Patent Publication Number: US-2021164594-A1

Title: Pre-assembled coupling assemblies with pipe fitting

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 16/044,161, filed Jul. 24, 2018, which claims the benefit of U.S. Provisional Application No. 62/538,480, filed on Jul. 28, 2017, each of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to couplings and pipe fittings. More specifically, this disclosure relates to couplings which are retained on pipe fittings to form a pre-assembled coupling assembly. 
     BACKGROUND 
     Pipe couplings are commonly used to connect two pipe elements, such as pipe lengths and pipe fittings, to assemble a piping system. Pipe fittings can include elbows, tees, caps, valves, reducers, sprinklers, and other types of pipe fittings. Slip-on pipe couplings are one type of pipe coupling which can be slipped over the ends of two adjacent pipe elements in a relaxed position and then tightened to a tensioned position to connect the two pipe elements together. It can be difficult for a single worker to align both pipe elements and secure the ends of the pipe elements within the coupling while tightening the coupling. Often multiple workers cooperate to couple the pipe elements together which can reduce efficiency and increase the man hours required to assemble the piping system. 
     SUMMARY 
     It is to be understood that this summary is not an extensive overview of the disclosure. This summary is exemplary and not restrictive, and it is intended to neither identify key or critical elements of the disclosure nor delineate the scope thereof. The sole purpose of this summary is to explain and exemplify certain concepts of the disclosure as an introduction to the following complete and extensive detailed description. 
     Disclosed is a pipe fitting configured for engagement with a coupling, the pipe fitting comprising a first end, the pipe fitting defining a raised lip at the first end; and a second end disposed opposite from the first end, the pipe fitting defining a groove between the raised lip and the second end. 
     Also disclosed is a pre-assembled coupling assembly comprising a coupling, the coupling defining a coupling bore extending through the coupling, the coupling comprising a gasket disposed within the coupling bore, the gasket being relaxed and uncompressed when the coupling is in a relaxed position; and a pipe fitting, the pipe fitting defining a first end and a second end, the first end inserted into the coupling bore, the coupling retained on the first end of the pipe fitting when the coupling is in the relaxed position. 
     Also disclosed is a method for using a pre-assembled coupling assembly, the method comprising providing a pipe fitting defining an inner end and an outer end, the pipe fitting defining an axis; axially inserting the inner end of the pipe fitting into a gasket, a portion of the pipe fitting within the gasket positioned radially outward from a portion of the gasket; and assembling a housing around the gasket, the housing and the gasket comprising a coupling, the coupling retained on the inner end of the pipe fitting when the coupling is in a relaxed position. 
     Various implementations described in the present disclosure may include additional systems, methods, features, and advantages, which may not necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims. The features and advantages of such implementations may be realized and obtained by means of the systems, methods, features particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such exemplary implementations as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure. The drawings are not necessarily drawn to scale. 
       Corresponding features and components throughout the figures may be designated by matching reference characters for the sake of consistency and clarity. 
         FIG. 1  is an end view of a pre-assembled coupling assembly comprising two couplings and a pipe fitting defining a raised-lip pipe in accordance with one aspect of the present disclosure. 
         FIG. 2  is a cross-sectional side view of the pre-assembled coupling assembly of  FIG. 1  taken along line  2 - 2  shown in  FIG. 1 . 
         FIG. 3  is end view of a raised-lip end of the raised-lip pipe of  FIG. 1 . 
         FIG. 4  is a detailed cross-sectional side view of the raised-lip end of the raised-lip pipe of  FIG. 1  taken along line  4 - 4  shown in  FIG. 3 . 
         FIG. 5A  is an exploded perspective view of another aspect of the pre-assembled coupling assembly wherein the pipe fitting defines an elbow fitting in accordance with another aspect of the present disclosure. 
         FIG. 5B  is an end view of the pre-assembled coupling assembly of  FIG. 5A . 
         FIG. 5C  is a cross-sectional side view of the pre-assembled coupling assembly of  FIG. 5A  taken along line  5 C- 5 C shown in  FIG. 5B . 
         FIG. 6A  is a perspective view of the elbow fitting of  FIG. 5A . 
         FIG. 6B  is an end view of the elbow fitting of  FIG. 5A . 
         FIG. 6C  is a cross-sectional side view of the elbow fitting of  FIG. 5A  taken along line  6 C- 6 C shown in  FIG. 6B . 
         FIG. 7  is a detailed cross-sectional side view of the pre-assembled coupling assembly of  FIG. 5A  with a pipe in accordance with another aspect of the present disclosure. 
         FIG. 8A  is a detailed cross-sectional side view of a first raised-lip end of the pre-assembled coupling assembly of  FIG. 5A  and the pipe of  FIG. 7  shown with the coupling in a tensioned position. 
         FIG. 8B  is a detailed cross-sectional side view of the first raised-lip end of the pre-assembled coupling assembly of  FIG. 5A  and the pipe of  FIG. 7  shown with the coupling in a relaxed position. 
         FIG. 9  is a detailed cross-sectional view of a pressure relief channel of the elbow fitting of  FIG. 5A  taken along line  9 - 9  shown in  FIG. 6B . 
         FIG. 10  is a detailed cross-sectional view of another aspect of the pressure relief channel in accordance with another aspect of the present disclosure. 
         FIG. 11  is a cross-sectional view of the pipe of  FIG. 7  with another aspect of the pre-assembled coupling assembly wherein the elbow fitting defines a secondary key in accordance with another aspect of the present disclosure. 
         FIG. 12  is a cross-sectional view of the pipe of  FIG. 7  with another aspect of the pre-assembled coupling assembly with another aspect of the elbow fitting in accordance with another aspect of the present disclosure wherein the elbow fitting is a recessed elbow fitting. 
         FIG. 13  is a cross-sectional side view of another aspect of the pre-assembled coupling assembly comprising another aspect of the coupling wherein the coupling comprises a C-style gasket in accordance with another aspect of the present disclosure. 
         FIG. 14  is a cross-sectional view of the pipe of  FIG. 7  with another aspect of the pre-assembled coupling assembly comprising another aspect of the coupling wherein the gasket is a modified rimmed gasket, and another aspect of the elbow fitting in accordance with another aspect of the present disclosure, wherein the elbow fitting is a grooved elbow fitting. 
         FIG. 15A  is a perspective view of another aspect of the pipe fitting defining a weldolet in accordance with another aspect of the present disclosure. 
         FIG. 15B  is an end view of the weldolet of  FIG. 15A . 
         FIG. 15C  is a cross-sectional side view of the weldolet of  FIG. 15A  taken along line  15 C- 15 C shown in  FIG. 15B . 
         FIG. 16A  is a perspective view of another aspect of the pipe fitting defining a mechanical tee in accordance with another aspect of the present disclosure. 
         FIG. 16B  is an end view of the mechanical tee of  FIG. 16A . 
         FIG. 16C  is a side view of the mechanical tee of  FIG. 16A . 
         FIG. 17A  is a perspective view of another aspect of the pipe fitting defining a tee fitting in accordance with another aspect of the present disclosure. 
         FIG. 17B  is an end view of the tee fitting of  FIG. 17A . 
         FIG. 17C  is a cross-sectional side view of the tee fitting of  FIG. 17A  taken along line  17 C- 17 C shown in  FIG. 17B . 
         FIG. 18A  is a perspective view of another aspect of the pipe fitting defining an end-of-line elbow in accordance with another aspect of the present disclosure. 
