Patent Publication Number: US-2013241191-A1

Title: Pressure-rated spline joint

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 61/611,941, filed Mar. 16, 2012, the entirety of which is incorporated by reference herein. 
    
    
     FIELD OF DISCLOSURE 
     The disclosed system and method relate to pipes. More particularly, the disclosed system and method relate to the connection of pipes using spline joints. 
     BACKGROUND 
     Pipes are frequently used in numerous industries to provide a conduit through which fluids, such as oil, gas, and water, flow. Some pipes, such as PVC pipes, can be coupled together using an o-ring or other type of gasket that have limited fluid-sealing capabilities. The limitations of such seals can be exacerbated when the pressure within the pipes increases as fluid passes through them. When the pipes are used to transport hazardous materials, such as uranium, the danger and fallout from a joint failure is magnified. 
     SUMMARY 
     In some embodiments, a pressure-rated joint includes a first pipe including a bell, and a second pipe including a portion that is disposed within the bell of the first pipe. A mechanical coupling and a chemical coupling are provided between the first pipe and the second pipe. 
     In some embodiments, a pressure-rated joint includes a first pipe including a bell that defines a circumferential groove about an interior of the bell and a hole that communicates with the circumferential groove. A second pipe has an external diameter that is less than an internal diameter of the bell such that the second pipe can be at least partially received within the bell. The second pipe defines a circumferential groove in an outer surface that forms a channel when aligned with the circumferential groove defined by the bell of the first pipe. A spline is disposed within the channel, and an adhesive coupling is formed between at least a portion of the first pipe and the second pipe. 
     In some embodiments, a method of forming a pressure-rated joint includes applying an adhesive to at least a portion of a first pipe, inserting at least a portion of a second pipe into at least a portion of the first pipe, and mechanically coupling the first pipe to the second pipe. The adhesive forms a chemical coupling between the first pipe and the second pipe. 
     In some embodiments, a method of forming a pressure-rated joint includes applying an adhesive to at least a portion of a first pipe, inserting at least a portion of the first pipe into at least a portion of a first pipe, and mechanically coupling the first pipe to the second pipe. The adhesive forms a chemical coupling between the first pipe and the second pipe. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a plan view of first and second pipes that are configured to be coupled together using a pressure-rated spline joint in accordance with some embodiments. 
         FIG. 1B  is a cross-sectional view of the pipes illustrated in  FIG. 1A  taken along line  1 B- 1 B in  FIG. 1A . 
         FIG. 1C  is a cross-sectional view of the pipes illustrated in  FIGS. 1A and 1B  having been joined by a pressure-rated spline joint in accordance with some embodiments. 
         FIG. 1D  is a plan view of the pipes illustrated in  FIGS. 1A and 1B  having been joined by a pressure-rated spline joint in accordance with some embodiments. 
         FIG. 2  is a flow diagram of one example of forming a pressure-rated spline joint. 
         FIG. 3A  is a cross-sectional view of a pair of pipes having a primer applied to certain areas prior to being coupled together in accordance with some embodiments. 
         FIG. 3B  is a cross-sectional view of the pipes illustrated in  FIG. 3A  having an adhesive applied to certain areas prior to being coupled together in accordance with some embodiments. 
         FIG. 3C  is a cross-sectional view of the pipes illustrated in  FIG. 3B  with one pipe being inserted into the other pipe in accordance with some embodiments. 
         FIG. 3D  is a cross-sectional view of the pipes illustrated in  FIG. 3C  when the one pipe is fully seated in the other pipe in accordance with some embodiments. 
         FIG. 3E  illustrates a spline being inserted into a channel defined by the pipes illustrated in  FIG. 3D  in accordance with some embodiments. 
         FIG. 3F  is a plan view of the pipes illustrated in  FIGS. 3A-3E  having been coupled together using a spline joint in accordance with some embodiments. 
         FIG. 3G  is a cross-sectional view taken along line  3 G- 3 G in  FIG. 3F  of the pipes coupled together using a spline joint in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     This description of the exemplary embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. The drawing figures are not necessarily to scale and certain features may be shown exaggerated in scale or in somewhat schematic form in the interest of clarity and conciseness. In the description, relative terms such as “horizontal,” “vertical,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. Terms including “inwardly” versus “outwardly,” “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. When only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. In the claims, means-plus-function clauses, if used, are intended to cover the structures described, suggested, or rendered obvious by the written description or drawings for performing the recited function, including not only structural equivalents but also equivalent structures. 
     The disclosed pressure-rated spline joint and method of forming the joint advantageously provides a fluid-tight seal between two pipes up to several hundred PSI. Such joints have a wide application including, but not limited to, the mining of hazardous materials such as, for example, uranium. Additionally, the disclosed joint can be quickly and cost-effectively assembled. The pressure-rated spine joint and method of forming the joint is described with reference to PVC pipes; however, one of ordinary skill in the art will understand that other pipe types that can be joint using adhesives, such as solvents or glues, can be utilized. 
     Turning now to the figures, and to  FIGS. 1A and 1B  in particular, a pair of pipes  110 ,  140  for being joined via a pressure rated spline joint  100  are illustrated. First pipe  110  includes outwardly flared bell section  112  along which a spline groove  114  is circumferentially formed on the interior surface  116  as best seen in  FIG. 1B . Spline groove  114  is located along the longitudinal length of bell section  112  such that the interior surface  116  includes first and second portions  118 ,  120 , which are located on either side of spline groove  114 . 
