Patent Publication Number: US-2010122734-A1

Title: Medical gas line apparatus and related methods

Description:
TECHNICAL FIELD 
     This invention is generally related to apparatus and methods for purging a medical gas line and, more particularly, to apparatus and methods for purging a gas line during installation of an outlet. 
     BACKGROUND 
     Medical gas lines typically found in a hospital room or similar environment include an outlet located on a wall providing access to a source of gas, such as oxygen, or a source of vacuum, for example. Conventional outlets of this type include a back body that is supported from a supporting structure of a wall, such as a wooden or metal stud and a front assembly. A check valve may extend outwardly into the room from the front assembly and is coupled to the back body to control the flow of gas in only one direction. 
     During installation of outlets of this type, it is sometimes necessary to form joints between metal (e.g., copper) tubes, for example, that are located upstream of the outlet. In order to prevent contamination of the check valve and other portions of the front assembly, all joining of the tubes is done in the absence of all or part of the front assembly (e.g., the check valve). Such tube joining operations may, for example, include brazing, which may result in oxidation of some of the metals involved in the joining process. In order to minimize such oxidation, certain codes, regulations, standards or simply common practice in the industry may require purging of the gas lines upstream of the outlet prior to the brazing operation, for example, with pure, dry nitrogen. 
     Purging of the gas lines may require the displacement of a spring-biased cap in a bore of the outlet. The spring-biased cap in outlets of this type blocks access to the gas line in the biased position. Conventionally, the cap is pushed open by wedging a screw-driver or some other tool in the bore of the outlet and the nitrogen is purged in a single direction, namely, from an area upstream of the outlet toward an area downstream thereof (e.g., into the hospital room). 
     Conventional purging, accordingly, is cumbersome and inconsistent. For example, the screw driver or other tool wedged in the bore may normally have a tendency to fall out of the bore during purging, thus requiring manual support of the screw driver during purging. Likewise, the process of purging is not easily repeatable as the depth of insertion of the wedging of the screw driver is not always consistent from one outlet to another. 
     Further, wedging of the screw driver may limit conventional purging to a single direction of gas flow, namely, from upstream to downstream of the outlet. It is desirable, therefore, to have apparatus and related methods that address these and other challenges of conventional apparatus and methods used to purge medical gas lines of the types described above. 
     SUMMARY 
     In one embodiment, an apparatus is provided for purging a medical gas line having an outlet that includes a back body having a bore in communication with the gas line. An elongate body of the apparatus includes a distal portion and a proximal portion. The distal portion is configured for insertion within the bore. The distal portion includes a first port and the proximal portion includes a second port that is in fluid communication with the first port for permitting the flow of gas through the elongate body. The elongate body may permit bi-directional flow of gas between the first and second ports. 
     The apparatus may include a gripping portion that is associated with the proximal portion of the elongate body for rotating the same. The gripping portion may, for example, include a hexagonal socket head bore at a proximal end of the elongate body. The second port may be disposed at a proximal end of the elongate body. The first port may be positioned in the distal portion to be in confronting relationship with a spring-biased cap of the outlet, with the distal portion being sized to engage the cap of the outlet to thereby actuate the flow of gas through the first port while permitting the first port to be unobstructed when the distal portion is in contacting engagement with the cap. 
     The apparatus may include a third port in the distal portion that is in fluid communication with the first port. The distal portion may include a first thread configured to engage a thread of the bore. Additional or alternatively, the proximal portion may include a second thread that is configured for engagement with a gas line fitting. 
     The apparatus may include a support member having a threaded aperture and configured for coupling with the back body of the outlet, with the distal portion having a first thread configured for coupling with the support member through the aperture. The support member may include at least one of a magnetic element or a fastener-receiving channel for releasably engaging the support member to the back body of the outlet. The back body may include a protruding portion adjacent the bore, with the support member including a recess sized to receive the protruding portion therein to thereby permit abutting contact between the support member and the back body. The apparatus may include a gripping portion cooperating with the support member to limit a depth of insertion of the elongate body into the bore. 
     In another embodiment an apparatus is provided for purging a medical gas line having an outlet that includes a back body having a bore in communication with the gas line. The apparatus includes a block having a threaded aperture and configured for coupling with the back body. The block includes a magnetic element for releasably coupling the block to the back body and a recess to receive a protruding portion of the back body adjacent the bore therein thereby permitting abutting contact between the block and the back body. The apparatus includes a plunger that includes a distal portion and a proximal portion, and a thread on the distal portion, with the thread being coupled to the block through the threaded aperture for support of the plunger within the bore of the back body. The distal portion includes a first port and the proximal portion includes a second port that is in fluid communication with the first port for permitting the flow of gas through the plunger. A third port in the distal portion is in fluid communication with the second port. 