         FIG. 18B  is an end view of the end-of-line elbow of  FIG. 18A  facing a raised-lip end of the end-of-line elbow. 
         FIG. 18C  is an end view of the end-of-line elbow of  FIG. 18A  facing a socket end of the end-of-line elbow. 
         FIG. 18D  is a cross-sectional side view of the end-of-line elbow of  FIG. 18A  taken along line  18 D- 18 D shown in  FIG. 18C . 
         FIG. 19A  is a perspective view of another aspect of the pre-assembled coupling assembly wherein the pipe fitting defines a check valve in accordance with another aspect of the present disclosure. 
         FIG. 19B  is a cross-sectional side view of the pre-assembled coupling assembly of  FIG. 19A . 
         FIG. 20A  is a perspective view of another aspect of the pre-assembled coupling assembly wherein the pipe fitting defines a disc valve in accordance with another aspect of the present disclosure. 
         FIG. 20B  is a cross-sectional side view of the pre-assembled coupling assembly of  FIG. 20A . 
         FIG. 21A  is a perspective view of another aspect of the pre-assembled coupling assembly wherein the pipe fitting defines a ball valve in accordance with another aspect of the present disclosure. 
         FIG. 21B  is a side view of the pre-assembled coupling assembly of  FIG. 21A  showing a partial cross-section. 
         FIG. 21C  is a detailed cross-sectional side view of the pre-assembled coupling assembly of  FIG. 21A  taken from Detail  21 C shown in  FIG. 21B . 
         FIG. 22A  is a perspective view of another aspect of the pre-assembled coupling assembly wherein the pipe fitting defines a flanged fitting in accordance with another aspect of the present disclosure. 
         FIG. 22B  is a cross-sectional side view of the pre-assembled coupling assembly of  FIG. 22A . 
         FIG. 23A  is a perspective view of another aspect of the elbow fitting wherein each of the raised-lip ends is a stop lip end in accordance with another aspect of the present disclosure. 
         FIG. 23B  is a side view of the elbow fitting of  FIG. 23A . 
         FIG. 23C  is a cross-sectional detail view of the stop lip end taken along line  23 C- 23 C shown in  FIG. 23A . 
         FIG. 24A  is an end view of an aspect of the pre-assembled coupling assembly comprising the elbow fitting of  FIGS. 23A . 
         FIG. 24B  is a cross-sectional detail side view of the stop lip end of the pre-assembled coupling of  FIG. 24A  taken along line  24 B- 24 B shown in  FIG. 24A  with the pipe of  FIG. 7 . 
         FIG. 25  is a side view of the elbow fitting defining another aspect of the stop lip ends wherein the raised lip is a continuous stop lip in accordance with another aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure can be understood more readily by reference to the following detailed description, examples, drawings, and claims, and the previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this disclosure is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, and, as such, can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. 
     The following description is provided as an enabling teaching of the present devices, systems, and/or methods in its best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects of the present devices, systems, and/or methods described herein, while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present disclosure are possible and can even be desirable in certain circumstances and are a part of the present disclosure. Thus, the following description is provided as illustrative of the principles of the present disclosure and not in limitation thereof. 
     As used throughout, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “an element” can include two or more such elements unless the context indicates otherwise. 
     Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. 
     For purposes of the current disclosure, a material property or dimension measuring about X or substantially X on a particular measurement scale measures within a range between X plus an industry-standard upper tolerance for the specified measurement and X minus an industry-standard lower tolerance for the specified measurement. Because tolerances can vary between different materials, processes and between different models, the tolerance for a particular measurement of a particular component can fall within a range of tolerances. 
     As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not. 
     The word “or” as used herein means any one member of a particular list and also includes any combination of members of that list. Further, one should note that conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain aspects include, while other aspects do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular aspects or that one or more particular aspects necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular aspect. 
     Disclosed are components that can be used to perform the disclosed methods and systems. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed that while specific reference of each various individual and collective combinations and permutation of these may not be explicitly disclosed, each is specifically contemplated and described herein, for all methods and systems. This applies to all aspects of this application including, but not limited to, steps in disclosed methods. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific aspect or combination of aspects of the disclosed methods. 
     Disclosed is a pre-assembled coupling assembly and associated methods, systems, devices, and various apparatus. The pre-assembled coupling assembly can comprise a pipe fitting and a coupling retained on an end of the pipe fitting. It would be understood by one of skill in the art that the disclosed pre-assembled coupling is described in but a few exemplary aspects among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom. 
       FIG. 1  is an end view of a pre-assembled coupling assembly  100  in accordance with the present disclosure, and  FIG. 2  is a cross-sectional view of the pre-assembled coupling assembly  100  of  FIG. 1  taken along line  2 - 2  as shown in  FIG. 1 . Angles and dimensions shown in  FIGS. 1-22B  are merely exemplary and should not be viewed as limiting. The structures and components shown can be scaled upwards or downwards, reshaped, or resized in other aspects. 
     The pre-assembled coupling assembly  100  can comprise a pipe fitting  110  and at least one coupling  170 . In some aspects, the coupling  170  can be a slip-on coupling, such as the slip-on coupling described in U.S. Pat. No. 9,194,516, issued on Nov. 24, 2015, which is hereby incorporated by reference in its entirety. 
     In the present aspect, the pre-assembly coupling assembly  100  can comprise two couplings  170   a,b  which can be substantially the same (referred to generally hereafter as “pipe coupling  170 ” or “pipe couplings  170 ” unless individually identified). Each coupling  170  can comprise a housing  171  and a gasket  140  which can be enclosed and encircled by the respective housing  171 . Each housing  171  can comprise a first segment  172   a  and a second segment  172   b . The first segment  172   a  can define a pair of fastener ears  174   a  disposed at opposite ends of the first segment  172   a.  The second segment  172   b  can define a pair of fastener ears  174   b  disposed at opposite ends of the second segment  172   b.  A pair of fasteners  176   a,b  , which can comprise nuts and bolts in some aspects, can extend through the fastener ears  174   a  of the first segment  172   a  and the fastener ears  174   b  of the second segment  172   b  to secure the first segment  172   a  to the second segment  172   b.    
     In the present aspect, each housing  171  can be substantially circular in shape, and each of the segments  172   a,b  can define a semicircular arc shape. Each housing  171  can define a coupling bore  182  extending through the housing  171  from a first end  178   a  to a second end  178   b  of the housing  171 . Each gasket  140  can be disposed within the respective coupling bore  182 . The coupling bore  182  can define an axis  101 . The first segment  172   a  can define a pair of shoulders  180   a  disposed at opposite ends of the first segment  172   a  and proximate to the respective fastener ears  174   a.  The second segment  172   b  can define a pair of shoulders  180   b  disposed at opposite ends of the second segment  172   b  and proximate to the respective fastener ears  174   b.    
     In the present aspect, the couplings  170  can be in a relaxed position. In the relaxed position of the coupling  170   s,  the shoulders  180   a  can be spaced apart from the shoulders  180   b , and the gasket  140  can be relaxed and uncompressed by the housing  171 . The fasteners  176   a,b  can be tightened to reconfigure the coupling  170  from the relaxed position to a tensioned position. In the tensioned position of the coupling  170 , the shoulders  180   a  of the first segment  172   a  can be pressed against the shoulders  180   b  of the second segment  172   b,  and the gasket  140  can be compressed radially inward relative to the axis  101 . In some aspects, each segment  172   a,b  can be deformed by the fasteners  176   a,b  , to align and engage the shoulders  180   a  of the first segment  172   a  with the shoulders  180   b  of the second segment  172   b.    
