body and the hook and loop closure strap  216  at the top of the cover  210  wraps around and engages itself. Note that the top  222  of the bunghole cover  210  (along with the closure strap  216 ) provide some flexibility for one, two, or more sections of suction tubing  256  to be used. Also, note that the bunghole cover  210 , while helping to prevent most materials from improperly entering or exiting the drum  250 , does allow for slight air permeation, which allows for the displacement of the liquid volume as the chemical is withdrawn from the drum  250 . 
         [0032]    Many variations on the specific design of the bunghole cover  210  shown in  FIGS. 2A through 2C  are possible. For example, although the body  212  of the bunghole cover  210  of  FIG. 2A  may be made of vinyl, the body  212  may also be made of rubber or any other chemically-resistant material appropriate for the application. Generally, the type of material may depend on the type of chemical stored in a drum  250  that needs to be covered. For example, if a chemical is known to interact with vinyl, then a different type of material may be used for constructing the body  212  of the bunghole cover  210 . In some embodiments, the body  212  may be made of a stretchable material to provide further flexibility. Also, any type of fastener or fastening mechanism may be used in place of the hook and loop strips  218  and/or hook and loop closure strap  216  of  FIGS. 2A-2C , for example, snaps, buttons, a zipper, adhesive, one or more clip(s), a tie string, and so forth. In some embodiments, the top portion  222  of the bunghole cover  210  may also include a cinch or other tightening closure mechanism. In some embodiments the bottom cinch  214  and/or top cinch can be a pull string, or some other type of elastic mechanism enclosed within a hem or seam along the bottom edge  224 . The cinch  214  may also be formed in any of several different ways. For example, the cinch  214  may be formed by folding the bottom portion  224  of the body  212  over on itself while inserting a piece of elastic material, and sewing the body  212  to the elastic and to itself. 
         [0033]    Also, the placement of the hook and loop material  218  or other fastening mechanism may be different than that shown in  FIGS. 2A through 2C . For example, there may be no hook and loop material  218  on the bottom of the cover  210 , or there may be no hook and loop material  218  along the sides of the cover  210 . In other embodiments, all of the hook and loop material  218  may extend from the body  212  of the bunghole cover  210  (just as the tab  220  at the lower right side in  FIG. 2B  does), or one or more strips of hook and loop material  218  may be placed more towards the center of the body  212  rather than on the sides and bottom  224 . The hook and loop material  218  (or other fastening mechanism, as discussed above) may be joined to the body  212  of the bunghole cover  210  in any of various ways, such as by sewing, adhesive, bonding, and so forth. The body  212  of the bunghole cover  210  may also be different than that shown in  FIG. 2B . For example, the body  212  may be a generally rectangular shape. Also, the bunghole cover  210  shown in  FIGS. 2A through 2C  may generally be adaptable to any of a 5-, 15-, 30-, or 55-gallon drum  250 . A larger bunghole cover  210 , similarly constructed, may be used for a larger chemical tote. 
         [0034]      FIGS. 3A through 3D  show a second embodiment of a bunghole cover  310 . Specifically,  FIG. 3A  shows an isometric perspective view of a second embodiment of a bunghole cover  310  that may be placed within a bunghole  352  of a storage drum  350 . The bunghole cover  310  shown in  FIG. 3A  may be made of foam  312 , which may be cut from a larger block of foam or may be injection molded foam. The foam  312  may be coated with a vinyl or other coating  318  to resist interaction with one or more chemical products, as well as to resist deterioration of the foam  312 . The foam  312  may be coated on all sides with the chemically-resistive coating  318  either during formation (e.g., as during the injection molding process) or after the foam  312  is formed. The coating  318  may allow the foam  312  to still be flexible so as to allow tubing  356  to be placed between the two halves  314 ,  316  of the bunghole cover. 
         [0035]      FIG. 3B  shows a top plan view of the second embodiment of a bunghole cover  310 . The cover  310  may include two halves  314 ,  316  that are similarly shaped. The two halves  314 ,  316  together may form a frustum.  FIG. 3C  shows a cross section view of the bunghole cover  310  shown in  FIG. 3B  along line  3 C- 3 C. As can be seen in  FIG. 3C , the sides of the bunghole cover  310  taper down so that the top  320  of the bunghole cover  310  is larger than the bottom  322 , thus generally forming a cork-type or inverted frustum shape, split in half In one embodiment, the top  320  of the bunghole cover  310  may be approximately three inches in diameter, which is slightly wider than the bunghole  352  for 5-, 15-, 30-, and 55-gallon storage drums, and the body of the cover  310  may taper down to be approximately two inches in diameter at the bottom  322 , which is slightly smaller than the bunghole  352  for 5-, 15-, 30-, and 55-gallon storage drums. Accordingly, the bunghole cover  310  shown in  FIGS. 3A through 3C  may be placed within the bunghole  352  of a drum  350  because the bottom  322  is smaller in diameter than the bung opening  352 , but may not fall through the bunghole  352  because the top  320  is larger in diameter than then bung opening  352 . 
