Abstract:
A method of installing a pipe coupling to connect a first pipe element to a second pipe element includes sliding the pipe coupling as a preassembled unit over an outermost surface of the first pipe element, the pipe coupling comprising a coupling segment and an annular gasket, the annular gasket comprising an annular body and a pair of sealing ribs extending substantially radially inward from the annular body, each sealing rib comprising a sealing ridge defining a sealing surface, the sealing surface of each sealing ridge being coannular in an undeformed state; introducing an end of the second pipe element to an end of the first pipe element to place the first pipe element and the second pipe element in end-facing relationship; aligning the pipe coupling over the first pipe element and the second pipe element; and securing the coupling to the first pipe element and the second pipe element.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 13/354,470, filed Jan. 20, 2012, which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    This disclosure relates to piping. More specifically, this disclosure relates to pipe coupling. 
       BACKGROUND 
       [0003]    Pipe elements such as pipes, valves, and meters typically are not made of one piece. Rather, such pipe elements are formed in finite lengths and must be joined. One way of joining such pipe elements is through the use of a coupling member. A sealing gasket is typically disposed in a central space of at least one coupling segment which is thereafter tightened around the pipe elements to be joined. 
       SUMMARY 
       [0004]    Disclosed is a method of installing a pipe coupling to connect a first pipe element to a second pipe element comprises sliding the pipe coupling as a preassembled unit over an outermost surface of the first pipe element, the pipe coupling comprising a coupling segment and an annular gasket, the annular gasket comprising an annular body and a pair of sealing ribs extending substantially radially inward from the annular body, each sealing rib comprising a sealing ridge defining a sealing surface, the sealing surface of each sealing ridge being coannular in an undeformed state; introducing an end of the second pipe element to an end of the first pipe element to place the first pipe element and the second pipe element in end-facing relationship; aligning the pipe coupling over the first pipe element and the second pipe element; and securing the coupling to the first pipe element and the second pipe element. 
         [0005]    Also disclosed is a method of installing a pipe coupling to connect a first pipe element to a second pipe element comprising sliding the pipe coupling as a preassembled unit over an outermost surface of the first pipe element, the pipe coupling comprising a coupling segment and an annular gasket having an innermost diameter greater than a diameter of the outermost surface of the first pipe element and a diameter of the outermost surface of the second pipe element, the annular gasket comprising an annular body and a pair of sealing ribs extending substantially radially inward from the annular body, each sealing rib comprising a sealing ridge defining a sealing surface, the annular gasket configured to slide over the diameters of the outermost surface of the first pipe element and the outermost surface of the second pipe element without contacting the outermost surfaces of the first pipe element and the second pipe element in an undeformed state; introducing an end of the second pipe element to an end of the first pipe element to place the first pipe element and the second pipe element in end-facing relationship; aligning the pipe coupling over the first pipe element and the second pipe element; and securing the coupling to the first pipe element and the second pipe element. 
         [0006]    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. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0007]    The features and components of the following figures are illustrated to emphasize the general principles of the present disclosure and 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. 
           [0008]      FIG. 1  is an exploded perspective view of a coupling in accord with one embodiment of the current disclosure. 
           [0009]      FIG. 2  is an outer perspective view of a segment of the coupling of  FIG. 1 . 
           [0010]      FIG. 3  is an inner perspective view of the segment of  FIG. 2 . 
           [0011]      FIG. 4  is a cross-sectional view of the segment of  FIG. 2 . 
           [0012]      FIG. 5  is a cross-sectional view of a gasket of the coupling of  FIG. 1 . 
           [0013]      FIG. 6  is a side view of the coupling of  FIG. 1  in an assembled and untightened position. 
           [0014]      FIG. 7  is a side view of the coupling of  FIG. 1  in an assembled and tightened position, including a cross-sectional view of pipe elements. 
           [0015]      FIG. 8A  is a cross-sectional view of the coupling of  FIG. 1  before installation on pipe elements. 
           [0016]      FIG. 8B  is a cross-sectional view of the coupling of  FIG. 1  during installation on pipe elements. 
           [0017]      FIG. 8C  is a cross-sectional view of the coupling of  FIG. 1  during installation on pipe elements. 
           [0018]      FIG. 8D  is a cross-sectional view of the coupling of  FIG. 1  during installation on pipe elements. 
           [0019]      FIG. 8E  is a cross-sectional view of the coupling of  FIG. 1  after installation on pipe elements. 
           [0020]      FIG. 9  is a cross-sectional view of the coupling taken in a plane indicated by line  9  in  FIG. 6 . 
           [0021]      FIG. 10  is a partial cross-sectional view of the coupling of  FIG. 1  assembled around pipe elements and in an untightened position. 
           [0022]      FIG. 11  is a partial cross-sectional view of the coupling of  FIG. 1  assembled around pipe elements and in a tightened position. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Disclosed is a pipe coupling and associated methods, systems, devices, and various apparatus. The pipe coupling includes at least one segment, at least one tightening element, and at least one gasket. The pipe coupling is adapted to seal pipe elements in end-to-end relationship. It would be understood by one of skill in the art that the disclosed pipe coupling is described in but a few exemplary embodiments among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom. 
         [0024]    One embodiment of a pipe coupling  100  is disclosed and described in  FIG. 1 . The pipe coupling  100  of the current embodiment includes two segments  110 , 110 ′ although any number of segments  110  may be used in various embodiments. The current embodiment includes tightening elements or fasteners that are nut and bolt fasteners. Two bolts  120   a,b  are disposed to interact with nuts  125   a,b  in threaded engagement. Various types of tightening elements may be used in various embodiments, and the disclosure of bolts  120   a,b , and nuts  125   a,b  should not be considered limiting. Fastener pads  130   a,b  protrude from segment  110  and fastener pads  130   a′,b ′ protrude from segment  110 ′. Fastener holes  132   a,b,a′,b ′ are defined in fastener pads  130   a,b,a′,b ′, respectively. In the current embodiment, the fastener holes  132   a,b,a′,b ′ are about centered within the fastener pads  130   a,b,a′,b ′, although they may be offset in various embodiments. Although the fastener pads  130   a,b,a′,b ′ and fastener holes  132   a,b,a′,b ′ are described in the current configuration, various locations and configurations of fastener pads  130   a,b,a′,b ′ and fastener holes  132   a,b,a′,b ′ are included in various embodiments. A gasket  150  is included with the pipe coupling  100 . The gasket  150  of the current embodiment is annular and adapted to surround and to seal fluid piping, although various configurations will be included in various embodiments. 