     The distal portion of the plunger may have an end that is configured to engage a spring-biased cap of the outlet in the bore of the back body to thereby actuate the flow of gas through the first and third ports, with at least one of the first or third ports being unobstructed during contacting engagement of the end of the plunger with the cap. The apparatus may include a tool-gripping portion that is associated with the proximal portion for rotating the plunger, with the tool-gripping portion including a detent cooperating with the block to limit a depth of insertion of the plunger into the bore. The block may include a pair of channels, each adapted to receive a fastener there along for releasably coupling the block relative to the back body of the outlet. 
     In yet another embodiment a medical gas line assembly is provided that includes a medical gas line outlet back body adapted for coupling with a wall in a room. The back body has a bore for providing access to the gas line. A pipe is coupled to the back body and is in fluid communication with the bore to permit the flow of gas between the pipe and through the bore. A support member is releasably coupled to the back body and includes a threaded aperture there through. A plunger is threadably coupled to the aperture and includes distal and proximal portions and first and second ports respectively in the distal and proximal portions and in fluid communication with one another to permit flow of gas through the plunger. The distal portion is adapted to engage a biased cap in the bore of the back body to actuate the flow of gas through the pipe and the first port. The plunger may have a length, for example, no greater than about one inch. 
     In another embodiment, a method is provided for purging a medical gas line through a back body of an outlet. The method includes supporting a valveless apparatus within a bore of the outlet providing access to a gas passage. The valveless apparatus is rotated to displace a biased cap of the outlet in the bore, with displacement of the biased cap opening access to the gas passage. The method includes feeding a gas through the gas passage and through first and second ports of the valveless apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an exemplary embodiment of a medical gas line assembly in accordance with the principles of the present invention; 
         FIG. 2  is a perspective, partially disassembled view of the assembly of  FIG. 1 ; 
         FIG. 3A  is a cross-sectional view taken generally along line  3 A- 3 A of  FIG. 1 ; 
         FIG. 3B  is a view similar to  FIG. 3A  showing a plunger of the assembly in a position different from that shown in  3 A; 
         FIG. 3C  is a cross-sectional view taken generally along line  3 C- 3 C of  FIG. 3B ; 
         FIG. 4  is a partially disassembled perspective view of a different embodiment of a medical gas line assembly; 
         FIG. 4A  is a partially disassembled perspective view of yet another different embodiment of a medical gas line assembly; 
         FIG. 5  is a perspective, partially disassembled view of an embodiment of an apparatus for purging a medical gas line; 
         FIG. 6  is a cross-sectional view taken generally along line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is an elevational view of the apparatus of  FIG. 5 ; and 
         FIG. 8  is a perspective, partially disassembled and partially broken-away view of another embodiment of a medical gas line assembly. 
     
    
    
     DETAILED DESCRIPTION 
     With respect to the figures, and particularly to  FIGS. 1-2 , a medical gas line assembly  10  is supported by a wall supporting structure such as a stud  12 . The medical gas line assembly  10  includes a back body  14  that is substantially made of a metal, such as brass, for example. The back body  14  includes a generally flat body  16  having one or more orifices  18  that receive fasteners such as screws or bolts (not shown) for securing the back body  14  to the stud  12 . A set of additional apertures  19  on the flat body  16  permit securing an outlet cover (not shown) to the flat body  16  from which a check valve or similar device (not shown) extends. 
     Jointly, the back body  14  and the front assembly (not shown, including the check valve or another similar device) define an outlet of the medical gas line assembly  10 . A pipe  20  extends from the back body  14  and fluidly communicates with a source of gas or a gas-receiving target in an area upstream of the pipe  20 . In use, for example, and without limitation, the pipe  20  may be coupled to a source of oxygen that feeds oxygen into a hospital room through the outlet. Alternatively, and also without limitation, the pipe  20  may be coupled to a source of vacuum to thereby provide a source of suction for air in the room. As used herein, the term “outlet” thus refers to outlets, as described herein, as well as devices that may be alternatively known as “inlets” coupled to the above-referenced source of vacuum. 