     First portion  118  of interior surface  116  extends from an outer edge  122  of groove  114  to end  124  of first pipe  110 . The second portion  120 , which may be referred to as a weld or mating portion, extends from interior edge  126  of groove  114  to the bottom  128  of bell  112 . As will be understood by one of ordinary skill in the art, the bottom  128  of bell  112  is the location at which the inner diameter of bell  112  begins tapering to the standard inner diameter of pipe  110 . In some embodiments, the length of second portion  120  is greater than a length of the first portion  118 . In some embodiments, first portion  118  has a length that is equal to second portion  120 , and in some embodiments, the length of the first portion  118  is greater than the length of second portion  120 . 
     A hole  130  is defined along the length of bell  112 . Hole  130  is sized and configured to receive a spline  160  therein. As best seen in  FIG. 1B , hole  130  is positioned longitudinally along bell  112  at a location that corresponds to where circumferential groove  114  extends around the internal surface  116  such that a spline  160  can be introduced into groove  114  through hole  130  as described in greater detail below. 
     Second pipe  140  has an outer diameter that is sized and configured to be received within the inner diameter of bell section  112  of pipe  110 . The outer surface  142  of pipe  140  defines a circumferential groove  144  along its length adjacent to end  146  of pipe  140 . In some embodiments, groove  144  is positioned along pipe  140  such that end  146  of pipe  140  is disposed adjacent to and abuts the bottom  128  of bell  112  when circumferential grooves  130 ,  144  align with one another. Put another way, the end portion  148  of pipe  140 , which extends from outer edge  150  of groove  144  to the end  146  of pipe  140 , has a length that is equal to a length of portion  120  of bell  112 . 
     When aligned grooves  114 ,  144  cooperate to define a channel  152  in which spline  160  is disposed as best seen in  FIG. 1C . Spline  160  may be formed from any material to provide a mechanical connection between pipes  110  and  140 . In some embodiments, for example, spline  160  is formed from nylon and has a diameter of approximately ¼ inch. However, one of ordinary skill in the art will understand spline  160  can be form other plastic materials or from a rubber or metal. 
     A pressure-rated fluid-tight seal  154  is provided between pipes  110  and  140  using a solvent-weld seal. In some embodiments, for example, seal  154  is formed by applying a primer to at least one of pipes  110 ,  140  and then an adhesive or glue to the primed section. Examples of such primers and adhesives include, but are not limited to, P-70 Primer and 705 PVC both available from WELD-ON of Compton, Calif. One of ordinary skill in the art will understand that other primers and/or adhesives can be utilized. 
     The creation of a pressure-rated spline joint  100  is described with respect to FIGS.  2  and  3 A- 3 G in which  FIG. 2  is a flow diagram of one example of a method  200  of forming a pressure-rated spline joint  100 . At block  202 , a primer for a solvent adhesive or glue is applied to one or both of the pipes being joined. For example and as illustrated in  FIG. 3A , a primer  156  for the solvent adhesive or glue  158  is applied to the second portion  120  of the inner surface  116  of pipe  110  and to the outer surface  142  of pipe  140 . In some embodiments, primer  156  is only applied to one of the second portion  120  of inner surface  116  or to the outer surface  142  of pipe  140  between groove  144  and end  146 . In some embodiments, primer  156  is applied to first portion  118  and second portion  120  of inner surface  116  of pipe  110  and/or to a complementary portion of outer surface  146  of pipe  140 . 
     Referring again to  FIG. 2 , a solvent glue/adhesive  158  is applied to pipes  110 ,  140  at block  204 . In some embodiments, such as the embodiment illustrated in  FIG. 3B , the solvent glue/adhesive  158  is applied to the same regions of pipes  102 ,  122  to which the primer  156  was applied. In some embodiments, the solvent glue/adhesive  158  is applied to regions of pipes  110 ,  140  that were not primed with a primer  156 . In some embodiments, the combination of the primer  156  and adhesive  158  effectively melts the PVC of pipes  110  and/or  140 . When allowed to “cure,” the pipes are effectively chemically bonded together to create a fluid-tight seal  154 . 
     At block  206 , second pipe  140  is inserted into first pipe  110 . As shown in  FIG. 3C , end  146  of pipe  140  is inserted into bell  112  of pipe  110  as illustrated by the bold arrows at the top of the figure. Pipe  140  is inserted into pipe  110  until end  146  of pipe  140  contacts bottom  128  of bell  112  and/or until groove  114  defined by pipe  110  aligns with groove  144  defined by pipe  140  to form channel  152  as illustrated in  FIG. 3D . 
     At block  208  ( FIG. 2 ), spline  160  is inserted into hole  130  defined by pipe  110  that communicates with channel  152  as illustrated in  FIG. 3E . Although a spline  160  is described as being used to provide a mechanical connection between pipes  110  and  140 , other mechanical coupling means can be used including, but not limited to, screws, a snap fit or tab and groove engagement mechanism, or a threaded connection between pipes  110  and  140  to identify just a few other possibilities. 
       FIGS. 3E and 3G  illustrate one example of the completed joint  100  with the spline  160  disposed within channel  152  and the seal  154  having been fully formed as the adhesive has fully cured. The combination of the spline and adhesive to create a joint  100  as described herein has been tested to provide a pressure-rated seal that is able to withstand pressures of close to 1,000 psi without failure. Such joints  100  can advantageously be utilized in a wide variety of applications including mining of uranium where numerous lengths of pipe are coupled to one another and are vertically inserted into a well. The mechanical securement between the pipes enable the pipes to be coupled together and inserted into a well prior to the adhesive fully curing, and the adhesive bond provides a fluid-tight seal between the pipe segments with improved sealing compared to gaskets or other non-chemical bonds. 
     Although the systems and methods have been described in terms of exemplary embodiments, they are not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the systems and methods, which may be made by those skilled in the art without departing from the scope and range of equivalents of the systems and methods.