     The pipe fitting  110  can extend into the coupling bore  182  of each of the couplings  170  at the first end  178   a  of the housing  171  of each respective coupling  170 . 
     In the aspect shown, the pipe fitting  110  can be a pipe  500 , wherein the pipe is a raised-lip pipe  1412 . The raised-lip pipe  1412  can define a standard grooved end  1402  and a raised-lip end  1404  disposed opposite from the standard grooved end  1402 . The raised-lip end  1404  can define a raised lip  518 . The raised lip  518  can retain the coupling  170   a  on the raised-lip end  1404  with the coupling  170   a  in the relaxed position due to interference between the raised lip  518  and the gasket  140  of the coupling  170   a.    
     The standard grooved end  1402  does not define the raised lip  518 . The standard grooved end  1402  can readily be inserted and withdrawn from the coupling  170   b  with the coupling  170   b  in the relaxed position. In practice, the coupling  170   b  can be comprised by a second pre-assembled coupling assembly  100  (not shown) comprising a second raised-lip pipe (not shown) or other pipe fitting  110 . The standard grooved end  1402  of each pre-assembled coupling assembly  100  can be stabbed into the coupling  170  of an adjacent pre-assembled coupling assembly  100  and tightened to form a piping system. Similarly, a standard grooved end  1402  of a second raised-lip pipe  1412  could be stabbed into the second end  178   b  of the coupling  170   a  to join the raised-lip end  1404  of the present pre-assembled coupling assembly  100  to the standard grooved end  1402  of the second raised-lip pipe  1412 , such as to form a pipeline. 
     It can be desirable for the coupling  170   a  to be retained on the raised-lip end  1404  of the raised-lip pipe  1412  so that the pre-assembled coupling assembly  100  can be easily attached to a second raised-lip pipe (not shown). For example, a user can hold the second raised-lip pipe  1412  with one hand, and the pre-assembled coupling assembly  100  can be slipped over the standard grooved end  1402  of the second raised-lip pipe  1412  with a second hand of the user. Additionally, because the coupling  170   a  can be retained on the raised-lip pipe  1412 , the user is less likely to lose or mix up parts, such as in a field environment, because the pre-assembled coupling assembly  100  may not come apart without a deliberate effort by the user. 
     In some aspects, both ends of the raised-lip pipe  1412  can be raised-lip ends  1404 , and both couplings  170   a,b  can be retained on the respective ends of the raised-lip pipe  1412  when the couplings  170   a,b  are in the relaxed position. A similar configuration is shown by an elbow fitting  2212  of  FIGS. 5A-6C . 
       FIG. 3  is an end view of the raised-lip end  1404  of the raised-lip pipe  1412  of  FIG. 1 , and  FIG. 4  is a cross-sectional view of the raised-lip end  1404  of the raised-lip pipe  1412  taken along line  4 - 4  shown in  FIG. 3 . In the present aspect, an outer pipe surface  504  of the raised-lip pipe  1412  can be substantially parallel with the axis  101 , and a ramped surface  619  of the raised lip  518  can define a 45-degree angle with the outer pipe surface  504 . In other aspects, the ramped surface  619  can be angled relative to the outer pipe surface  504  at greater or fewer than 45 degrees. In the present aspect, the raised lip  518  can extend radially outward about 0.100″ from the outer pipe surface  504 ; however in other aspects, the raised lip  518  can extend radially outward more than or less than 0.100″. 
       FIGS. 5A-C  show multiple views of another aspect of the pre-assembled coupling assembly  100  wherein the pipe fitting  110  can be the elbow fitting  2212 .  FIG. 6A-C  show multiple views of the elbow fitting  2212  of  FIGS. 5A-C . In the aspect shown, the elbow fitting  2212  can define a first raised-lip end  2202   a  and a second raised-lip end  2202   b  disposed opposite from the first raised-lip end  2202   a.  The first raised-lip end  2202   a  can be substantially similar to the second raised-lip end  2202   b  in the present aspect. In other aspects, the elbow fitting  2212  can define a standard grooved end, such as the standard grooved end  1402  shown in  FIG. 2 , opposite from the first raised-lip end  2202   a.  The pre-assembled coupling assembly  100  can comprise a first coupling  170   a  retained on the first raised-lip end  2202   a  by a first raised lip  518   a  and a second coupling  170   b  retained on the second raised-lip end  2202   b  by a second raised lip  518   b.  In the present aspect, the first raised-lip end  2202   a  can define a groove  514  extending radially inward into the first raised-lip end  2202   a  between an outer lip  512  and the raised lip  518   a.    
     In the present aspect, the elbow fitting  2212  can be a 90-degree elbow. In other aspects, the elbow fitting  2212  can be a different type of elbow, such as a 45-degree elbow for example and without limitations. In other aspects, the elbow fitting  2212  can define a U-shape or any other suitable shape. 
     As shown, each raised-lip end  2202   a,b  can define a plurality of pressure relief channels  520  defined into the respective raised lip  518 . In the present aspect, each raised-lip end  2202   a,b  can define four pressure relief channels  520  which can be equally circumferentially spaced around the raised lip  518 . In other aspect, the raised-lip ends  2202   a,b  can define greater or fewer than four pressure relief channels  520 , and the pressure relief channels  520  can be distributed in any suitable configuration around the raised lip  518 . 
       FIG. 7  is a detailed cross-sectional view of the first raised-lip end  2202   a  of the pre-assembled coupling assembly  100  of  FIGS. 5A-C  taken along line  5 C- 5 C as shown in  FIG. 5B  with a pipe  500  in accordance with another aspect of the present disclosure. In the present aspect, the pipe  500  can be a standard pipe, and the pipe end  502  can be a standard grooved end  1402 . The housing  171  of the coupling  170   a  can define a first ridge  578   a  disposed at the first end  178   a  of the housing  171  and a second ridge  578   b  disposed at the second end  178   b  of the housing  171 . The ridges  578   a,b  can extend radially inward relative to the axis  101 . The housing  171  can define a gasket groove  570  within the coupling bore  182  which can be disposed between the ridges  578   a,b , and the gasket  140  can be seated within the gasket groove  570 . 
     The gasket  140  can define a sealing ridge  548   a  disposed proximate to the first end  178   a  of the housing  171  and a sealing ridge  548   b  disposed proximate to the second end  178   b  of the housing  171 . The sealing ridges  548   a,b  can extend radially inward from the gasket  140  relative to the axis  101 . The gasket  140  can also define a center ridge  540  disposed between the sealing ridges  548   a,b . The center ridge  540  can extend radially inward from the gasket  140 , and the center ridge  540  can define a pair of ribs  550   a,b  at a radially innermost end of the center ridge  540 . The gasket  140  can define a sealing channel  552   a  disposed between the sealing ridge  548   a  and the rib  550   a  and a sealing channel  552   b  disposed between the sealing ridge  548   b  and the rib  550   b.    
     The pipe  500  can define an inner pipe surface  506  and an outer pipe surface  504  disposed opposite from the inner pipe surface  506 . The inner pipe surface  506  can define a pipe bore  510  extending through the pipe  500 , and the pipe bore  510  can carry pressurized fluids through the piping system. A circumferential groove  508  can be defined extending radially inward into the outer pipe surface  504  relative to the axis  101 . The groove  508  can be disposed proximate to the end  502  of the pipe  500 . The second ridge  578   b  can be configured to engage the groove  508  when the end  502  of the pipe  500  is inserted into the coupling bore  182  and the coupling  170  is in the tensioned position. When engaged with the groove  508 , the second ridge  578   b  secures the coupling  170  to the pipe  500  and prevents axial movement of the pipe  500  relative to the coupling  170 . 