     The pipe  20  is coupled to the back body  14  through a cylindrical housing  30 , shown in phantom in  FIGS. 1-2  coupled to the flat body  16  at a proximally-facing end  32  of the housing  30  that protrudes through an aperture  34  ( FIG. 3A ) of the flat body  16  and is exposed to a proximal side  36  of the flat body  16 . A retainer ring  40  surrounds the aperture  34  and is partially received within an annular recess (not shown) at the end  32  of the housing  30  to thereby secure the pipe  20  and housing  30  from axial movement (i.e., along the length of the housing  30 ) relative to the flat body  16 . The housing  30  thus defines a bore  38  of the back body  14 . 
     With continued reference to  FIGS. 1-2 , the flat body  16  may include one or more lateral projections  46  permitting coupling of the back body  14  with adjacent structures such as an additional back body  14 ′ of an adjacent outlet, as generally shown in  FIG. 1 . A plurality of proximally projecting segments  58  define a space of the back body  14  that receives the outlet cover (not shown). Examples of components such as those described above are, for example, available from the Amico Corporation of Ontario, Canada, under part No. 6-233110. 
     An apparatus for purging the medical gas line, for example to remove debris and/or oxide material from a pipe coupling upstream of the pipe  20 , is generally designated with the numeral  59  and includes a plunger  60  threadably coupled to a support member in the form of a block or plate  62  through a threaded aperture  66  of the block  62 . The plunger  60  may be made of any suitable material such as, and without limitation, metal, plastic, or wood. In this particular embodiment, for example, the plunger  60  is made of a plastic such that the plunger  60  may be either cleaned, washed, or discarded after use, if so desired, and be of generally low cost. As explained in further detail below, the plunger  60  fluidly communicates with the interior of the housing  30  to allow gas, such as oxygen or pure, dry nitrogen, to flow through the back body  14  and thereby purge the gas line. The block  62 , as explained below, cooperates with the flat body  16  to support the plunger  60  and limit the insertion depth thereof into the housing  30  through the bore  38 . 
     In a specific embodiment, the block  62  is releasably coupled to the back body  14  during installation of the medical gas line to facilitate purging of the gas line. To this end, the block  62  includes one or more magnetic elements that facilitate such coupling. In this particular embodiment, the magnetic elements are in the form of four magnets  70  disposed at the corners of the block  62  on the distally-facing side  82  thereof (see  FIG. 2 ). The magnets  70  permit releasable coupling of the block  62  to a ferrous flat body  16  or at least to ferrous portions or components of the flat body  16 . It is contemplated, in the alternative or in addition, that the magnetic elements of the block  62  may be in the form of ferrous metallic components that are engageable with correspondingly-located magnets forming part of the back body  14 . 
     With continued reference to  FIGS. 1-2 , releasable coupling between the block  62  is further facilitated by a pair of generally U-shaped channels  84  extending generally along the top and bottom faces  86 ,  88  of the block  62  and configured to receive respective fasteners such as screws or bolts (not shown). More specifically, the fasteners, if used, engage a corresponding pair of the apertures  19  of the flat body  16  to thereby temporarily secure (i.e. during installation of the gas line assembly) the block  62  to the back body  14 . It is contemplated that an alternative block may include channels having other shapes, locations and/or in a different number or include no such channels at all. 
     Coupling of the block  62  is also facilitated by a recess  90  on the distally-facing side  82 . More particularly, the recess  90  is generally shaped and sized to receive the end  32  of the housing  30  and the retainer ring  40  during coupling engagement with the back body  14 . This coupling thus permits abutting contact between the distally-facing side  82  of the block  62  and the flat body  16  of the back body  14 , as best appreciated in  FIGS. 3A-3C . 
     With continued reference to  FIGS. 1-2  and further referring to  FIGS. 3A-3C , the plunger  60  has a generally elongate body and includes a distal portion  94  and a proximal portion  96 . A distally located first port  98  of the plunger  60  is in fluid communication with a proximally located second port  99  through an internal axial lumen  100  ( FIGS. 3A-3C ) and permits the flow of gas through the plunger  60 . Each of a pair of distally located third and fourth ports  101   a ,  101   b  is in fluid communication with one another and with the first and second ports  98 ,  99 . The third and fourth ports  101   a ,  101   b  communicate with one another through an internal transverse lumen  102  and communicate with the first and second ports  98 ,  99  through the axial lumen  100 . 