         [0025]      FIGS. 2, 3, and 4  show segment  110 . In the current embodiment, segment  110 ′ is substantially identical to segment  110 . As seen in  FIG. 2 , each segment  110  includes two ends  203 , 207  and a segment body  210  disposed between the two ends  203 , 207 . Each segment  110  in the current embodiment is about semicircular, although other configurations may be used in various embodiments. Proximate each end  203 , 207  is a shoulder  213 , 217  protruding outwardly from the segment  110 . Each shoulder  213 , 217  provides a connection point for a fastener which, in the current embodiment, is a bolt  120 . Each shoulder  213 , 217  includes fastener holes  132   a,b  defined in fastener pads  130   a,b.    
         [0026]    Each segment body  210  includes a central portion  215  and at least one edge portion  225   b  ( 225   a  not shown in  FIG. 2 ). In the current embodiment, the edge portions  225   a,b  are designed to interact with a groove in the pipe elements to be sealed and joined, although some embodiments may be designed to interact with non-grooved pipe elements. 
         [0027]    As can be seen in  FIG. 2 , each fastener hole  132   a,b  includes a first linear extent or an axial length  233 , 237  and a second linear extent or transverse length  243 , 247 . The axial lengths  233 , 237  and the transverse lengths  243 , 247  are measured at top surfaces  364 , 314  of the fastener pads  130   a,b . These dimensions increase through the fastener pads  130   a,b  in the current embodiment because they are cast, and a draft angle is used in casting. In various embodiments, these dimensions may remain constant if, for example, the fastener holes  132   a,b  are made via a machining step. In the current embodiment, each fastener hole  132   a,b  is about ovular in shape, although other embodiments may include various shapes. The shape of the current embodiment of the fastener holes  132   a,b  provides interference with the bolts  120   a,b  to reduce rocking motion, as will be described later with reference to  FIG. 9 . Each segment  110  includes an outer surface  250  and an inner surface  260 . A contact surface  262   b  ( 262   a  shown in  FIG. 3 ) is included on the inside of each edge portion  225   a,b . Also seen in  FIG. 2  is a tongue  280 , as will be described in more detail with reference to  FIGS. 3, 4, and 6 . 
         [0028]    As seen more clearly in  FIG. 3 , the tongue  280  protrudes from the end  207  of the segment  110 . The shoulder  217  can be seen protruding outwardly from the segment  110 . In the current embodiment, the shoulder  217  includes a bottom surface  312  and a top surface  314 . The bottom surface  312  and the top surface  314  are substantially parallel in the current embodiment and are angled in order to ensure proper alignment upon deformable tightening of the pipe coupling  100 , as will be discussed later with reference to  FIG. 4 . However, in some embodiments, the bottom surface  312  and the top surface  314  are not angled. A wall  317  of the shoulder  217  is seen along the outside of the shoulder  217 . The wall  317  in the current embodiment defines a draft portion  316  having a draft angle such that the thickness of the shoulder  217  at a beginning of the draft  318  is thicker than the thickness at an end of the draft  319 . The angle of the draft portion  316  is consistent between the beginning of the draft  318  and the end of the draft  319  so that the region defining the draft angle is a linear taper in the current embodiment, although other shapes may be used in various embodiments. A radiused portion  321  extends beyond the draft portion  316  to provide an end  334  of the shoulder  217  beyond the fastener hole  132   b . The wall  317  includes an outer surface  322 . 
         [0029]    As can be seen from the view of  FIG. 3 , the shoulder  217  includes a taper portion  326 . The taper portion  326  terminates at the end  334  of the shoulder  217  and melds at the other end with a parallel portion  327  of the shoulder  217 . As previously described, the bottom surface  312  is parallel to the top surface  314  in the parallel portion  327 . A ledge surface  331   a,b  provides a quick transition to the taper portion  326 , which includes a taper bottom surface  332  that is not parallel to the top surface  314 . An inner surface  335   b  of the fastener hole  132   b  can also be seen in the current view. 
         [0030]    The tongue  280  includes three portions in the current embodiment: a central portion  342 , a first side portion  344 , and a second side portion  346 . The side portions  344 , 346  are oriented with respect to the central portion  342  such that an angle is formed between each. In the current embodiment, the angle is greater than ninety degrees. The tongue  280  includes an outer surface  352 , an inner surface  354 , and a mating surface  355 . The mating surface  355  is angled at a tip angle  430 , which is shown in  FIG. 4 . The mating surface  355  is located on a leading edge of the tongue  280 . 
         [0031]    Shown along the other end  203  is the other shoulder  213 . The shoulder includes a bottom surface  362  and a top surface  364  that are substantially parallel. The shoulder  213  includes a draft portion  366  and a radiused portion  371 . A taper portion  376  is included just like with shoulder  203 . A parallel portion  377  is also included where the bottom surface  362  is parallel to the top surface  364  in the region. Ledge surfaces  381   a,b  (not shown) are also included just like ledge surfaces  331   a,b , and a taper bottom surface  382  is also included. 
         [0032]    A groove  380  is defined in the shoulder  213 . The groove  380  is sized to accept the tongue  280 . The groove  380  includes a central wall  392  and two side walls  394 , 396 . The groove  380  is further defined by a mating surface  395 . In assembly, the mating surface  395  contacts the mating surface  355 ′ of another segment  110 ′. A groove shoulder surface  389  is included on the inside of the groove  380 . A draft portion  388  can be seen proximate the end of the segment  110  nearest the groove  380 . The draft portion  388  provides a relief from the inner surface  260  to the mating surface  395  to line up with the tongue  280 ′, which is slightly set back from the inner surface  260 ′. The draft portion  388  helps prevent the coupling  100  from pinching the gasket  150  during installation, as pinching of the gasket  150  can lead to failure of the gasket  150  including slicing and rupture of the gasket  150 . A draft portion shoulder surface  387   a,b  ( 387   b  not shown) provides the part of the step-down from a shoulder surface  296   a,b  ( 296   b  not shown) to the mating surface  395 . 