     The first raised-lip end  2202   a  can be substantially similar to the second raised-lip end  2202   b  (second raised-lip end  2202   b  shown in  FIG. 6C ) of the elbow fitting  2212  in the present aspect. In other aspects, the raised-lip ends  2202   a,b  can differ from one another. In the orientation shown, the raised-lip end  2202   a  can be an inner end  516  of the pipe fitting  110  which is inserted into the coupling bore  182 . The first raised-lip end  2202   a  can define an outer lip  512  which can be disposed external to the coupling bore  182  when the first raised-lip end  2202   a  is inserted into the coupling bore  182 . The outer lip  512  can extend radially outward from the elbow fitting  2212 . In the present aspect, the outer lip  512  can radially overlap with the first ridge  578   a  of the housing  171  when the coupling is in the relaxed position. The outer lip  512  can provide a physical stop which can thereby prevent over-insertion of the first raised-lip end  2202   a  into the coupling bore  182 . 
     The raised lip  518   a  can be disposed at the first raised-lip end  2202   a,  and the raised lip  518   a  can extend radially outward from the first raised-lip end  2202   a  relative to the axis  101 . In the present aspect, the raised lip  518   a  can be disposed radially inward from the outer lip  512 , therefore allowing the first raised-lip end  2202   a  and the raised lip  518   a  to be inserted into the coupling bore  182  with the coupling  170  in the relaxed position. In other aspects, the raised lip  518  can extend radially outwards beyond the first ridge  578   a  with the coupling  170  in the relaxed position, thereby preventing insertion and removal of the inner end  516  from the coupling bore  182 . In such aspects, the first segment  172   a  and the second segment  172   b  of the housing  171  can be assembled around the first raised-lip end  2202   a  of the elbow fitting  2212  to capture the first raised-lip end  2202   a  within the coupling bore  182 . In such aspects, the inner end  516  of the elbow fitting  2212  may not be removed from the coupling bore  182  without disassembling the housing  171 . 
     The raised lip  518  can be sized to radially interfere with the sealing ridge  548   a  of the gasket  140  when the gasket  140  is in the relaxed and uncompressed state. For example, a radially outermost portion of the raised lip  518  can be disposed radially outward from a radially innermost portion of the sealing ridge  548   a  when the raised lip  518  is axially positioned between the sealing ridges  548   a,b  relative to the axis  101 . The gasket  140  can comprise an elastic material, such as a rubber, a polymer, an elastomer, or any other suitable material, and the gasket  140  can be flexible and resilient. 
     Interference between the raised lip  518  and the sealing ridge  548   a  can prevent accidental removal of the first raised-lip end  2202   a  of the elbow fitting  2212  from the coupling bore  182  when the coupling  170   a  is in the relaxed position. The sealing ridge  548   a  can stretch over the raised lip  518  when the first raised-lip end  2202   a  is inserted into or withdrawn from the coupling bore  182 . In the present aspect, the sealing ridge  548   a  can be in a relaxed state when the coupling  170  is in the relaxed position, and the sealing ridge  548   a  is axially positioned between the raised lip  518  and the outer lip  512  of the first raised-lip end  2202   a  relative to the axis  101 . 
     In the present aspect, the first raised-lip end  2202   a  of the elbow fitting  2212  can be withdrawn from the coupling bore  182  of the coupling  170   a  with a deliberate force when the coupling  170   a  is in the relaxed position. By exerting the deliberate force, the sealing ridge  548   a  can stretch over the raised lip  518  to allow the elbow fitting  2212  to be removed from the coupling  170   a.  The resistance provided by the sealing ridge  548   a  can be optimized to prevent accidental disassembly of the pre-assembled coupling assembly  100  while still allowing for deliberate disassembly of the pre-assembled coupling assembly  100  without undue difficulty. For example, with the coupling  170   a  in the relaxed position, the pre-assembled coupling assembly  100  can be disassembled with the fingers of a user possessing typical hand strength without the need for tools while also resisting separation of the coupling  170   a  from the elbow fitting  2212  by the force of gravity and general handling of the pre-assembled coupling assembly  100 . For example, the coupling  170   a  and the elbow fitting  2212  can resist separation if a user carries the pre-assembled coupling assembly  100  without supporting both the coupling  170   a  and the elbow fitting  2212 . 
     In the present aspect, the first raised-lip end  2202   a  can define a groove  514  extending radially inward into the first raised-lip end  2202   a  between the outer lip  512  and the raised lip  518 . The groove  514  can be configured to receive the first ridge  578   a  of the housing  171  when the coupling  170   a  is in the tensioned position. Engagement between the first ridge  578   a  and the groove  514  can secure the elbow fitting  2212  to the coupling  170   a  and prevent the first raised-lip end  2202   a  of the elbow fitting  2212  from being withdrawn from the coupling bore  182  when the coupling  170   a  is in the tensioned position. 
     The raised lip  518  can define at least one pressure relief channel  520  defined at the first raised-lip end  2202   a  of the elbow fitting  2212 . The pressure relief channel  520  can extend through the raised lip  518  as shown and further described with respect to  FIGS. 9 and 10  below. 
       FIG. 8A  is a detailed cross-sectional view of the pipe  500 , the elbow fitting  2212 , and the coupling  170   a  of  FIG. 7  with the coupling  170   a  in the tensioned position and with the pre-assembled coupling assembly  100  in a pressurized condition in which fluid is allowed to flow into the pipe  500  to apply fluid pressure to the elbow fitting  2212  and the gasket  140 . In the tensioned position, the gasket  140  can be compressed radially inward to form seals with the pipe  500  and the elbow fitting  2212 . The sealing ridge  548   a  can form a seal with a sealing surface  612  defined by the first raised-lip end  2202   a  of the elbow fitting  2212 . In the present aspect, the sealing surface  612  can be defined between the raised lip  518   a  and the groove  514 , and the raised lip  518   a  can extend radially outward from the sealing surface  612 . The sealing ridge  548   b  can form a seal with a sealing portion  604  of the outer pipe surface  504  of the pipe  500  defined between the groove  508  and the end  502  of the pipe  500 . 
     The raised lip  518   a  can also define a ramped surface  619 . The ramped surface  619  can be angled, as shown in  FIG. 6A , thereby taking the shape of a truncated cone, or can be curved in other aspects. The angle or curve of the ramped surface  619  can be configured to guide the sealing ridge  548   a  into position around the sealing surface  612  as the first raised-lip end  2202   a  is inserted into the coupling  170   a,  and the gasket  140  can also be configured to prevent removal of the gasket  140  from over the raised lip  518   a  when the gasket  140  is in the relaxed position. 