     During coupling engagement of the plunger  60  with the bore  38  of the back body  14 , the distal portion  94  threadably engages the threaded aperture  66  of the block  62  and extends into the bore  38 . To this end, the distal portion  94  includes a first thread  94   a  that matches a thread  66   a  of the aperture  66 . Rotation of the plunger  60 , accordingly, results in axial movement (along an axis  60   a  of the plunger  60 ) thereof through the aperture  66  and into the bore  38 . Rotation of the plunger  60  is facilitated by a gripping portion in the form, in this exemplary embodiment, of a male hexagonal tool-gripping portion  112  associated generally with the proximal portion  96  of the plunger  60 . The tool-gripping portion  112  is sized and shaped to permit rotation of the plunger  60  either by hand or by a suitable tool such as a wrench, pliers or another type of tool. A second thread  96   a  of the proximal portion  96  permits coupling of the plunger  60  to gas line fittings or similar devices to aid in the flow of gas between the hospital room and areas upstream of the pipe  20 , if so desired by the user. 
     Purging of the gas medical line is described with particular reference to the sequence illustrated in  FIGS. 3A ,  3 B, and  3 C. In  FIG. 3A , the plunger  60  is illustrated being threadably engaged with the aperture  66  of the block  62  and extending through the block  62  partially into the bore  38  of the back body  14 . In the figure, a spring-biased cap  124  in the bore  38  is shown in an extended position, blocking access to the flow of gas to (or from) the pipe  20  from (to) an area generally assigned the numeral  130  and which corresponds to an interior of the hospital room or the like. The spring-biased cap  124  is biased by a coil spring  132  disposed in the housing  30  and located distally of the cap  124 . The axial position of the plunger  60  in  FIG. 3A  is such that a distal end  142  thereof is slightly spaced from the cap  124 . 
     With specific reference to  FIGS. 3B-3C , the plunger  60  is illustrated in an axial position further within the bore  38  relative to the position shown in  FIG. 3A . More specifically, the distal portion  94  of the plunger  60  is shown having distally displaced the cap  124  and being in contacting engagement with a first plurality of wings  150  extending proximally from the cap  124 . In this regard, the distal end  142  of the plunger  60  is sized and shaped to engage the wings  150 , thereby actuating the flow of gas, without obstructing the first port  98 , as illustrated in  FIG. 3B . This engagement compresses the coil spring  132 , moving the cap  124  distally (arrow  160 , generally), and permitting the flow of gas through the plunger  60  and the pipe  20 . More specifically, gas flows through the unobstructed first, third, and fourth ports  98 ,  101   a ,  101   b  at the distal end  142  of the plunger  60 , through gaps  164  (one shown in  FIG. 3B ) between a second plurality of wings  170  of the cap  124  and the housing  30 , and through the second port  99  in the proximal portion  96  of the plunger  60 . An exemplary flow of gas is schematically and generally illustrated with arrows  178 . 
     During use, such as when purging the gas line to remove debris (e.g., oxide) associated with a brazing operation or to purge air to replace with a gas such as nitrogen, the gas flows through pipe  20 , through the housing  30 , and through the plunger  60  towards the area  130 . In this regard, the gas carries therewith any debris that may be present, and is expelled towards area  130 . The purging operation is performed until the flow of gas indicates that debris is no longer present in the gas line, including the pipe  20  and housing  30 . Alternatively, the purging operation is performed until oxygen is no longer detected in the gas line. Once the purging is completed, the plunger  60  may be discarded, if so desired, with at least some of the debris retained on its surfaces. In the alternative, the plunger  60  may be cleaned, if needed, and subsequently reused. While the exemplary purging herein described suggests a flow of gas from an upstream area (upstream of the pipe  20 ) and toward the area  130  in the interior of the hospital room, it is contemplated that the purging may include the flow of gas in the opposite direction, which is facilitated by the bi-directional nature of the plunger  60  and its secure engagement within the bore  38 . Moreover, purging may involve the flow of a gas other than nitrogen. In purging operations involving the flow of gas in the opposite direction, the threads  96   a  permit coupling of a gas line fitting coupled, for example, to a source of nitrogen, such that purging may be effected in such direction away from the area  130 . 