         [0033]    Each edge portion  225   a,b  of the segment  110  includes a contacting portion  292   a,b  and a support portion  294   a,b . The contact surface  262   a,b  is included at the end of the contacting portion  292   a,b . The shoulder surface  296   a  ( 296   b  not shown) can be seen at the inside end of the support portion  294   a  (inside end of the support portion  294   b  not shown). Three nodes  297   a , 298   a  ( 299   a,b  and  297   b , 298   b  not shown) protrude from the shoulder surface  296   a,b  between the support portion  294   a,b  and the contacting portion  292   a,b . Each node  297   a,b  and  298   a,b  include a width that decreases from the support portion  294   a,b  to the contacting portion  292   a,b . Although the nodes  297   a,b ,  298   a,b , and  299   a,b  are pyramidal in the current embodiment, they may be various shapes in various embodiments. 
         [0034]    The gasket  150  is designed to interact with the inner surface  260  of each segment  110  in the pipe coupling  100 , as will be discussed with reference to  FIG. 5 . 
         [0035]    As seen in the cross-sectional view of  FIG. 4 , the top surfaces  314 , 364  and the bottom surfaces  312 , 362  are aligned at angles  415 , 416 , 417 , 418  with respect to a horizontal axis  420  of the segment  110 . A vertical axis  425  is shown for reference. The angles  415 , 416 , 417 , 418  allow for deflection of the segment  110  in use. In some embodiments, the angles  415 , 416 , 417 , 418  will be zero such that the top surfaces  314 , 364  are aligned with the horizontal axis  420  when no deflection is present. The tip angle  430  of the tongue  280  can be seen such that the mating surface  355  is aligned angularly with respect to the horizontal axis  420 . The tip angle  430  is greater than the other angles  415 , 416 , 417 , 418  in the current embodiment, although other configurations may be found in various embodiments. When the segment  110  is deflected, the mating surface  355  contacts the mating surface  395  of another segment  110 . In various embodiments, the tip angle  430  is approximately the same as the angles  415 , 417  of the top surface  314  and bottom surface  312 , respectively. 
         [0036]    Also seen in cross-sectional view, each fastener hole  132   a,b  is drafted such that each fastener hole  132   a,b  defines a cone-shaped void that is approximately ovular in cross-section, although various cross-sectional shapes may be found in various embodiments. As such, each fastener hole  132   a,b  includes a smaller aperture at the top surface  314 , 364  than where the fastener hole  132   a,b  emerges into the taper bottom surface  332 , 382  and the bottom surface  312 , 362 . This configuration may be omitted in various embodiments. 
         [0037]    As can be seen in  FIG. 5 , the gasket  150  is ring-shaped and includes an annular body  510  having a radially outer surface  515 . The radially outer surface  515  interacts with the inner surface  260  of each segment  110  in the pipe coupling  100 . The radially outer surface  515  of the annular body  510  includes a deformation groove  517 . The annular body  510  includes side portions proximate axial ends of the annular body  510 . Extending substantially radially inward from the side portions of the annular body  510  are a pair of sealing ribs  520   a,b . Each sealing rib  520   a,b  extends substantially radially inwardly and increases in thickness from radially outside to radially inside. Each sealing rib  520   a,b  also has an axially outer surface  521   a,b  extending from the radially outer surface  515  to the start of an axially outer drafted edge  522   a,b . Each axially outer surface  521   a,b  is angled with respect to a radial direction. The angle of each axially outer surface  521   a,b  is consistent around the entirety of the annular body  510 , so that axially outer surfaces  521   a,b  are shaped as a truncated cone. In the current embodiment, each axially outer surface  521 , a,b  is angled between nineteen and twenty-two degrees with respect to a radius of the gasket  150 , although other configurations may be present in various embodiments. 
         [0038]    Each sealing rib  520   a,b  has a sealing ridge  525   a,b  extending axially inward from a radially inward end  551   a,b  of each sealing rib  520   a,b . Each sealing ridge  525   a,b  extends substantially axially inward from the radially inward end  551   a,b  of each sealing rib  520   a,b , such that the two sealing ridges  525   a,b  extend toward each other. The axially outer drafted edges  522   a,b  extend from the radially inward end  551   a,b  to a contact portion  555   a,b . Each axially outer drafted edge  522   a,b  may be rounded, slanted, or various shapes in cross-section in various embodiments. Such cross-sectional shapes translate to conical and paraboloid shapes in various embodiments. Such shapes are truncated, as a full cone or paraboloid would not allow insertion of pipe elements in the gasket  150 . In the embodiment shown in  FIG. 5 , the axially outer drafted edges  522   a,b  are slanted at an angle approximately between 27° and 28° from a radial direction, although various other angles may be present in various embodiments. Contact portions  555   a,b  extend along the sealing ridges  525   a,b  from the axially outer drafted edges  522   a,b  to an axially inner drafted edge  527   a,b . Each contact portion  555   a,b  includes a sealing surface  526   a,b  facing radially inward and coplanar or collinear with each other in the cross-sectional view. The coplanar/collinear arrangement in cross-sectional view denotes a coannular surface profile of the sealing surfaces  526   a,b  in the current embodiment, although the surfaces may be of different diameters in various embodiments. The sealing surfaces  526   a,b  are intended to contact pipe elements placed inside of the gasket  150  to provide a fluid seal for the pipe elements. The sealing surfaces  526   a,b  face radially inwardly and extend substantially axially at rest. In other words, by “face radially inwardly,” when the sealing surfaces  526   a,b  are not in contact with pipe elements, the sealing surfaces  526   a,b  approximate a cylinder that is about coaxial with the pipe elements intended to be used with the coupling  100 . Thus, the sealing surfaces  526   a,b  appear as lines that are parallel with the axis of pipe elements  710  in cross-sectional view, as seen in  FIGS. 8A-8E . Any angle with respect to the pipe elements  710  is minimal. 
