Abstract:
A reusable, lockable, domed, hermetically sealing, flush-mount compression plug is locked with a removable rotatable locking compression key. Rotation of the compression key causes vertical compression and radial extension of the plug&#39;s sealing compression gasket causing pressure of the gasket against the inner walls of the opening preventing movement of the plug. Once the plug is locked in place, the key is removed making the plug un-lockable only to those who have the key and know how to remove the domed cap that is fitted onto the plug after the key is removed. Once the cap is in place, its flush mount design allows unimpeded placement of a man-hole cover. The dome shape of the cap assures that no moisture, liquids or foreign objects will collect on the surface of the cap. The plug has a “quad sealing assembly” comprised of four individual seals to provide hermetically sealing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a Non-Provisional Application of Provisional 62/321,329 filed on Apr. 12, 2016. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable 
       REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX 
       [0003]    Not Applicable 
       BACKGROUND OF THE INVENTION 
       [0004]    The present invention relates generally to improved sealing devices and, particularly, to a lockable compressible plug for hermetically sealing an opening having a smooth flush-domed security cap and a key for locking and unlocking the plug. 
         [0005]    The background information discussed below is presented to better illustrate the novelty of the present invention. This background information is not admitted prior art. 
         [0006]    The problems presented by openings that require plugging, and attempts to solve these problems have a long history. For example, in the age-old profession of wine and spirits making, “bung holes”, the holes drilled into beech wood casks used in the fermentation process, required plugging. Such plugs were often made of materials such as cork and wood that with age would rot or dry and shrink. As alcoholic beverages continue to be aged in wooden casks having bung holes, there is still a need for secure, reliable stoppers. As technology progresses, both the kinds of holes that need plugging and the means to plug those holes are required to be more sophisticated, and the ability to provide for a tight seal more challenging. 
         [0007]    The plumbing industry is especially demanding in its needs for sealing plugs. Plumbers require sealing plugs when testing for leaks in drain and vent pipes and in the pipe connections of a plumbing system. To conduct mandated pressure tests, plumbers need plugs or stoppers to seal drain, waste, or vent pipes so that these pipes can be tested for their ability to withstand the predetermined internal pressures. 
         [0008]    In addition, plumbers, especially those that service the plumbing in our homes, have a need for inexpensive, yet reliable, plugs so that they can achieve the air-tight and liquid-tight conditions required for successful “plugging”. The piping from which plumbing is constructed come in various sizes and are made of various materials, including cast iron, copper, clay, and polyvinylchloride accordingly the plugs and stoppers must be able to create the needed seal regardless of the size of the pipe or the material of which the piping is made. 
         [0009]    The insulation industry also has a need for hermetically sealing plugs to plug the holes that are drilled into the side of houses and mobile homes to facilitate the installation of insulation material. After holes are drilled through which the insulation is installed, the holes must be plugged to protect the insulation from the environment and to keep it inside the wall space. 
         [0010]    Containers and especially containers carrying explosive or toxic materials require leak-proof stoppers that will prevent their accidental or unauthorized removal. 
         [0011]    The coating industry often is faced with applying a coating to parts, such as piping, but there are times when the coating must not be applied to the internal surface of the pipes. For example, when the coating would be incompatible with the fluids or gases that will come into contact with the internal surface area of the pipe, the internal surfaces of the pipe must be sealed off during the coating procedure. Thus, there is a need for the means to mask or to close the openings to prevent coating material from coming into contact with those parts that are not to be coated. 