     Purging may include the use of nitrogen that is made to flow through the gas line until oxygen is no longer detected in the gas line, for example, as mandated by a code, regulation, or standards pertaining to a particular application in the health care industry or similar. An example of such codes, regulations or standards may be found in publications by the National Fire Protection Association (“NFPA”) or by the International Organization for Standardization (“ISO.”) The oxygen in the gas line may be detected or measured, for example, with an oxygen concentration probe connected to an oxygen analyzer. Notably, the plunger  60  of this embodiment includes a portion  180  of the axial lumen  100  that is sized and shaped to receive a probe  181  to facilitate such measurement by a schematically represented instrument  182 . In this embodiment, for example, the portion  180  has a length of about ⅝ of an inch and a diameter of about ¼ of an inch, although this is merely illustrative as other alternative dimensions are similarly contemplated. The portion  180  may additionally or alternatively be sized and shaped to receive a different type of probe to measure other quality characteristics of the gas in the gas line flowing through the plunger  60 . 
     With particular reference to  FIG. 3B , and as noted above, the gripping portion  112  cooperates with the block  62  to limit axial displacement of the plunger  60  into the bore  38 . More specifically, a distally-facing surface  112   a  of the tool-gripping portion  112  abuts a proximally-facing face  186  of the block  62  such that further distal advancement of the plunger  60  is precluded. Accordingly, the tool-gripping portion  112  provides a detent or limiting feature that predetermines the maximum insertion depth of the plunger  60  into the bore  38 . 
     While the plunger  60  described above includes a total of three ports generally at the distal end  142 , it is contemplated that it may alternatively include ports in any number located and/or oriented in configurations different from those shown. For example, and without limitation, an alternative plunger may include a single port at the distal end. Likewise, it is contemplated that an alternative plunger may include ports at its proximal end in any number other than one or have a single port oriented differently from the exemplary orientation of the second port  99  of the plunger  60 . 
     With reference to  FIG. 4 , an alternative embodiment of a medical gas line assembly  250  includes a back body  254  of an outlet that has a form different from that shown in the preceding figures. The back body  254  may, for example, take the form of an outlet back body available from the Amico Corporation of Ontario, Canada. For ease of understanding, like reference numerals in  FIG. 4  refer to like features in  FIGS. 1-3C . The back body  254  includes two proximally projecting segments  258  each having a vertical flange portion  262 . The assembly includes a purging apparatus  270  having a block  62  and plunger  60  similar to those described above with respect to the preceding figures. The block  62 , in this embodiment, is illustrated being releasably coupled to the back body  254  through a pair of screws  276  received along the corresponding channels  84 . As it can be ascertained from  FIGS. 1-4 , the purging apparatus  270  is sufficiently versatile to work generally as described above with more than one type of back body, such as back bodies  14 ,  254 . Accordingly, the description of the structure and functionality of the assembly of  FIGS. 1-3A  may be referred to for an understanding of the assembly  250  as well. 
     With reference to  FIG. 4A , in which like reference numerals refer to like features of  FIG. 4 , an alternative embodiment of a medical gas line assembly  250   a  includes a purging apparatus  270   a  similar to purging apparatus  270  of  FIG. 4  but including a pair of channels  84   a  relatively longer than the channels  84  of purging apparatus  270 . The purging apparatus  270   a , moreover includes a supporting structure in the form of a plate  286  and a pair of generally concentric, proximally extending portions  287 ,  289 . Notably, the portions  287 ,  289  permit a reduction, relative to the block  62  of  FIG. 4 , in the overall weight and size of the supporting member of the purging apparatus  270   a . More particularly, the portions  287 ,  289  provide a sufficient length for the threaded aperture thereof to thereby firmly support the plunger  60 . 
     With reference to  FIGS. 5-7 , in which like reference numerals refer to like features in the preceding figures, another embodiment of a medical gas line assembly  300  ( FIG. 7 ) includes a purging apparatus  310  having a support member in the form of a block  312  that is thinner relative to the block  62  of  FIGS. 1-4 . The block  312  of this embodiment includes a pair of magnets  316  at the top and bottom thereof for releasable coupling with a back body  14  of an outlet ( FIG. 7 ). The block  312  includes a recess  330  similar to the recess  90  of the preceding embodiments and which includes a centrally located distally protruding portion  334  that is axially sized to abut the flat body  16  of the back body  14 . The protruding portion  334  provides a suitable length for a thread  336   a  of an aperture  336  of the block  312  that is similar to the aperture  66  of  FIGS. 1-4 . 
     The medical gas line assembly  300  includes a plunger  354  having a thread  354   a  and a pair of opposed distal ports  356   a ,  356   b , and a single proximal port  358  ( FIG. 6 ). The distal ports  356   a ,  356   b  are located similarly to the third and fourth ports  101   a ,  101   b  of the plunger  60 , while the proximal port  358  is located similarly to the second port  99  of the plunger  60  ( FIGS. 1-4 ). The plunger  354  of this embodiment is relatively short compared to the plunger  60  of  FIGS. 1-4 . For example, and without limitation, the length (i.e., along the axis  354   b ) of the plunger  354  may be of about one inch or less. 