         [0039]    The orientation of the sealing surfaces  526   a,b  is intended to ease the insertion of pipe elements into contact with the sealing surfaces  526   a,b  of gasket  150 . Extending from each sealing surface  526   a,b  is the axially inner drafted edge  527   a,b . The axially inner drafted edges  527   a,b  may be rounded, slanted, or various shapes in cross-section in various embodiments. Such cross-sectional shapes translate to paraboloid and conical shapes in various embodiments. Such shapes are truncated, as a full cone or paraboloid would not allow insertion of pipe elements in the gasket  150 . The axially inner drafted edges  527   a,b  define the termination of the sealing ridge  525   a,b  along the axially inward direction. 
         [0040]    A center rib  530  extends radially inward from the annular body  510 . The center rib  530  includes a central groove  531  and two sealing members  557   a,b  which each include a sealing surface  532   a,b . Each sealing member  557   a,b  in the current embodiment is a rounded protrusion from the central groove  531 . In various embodiments, various shapes and configurations of sealing members  557   a,b  may be used, including flattened shapes, combinations of protrusions, and unconnected surfaces, among others. The sealing surface  532   a,b  is included on the sealing member  557   a,b , respectively. The central groove  531  is positioned between the sealing surfaces  532   a,b  such that the sealing surfaces  532   a,b  of the sealing members  557   a,b  are capable of contacting the pipe elements and providing additional sealing interaction therewith. 
         [0041]    Each sealing rib  520   a,b  has an innermost radial extent as measured from the annular body  510 . In addition, each sealing rib  520   a,b  has an edge radial extent as measured from the annular body  510  to an axially innermost end of each of the axially inner drafted edges  527   a,b . The center rib  530  has an innermost radial extent as measured from the annular body  510 . The innermost radial extent of the center rib  530  is closer to the annular body  510  than the innermost radial extent of each of the pair of sealing ribs  520   a,b . Additionally, in the current embodiment, the innermost radial extent of the center rib  530  is closer to the annular body  510  than the edge radial extent of each of the pair of sealing ribs  520   a,b . The innermost radial extent of the center rib  530  may be as far from the annular body as, or farther from the annular body  510  than, the edge radial extent of each of the pair of sealing ribs  520   a,b  in various embodiments. The innermost radial extent of the center rib  530  may also be equally as far from the annular body  510  as the innermost radial extent of each of the pair of sealing ribs  520   a,b  in various embodiments. 
         [0042]    The gasket  150  may be made of rubber, plastic, cork, wood, metal, ceramic, polymer, elastomer, rosin, foam, any combination of the foregoing materials, or any material suitable for sealing two pipe elements joined in end-to-end relationship. “Pipe elements” may mean pipes, valves, meters, or any other piping joint suitable to be sealed. 
         [0043]    The annular body  510 , the sealing ribs  520   a,b , and the center rib  530  define gasket channels  540   a,b  as seen in  FIG. 5 . The gasket channels  540   a,b  are pockets into which fluid media may flow when the gasket  150  is in use. The gasket channels  540   a,b  are tubular channels in the current embodiment but may be various shapes in various embodiments. When placed in sealing contact with an exterior surface of a pipe element, the gasket channels  540   a,b  allow some fluid pressure to aid in sealing the sealing ridges  525   a,b  against pipe elements, although such use is not necessary for successful sealing of the gasket  150 . The center rib  530  decreases in thickness from its radial outermost to its termination radially inward. 
         [0044]    In addition, when the gasket  150  is in use, the sealing members  557   a,b  and the groove  531  act to prevent substantial fluid media flow into the gasket channels  540   a,b . When placed in sealing contact with exterior surfaces of pipe elements, the sealing surfaces  532   a,b  of the sealing members  557   a,b  prevent substantial fluid media flow into gasket channels  540   a,b , retaining fluid media flow in the groove  531 . The gasket, in alternative embodiments, may include a plurality of center ribs, each with at least one sealing member and at least one sealing surface, which perform the same function as described above to prevent substantial media flow into the gasket channels. 
         [0045]    One problem that the center rib  530  can alleviate is the buildup of fluids in the gasket channels  540   a,b . For example, in applications where fluid media is water in cold temperature environments, preventing water buildup in the gasket channels  540   a,b  can lead to damage to the gasket  150  if the water freezes and, thereby, expands. 
         [0046]      FIG. 6  shows the coupling  100  in an assembled but untightened position. It can be seen in this view that each top surface  314 , 314 ′ is parallel to each bottom surface  312 , 312 ′, respectively. Likewise, each top surface  364 , 364 ′ is parallel to each bottom surface  362 , 362 ′, respectively. However, the fastener pads  130   a,b,a′,b ′ are not aligned. In other words, the surfaces of adjacent fastener pads  130   a,b,a′,b ′ are not parallel. As can be seen, top surface  314  is not parallel to top surface  364  because angles  415  and  416  do not align. This angular misalignment allows each segment  110 , 110 ′ to deflect under tightening pressure of the bolts  120   a,b  and nuts  125   a,b  to provide so that the top surfaces  314 , 314 ′ and  364 , 364 ′ are substantially parallel when the segments  110 , 110 ′ are deformed. In various embodiments, the top surfaces  314 , 314 ′ and  364 , 364 ′ may be parallel before deforming the segments  110 , 110 ′. In such embodiments, the top surfaces  314 , 314 ′ and  364 , 364 ′ may be non-parallel after deflection. 
         [0047]    As can be seen in  FIG. 6 , the groove shoulder surface  389  of segment  110 ′ is angled so that it aligns with an outer surface  352 ′ of tongue  280 ′ of segment  110 ′ upon deformation of the segments  110 , 110 ′ as will be shown below in  FIG. 7 . Upon deformation of the segments  110 , 110 ′ (as described below), the grooved shoulder surface  389  of segment  110  becomes parallel and flush with outer surface  352 ′ of tongue  280 ′ of segment  110 ′, and grooved shoulder surface  389 ′ of groove  380 ′ of segment  110 ′ becomes parallel and flush with outer surface  352  of segment  110 . 