     The outer lip  512  can also define a ramped surface  613  facing axially towards the pipe  500 . The ramped surface  613  can also define a side of the groove  514  axially outward from the coupling  170   a.  The ramped surface  613  can be angled, as shown in  FIG. 8A , thereby taking the shape of a truncated cone, or can be curved in other aspects, and can extend to a bottom of the groove  514 . The angle or curve of the ramped surface  613  can be configured to guide the first ridge  578   a  into position in the groove  514  when the coupling  170   a  is tightened into the tensioned position. The ramped surface  613  can thereby function as a locating feature to allow the user to ensure that the coupling  170   a  is properly positioned over the first raised-lip end  2202   a  of the elbow fitting  2212  and, when the pipe  500  is inserted into the coupling  170   a  to abut the first raised-lip end  2202   a,  as shown in  FIG. 8B , the coupling  170   a  is likewise properly positioned over the pipe  500  such that the second ridge  578   b  is aligned over the groove  508 . Thus, when the coupling  170   a  is tightened into the tensioned position, the second ridge  578   b  can be properly guided into the groove  508 . In various aspects, the groove  514  can be narrower in the axial direction than the groove  508  so that the second ridge  578   b  can be spaced slightly in the axial direction from sides of the groove  508 . This can ensure that the second ridge  578   b  properly seats into the groove  508  without inadvertently contacting sides of the groove  508  when the coupling  170   a  is tightened. 
     Further, the grooves  508 , 514  of the pipe  500  and the first raised-lip end  2202   a , respectively, can each define side stop surfaces  609 , 615 , respectively. The side stop surfaces  609 , 615  act as stops to prevent the pipe  500  and the elbow fitting  2212 , respectively, from being removed from the coupling  170   a  when the coupling  170   a  is in the tensioned position by engaging the ridges  578   a,b  when either or both of the pipe  500  and the elbow fitting  2212  are pushed or pulled axially outward from the coupling  170   a,  such as when the pre-assembled coupling assembly  100  is in the pressurized condition. 
       FIG. 8A  also shows that portions of the first segment  172   a  and, similarly, the second segment  172   b  (shown in  FIG. 7 ) can contact the outer surfaces  504  of the pipe  500  and the elbow fitting  2212  adjacent to the grooves  508 , 514 , respectively, when the coupling  170   a  is in the tensioned condition. However, in other aspects, the segments  172   a,b  may contact only one or both of the grooves  508 , 514 , or contact the groove  508  and the outer surface of the elbow fitting  2212  adjacent to the groove  514 , or contact the groove  514  and the outer surface  504  of the pipe  500  adjacent to the groove  508 . 
     In the tensioned position, the center ridge  540  can be compressed radially inward, and the rib  550   a  can contact the raised lip  518   a.  In some aspects, the rib  550   a  can form a secondary seal with the raised lip  518   a.  In the present aspect, the pressure relief channel  520  can maintain fluid communication between the sealing channel  552   a  and the pipe bore  510 . By maintaining fluid communication between the sealing channel  552   a  and the pipe bore  510 , pressurized fluids carried by the pipe  500  can exert pressure within the sealing channel  552   a  which can energize the seal formed between the sealing ridge  548   a  and the sealing surface  612  of the first raised-lip end  2202   a.  The sealing channel  552   a  can define a U-shape of the sealing ridge  548   a,  and pressure exerted within the sealing channel  552   a  can press an axially inner end  648   a  of the sealing ridge  548   a  against the sealing surface  612 . The sealing ridge  548   b  can function similarly, and pressurized fluids within the sealing channel  552   b  can press an axially inner end  648   b  of the sealing ridge  548   b  against the sealing portion  604  of the outer pipe surface  504  of the pipe  500  to energize the seal between the sealing ridge  548   b  and the pipe  500 . 
       FIG. 8B  is a detailed cross-sectional view of the pipe  500 , the elbow fitting  2212 , and the coupling  170   a  of  FIG. 7  with the coupling  170   a  in the relaxed position with the pipe  500  inserted into the coupling  170   a  and abutting the first raised-lip end  2202   a.  The cross-section of  FIG. 8B  is taken from a sectional line extending through mid-sections of the first segment  172   a  and the second segment  172   b  (shown in  FIG. 7 ). When the pipe  500  is inserted into pre-assembled coupling assembly  100  with a pipe fitting  110 , the end  502  of the pipe  500  abuts an inner end of the pipe fitting  110 , such as the first raised-lip end  2202   a  in this aspect. With the ramped surface  619  preventing withdrawal from the gasket  140  and thereby the coupling  170   a , and with the ramped surface  613  preventing further insertion of the first raised-lip end  2202   a  into the coupling  170   a,  the pipe  500  can thereby be held in position to locate the second ridge  578   b  over the groove  508 . In the current aspect, the sealing ridge  548   a  can also be in contact with the sealing surface  612  when the coupling  170   a  is in the relaxed position, further holding the first raised-lip end  2202   a  in the coupling  170   a.    
     As shown in  FIG. 8B , in some aspects, the bottom of the groove  514  can define a smaller diameter than a bottom of the groove  508 . This can provide the benefit of the second ridge  578   b  rigidly contacting the pipe  500  before the first ridge  578   a  contacts the elbow fitting  2212 , ensuring that the coupling  170   a  is rigidly attached to the pipe  500 . The sealing surface  612  of the first raised-lip end  2202   a  can also define a larger diameter than the sealing portion  604  of the pipe  500 , which can better hold the gasket  140 , and thereby the coupling  170   a,  on the elbow fitting  2212 . The diameter of the sealing surface  612  can be sized such that the gasket  140  contacts the sealing surface  612  in the relaxed position, or can be sized such that the gasket  140  does not contact the sealing surface  612  in the relaxed position but is closer to the gasket  140  than the sealing portion  604 . 
       FIG. 9  is a detail cross-sectional view of a one of the pressure relief channels  520  of  FIGS. 6A-C  taken along line  9 - 9  shown in  FIG. 6B . The pressure relief channel  520  can comprise an angled surface  1020  and an axial surface  1018 . The angled surface  1020  can be angled relative to the first raised-lip end  2202   a  of the elbow fitting  2212  and relative to the sealing surface  612 . In the present aspect, the angled surface  1020  can define an about 30-degree angle with the first raised-lip end  2202   a  of the elbow fitting  2212 ; however in other aspects, the angle can be larger or smaller than 30 degrees. The axial surface  1018  can be substantially parallel to the axis  101  (shown in  FIG. 7 ) and the sealing surface  612 . The axial surface  1018  can be defined radially outward from the sealing surface  612  of the first raised-lip end  2202   a  of the elbow fitting  2212  and radially inward from the raised lip  518  (shown in  FIG. 5 ). 
     The raised lip  518  can define a rounded transition surface  1016  defined at the first raised-lip end  2202   a  of the elbow fitting  2212 . The raised lip  518  can define the ramped surface  619  extending to the sealing surface  612 . In the present aspect, the ramped surface  619  can define an about 45-degree angle with the sealing surface  612 ; however, in other aspects, the angle can be greater or smaller than 45 degrees. 
       FIG. 10  is a detail cross-sectional view of another aspect of the pressure relief channels  520  of  FIG. 6A-C  taken along line  9 - 9  shown in  FIG. 6B . Rather than defining the angled surface  1020  as shown in  FIG. 9 , the pressure relief channel  520  can define a radial surface  1120 , which can be substantially perpendicular to the axis  101  (shown in  FIG. 9 ) and the axial surface  1018 . In the present aspect, the radial surface  1120  can be substantially parallel to the first raised-lip end  2202   a  of the elbow fitting  2212 . In the present aspect, the radial surface  1120  can extend completely across the first raised-lip end  2202   a  of the elbow fitting  2212 . 