         [0012]    Environmental ground water monitoring requires not only tight sealing plugs, but also plugs that have the ability to be locked. When, for example, a spill such as leakage of gasoline from a gas station&#39;s underground gasoline storage tanks is reported by a gas station, environmental regulations now require that monitoring wells be installed in the area of concern. The wells are used to collect ground water samples to first determine the extent of the spill and, subsequently, to monitor the success of the clean-up efforts or of the containment program. Once a monitoring well is put into place; samples of ground water from each well are collected for testing to see if the contaminant remains present in the ground water that flows into that well. It is well-accepted that this system works well, but only, of course, as long as no extraneous contaminate is allowed to enter into the well. If a monitoring well opening is left uncapped contamination of the well is likely. It is easy to understand that monitoring wells need to be capped (plugged). Contamination, however, can occur even when a well is capped. For example, when a driver of a gasoline delivery truck mistakes the monitoring well inlet for a gas storage tank inlet and pumps gasoline into the monitoring well. In such a case, the need for a lockable well cover is apparent. Sometimes the introduction of a contaminant into a monitoring well is deliberate. This may occur as a mischievous act; or can be malevolent. In either case, deliberate contamination can destroy, at least a part of if not all of, a monitoring well program. This can be prevented by the use of a hermetically sealed well cover that can be locked. 
       SUMMARY 
       [0013]    There have been several attempts at fulfilling the need for a hermetically sealing plug that can be locked, but none provide the advantages of the plug introduced herein. 
         [0014]    The inventive concept developed by the present Inventor progressed into a set of inventive principles that provide for the construction of a reusable, lockable, domed, hermetically sealing, flush-mount compression plug for hermetically sealing an opening. The plug comes with several novel features. One is the completely removable rotatable compression key that is required to lock and unlock the plug. The plug is locked in place by the rotational action of the compression key that causes the vertical compression and radial extension of the sealing compression gasket body of the plug. Once the compression gasket has been radially extended against the inner walls of the pipe to be sealed, the pressure of the gasket against the inner walls of the pipe to be sealed prevents any movement of the plug, thus, locking the plug in place. In the example, illustrated herein, the compression key is structurally designed to work with a threaded mating central bolt. When the plug is in place in the opening of the tubular orifice, well pipe or other acceptable opening the plug is designed to seal and the key is fitted onto the accepting mating part of the bolt, rotating the key rotates the bolt causing compression and extension of the sealing compression gasket, locking the plug in place. The compression key&#39;s design provides for a secure hand grip on the key making turning the key, in either direction, a comfortable action. Once the key results in causing the plug to be locked in place, the key is then removed from the plug making the plug un-lockable only to those who have the key and know how to remove the domed cap that is fitted onto the plug after the key is removed. Once the domed-cap is in place on the plug, its design conveys to the capped plug the look of a one-piece structure making it unobvious as to how the inner workings of the lock can be accessed. And, although the cap is designed to be removed from the plug without the assistance of tools, its friction-fit closure misleads the casual passerby as to how the cap is removed. Once the cap is in place, its flush mount design allows unimpeded placement of the man-hole cover. This is to be contrasted from currently available high profile capped plugs that, because of their above the plug locking mechanisms, stick-up out of the casing (man-hole) creating problems for man-hole covers to be connected. Moreover, the dome shape of the cap assures that no moisture, liquids or foreign objects will collect on the surface of the cap. 
         [0015]    The inventive principles additionally provide the lockable plug with a “quad sealing assembly” to hermetically seal an opening. In other words, the plug offers a system of seals that together comprise four individual seals. In the example described herein the four seals are: (1) an O-ring type seal that seals the domed flush-mount cap to the body of the plug to keep contaminants from getting into the orifice of the plug; (2) the seal that is formed to protect against the entry of any contaminant entering the interior of the plug while the cap is removed, provided by a gasket seal; (3) the seal that is formed to prevent contaminant entry into the interior of the plug through the boundary between the compression gasket top plate and the compression gasket provided by a flange of the compression gasket capping plate; and (4) the seal that is formed when the body of the compression gasket is expanded to completely seal the opening. Additionally, the material of the compression gasket is sensitive to changes in its environment and will expand due to changes in environmental or physical conditions and the body of the gasket is constructed with additional length to add extra sealing protection. Increasing the length of the gasket body increases seal security by increasing the area of contact between the sealing compression gasket and the pipe that the plug is sealing. The sealing compression gasket body of the plug offers advantages that cannot be provided by a plug body constructed of polyvinyl chloride (PVC). The inside diameter of a pipe to be sealed, such as a well casing, is not a constant. The wall thickness of the pipe to be plugged determines, in part, the inside diameter of the pipe. Moreover, the interior surface of the pipe to be plugged is generally not as smooth as outside surface which adds to the variation of the inside diameter of the pipe which varies between manufactures. Thus, a plug made of a material that cannot conform to such deviations in the size of the inner diameter of the pipe it is plugging, cannot provide a secure seal and thus, offers greater chances for entrance of contaminants. This sealing assembly although advantageously improved is of simple construction, easy to make and use, reusable, not subject to rot or microbial degradation, will not transfer undesirable odors, and is economical to manufacture. 