         [0048]    As can be seen in  FIG. 6 , the annular nature of the gasket  150  defines a coupling void  410  within the gasket  150  that is adapted for certain diameters of pipe elements. In practice, when pipe elements are introduced within the gasket  150 , they are placed inside the coupling void  410 . Also seen in  FIG. 6 , a central axis of each of the bolts  120   a,b  is parallel to the vertical axis  425  such that heads  612   a,b  of the bolts  120   a,b  sit at an angle with the top surfaces  314 ,  316 . In alternative embodiments, the bolts  120   a,b  may be angled with respect to the vertical axis  425  such that heads of the bolts  120   a,b  sit flush against the top surfaces  314 , 364 . In the current embodiment, the gasket  150  sits within the segments  110 , 110 ′. Each of the sealing surfaces  526   a,b  of the gasket  150  has the same cylindrical profile and the same radius as the contact surfaces  262   a,b,a′,b ′. In alternative embodiments, the sealing surfaces  526   a,b  of the gasket  150  may have a smaller or a larger radius than the contact surfaces  262   a,b,a′,b ′. In many embodiments, sealing surfaces  526   a,b  are in contact with the outer surfaces of the pipe elements before the tightening elements (bolts  120   a,b  and nuts  125   a,b ) are engaged. In those embodiments, further compression of the gasket  150  will not necessarily produce a more effective seal. However, in other embodiments, it may be necessary for the segments  110 , 110 ′ to compress the gasket  150  to effectuate a useful seal against the outer surface of the pipe elements. In many embodiments, sealing surfaces  532   a,b  are positioned in contact with or slightly above contact with the pipe elements. In those embodiments, deformation of the gasket  150  is necessary to seal the sealing surfaces  532   a,b  against the pipe elements. In some embodiments, however, sealing surfaces  532   a,b  are in sufficient engagement with the pipe elements prior to engagement of the tightening elements (bolts  120   a,b  and nuts  125   a,b ) so that further tightening does not necessarily effectuate a better seal. 
         [0049]    Upon compression of the gasket  150  by the segments  110 , 110 ′, the gasket  150  will most naturally deform from about circular in shape to an oblong shape. In most applications, compression by the segments  110 , 110 ′ on the gasket  150  will compress the gasket along the vertical axis  425 , but the gasket  150  will tend to extend along the horizontal axis  420 . This occurs particularly because the segments  110 , 110 ′ first contact the pipe elements—and, thus, first compress the gasket  150 —at a point central to the segments  110 , 110 ′. As shown in  FIGS. 4 and 6 , the tongues  280 , 280 ′ of the segments  110 , 110 ′ extend beyond the horizontal axis  420 , thereby preventing the annular deformation of the gasket  150 . Deformation of the gasket  150  is properly directed to the deformation groove  517  by the tongue  280  and groove  380  configuration of the coupling  100 . The restraint against oblong deformation provided by the tongues  280 , 280 ′ promotes more uniform compression of the gasket  150  against the pipe elements, thereby providing a more reliable seal. 
         [0050]    Tightening of the tightening elements (bolts  120   a,b  and nuts  125   a,b ) seats the gasket  150  against the pipe elements. When the segments  110 , 110 ′ are properly deformed and the gasket  150  is properly seated, the coupling  100  restrains the pipe elements from pullout because the contacting portion  292   a,b.a′,b ′ (not shown in  FIG. 6 ) of each segment  110 , 110 ′ is seated inside at least one groove of at least one pipe element. The gasket  150  is compressed in sealed engagement with the pipe elements. In some embodiments, the sealing members  557   a,b  may be replaced by a single sealing member that extends between the two pipes. Such deformation allows heads  612   a,b  of the bolts  120   a,b  to seat flush against the top surfaces  314 , 364  of segment  110  while nuts  125   a,b  seat flush against the top surfaces  314 ′, 364 ′ of segment  110 ′. 
         [0051]    When properly seated, media (such as water, gas, or other fluid) may be allowed to flow through the pipe elements. The gasket  150  seals such media in at least one of two ways. If the gasket  150  is compressed so that sealing surfaces  532   a,b  of the sealing members  557   a,b  are properly seated against the outside of the pipe elements, such sealing interaction may be sufficient to contain the media inside the pipe elements without breaching the joint. In some applications, such sealing engagement may be impossible to attain, or the pressure of media within the pipe elements may be too great for such a sealing engagement to effectuate a proper seal. In such applications, media may travel past the sealing members  557   a,b  and into the gasket channels  540   a,b.    
         [0052]    If media passes into the gasket channels  540   a,b , there are two safeholds against leakage. First, in many applications, sealing surfaces  526   a,b  are in sealing engagement with the pipe elements prior to compression of the gasket  150  by the segments  110 , 110 ′, and further compression of the gasket  150  enhances such sealing engagement. In other applications, sealing engagement of the gasket  150  with the pipe elements is achieved by compression of the gasket  150  by the segments  110 , 110 ′. Second, if media passes into the gasket channels  540   a,b , it is assumed that such media is of a higher pressure than atmospheric. As such, the higher pressure in the gasket channels  540   a,b  further forces the sealing ridges  525   a,b  against the pipe elements. The higher pressure results in an even more effective seal by using the pressure of the media inside the pipe elements to effectuate a more complete seal. If liquid media is found in the pipe, such liquid may provide additional air-tight seal to further aid the engagement of the gasket  150  with the pipe elements. In some embodiments, gas-proofing grease may be applied to the contact surfaces  526   a,b  and  532   a,b  to aid in sealing. In many embodiments, grease is unnecessary. 
         [0053]    In the current embodiment, the coupling  100  is assembled in the untightened position of  FIG. 6  before use. In other embodiments, the coupling  100  may be assembled in various pieces as part of the method of use. 