       FIG. 11  shows another aspect of the pre-assembled coupling assembly  100  wherein the elbow fitting  2212  can define a secondary key  1378  extending radially outward from a cylindrical portion  1314  of the elbow fitting  2212  defined proximate to the inner end  516  of the elbow fitting  2212 . The secondary key  1378  can be disposed adjacent to the groove  514 , and the groove  514  can be disposed between the secondary key  1378  and the inner end  516 . In the present aspect, the inner end  516  may not define the raised lip  518  (shown in  FIG. 10 ) and may be a plain grooved end, similar to the standard grooved end  1402  of the raised-lip pipe  1412  of  FIG. 2 . 
     The coupling  170   a  can comprise a grooved housing  1371  comprising another aspect of the first segment  172   a  and the second segment  172   b.  The grooved housing  1371  can define a secondary shoulder  1370  attached to the first ridge  578   a.  A secondary groove  1372  can be defined between the secondary shoulder  1370  and the first ridge  578   a.  The secondary key  1378  can be received within the secondary groove  1372  to retain the coupling  170   a  on the elbow fitting  2212 . 
     During assembly, the coupling  170   a  in the relaxed position can be slipped over the end  502  of the pipe  500 , and the end  502  can be positioned in facing engagement with the inner end  516  of the elbow fitting  2212 . With the end  502  in facing engagement with the inner end  516 , the secondary key  1378  can be positioned adjacent to the first ridge  578   a.  Once the coupling  170   a  is in the tensioned position and the pipe  500  is pressurized, the inner end  516  of the elbow fitting  2212  can pull away from the end  502  of the pipe  500  due to end cap forces from pressurized fluids transmitted by the pipe  500 . Contact between the secondary key  1378  and the secondary shoulder  1370  can limit axial movement of the elbow fitting  2212  relative to the coupling  170   a  and the pipe  500 . 
       FIG. 12  shows a cross-sectional side view of another aspect of the pre-assembled coupling assembly  100 . The pipe fitting  110  can be a recessed elbow fitting  3012 . The recessed elbow fitting  3012  can be similar to the elbow fitting  2212  except that the recessed elbow fitting  3012  can define a recessed raised-lip end  3002  in place of the raised-lip ends  2202   a,b  (shown in  FIG. 2 ). The outer lip  512  can be disposed axially outward from the coupling  170   a  with respect to the axis  101 . The recessed elbow fitting  3012  can define a shoulder  3060  disposed between the sealing surface  612  and the raised lip  518 . The shoulder  3060  can extend radially inward from the sealing surface  612  with respect to the axis  101 . The recessed elbow fitting  3012  can further define a groove  3014  axially disposed between the raised lip  518  and the shoulder  3060  with respect to the axis  101 . The groove  3014  can extend radially inward from the raised lip  518  with respect to the axis  101 . 
     In the present aspect, the raised lip  518  can be a recessed raised lip  3018  disposed radially inward from the sealing surface  612  with respect to the axis  101 . The pressure relief channels  520  can be recessed pressure relief channels  3020  which can radially extend through the recessed raised lip  3018  and can axially extend between the recessed raised-lip end  3002  and the shoulder  3060  with respect to the axis  101 . 
     In the present aspect, the gasket  140  can be a rimmed gasket  3040 . The rimmed gasket  3040  can define an inner rim  3050  which can extend radially inward from the center ridge  540  of the rimmed gasket  3040 . The inner rim  3050  can define a radially inner end  3052 . With the recessed raised-lip end  3002  disposed within the coupling bore  182 , the inner rim  3050  can be positioned adjacent to the shoulder  3060 . The radially inner end  3052  of the inner rim  3050  can be received within the groove  3014  of the recessed elbow fitting  3012 , and the recessed raised lip  3018  can radially overlap with the radially inner end  3052  of the inner rim  3050  with respect to the axis  101 . Radial overlap of the recessed raised lip  3018  and the radially inner end  3052  can retain the coupling  170   a  on the recessed elbow fitting  3012  when the coupling  170   a  is in the relaxed position. 
     The end  502  of the pipe  500  can also be inserted into the coupling bore  182  with the coupling  170   a  in the relaxed position. With the end  502  of the pipe  500  disposed within the coupling bore  182 , the inner rim  3050  can extend axially inwards from the rimmed gasket  3040  between the end  502  of the pipe  500  and the shoulder  3060 , thereby preventing contact between the end  502  of the pipe  500  and the shoulder  3060 . The recessed raised-lip end  3002  can be inserted into the end  502  of the pipe  500 . The recessed raised lip  3018  can define a tapered pipe alignment surface which can facilitate insertion of the recessed raised-lip end  3002  of the recessed elbow fitting  3012  into the end  502  of the pipe  500 . 
       FIG. 13  shows a cross-sectional side view of another aspect of the pre-assembled coupling assembly  100 . The coupling  170   a  of the present aspect of the pre-assembled coupling assembly  100  can comprise a C-style gasket  3140  which may not define the center ridge  540  (shown in  FIG. 7 ) of the gasket  140  (shown in  FIG. 7 ). The C-style gasket  3140  can define a pair of sealing ridges  3148   a,b . In the present aspect, the sealing ridges  3148   a,b  can extend axially and radially inward relative to the axis  101 , as demonstrated by sealing ridge  3148   b,  when the C-style gasket  3140  is in a relaxed and uncompressed state. Once the end  502  of the pipe  500  (not shown) is inserted into the coupling  170   a,  the sealing ridge  3148   b  can stretch over the end  502  of the pipe  500  and rotate radially outward with respect to the axis  101 . 
       FIG. 14  shows a cross-sectional side view of another aspect of the pre-assembled coupling assembly  100  wherein the pipe fitting  110  can be a grooved elbow fitting  3212 . The grooved elbow fitting  3212  can define an inner end  3202 , and a circumferential groove  3222  can be defined at the inner end  3202 , and the circumferential groove  3222  can extend around a circumference of the grooved elbow fitting  3212 . The circumferential groove  3222  can be defined extending radially inward from the sealing surface  612 . In the present aspect, the circumferential groove  3222  can define a triangular cross-sectional shape; however in other aspects, the circumferential groove  3222  can define a different cross-sectional shape, such as semi-circular, rectangular, or any other suitable shape. In the present aspect, the raised lip  518  can be a recessed raised lip  3218  disposed radially inward from the sealing surface  612  with respect to the axis  101 . The inner end  3202  can also define pressure relief channels  3220  extending radially through the inner end  3202  and intersecting the circumferential groove  3222  with respect to the axis  101 . With the end  502  of the pipe  500  inserted into the coupling  170   a , the end  502  of the pipe  500  can contact the inner end  3202  of the grooved elbow fitting  3212 . 
     The coupling  170   a  can comprise a modified rimmed gasket  3240  which can define an inner rim  3250  which can extend radially inward from the center ridge  540  with respect to the axis  101 . A radially inner end  3252  of the inner rim  3250  can define a cross-sectional shape formed complimentary to the cross-sectional shape of the circumferential groove  3222 . In the present aspect, the radially inner end  3252  can define the triangular cross-sectional shape for example and without limitation. The radially inner end  3252  of the inner rim  3250  can engage the circumferential groove  3222 , and engagement between the radially inner end  3252  and the circumferential groove  3222  can retain the coupling  170   a  on the inner end  3202  of the grooved elbow fitting  3212  when the coupling  170   a  is in the relaxed position. 