         [0016]    Still other benefits and advantages of this invention will become apparent to those skilled in the art upon reading and understanding the following detailed specification and related drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    In order that these and other objects, features, and advantages of the present invention, may be more fully comprehended, the invention will now be described, by way of example, with reference to the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures, and in which: 
           [0018]      FIG. 1  is a cutaway perspective view of a flush-mount domed-cap, lockable, compression plug and key made in accordance with this invention. 
           [0019]      FIG. 2  is an exploded top-down perspective view of the flush-mount domed-cap, lockable, compression plug and key, as illustrated in  FIG. 1 . 
           [0020]      FIG. 3  is an exploded bottom-up perspective view of the flush-mount domed-cap, lockable, compression plug and key, as illustrated in  FIG. 1 . 
           [0021]      FIG. 4  is a bottom-up perspective view of the flush-mount domed-cap, lockable, compression plug, as illustrated in  FIG. 1 . 
           [0022]      FIG. 5  is a perspective view of a key used in the flush-mount domed-cap, lockable, compression plug, as illustrated in  FIG. 1 . 
           [0023]      FIG. 6  is a perspective view of a domed-cap used in the flush-mount domed-cap, lockable, compression plug, as illustrated in  FIG. 1 . 
           [0024]      FIG. 7  is a plane view of the flush-mount domed-cap, lockable, compression plug and key, as illustrated in  FIG. 1 . 
           [0025]      FIG. 8  is a plane view of a flush-mount domed-cap, lockable, compression plug and cap. 
           [0026]      FIG. 9  is a top-down perspective view of the flush-mount domed-cap, lockable, compression plug and key, as illustrated in  FIG. 1 . 
           [0027]      FIG. 10  is a top-down perspective view of a flush-mount domed-cap, lockable, compression plug with cap. 
           [0028]      FIG. 11  is a perspective view of a flush-mount domed-cap, lockable, compression plug installed in a well encased in a man-hole casing. 
       
    
    
     A LIST OF THE REFERENCE NUMBERS AND RELATED PARTS OF THE INVENTION 
       [0000]    
       
           2  Grasping handle of compression key  20 . 
           3  Easy grip hand / finger indent friction holds. 
           4  Neck of compression key  20 . 
           5  Through-apertures of compression key  20 . 
           6  Shoulder of compression key  20 . 
           8   a  Slot and projection structures on inner circumference surface of key shoulder  6  for mating with slot and projection structures  8   b  of bolt  60 . 
           8   b  Slot and projection structures on the outer surface of flange  62  of bolt  60  for mating with slot and projection structures  8   a  of key shoulder  6 . 
           10  Reusable, lockable, domed, hermetically sealing, flush-mount compression plug. 
           14   a  Seal mechanism, an O-ring for example. 
           14   b  Groove for accepting seal mechanism  14   a.    