         [0054]    The coupling  100  in  FIG. 7  is shown tightened and deformed around a pair of pipe elements  710   b,a  ( 710   a  not shown in  FIG. 7 ). The segments  110 , 110 ′ in the current view are fully deformed in the current embodiment, and contact surfaces  262   b,a ′ touch a groove surface  714   b,a  ( 714   a  not shown in  FIG. 7 ), which is the outer surface of the pipe element  710  within the groove  720   b,a  (not shown in  FIG. 7 ). Contact surface  262   a  of segment  110  and contact surface  262   b ′ of segment  110 ′ are not shown in  FIG. 7  because they are obstructed by the view. As described above, in some embodiments, the shoulder surfaces  296   a,b,a′,b ′ may contact an outermost surface of each pipe element  710   a,b  outside of the groove  720   b,a  (not shown in  FIG. 7 ), and the contact surfaces  262   a,b,a′,b ′ may never contact the groove surface  714   a,b  of each pipe element  710   a,b  within each groove  720   a,b . In other embodiments, the contact surfaces  262   a,b,a′,b ′ contact the groove surfaces  714   a,b.    
         [0055]    When the segments  110 , 110 ′ travel toward each other and deform under the tightening of the tightening elements (nuts  120   a,b  and bolts  125   a,b ), the gasket  150  is deformed in accord therewith. In some embodiments, a rigid or semi-rigid gasket  150  may be included. The process for accommodating such a material may be altered from that described herein. The gasket  150  includes the deformation groove  517  to allow a place for material to go upon deformation of the gasket  150 . 
         [0056]    Installation of the coupling  100  on the pair of pipe elements  710   a,b  is illustrated in  FIGS. 8A-8E . For the current embodiment, the coupling  100  is introduced to a pair of pipe elements  710   a,b  in the preassembled but untightened position of  FIG. 6 . Each pipe element  710   a,b  may include at least one groove  720   a,b  for alignment with contact surfaces  262   a,b,a′,b ′. In the currently described method, the coupling  100  is aligned with an end  725   a  of the first pipe element  710   a  as shown in  FIG. 8A . The coupling  100  is installed by placing the end  725   a  of the first pipe element  710   a  in the coupling void  410  and forcing the coupling  100  onto the first pipe element  710   a  as shown in  FIG. 8B . As seen in  FIG. 8B , sealing surfaces  526   a,b  and sealing surfaces  532   a,b  are a small distance away from an outer surface  715   a  of the first pipe element  710   a , although the sealing surfaces  526   a,b  and  532   a,b  may contact the outer surface  715   a  in some embodiments. In the currently-described method, the entire coupling  100  is forced beyond the groove  720   a  of the first pipe element  710   a  so that the contact surfaces  262   b,b ′ have passed the groove  720   a . In some embodiments, it may not be necessary to force the entire coupling  100  beyond the groove  720   a . As seen in  FIG. 8C , the second pipe element  710   b  having an end  725   b  is introduced in end-facing relationship to the end  725   a  of the first pipe element  710   a . In the current embodiment, the pipe elements  710   a,b  are approximately the same diameter, although non-uniform diameter pipe elements may be joined in various embodiments. In the current embodiment, each pipe element  710   a,b  has ends  725   a,b  that are flared slightly. Grooves  720   a,b  can be formed in one of two ways: rolled or machined. If the grooves  720   a,b  are machined, the pipe elements  710   a,b  are unlikely to have flares on the ends  725   a,b  as shown. However, if the grooves  720   a,b  are rolled, the pipe elements  710   a,b  are more likely to have flares on the ends  725   a,b . As such, the coupling  100  of the current embodiment is designed to accommodate the potential flaring of ends  725   a,b . The coupling  100  is sized to fit over the largest possible flare of the ends  725   a,b  in the current embodiment based on standard tolerancing for creating the grooves  720   a,b.    
         [0057]    When the second pipe element  710   b  is about aligned with the first pipe element  710   a , the coupling  100  is moved so that the gasket  150  is aligned on outer surfaces  715   a,b  over the ends  725   a,b  of the pipe elements  710   a,b  and with the contact surfaces  262   a,b,a′,b ′ aligned with the grooves  720   a,b , as shown in  FIG. 8D . As seen in  FIG. 8E , when the segments  110 , 110 ′ are clamped down, the gasket  150  deforms into sealing engagement the outer surfaces  715   a,b  of the pipe elements  710   a,b  and the contact surfaces  262   a,b,a′,b ′ sit within the grooves  720   a,b  and touch groove surfaces  714   a,b . In various embodiments, the contact surfaces  262   a,b,a ′b′ may not touch groove surfaces  714   a,b  upon clamping down the segments  110 , 100 ′. 
         [0058]    Several features of the gasket  150  ease installation as described. Friction can cause installation of rubber gaskets to bind against outer surfaces  715   a,b  of pipe elements  710   a,b . With reference to  FIG. 3 ,  FIG. 5 ,  FIG. 6 , and the method previously described with  FIGS. 8A-8E , axially outer drafted edges  522   a,b  and axially inner drafted edges  527   a,b  are both drafted to ease the pipe elements  710  into the coupling void  410 . Axially outer drafted edges  522   a,b  and axially inner drafted edges  527   a,b  also help to prevent rollover of the sealing ridges  525   a,b  of the gasket  150  during sliding on and off, as the drafted profiles are less likely to bind against the outer surfaces  715   a,b  of the pipe elements  710   a,b . Additionally, contact portions  555   a,b  are substantially parallel to the outer surface  715   a,b  of the pipe elements  710   a,b  even when the gasket  150  is not seated on a pipe elements  710   a,b . Additionally, the configuration of the center rib  530  with respect to the sealing ribs  527   a,b , as discussed above with reference to  FIG. 5 , prevents the center rib  530  from obstructing the installation of the coupling  100  by providing limiting contact between the center rib  530  and the outer surface  715   a,b  of pipe elements  710   a,b  before deformation of the gasket  150 . When the segments  110 , 110 ′ are clamped down, the gasket  150  deforms, and the center rib  530  contacts the outer surface  715   a,b  of pipe elements  710   a,b . This configuration allows the gasket  150  to slide onto the pipe elements  710   a,b  without biasing the sliding in one direction and prevents binding of the sealing ridges  525   a,b  during installation. These features prevent the gasket  150  from rolling over when the coupling  100  is installed on the pipe elements  710   a,b  and allows the gasket  150  to be properly placed over the joint between the pipe elements  710   a,b  for proper sealing, among other advantages. When the gasket  150  is properly aligned over the joint, each of the sealing members  557   a,b  may contact the outer surface  715   a,b  of one pipe element  710   a,b  or may be aligned above the surface  710   a,b  of the pipe elements  715   a,b . However, the alignment of the sealing members  557   a,b  is not critical to effectuate a seal of the joint. 