         [0036]      FIG. 3D  shows the second embodiment of a bunghole cover  310  placed in the bunghole  352  of a storage drum  350 , with a portion of suction tubing  356  protruding from the bunghole  352  and bunghole cover  310 . As can be seen in  FIG. 3D , the sides of the bunghole cover  310  engage the sides of the bunghole  352  near the top  320  of the bunghole cover  310  at the point where the diameter of the sides of the bunghole cover  310  approximately equal the diameter of the bunghole  352 . As can also be seen in  FIG. 3D , one, two, or more sections of tubing  356  may be used with the second embodiment of a bunghole cover  310 . 
         [0037]    The second embodiment of a bunghole cover  310  shown in  FIGS. 3A through 3D  may be used alone or in combination with the first embodiment of a bunghole cover  210  shown in  FIGS. 2A through 2C . Specifically, the second embodiment of a bunghole cover  310  may be placed in the bunghole  352  of a storage drum  350 , while the first embodiment of a bunghole cover  210  may be wrapped around the side-walls of the bunghole  352 . Combining the first  210  and second  310  embodiments together may provide greater reduction in off-gassing, more security to keep the suction tubing  356  in place, additional barriers for protecting against contamination, and so forth. Nonetheless, either of the first  210  and/or second  310  embodiments of a bunghole cover may be used separately. 
         [0038]    If the first  210  and second  310  embodiments are used together, a strap (not shown) may be attached between the first embodiment  210  and the second embodiment  310  in order to keep them together. For example, small holes may be made in the body  212  of the first embodiment  210 , and in the first and second halves  314 ,  316  of the second embodiment  310 , and a string or strap may be placed through the holes and tied. 
         [0039]    As with the first embodiment  210  described above, the second embodiment (alone or in combination with the first embodiment  210 ) of a bunghole cover may allow for slight air permeation into the drum  350  in order to allow for displacement of liquid volume as a stored chemical is withdrawn from the storage drum  350 . It also allows for one, two, or more sections of suction tubing  356  to be used. 
         [0040]    As with the first embodiment  210 , many variations to the second embodiment  310  are possible. For example, the shape of the second embodiment  310  may vary, and may be, for example, in the shape of a frustum, a tapered hexagonal section, a tapered square section, etc. Additionally, the second embodiment of a bunghole cover  310  may not have a chemically-resistive coating in order to make the foam  312  less costly. In other embodiments the foam  312  may only be coated on the bottom. In still other embodiments, a material other than foam may be used. For example, capsules shaped similarly to the foam  312  shown in  FIG. 3A  may be filled with gel, water, sand, air, cotton, rubber, beads, or another material and placed within the bunghole  352  of a drum  350 . A flexible and compressible rubber or elastomer material may be used. Also, in some embodiments, a strap or other type of connection may be used to join the two halves  314 ,  316  of the bunghole cover  310  to help prevent a user from dropping the two halves  314 ,  316  in the storage drum  350  during installation. Also, the dimensions of the bunghole cover  310  may vary from the dimensions described above. For example, the bottom  322  of the cover  310  may be only one inch in diameter, and the top  320  of the cover  310  may be four inches in diameter. Furthermore, when the second embodiment of a bunghole cover  310  is used for larger chemical totes, the dimensions of the bunghole cover may be adapted to the bungholes or openings of the chemical totes. 
         [0041]      FIGS. 4A through 4E  show a third embodiment of a bunghole cover  410 . Specifically,  FIG. 4A  shows an isometric view of the third embodiment of a bunghole cover  410  in a closed position. The third embodiment may take the form of a plastic clamp  412  housing a foam body. The main body  414  of the bunghole cover  410  may be an exterior shell made of non-adherent plastic and may be formed, for example, by an injection molding technique. The main body  414  may be generally circular in shape, and may be comprised of two halves  418 ,  420 . 