           20  Compression key. 
           22  Outer flange of compression gasket capping plate  30 . 
           23  Outer rim of outer flange  22  of compression gasket capping plate  30 . 
           24  Under-side of compression gasket capping plate  30 . 
           25  Inner flange of compression gasket capping plate  30 . 
           26  Annular axial bore of compression gasket capping plate  30 . 
           28  Axial neck of compression gasket capping plate  30 . 
           29  Compression gasket. 
           30  Compression gasket capping plate. 
           40  Annular elastomeric sealing gasket. 
           42  Flange of gasket  40 . 
           43  Upper side of flange of gasket  40 . 
           44  Axial opening of gasket  40 . 
           46  Sleeve of gasket  40 . 
           50  Compression gasket base plate. 
           52  Flange of compression gasket base plate  50 . 
           53  Borehole of compression gasket base plate  50 . 
           54  Axial neck of compression gasket base plate  50 . 
           56  Threads of central bore of compression gasket base plate  50 . 
           58  Axial, upwardly facing, internal shoulder of compression gasket base plate  50 . 
           60  Threaded bolt. 
           62  Flange of treaded bolt  60 . 
           66  Threads of threaded bolt  60 . 
           68  Tapered end of threaded bolt  60 . 
           88   a  First optional aperture in tapered end of threaded bolt  60 . 
           88   b  Second optional aperture in tapered end of threaded bolt  60 . 
           89  Anvil stopper. 
           90  Flush-domed capping plate. 
           92  Outer edge of flush-domed capping plate  90 . 
           94  Inner sealing rim of flush-domed capping plate  90 . 
           95  Friction-tight grippers on inner sealing rim  94  of flush-domed capping plate  90 . 
           100  Manhole casing. 
           110  Manhole cover. 
           120  Monitoring well casing. 
       
     
         [0073]    It should be understood that the drawings are not necessarily to scale. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not limited to the particular embodiments illustrated herein, but encompasses many embodiments as are discussed throughout the specification. 
       DEFINITIONS 
       [0074]    Hermetic seal, as used herein, is the quality of something being airtight (excluding passage of air, oxygen, or other gases). 
         [0075]    Keyhole or keyway, as used herein, is a hole or aperture (as in a lock) for receiving a key. Lock keyway shapes vary widely with lock manufacturer, and many manufacturers have a number of unique profiles requiring a specifically milled key blank to engage the lock&#39;s tumblers. 
         [0076]    Opening, as used herein, refers to any opening that requires a lockable hermetically sealing plug to secure the opening from unauthorized entrance, including, but not limited to pipes, such as monitoring well or other types of well piping, drain and vent pipes, and in pipes of pipe connections of a plumbing system. The invention is also contemplated for use in conducting mandated pressure tests, plugging bung holes, holes drilled into surfaces, and any type of container requiring plugging. 
       DETAILED DESCRIPTION 
       [0077]    Referring now particularly to the drawings, it should be noted that the disclosed invention is disposed to embodiments in various sizes, shapes, and forms. It should be appreciated by those of ordinary skill in the art that, for example, the shape of the key illustrated could change considerably while still complying with the principles of the inventive concept that require a lock that is easy to grasp, that is easy to carry, such as having a means for carrying the lock on a key chain or the like, and that is fabricated to have a shaped mechanism that controls the locking and unlocking ability of the plug. The shape of the key-hole mechanism, can course, be of many designs and still perform the requirements of the inventive principles. Therefore, the embodiments described herein are provided with the understanding that the present disclosure is intended as illustrative and is not intended to limit the invention to the embodiments described herein. 
         [0078]      FIGS. 1-3 , illustrate one embodiment, of the present invention. Namely, the figure illustrates the components of the reusable lockable, domed, hermetically sealing, flush-mount compression plug  10  for sealing an opening. The structure and materials used to manufacture the plug completely prevent liquids, or other matter, from passing through or around plug  10  in an opening to be plugged. Importantly, the invention also provides for the plug to be locked and the key removed providing for the locked plug to be flush mounted. This is important because if a compression key protrudes from the top of a plug used to seal, for example, a monitoring well, it would be difficult, if not impossible to install a manhole cover over the well. Once the plug of the present invention is locked and the compression key removed the plug cannot be taken out of the plugged opening. 