         [0059]    When the coupling  100  is aligned on the joint of the pipe elements  710   a,b , the tightening elements are used to draw the segments  110 , 110 ′ together. In the current embodiment, this takes the form of nuts  125   a,b  tightening down on bolts  120   a,b  to compress the fastener pads  130   a,b,a′,b ′ toward each other. In some embodiments, the coupling  100  is rigid and includes no deflection of the segments  110 , 110 ′. In the current embodiment, the engagement of the tightening elements (bolts  120   a,b  and nuts  125   a,b ) first cause the segments  110 , 110 ′ to travel toward each other. When the segments  110 , 110 ′ contact the pipe elements  710   a,b , the segments  110 , 110 ′ deform (deflection) until each segment  110 , 110 ′ is in the desired engagement with the pipe elements  710   a,b . The deformation of the segments  110 , 110 ′ can be seen by comparing  FIGS. 6 and 7 . The contact surfaces  262   a,b,a′,b ′ contact groove surfaces  714   a,b  of the grooves  720   a,b  in the pipe elements, at which time the segments  110 , 110 ′ begin deflection. In some embodiments, shoulder surfaces  296   a,b,a′,b ′ (refer to  FIG. 4  for the location of shoulder surfaces  296   a,b,a′,b ′) contact the outer surface of the pipe elements such that the contact surfaces  262   a,b,a′,b ′ never contact the groove surfaces  714   a,b.    
         [0060]    As can be seen in  FIG. 7 , the segments  110 , 110 ′ may deflect so that bottom surfaces  362 , 362 ′ are in contact with bottom surfaces  312 ′, 312 , respectively, in some embodiments. This configuration need not be present in all embodiments. In some embodiments, the mating surfaces  355 , 355 ′ will contact mating surfaces  395 ′, 395 , respectively, before the bottom surfaces  362 , 362 ′ contact bottom surfaces  312 ′, 312 , respectively. In some embodiments, bottom surfaces  362 , 362 ′ will contact bottom surfaces  312 ′, 312  before mating surfaces  355 , 355 ′ contact mating surfaces  395 ′, 395 , respectively. Because of the deflection and deformation of the segments  110 , 110 ′, the angles  415 , 416 , 417 , 418 , as pointed out in  FIG. 4  (angles  415 ′, 416 ′, 417 ′, 418 ′ not shown), are reduced as the top surfaces  314 , 314 ′ and  364 , 364 ′ and the bottom surfaces  312 , 312 ′ and  362 , 362 ′ approach a position parallel with the horizontal axis  420 . As shown, mating surfaces  355 , 355 ′ are in contact with mating surfaces  395 ′, 395 , respectively, as well. 
         [0061]    Seen in the cross-sectional view of  FIG. 9 , each bolt  120   a,b  (b not shown in  FIG. 9 ) includes a head  612   a,b  (b not shown in  FIG. 9 ), a threaded portion  810   a,b  (b not shown in  FIG. 9 ), a shank portion  815   a,b  (b not shown in  FIG. 9 ), and a collar portion  820   a,b  (b not shown in  FIG. 9 ). Combined together, each threaded portion  810   a,b , shank portion  815   a,b , and collar portion  820   a,b  is termed the shaft portion. Each shaft portion may omit any combination of the threaded portion  810 , shank portion  815 , and collar portion  820  in various embodiments. The nuts  125   a,b  (b not shown in  FIG. 9 ) engage the bolts  120   a,b  (b not shown in  FIG. 9 ) along part of the threaded portion  810   a,b . Tightening of the nuts  125   a,b  compresses the fastener pads  130   a,b,a′,b ′ and deforms the segments  110 , 110 ′ to conform to the shape of the pipe elements, as previously described. 
         [0062]    As previously described, when the coupling  100  is installed onto pipe elements, the assembled and untightened coupling  100  is installed over the edge of the first pipe element  710   a  until it passes completely over any groove  720   a  in the first pipe element  710   a  after which the second pipe element  710   b  is placed end-facing to the first pipe element  710   a . The coupling  100  is then slid into position straddling the first and second pipe elements  710   a,b . Although (as previously described) it is common for gaskets to bind during such installation, it is also possible for friction to cause rocking of the segments  110 , 110 ′ not only against any gasket but also against the exterior of the pipe elements  710   a,b . If a leading edge of one segment  110 , 110 ′ catches against the exterior of the pipe element  710   a,b , the segments  110 , 110 ′ have a tendency to rock with respect to each other. Rocking of segments  110 , 110 ′ can cause additional binding of the gasket  150 , making installation of the coupling  100  difficult and potentially damaging to components of the coupling  100 , including the gasket  150 . 