         [0042]      FIG. 4B  shows an isometric view of the third embodiment of a bunghole cover  410  in an open position. As shown in  FIG. 4B , each of the two halves  418 ,  420  may have opposing tangential flange structures  416 ,  426  defining apertures. Each half  418 ,  420  may have a single flange structure  416  on one side and a double flange structure  426  on the opposite side. The flanges of the double flange structure  426  are parallel and spaced apart and the single flange structure  416  is positioned on the side of each half  418 ,  420  such that it may fit between the flanges of the double flange structure  426 . In this manner, the two halves  418 ,  420  may be identical, which may facilitate manufacturing. The two halves  418 ,  420  may be joined together by interlocking the single flange structure  416  of each half  418 ,  420  with the double flange structure of each half  418 ,  420 . When the single flange structure  416  interlocks with the double flange structure  426 , the apertures in the flange structures  416 ,  426  align. The two halves  418 ,  420  of the bunghole cover  410  may be joined by a pin  424  placed through the aperture in the overlapping flange structures  416 ,  426  on one side of the main body  414 . The pin  424  (which may be plastic) may form a hinge-type structure as shown in  FIG. 4B . The tangential flange structures  416 ,  426  on the other side of the two halves  418 ,  420  may similarly be interleaved and a locking mechanism (not shown) may be placed through the apertures in the flange structures  416 ,  426  to lock the cover  410  on the bunghole  452  of a chemical drum  450 . Exemplary lock mechanisms may include plastic zip ties, wire, pad locks, spring clips, or any other mechanism capable of insertion through the apertures in the flange structures  416 ,  426 . 
         [0043]    As can be further seen in  FIG. 4B , a material such as foam  430  may fill the cavity of the main body  414  or exterior shell of the third embodiment of a bunghole cover  410 . The foam  430  may be similar to the foam  312  described above in connection with  FIGS. 3A through 3C  (the second embodiment of a bunghole cover  310 ) in that it may have a chemically-resistant coating  346 . Also, as discussed above, capsules filled with water or sand or other material, rubber filler, or any other material may be used to fill the cavity of the exterior shell  414 . In this embodiment, the foam halves  430  may form a disk-shape as opposed to an inverted frustum as in the second embodiment. As shown in  FIG. 4B , the foam  430  or other material may extend throughout the cavity, but in other embodiments it may not. The foam  430  (or other material) inserts may be replaceable. 
         [0044]      FIG. 4B  also shows that the third embodiment of a bunghole cover  410  may include a flange  432  on the bottom that clamps around the raised lip or spout of the bunghole  152  to fasten the cover  410  in place around the bunghole  452 . Although many dimensions are possible, the flange  432  may extend in some embodiments approximately a half an inch downward from the outside edge of the main body exterior shell  414 , and may have a lip  434  that extends approximately a quarter of an inch towards the center of the cover  410  to fit underneath the threading on the spout of the bunghole  152 , which is a common configuration of many chemical drums  150 . 
         [0045]      FIG. 4C  shows a top plan view of the third embodiment of a bunghole cover  410 , and  FIG. 4D  shows a cross-section view of the bunghole cover  410  of  4 C viewed along line  4 D- 4 D.  FIG. 4E  shows the bunghole cover  410  of  FIGS. 4A-4D  placed around the bunghole  452  of a chemical storage drum  450  with a section of suction tubing  456  exiting out of the drum  450  through the bunghole cover  452 . The third embodiment of the bunghole cover  410  as shown in  FIGS. 4A through 4E  may be easy to install and is also durable, particularly if the foam inserts  430  are replaceable. The third embodiment  410  may be useful in high traffic areas. As with the first  210  and second  310  embodiments described above, the third embodiment of the bunghole cover  410  may allow for slight air permeation through the small gap between the halves of foam  430  around the suction tubing  456  into the drum  450  in order to allow for displacement of liquid volume as a stored chemical is withdrawn from the storage drum  450 . It also allows for one, two, or more sections of suction tubing  456  to be used. 
         [0046]    The flange  432  on the bottom of the cover  410  may have many different dimensions than that shown in  FIGS. 4B and 4D  and described above. For example, the flange  432  may extend one inch downward. Also, the flange may not be flush with the edges of the main body  414 . In some embodiments, the flange  432  and lip  434  may be formed with the main body  414  in, for example, an injection molding process, or the flange  432  and lip  434  may be joined to the main body  414  later. Additionally, the flange  432  may be used without a lip  434 . As also explained above, the foam  430  within the main body shell  414 , may be a different material, or a capsule may be used in place as well. In some embodiments, the foam  430  and the main body shell  414  may be shaped so that the foam  430  (or other) inserts in the third embodiment of a bunghole cover  410  are similar or identical to the foam  312  (or other material) used in the second embodiment of a bunghole cover  310  as shown in  FIGS. 3A through 3D . Also, a different connection mechanism  424  may be used rather than the pin described above. 