       FIGS. 15A-C  show multiple views of another aspect of the pipe fitting  110  wherein the pipe fitting  110  can be a weldolet  1812 . The weldolet  1812  can define a raised-lip end  1802  disposed opposite from a coped end  1804 . The raised-lip end  1802  can define the raised lip  518  and the pressure relief channels  520 . The coped end  1804  can define a coped profile  1808  configured to match a radius of curvature of a pipe (not shown). The coped end  1804  can also define a beveled edge  1806 , and the weldolet  1812  can be configured to attach to an outer surface of the pipe (not shown), such as by welding, in order to attach a nipple for the pipe (not shown). A coupling, such as the coupling  170   a  of  FIG. 1 , can be slipped over the raised-lip end  1802  and retained by the raised lip  518  to form another aspect of the pre-assembled coupling assembly  100 . The weldolet  1812  can define a secondary key  1818 , similar to the secondary key  1378  shown in  FIG. 11 , which can act as a stop for the coupling  170   a  when the raised-lip end  1802  of the weldolet  1812  is inserted into the coupling  170   a.  In some aspects, the coupling  170  can receive the secondary key  1378  in a secondary groove (not shown) which can be similar to the secondary groove  1372  of the coupling  170  of the aspect of  FIG. 11 . 
       FIGS. 16A-C  show multiple views of another aspect of the pipe fitting  110  wherein the pipe fitting  110  can be a mechanical tee  1912 . The mechanical tee  1912  can define a saddle  1906  configured to fit around an outer pipe surface of a pipe (not shown). The saddle  1906  can define a pair of fastener holes  1908  which can receive fasteners (not shown) to secure the mechanical tee  1912  to the other pipe. The mechanical tee  1912  can define a raised-lip end  1902  disposed opposite from the saddle  1906 . In the present aspect, the mechanical tee  1912  can define a coped end  1904  disposed opposite from the raised-lip end  1902  which can extend downwards between the saddle  1906 . The coped end  1904  can be received by a hole (not shown) defined by the pipe, and the mechanical tee  1912  can be secured and sealed to the other pipe to provide a tee connection. A coupling, such as the coupling  170   a  of  FIG. 1 , can be attached to the raised-lip end  1902  and retained by the raised lip  518  to form another aspect of the pre-assembled coupling assembly  100 . 
       FIGS. 17A-C  show multiple views of another aspect of the pipe fitting  110  wherein the pipe fitting  110  can be a tee fitting  2412 . The tee fitting  2412  can define three raised-lip ends  2402   a,b,c , respectively defining the raised lips  518   a,b,c . The raised-lip ends  2402   a,b  can be disposed opposite from one another on the tee fitting  2412 , and the raised-lip end  2402   c  can extend outwards substantially perpendicular to the raised-lip ends  2402   a,b . In other aspects, one or more of the raised-lip ends  2402   a,b,c  can be a standard grooved end, such as the standard grooved end  1402  shown in  FIG. 2 , in place of a raised-lip end  2402 . Couplings  170 , as shown in  FIG. 1 , can be slipped over any or all of the raised-lip ends  2402   a,b,c  and retained by the respective raised lips  518   a,b,c  to form another aspect of the pre-assembled coupling assembly  100 . 
       FIGS. 18A-D  shows multiple views of another aspect of the pipe fitting  110  wherein the pipe fitting  110  can be an end-of-line elbow  2512 . The end-of-line elbow  2512  can define a raised-lip end  2502  and a socket end  2504 . The socket end  2504  can define a socket  2506 . The socket  2506  can be a threaded socket which can be configured to receive a threaded plug, a threaded pipe end, a hose connection, or any other suitable threaded fitting in the present aspect. In other aspects, the socket  2506  can be a tapered socket, as commonly used with polyvinyl chloride (PVC) piping for example and without limitation, or a weld socket, as commonly used with socket-weld pipe connections. The raised-lip end  2502  can define the raised lip  518 . A coupling  170 , as shown in  FIG. 1 , can be slipped over the raised-lip end  2502  and retained by the raised lip  518  to form another aspect of the pre-assembled coupling assembly  100 . 
       FIGS. 19A-B  show multiple views of another aspect of the pre-assembled coupling assembly  100  wherein the pipe fitting  110  can be a check valve  2612 . In the present aspect, the check valve  2612  can define a pair of raised-lip ends  2602   a,b . The raised-lip end  2602   a  can be disposed opposite from the raised-lip end  2602   b  on the check valve  2612 . In other aspects, a one of the raised-lip ends  2602   a,b  can be a standard grooved end, such as the standard grooved end  1402  shown in  FIG. 2 . Each raised-lip end  2602   a,b  can respectively define the raised lip  518   a,b . The couplings  170   a,b  can be positioned and retained on the raised-lip ends  2602   a,b , respectively. 
       FIGS. 20A-B  shows multiple views of another aspect of the pre-assembled coupling assembly  100  wherein the pipe fitting  110  can be a disc valve  2712 . In the present aspect, the disc valve  2712  can define a pair of raised-lip ends  2702   a,b . The raised-lip end  2702   a  can be disposed opposite from the raised-lip end  2702   b  on the disc valve  2712 . In other aspects, a one of the raised-lip ends  2702   a,b  can be a standard grooved end, such as the standard grooved end  1402  shown in  FIG. 14 . Each raised-lip end  2702   a,b  can respectively define the raised lip  518   a,b . The couplings  170   a,b  can be positioned and retained on the raised-lip ends  2602   a,b , respectively. 
       FIGS. 21A-C  show multiple views of another aspect of the pre-assembled coupling assembly  100  wherein the pipe fitting  110  can be a ball valve  2812 . In the present aspect, the ball valve  2812  can define a pair of raised-lip ends, as represented by the raised-lip end  2802 . The raised-lip end  2802  can respectively define the raised lip  518 . The couplings  170   a,b  can be positioned and retained on the raised-lip ends, respectively. 
       FIGS. 22A-B  show multiple views of another aspect of the pre-assembled coupling assembly  100  wherein the pipe fitting  110  can be a flanged fitting  2912 . The flanged fitting  2912  can define a raised-lip end  2902  and a flanged end  2904 . The flanged end  2904  can define a flange  2906  configured to couple with a flange (not shown) of another pipe fitting (not shown). The raised-lip end  2902  can define the raised lip  518 . In the relaxed position, the coupling  170  can be retained on the raised-lip end  2902  by interference between the raised lip  518  and the gasket  140 . 
       FIG. 23A  is a perspective view of another aspect of the elbow fitting  2012  wherein each of the raised-lip ends  2002   a,b  is a stop lip end  1712   a,b , respectively, in accordance with another aspect of the present disclosure.  FIG. 23B  is a side view of the elbow fitting  2012  of  FIG. 23A . On the elbow fitting  2012 , each of the raised lips  518   a,b  can be a stop lip  1718   a,b . The stop lips  1718   a,b  can be spaced inward towards the adjacent outer lip  512  and away from the respective stop lip end  1712   a,b . The pressure relief channels  520  can also be defined by circumferential gaps  1720  in the respective stop lips  1718   a,b  in the present aspect. 
       FIG. 23C  is a cross-sectional detail view of the stop lip end  1712   a  taken along line  23 C- 23 C shown in  FIG. 23A . The stop lip end  1712   a  can also be representative of the stop lip end  1712   b.  The stop lip end  1712   a  can define a bore  1790 , and the bore  1790  can define an axis  1701 . Unlike the raised lips  518   a,b  of the aspects of the elbow fitting  2212  of  FIGS. 5A-8B , in this aspect, the raised lip  518   a,  stop lip  1718   a,  does not extend to the stop lip end  1712   a , itself. Instead, a step surface  1716  can be defined between the stop lip  1718   a  and the stop lip end  1712   a.  In the present aspect, the step surface  1716  can be a cylindrical surface. In the present aspect, the step surface  1716  can be radially aligned with the sealing surface  612 ; however in other aspects, the step surface  1716  can be defined radially inward or radially outward from the sealing surface  612 . In the present aspect, the step surface  1716  can be defined radially outward from the groove  514  but radially inward from the stop lip  1718   a  and the outer lip  512 . In the present aspect, the stop lip  1718   a  can extend radially outwards even with the outer lip  512 ; however in other aspects, the stop lip  1718   a  can extend radially outwards beyond the outer lip  512 . 