         [0063]    The shape of the fastener hole  132   a  (see  FIG. 2 ) includes an axial length  233  (axial length  237  of fastener hole  132   b  not shown) that tends to prevent such rocking of the segments  110 . For the fasteners of the current embodiment, each of the heads  612   a,b , threaded portions  810   a,b , and shank portions  815   a,b  are symmetrical about the center of the bolt  120   a,b , respectively. The shank portions  815   a,b  are cylindrical, the threaded portions  810   a,b  are cylindrical except that each has threading along its outermost edge, and the heads  612   a,b  are cross-sectionally circular at cross-sections taken orthogonal to the center axis. However, the collar portions  820   a,b  are not cylindrical but instead include a profile approximating that of the fastener holes  132   a,b  as measured at the top surfaces  364 , 314 . Each collar portion  820   a,b  includes an axial length  830   a,b  that is about the same as the diameter of the shank portions  815   a,b . The collar portions  820   a,b  also include a transverse length (not shown) that is proportionally larger than the axial length  830   a,b . The axial length  830   a,b  of each collar portion  820   a,b  may be smaller than the axial length  233 , 237  of each fastener hole  132   a,b , the transverse length of each collar portion  820   a,b  may be smaller than the transverse length  243 , 247  of each fastener hole  132   a,b , and the axial length  233 , 237  of each fastener hole  132   a,b  is smaller than the transverse length  830   a,b  of each collar portion  820   a,b.    
         [0064]    The arrangement of each collar portion  820   a,b  engages the fastener hole  132   a,b  in assembly and retains the bolt  120  in a fixed arrangement with respect to the segment  110  in each fastener hole  132   a,b . This allows a user to tighten the nuts  125   a,b  without need to restrain the bolts  120   a,b , as the collar portions  820   a,b  retain the bolts  120   a,b  through interaction with the fastener holes  132   a,b . This result occurs because the axial length  233 , 237  of each fastener hole  132   a,b  is smaller than the transverse length  830   a,b  of each collar portion  820   a,b . Such an arrangement would result even if the orientation of the fastener holes  132   a,b  were at a different angle. 
         [0065]    However, the arrangement as displayed also prevents the rocking of the segments  110 , 110 ′ by keeping the shank portions  815   a,b , the collar portions  820   a,b , and the threaded portions  810   a,b  in close proximity to the inner surfaces  335   a,b,a′,b ′ of the fastener holes  132   a,b,a′,b ′. Should one of the segments  110 , 110 ′ begin a rocking motion, at least one of the inner surfaces  335   a,b,a′,b ′ will contact at least one of the bolts  120   a,b  along at least one of the collar portions  820   a,b , the shank portions  815   a,b , and the threaded portions  810   a,b  thereby providing a mechanical stop to prevent further rotation of the segments  110 , 110 ′ with respect to the bolts  120   a,b  and, thereby, with respect to the other segment  110 ′, 110 . 
         [0066]    Although all sides of the fastener holes  132   a,b,a′,b ′ are shown as drafted in the current embodiment, some sides may be drafted or may be parallel in various embodiments. For example, in the current embodiment, fastener holes  132   a,b,a′,b ′ are drafted because the segments  110 , 110 ′ are cast. However, if fastener holes  132   a,b,a′,b ′ were machined, it would not be necessary to draft the fastener holes  132   a,b,a′,b′.    
         [0067]    As seen in  FIG. 10 , each pair of contact surfaces  262   a,b  and  262   a′,b ′ ( 262   b  and  262   b ′ shown in  FIGS. 10 and 11 ) defines a predeformation radius  1001 , 1001 ′. Likewise, each pipe element  710   a,b  defines a radius  1002   a,b . In the current embodiment, when the coupling  100  is in the untightened position, the predeformation radii  1001 , 1001 ′ of each pair of contact surfaces  262   a,b  and  262   a′,b ′, respectively, is greater than the radii  1002   a,b  of the pipe elements  710   a,b . Groove radii  1003   a,b  are also shown on the pipe elements  710   a,b , respectively. Because the predeformation radii  1001 , 1001 ′ are larger than the radii  1002   a,b , the coupling  100  can be more easily maneuvered over each pipe element  710   a,b  as described more thoroughly with reference to  FIGS. 8A-8E . Having larger predeformation radii  1001 , 1001 ′ than radii  1002   a,b  allows the coupling  100  to be slid onto the pipe elements  710   a,b  as a preassembled unit. As described above, once the coupling  100  is aligned over the pipe elements  710   a,b , no further assembly of the coupling  100  is required. Instead, the user need only tighten the nuts  125   a,b  on the bolts  120   a,b  to secure the coupling  100  in sealing engagement with the pipe elements  710   a,b.    
         [0068]    As seen in  FIG. 11 , once the nuts  125   a,b  are tightened onto the bolts  120   a,b , each segment  110 , 110 ′ of the coupling  100  deforms in conformity with the grooves  720   a,b . Once deformed, a postdeformation radius  1101 , 1101 ′ is defined by each pair of contact surfaces  262   a,b  and  262   a′,b ′ ( 262   b  and  262   b ′ shown in  FIGS. 10 and 11 ), respectively. In the current embodiment, each postdeformation radius  1101 , 1101 ′ is equal to the groove radii  1003   a,b  because the contact surfaces  262   a,b,a′,b ′ contact the groove surfaces  714   a,b . In embodiments where the contact surfaces  262   a,b,a′,b ′ do not contact the groove surfaces  714   a,b , the postdeformation radii  1101 , 1101 ′ may be larger than the groove radii  1003   a,b . Although not required in all embodiments, the postdeformation radii  1101 , 1101 ′ will likely be smaller than the radii  1002   a,b  even if the postdeformation radii  1101 , 1101 ′ is larger than the groove radii  1003   a,b.    
         [0069]    This assembly configuration represents one of many possible assembly configurations. One skilled in the art will understand obvious variations of this assembly configuration are included within this disclosure, including variations of steps, combinations of steps, and dissections of steps, among others. Where materials are chosen for the elements of this assembly—particularly, rubber, metal, and cast iron—similar material choices may also be used and would be obvious to one in the art. As previously disclosed, the gasket  150  may be made of rubber, plastic, cork, wood, metal, ceramic, polymer, elastomer, rosin, foam, any combination of the foregoing materials, or any material suitable for sealing two pipe elements joined in end-to-end relationship. The segments  110 , 110 ′ may be made of cast iron, steel, aluminum, titanium, copper, brass, various plastics, polymers, resins, or any material of sufficient strength to withstand the tightening load of the fasteners. 
         [0070]    It should be emphasized that the embodiments described herein are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Many variations and modifications may be made to the 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. 
         [0071]    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. 
         [0072]    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.