         [0047]      FIGS. 5A and 5B  show a fourth embodiment of a bunghole cover  510 . Specifically,  FIG. 5A  shows the bottom or under side of the fourth embodiment  510  laid flat. The cover  510  may be made of a form of nitrile  512  (such as nitrile butadiene rubber or NBR) and may be approximately five to seven mils thick. The length and width of the cover  510  may vary depending on the size of the bunghole, but in general may be approximately five inches by twelve inches for bungholes on 5-, 15-, 30-, and 55-gallon drums. A sufficient length may allow the nitrile sheet  510  to wrap around and adhere to itself to enhance the seal. An adhesive  514  may coat the exterior border on the bottom or under side of the nitrile sheet  510 . The adhesive  514  may be a synthetic elastomer or other type of adhesive  514  that sticks to nitrile  512  and polyethylene drums. For example, the adhesive  514  may be 3M™ Hi-Strength 90 Adhesive, 3M™ Scotch-Weld™ Hi-Strength Cylinder Spray Adhesive, 3M™ Scotch-Weld™ High Performance Industrial Plastic Adhesive, and so forth. 
         [0048]    Strips of plastic release (not shown) may be placed over the adhesive  514  on the nitrile  512  for storage and shipping. Also, one or more tabs may be placed on the sides of the nitrile sheet, which may or may not also have adhesive. The tabs  518  may facilitate removal of the fourth embodiment of a bunghole cover  510 , which may be used as a one-time, quick-to-apply, quick-to-remove bunghole cover  510 . 
         [0049]      FIG. 5B  shows the bunghole cover  510  of  FIG. 5A  wrapped around the sidewall  562  of the bunghole  552  of a chemical storage drum  550 . It also shows two sections of suction tubing  556  protruding from the bunghole  552  and bunghole cover  510 . 
         [0050]    As with the first  210 , second  310 , and third  410  embodiments described above, the fourth embodiment  510  of a bunghole cover may allow for slight air permeation into the drum  550  in order to allow for displacement of liquid volume as a stored chemical is withdrawn from the storage drum  550 . It also allows for one, two, or any number of sections of suction tubing  556  to be used—two sections of suction tubing  556  are shown in  FIG. 5B . 
         [0051]    Many variations are also possible for the fourth embodiment of a bunghole cover  510 . For example, the main body or sheet  510  may be made from a material other than nitrile, for example, vinyl, rubber, or any material that is resistant to chemical deterioration and chemical reactions, which may vary depending on the chemical stored. Also, many different types of adhesive  514  may be used. For example, a stronger adhesive  514  may be used for applications that need to last longer, whereas a weaker adhesive  514  may be used for more temporary applications. 
         [0052]    Many of the embodiments  210 ,  310 ,  410 ,  510  of a bunghole cover disclosed above may provide the benefits of reducing the risk of chemical splashing and exposure, reducing chemical off-gassing (which in turn may reduce environmental contamination and reduce odors around the chemical storage drums), increasing the shelf-life of stored chemicals by reducing the release of product actives, reducing contamination of stored chemicals by helping prevent liquids, solids, and gasses from entering the storage drum and interacting with the stored chemical, preventing cross-contamination of chemicals, and/or improving indoor air quality. Also, the embodiments disclosed above may all be installed either at the same time a chemical feed system  100  is installed or they may be installed on a bunghole even after the chemical feed system  100  is already in place. Furthermore, many of the embodiments above may be easily removed from the storage drum  150  and, in some cases, may even be reused on other chemical storage drums  150 . 
         [0053]    A variety of embodiments and variations of structures and methods are disclosed herein. Where appropriate, common reference numbers and words were used for common structure and method features. However, unique reference numbers and words were sometimes used for similar or the same structure or method elements for descriptive purposes. As such, the use of common or different reference numbers or words for similar or the same structural or method elements is not intended to imply a similarity or difference beyond that described herein. 
         [0054]    All directional and relative references (e.g., proximal, distal, upper, lower, upward, downward, left, center, right, side, lateral, front, middle, back, rear, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are given by way of example to aid the reader&#39;s understanding of the particular embodiments described. They should not be read to be requirements or limitations, particularly as to the position, orientation, or use of the invention unless specifically set forth in the claims. Connection references (e.g., attached, coupled, connected, and joined, etc.) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other, unless specifically set forth in the claims. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary. 
         [0055]    The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention as claimed below. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the claims. Other embodiments are therefore contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular embodiments and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.