     With particular reference to  FIG. 6 , the plunger  354  includes a gripping portion in the form of a female hexagonal socket head  359  at the proximal end  360  of the plunger  354 , configured to receive a tool such as a hexagonal shaped wrench to thereby facilitate rotation of the plunger  354 . The ports  356   a ,  356   b , and  358 , as illustrated, are in fluid communication with one another through lumens  361 ,  363 , to permit the flow of gas through the plunger  354  generally in the manner described above with respect to the embodiment of  FIGS. 1-4 . 
     With particular reference to  FIG. 7 , the length of the plunger  354  is suitably chosen to be substantially flush with the proximally-facing face  312   a  of the block  312  when the plunger  354  is fully inserted within the bore  38 . Accordingly, the purging apparatus  310  defined by the block  312  and the plunger  354  can be packaged and distributed as a pre-assembled unit with the back body  14  with a minimum or negligible amount of additional packaging space than what is already devoted to packaging of the back body  14  alone. The length of the plunger  354 , moreover, is suitably chosen to be sufficient so as to remain rigidly threadably engaged with the threads  336   a  of the aperture  336  ( FIG. 5 ) of the block  312  and still be able to displace the cap  124  ( FIGS. 3A-3C ) to actuate the flow of gas through the back body  14  and the plunger  354 . 
     With particular reference to  FIG. 8 , in which like reference numerals refer to like features in  FIGS. 1-7 , yet another embodiment of a medical gas line assembly  400  includes a back body  406  that may, for example be similar to either of the back bodies  14 ,  254  illustrated in  FIGS. 1-7 , the description of which may be referenced for an understanding of the back body  406  of this embodiment as well. The back body  406  of the assembly  400  includes a bore  438  similar to bore  38  of  FIGS. 1-7  but which further includes a thread  438   a . A purging apparatus  420  is similar to that described with reference to the embodiment of  FIGS. 1-4  but does not include a separate supporting structure. In this regard, therefore, the purging apparatus  420  is in the form of a plunger similar to the plunger  60  described with reference to the embodiment of  FIGS. 1-4  and includes a thread  494   a  configured to threadably engage the thread  438   a  of the bore  438 . 
     An axial lumen  496  extends from the second port  499  of the apparatus  420  and may have a suitably chosen diameter such as, for example, about ¼ of an inch. In this exemplary embodiment, the distally-facing surface  112   a  of the tool-gripping portion  112  directly abuts the proximally-facing end  32  of the housing  30  to thereby predetermine the maximum insertion depth of the plunger  420  into the bore  38 . Notably, the plunger  420  does not require a support member such as block  62 ,  312  due to the threaded engagement between the plunger  420  and the bore  438 . In this regard, therefore, the plunger  420  is self-supporting within the bore  438 . 
     While the all of the above embodiments include back bodies of outlets each having a spring-biased cap, it is contemplated that other types of caps may be present or even no cap at all. The plungers herein described, therefore, are contemplated to work with such alternative back bodies and still fall within the scope of the present disclosure. An alternative back body, for example, may be associated with a Waste Anaesthetic Gas Disposal (“WAGD”) which may require no cap at all. In such alternative embodiments, accordingly, the plunger or the combination of the plunger and block, may facilitate purging in either direction i.e., from an area generally upstream of the pipe  20  and toward the area  130  in the interior of the hospital room or viceversa. Likewise, while some of the above embodiments include support members in the form of blocks or plates, it is contemplated that alternative support members may take any other suitable shapes or structures so long as they provide a way to support the respective plunger within the bore of the back body of the outlet. 
     While the above embodiments describe back bodies supported directly by a stud or similar wall supporting structure, it is contemplated that they may alternatively be supported by a headwall or a ceiling service unit and still fall within the scope of the present disclosure. Exemplary headwalls and ceiling service units, may for example be configured for coupling to and support from a wall in a room (e.g., a side wall or ceiling). 
     From the above disclosure of the general principles of the present invention and the preceding detailed description of exemplary embodiments, those skilled in the art will readily comprehend the various modifications to which this invention is susceptible. Therefore, this invention is intended to be limited only by the scope of the following claims and equivalents thereof.