         [0079]    The major components of the plug illustrated in  FIGS. 1-3  are compression key  20 , compression gasket capping plate  30  having borehole  26  therethrough, annular resilient elastomeric compression sealing gasket  40  having opening  44  therethrough, compression gasket base plate  50  having threaded borehole  53  therethrough, and bolt  60  having a first end and a second end. Protuberance and slot structures  8   b  on the outer surface of the first end of bolt  60  are positioned above the bolt&#39;s outwardly projecting flange  62 . Bolt  60  is fitted with threads  66  along most of its length. In this example, compression key  20  comprises grasping handle  2  with easy grip hand/finger indent friction holds  3 , neck  4 , shoulder  6 , and through-apertures  5 . Shoulder  6  approximates the structure of a bottle cap. It differs from a threaded bottle cap, however, in that in place of the threads found in a typical bottle cap, shoulder  6  has slot and projection structures  8   a  on its inner circumference for mating with slot and projection structures  8   b  on the outer surface of the first end of bolt  60 . Plug  10  is formed when bolt  60 , the central structure of the plug, has its second end inserted through bore  26  of compression gasket capping plate  30  and through opening  44  of elastomeric compression sealing gasket  40  to engage threads  66  with the mating threads of borehole  53  of compression gasket base plate  50 . In this configuration, compression gasket base plate  50  supports the lower end of elastomeric compression sealing gasket  40 . Elastomeric compression sealing gasket  40  supports and is capped by compression gasket capping plate  30 . Once the plug is positioned in an opening to be sealed and compression key  20  is positioned over the first end of bolt  60 , rotation of compression key  20  causes rotation of threaded bolt  66  urging compression gasket capping plate  30  and compression gasket base plate  50  toward each other causing axial compression and horizontally outward extension of compression sealing gasket  40 , achieving a hermetic seal of the opening and a lock that locks the plug in place. Protecting against contaminant entering into opening  44  of sealing gasket  40 , gasket  29  is seated on inwardly outwardly projecting flange  25  of compression gasket capping plate  30  to form a seal between flange  25  and outwardly projecting flange  62  threaded bolt  60  within the formed plug. Second end  68  of bolt  60 , as illustrated, is optionally tapered and, additionally, may optionally include one or more apertures  88   a  and  88   b . When present, apertures  88   a  and  88   b  provide for hanging a variety of devices, such as hanging of a tool or, if the sealing plug is used to seal a monitoring well, an instrument tethering device may be hung from one or both of the apertures. Another optional structure is anvil stopper  89  that provides some protection from the loss of compression gasket base plate  50  in the event that inner-diameter threaded compression gasket base plate  50  is unscrewed to the tapered end  68  of threaded bolt  60 . Anvil stopper  89  is constructed to catch compression gasket base plate  50  so it can be re-screwed on bolt  60  before it can be lost. 
         [0080]    Annular elastomeric sealing gasket  40  comprises hollow gasket sleeve  46  having axial opening  44  and outwardly extending flange  42  having an outer diameter of larger than the opening to be sealed by plug  10 . This provides for the following three advantages. The first is that the size-extended outer diameter of flange  42  provides for gasket  40  to be supported on the rim of the opening to be sealed. Secondly, the size-extended outer-diameter of flange  42  supports flange  22  of compression gasket capping plate  30 . The third advantage of the size-extended outer diameter of flange  42  is that it provides for a compressible, moldable seal between the underside of flange  42  and the rim of the opening to be sealed. Compressible flange  42  conforms to any irregularities present on the surface of the rim of the opening to be sealed, ensuring the formation of a water and air-tight seal. Upper side  43  of flange  42  faces under-side  24  of compression gasket capping plate  30 . The unflanged end of gasket sleeve  46  faces compression gasket base plate  50 , as is described below. 
         [0081]    Compression gasket capping plate  30  supplies counter support for gasket  40  when gasket  40  is in the state of compression. Axial neck  28  of compression gasket capping plate  30  extends into opening  44  from lower side  24  of compression gasket capping plate  30 . The diameter of the outer-surface of neck  28  is complementary to the diameter of the inner-surface of hollow sleeve  46  of gasket  40 . Constructed as a unitary molded piece, annular inner-surface of flange  42  and annular inner-surface of the hollow gasket sleeve  46  receive support from the annular outer-surface of axial downwardly facing internal first shoulder  28  providing lateral support for gasket  40  especially while gasket  40  is under compression (which compression is discussed more fully below). It should be noted here that axial downwardly facing internal neck  28  is manufactured integrally, that is, it is constructed as a unitary molded piece with compression gasket capping plate  30 . Flange  22  of compression sealing gasket capping plate  30  sits on and is supported by upper side  43  of flange  42 . The outer rim  23  of flange  22  like the outer rim of flange  42  has its diameters greater than the opening in the part to be sealed, thereby permitting the plug to rest of the rim of the opening to be sealed (see  FIG. 11 ) and to form one of the four seals that are offered in the present invention. Compression gasket base plate  50  comprises borehole  53  having threads  56 , flange  52 , axial upwardly facing internal shoulder  58 , and axial downward facing, neck  54  that in this example are manufactured integrally to form compression gasket base plate  50 . Flange  52  provides a supporting surface for gasket  40 . The outer diameter of axial, upwardly facing internal shoulder  58  is complementary to the inner diameter of gasket  40 . Internal shoulder  58  provides lateral support to the lower end of hollow sleeve  46  of gasket  40  especially while gasket  40  is under compression. Additionally, the lateral support provided by shoulder  58  ensures the integrity of gasket  40  while gasket  40  is under compression. Axial, downward facing, external neck  54  also provides support for gasket  40 , especially when gasket  40  is under compressive pressure, and importantly presents the annular, inner surfaces threads  56  that are complementary to threads  66  of threaded bolt  60 . As was discussed above, it is the action of threads  66  with threads  56  that urge the compression plates toward one another to compress and thus extend gasket  40  forming the gasket seal and providing the gasket locking mechanism. 
         [0082]    Plug  10  has a “Quad sealing assembly”, that in the example described herein, comprises: (1) the seal that is formed when O-ring  14   a  (see  FIG. 2 ) is inserted into accepting groove  14   b  of outer flange  22  of compression sealing gasket capping plate  30  providing for a seal between outer flange  22  and domed flush-mount cap  90  when cap  90  is positioned on the plug to keep contaminants from getting into the orifice of the plug; (2) the seal that is formed when gasket  29  is seated on an inner flange of bore  26  of capping plate  30  to form a seal between capping plate  30  and flange  62  of threaded bolt  60  when threaded bolt  60  projects through bore  26  of capping plate  30  to providing protection against entry of a contaminant into the opening of the compression sealing gasket while cap  90  is being removed; (3) the seal that is formed by flange  42  of compression gasket  40  and the surface of the opening to be sealed when the plug is in use in an opening to be sealed to prevent contaminant entry into the interior of the plug through the boundary between the compression gasket flange and the surface of the opening to be sealed, and (4) the seal that is formed when the elongate body of sealing gasket  40  is compressed by the rotation action of compression key  20  on threaded bolt  60  that results in the vertical, axial compression and the horizontal expansion of compression sealing gasket  40  to provide both a seal between gasket  40  and the inner wall of the pipe having an opening to be sealed to prevent contaminant entry into the space between, for example, a well casing and the plug, and the lock that keeps the locked plug from being removed from the opening it is sealing. 
         [0083]      FIG. 4  to  FIG. 8  illustrate domed flush-mounted compression plug  10  ready for installation into an opening to be plugged.  FIGS. 4, 5, and 7  illustrate plug  10  with key  20  ready to be inserted into bore  26  of compression gasket capping plate  30 .  FIG. 9  illustrates key  20  inserted into bore  26  of compression gasket capping plate  30 . It is to be understood that the present inventive principles require a locking system that both locks the plug in place and provides for plug  10  to be flush-mounted, that is, once the plug is locked in the opening to be plugged the compression key emanating upwards from the plug is removed allowing for the unimpeded insertion of an outer cover, such as a man-hole cover over the locked plug in opening, which in this example is an opening of a monitoring well pipe. The design of exemplar compression key  20  provides a secure hand grip on the key making turning the key, in either direction, a comfortable action to assure adequate tightening. Once compression key  20  creates the lock, is removed from the locked-in-place plug and is replaced by the domed cap, the plug is un-lockable only to those who have the key and know how to remove the cap. 
         [0084]    Once the plug is locked, the key, in this example, is removed and replaced by cap  90  as seen in  FIG. 6 , friction-tight grippers  95  provided on inner sealing rim  94  of flush-domed capping plate  90  provide for a friction fit of the cap on the plug. It should be understood that there are many ways to provide for a friction-fit closure and all of these are contemplated by the inventive principles. It is not a particular method of creating the friction; it is the fact of having a friction-fit between the cap and the inner-surface of bore  26 . Inner sealing rim  94  of flush-domed capping plate  90  fits over the slot and projection structures of part  8   b  to rest on flange  62  of bolt  60 . Outer edge  92  of flush-domed capping plate  90  has the same outer diameter as compression gasket capping plate  30  providing for the part of the plug that sits on top of the opening to be plugged to appear to be a single unit making it less susceptible to attempted unauthorized entry.  FIG. 11  illustrates a flush-mount domed-capped locked compression plug installed in monitoring well casing  120  that is encased in man-hole casing  100  having manhole cover  110 . 
         [0085]    Plug  10 , key  20  and cap  90  are reusable. Moreover, plug  10  is easily and inexpensively manufactured by injection molding using a variety of thermoplastics, including, but not limited to, polyvinyl chloride, Teflon, Nylon and glass filled Nylon, Valox and glass filled Valox. 
         [0086]    Annular resilient elastomeric sealing gasket  40  is also reusable, if desired. Sealing gasket  40  is easily and inexpensively manufactured by injection molding using a variety of thermoplastic materials having appropriate properties, such as hardness, resiliency, resistance to heat and cold, and resistance to the corrosive effect of certain liquids. The thermoplastics that can be used, include, but not limited to, Santoprene, natural or man-made rubber, Viton and Buna Nitrile. The preferred embodiment of gasket  40  was manufactured with the required hardness as measured by a durometer, wall thickness, and length to obtain maximum compression and to achieve the maximum contact area between sleeve  46  of gasket  40  and the interior surface of the device whose opening is to be sealed in order to ensure the formation of a hermetic seal and to prohibit the sealing plug from becoming dislodged from forces incurred during use. 
         [0087]    Compressible sealing plug assemblies made according to this invention may be of any suitable size and configuration required to achieve a hermetic seal with an opening in a part, as required or desired. 
         [0088]    The compressible plug assemblies according to the invention cannot be dislodged from an opening by the expanding gas, liquid, or solid forces within a heated or cooled part with an opening to be sealed. In addition, the elastomeric, resilient, compressible sealing gasket can form a hermetic seal with an opening even when the opening is threaded; because the gasket is made of material which can conform to the spaces inherent in a threaded surface. 
         [0089]    Although the embodiment discussed above was described as used to seal a monitoring well pipe, the invention is contemplated to be used to hermetically seal a number of different openings, including, but not limited to drain and vent pipes and in the pipe connections of a plumbing system. The plug according to the present invention would be most useful in conducting mandated pressure tests, to plug bung holes, holes drilled into surfaces for various reasons, bottles, and end of pipe and other part openings that need to be coated with a material that cannot, for whatever reason, be applied onto the interior surface of the part to be coated. Another contemplated use in for sealing those pipes that are used for transporting items that are especially well-stored in pipe-like containers. This use would be especially useful for locking the pipe-like containers that so often must be left standing out in the open, such as when the pipe-like containers are anchored on the top of a truck meant to carry piping supplies, when that truck is parked in the street for some length of time. Accordingly, the ways that the domed, lockable, hermetically sealing compression plug for an opening are used are limited only by the imagination of the user. 
         [0090]    The foregoing description, for purposes of explanation, used specific and defined nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the invention. Thus, the foregoing descriptions of the specific embodiment of the lockable compression plug are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Those skilled in the art will recognize that many changes may be made to the features, embodiments, and methods of making the embodiments of the invention described herein without departing from the spirit and scope of the invention. Furthermore, the present invention is not limited to the described methods, embodiments, features or combinations of features but include all the variation, methods, modifications, and combinations of features within the scope of the appended claims. The invention is limited only by the claims.