     The stop lip  1718   a  can define an outer surface  1719   a  facing the outer lip  512  and an inner surface  1719   b  facing the stop lip end  1712   a  of the elbow fitting  2212 . The outer surface  1719   a  can define an outer angle Ai relative to a radial direction of the axis  1701 , and the inner surface  1719   b  can define an inner angle A 2  relative to the radial direction of the axis  1701 . In the present aspect, each of the angles A 1 ,A 2  can be less than 45 degrees. In some aspects, the angles A 1 ,A 2  can be 0 degrees, and the inner surface  1719   a  and the outer surface  1719   b  can be parallel to the radial direction of the axis  1701 . 
       FIG. 24A  is an end view of an aspect of the pre-assembled coupling assembly  100  comprising the elbow fitting  2212  of  FIGS. 23A-C .  FIG. 24B  is a cross-sectional detail side view of the stop lip end  1712   a  of the pre-assembled coupling  100  of  FIG. 24A  taken along line  24 B- 24 B shown in  FIG. 24A  with the pipe  500  of  FIG. 7 . In the present aspect, the stop lip  1718   a  can be specifically shaped to prevent insertion and withdrawal of the stop lip end  1712   a  of the elbow fitting  2212  into the coupling bore  182  when the coupling  170   a  is in the relaxed position. For example, the stop lip  1718   a  can extend radially outward far enough to radially overlap with the ridge  578   a.  Consequently, if a user attempts to insert the stop lip end  1712   a  into the coupling bore  182  in the relaxed state or remove the stop lip end  1712   a  from the coupling bore  182  in the relaxed state, interference between the stop lip  1718   a  and the ridge  578   a  will prevent the user from succeeding. Instead, the user must disassemble the coupling  170   a  by separating the first segment  172   a  from the second segment  172   b  of the housing  171  to insert or remove the stop lip end  1712   a  from the coupling bore  182 . Therefore, to assemble the pre-assembled coupling  100 , the user must first insert the stop lip end  1712   a  into the gasket  140  and then assembled the housing  171  around the gasket  140  in the present aspect. In some aspects, the stop lip end  1712   a  cannot be stabbed into the gasket  140  without a tool to aid in expanding the sealing ridge  548   a  over the stop lip  1718   a,  particularly in aspects wherein the inner angle A 2  (shown in  FIG. 23C ) approaches a very small value, such as less than 10 degrees. 
       FIG. 25  is a side view of the elbow fitting  2212  defining another aspect of the stop lip ends  1712   a,b  wherein the raised lip  518  is a continuous stop lip  1918  which does not define the circumferential gaps  1720  (shown in  FIG. 23A ). 
     To pre-assemble the pre-assembled coupling assembly  100 , the inner end  516  of the pipe fitting  110  can be inserted into a relaxed gasket  140 , without the housing  171  assembled around the gasket  140 , 3140  so that the inner end  516  can be axially positioned between the sealing ridges  548   a,b , 3148   a,b . In some aspects, the sealing ridge  548   a  can contact the sealing surface  612  of the pipe fitting  110 . As discussed above, in aspects defining the stop lip  1718   a,b , a tool or tools may be required to stretch the sealing ridge  548   a  over the stop lip  1718   a,b.    
     In aspects of the pipe fitting  110  such as that of  FIGS. 1-8, 13, 15-22B , the gasket  140 , 3140  can be retained on the inner end  516  of the pipe fitting  110  due to interference between the sealing ridge  548   a , 3148   a  and the raised lip  518 . In such aspects the sealing ridge  548   a , 3148   a  can be stretched over the raised lip  518  when inserting the inner end  516  through the sealing ridge  548   a , 3148   a  and elastic resistance of the sealing ridge  548   a , 3148   a  can resist withdrawal of the inner end  516  outward through the sealing ridge  548   a , 3148   a,  thereby retaining the relaxed gasket  140 , 3140  on the pipe fitting  110 . In aspects of the pipe fitting  110  such as those of  FIGS. 12 and 14 , the inner rim  3050 , 3250  of the gasket  140  can stretch over the raised lip  518 , 3018 , 3218  upon insertion of the inner end  516  into the relaxed gasket  140 , 3040 , 3240 , and the inner rim  3050 , 3250  can seat in the groove  3014 , 3222 . Elastic resistance of the inner rim  3050 , 3250  can resist withdrawal of the inner end  516  of the pipe fitting  110  back through the inner rim  3050 , 3250 , thereby retaining the relaxed gasket  140  on the inner end  516  of the pipe fitting  110 . In these aspects of the pipe fitting  110 , the housing  171  of the coupling  170  can then be assemble around the gasket  140 , 3040 , 3140 , 3240  by positioning the gasket  140 , 3040 , 3140 , 3240  within the gasket groove  570  of the segments  172   a,b  and fastening the segments  172   a,b  together with the fasteners  176   a,b . The gasket  140 , 3040 , 3140 , 3240  can then retain the coupling  170  on the inner end  516  of the pipe fitting  110 . 
     Alternatively, for the aspect of the pipe fitting shown in  FIG. 11 , the coupling  170  may not be retained on the inner end  516  of the pipe fitting  110  by elastic resistance of the gasket  140 . Instead the relaxed gasket  140  can be freely slipped over the inner end  516  with no or minimal resistance, and the grooved housing  1371  can be assembled around the gasket  140  and the secondary key  1378 . The segments  172   a,b  can be aligned so that the gasket  140  fits within the gasket groove  570 , and the secondary key  1378  fits within the secondary groove  1372 , thereby retaining the coupling  170  on the pipe fitting  110  through interference between the secondary groove  1372  and the secondary key  1378 . 
     Once the coupling  170  is secured on the inner end  516  of the pipe fitting  110 , the pipe  500  or another pipe fitting  110  can be stabbed into the assembled coupling  170  opposite from the pipe fitting  110  when the coupling  170  is in the relaxed position. The coupling  170  can then be tightened to the tensioned position by tightening the fasteners  176   a,b , thereby securing and sealing the pipe fitting  110  to the pipe  500  or another pipe element. In other aspects, the assembled coupling  170  in the relaxed position can be slipped over the pipe fitting  110  to secure the coupling  170  on the inner end  516  of the pipe fitting  110 . By contrast, aspects defining the stop lip  1718   a,b  can be specifically configured to prevent the assembled coupling  170  from being slipped over the stop lip  1718   a,b.    
     The disclosed examples of pipe fittings  110  are exemplary and should not be viewed as limiting. The pipe fitting  110  can be any type of fitting such as a reducer, sprinkler, wye fitting, nipple, trap, valve, regulator, adapter, quick disconnect coupling end, or any other suitable type of fitting. 
     One should note that conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more particular embodiments or that one or more particular embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment. 
     It should be emphasized that the above-described embodiments are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Any process descriptions or blocks in flow diagrams should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included in which functions may not be included or executed at all, may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. Further, the scope of the present disclosure is intended to cover any and all combinations and sub-combinations of all elements, features, and aspects discussed above. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure.