Abstract:
A pipe gasket for providing a sealing between a pair of sanitary pipes, each pipe including a pipe flange having a grooved face and an outer face. The pipe gasket can be fixedly attached to one pipe flange to facilitate ease in assembly and to also provide proper seal alignment. The pipe gasket includes a support element having at least two protrusions extending from an outer circumference toward an inner circumference, each protrusion for cooperatively engaging the outer face of at least one of the pipe flanges and a sealing element formed with the support element to provide a fluid tight seal between the pair of sanitary pipes.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Plants processing foods, pharmaceuticals, biological and technological fluid materials generally require fluid piping systems that must be free from voids and crevices to prevent accumulations of materials. A typical fluid piping system includes multiple sections of pipe or tubing coupled together. To that end, each coupling joint of the system is of particular importance because it must provide a bacteria-tight seal without obstructing the flow of the material.  
         [0002]     A coupling joint typically includes a pair of pipe ends having respective flanges, a gasket, and a fastening device. To assembly the coupling joint, care must be taken to ensure the gasket is properly seated between the pair of pipe ends. Improper seating of the gasket can lead to an improper seal. Further, in instances where too little contact pressure is applied by the fastening device, valleys in the inner diameter of the coupling joint surface will not be adequately filled by the gasket material to prevent accumulation of microorganisms. Furthermore, in instances where too much contact pressure is applied, the gasket material may be extruded into the pipe lumen thereby causing an obstruction or partial dam that could cause material to be trapped.  
       SUMMARY OF THE INVENTION  
       [0003]     Many types of pipe gasket exist today, the vast majority of which are manufactured from elastomeric materials. When fitting/seating such gaskets between pipe ends of a pipe joint, it can be very difficult to keep the soft elastomer in position to ensure that it accurately forms a quality seal between the two pipe ends as the pipe ends are closed together. In practice, it is often impossible to tell whether the gasket is correctly aligned with the pipe ends following tightening of a pipe joint without first testing the integrity of the pipe joint by pressure testing the pipe bore itself. Further, it is difficult to hold the gasket in place when joining the two pipe ends. Furthermore, should the gasket fall off of the assembly, it can become contaminated. As such, assembly is clearly time consuming and can be expensive.  
         [0004]     The present invention provides a pipe gasket for providing a seal between a pair of pipes, each pipe including a pipe flange having a grooved face and an outer face. The pipe gasket can be fixedly attached to one pipe flange to facilitate ease in assembly and to also provide proper seal alignment. The gasket includes a support element having at least two protrusions extending from an outer circumference toward an inner circumference, each protrusion for cooperatively engaging the outer face of at least one of the pipe flanges and a sealing element formed with the support element to provide a fluid tight seal between the pair of pipes.  
         [0005]     According to one aspect, the support element defines a plurality of holes in close proximity to the inner circumference, outer portions of the sealing element couples through the holes. The holes can be evenly spaced around the inner circumference of the support element. The support element can be made from metal, plastic, or other suitable material and can be color-coded.  
         [0006]     In one embodiment, the support element includes three inwardly directing protrusions. Each protrusion can be evenly spaced about the outer circumference of the support element. Further, each protrusion can have a width of between 1 and 49 percent of the outer circumference of the support element, and preferably approximately sixteen percent of the outer circumference of the support element. Furthermore, each protrusion can extend inwardly between 1 and 89 degrees from the outer circumference of the support element, and preferably approximately eight degrees from the outer circumference of the support element. Each protrusion can also include an engagement portion for engaging an outer face of at least one of the pipe flanges. The protrusions can include a surface for placing indicia representative of the pipe gasket.  
         [0007]     The sealing element includes an alignment portion for aligning respective grooved faces of each pipe flange. The alignment portion can be an O-ring. The sealing element can be made from an elastomer. The elastomer can be an ethylene propylene diene monomer, a fluoroelastomer, or a perfluoroelastomer. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.  
         [0009]      FIG. 1A  is a cross-sectional side view of an embodiment of a pipe gasket of the present invention in engagement with a first pipe flange;  
         [0010]      FIG. 1B  is a cross-sectional side view of the embodiment of  FIG. 1A  in connection with a second pipe flange;  
         [0011]      FIG. 1C  is a cross-sectional side view of the embodiment of  FIG. 1B  coupled together;  
         [0012]      FIG. 2A  is a plan view of an embodiment of a pipe gasket of the present invention;  
         [0013]      FIG. 2B  is a cross-sectional side view of an embodiment of a pipe gasket of the present invention;  
         [0014]      FIG. 2C  is a cross-sectional exploded view of a gripper portion of the support element of  FIGS. 2A and 2C ;  
         [0015]      FIG. 2D  is a cross-sectional exploded view of a support element of  FIGS. 2A and 2C ;  
         [0016]      FIG. 3A  is a plan view of another embodiment of a pipe gasket of the present invention;  
         [0017]      FIG. 3B  is a cross-sectional side view of another embodiment of a pipe gasket of the present invention;  
         [0018]      FIG. 3C  is a cross-sectional exploded view of a gripper portion of the support element of  FIGS. 3A and 3B ; and  
         [0019]      FIG. 4  is a flow diagram for a process of making a pipe gasket of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     A description of preferred embodiments of the invention follows.  
         [0021]     Generally, the present invention is directed toward a mechanism for retaining a pipe gasket on a pipe end during a pipe joint assembly process. The present invention also provides the following features: 1) proper seal alignment of the pipe gasket between the pipe joint; 2) a mechanical stop to prevent over-tightening of the pipe gasket; 3) color-coding and indicia marking means for preventive maintenance, material identification, and application identification purposes. The pipe gasket of the present invention should adhere to the Bioprocessing Equipment ASME BPE Standards. It should be understood by one skilled in the art that an form of “pipe” is synonymous with any form of “tube.” 
         [0022]      FIGS. 1A-1C  show a cross-sectional assembly  50  process for joining two sanitary pipe fittings  60   a ,  60   b . Each sanitary pipe fitting  60   a ,  60   b  includes a flange  61 , a recess or annular groove  62 , an outer face  64 , and an inner diameter (ID)  66 . The flange  61  may be of the type designed to cooperate with a conventional hinged clamp  70  for securing the assembly  50 . A pipe gasket  100  of the present invention is used to provide a bacterial-tight seal between the two sanitary pipe fittings  60   a ,  60   b.    
         [0023]     The pipe gasket  100  includes a support element  110  and a sealing element  130 . The support element  100  include at least two protrusions  120  for coupling the gasket to either pipe fitting  60   a ,  60   b . The protrusions  120  extend from the outer circumference toward the inner circumference of the support element  110  and cooperate with each other to provide sufficient retaining force against the outer face  64  of either pipe fitting  60   a ,  60   b.    
         [0024]     The support element  110  can be manufactured in one piece from engineering plastics material, such as polyphenylsulfone (Radel), metal, or other material known in the art.  
         [0025]     In a preferred embodiment, the sealing element  130  can be manufactured from a soft material, such as rubber or an elastomer. For example, the sealing element  160  can be manufactured from ethylene propylene diene monomer (EPDM), fluoroelastomer (FKM), a perfluoroelastomer (FFKM), or although other elastomer known. In an alternative embodiment, the sealing element  130  can be manufactured from a fluropolymer resin. The sealing element  130  can include an alignment portion  132 , such as an O-ring, for seating grooves  62  of respective pipe fittings  60   a ,  60   b . The sealing element  130  is preferably annular and has a inner diameter (ID)  68  which corresponds substantially to the ID  66  of the pipe fitting  60   a ,  60   b . In some embodiments, the ID  68  of the sealing element  130  may be slightly larger than the ID  66  of the pipe fitting  60   a ,  60   b . In yet another embodiment, the support element  110  and the sealing element  130  can be formed as a unitary piece.  
         [0026]     When a hinged clamp  70  is tightened, it acts against tapered outside surfaces of the flanges  61  such that a seal is produced between the flanges  61  and the pipe gasket  100 . The support element  110  prevents the sealing element  130  from being destroyed or significantly distorted by over tightening of clamp  70 . In instances where the ID  68  of the sealing element  130  is slightly larger than the ID  66  of the pipe fitting  60   a ,  60   b , the sealing element  130  expands radially until the ID  68  of the sealing element  130  substantially equals the ID of the pipe fitting  60   a ,  60   b.    
         [0027]      FIGS. 2A-2D  show a detailed view of the pipe gasket  100  of the present invention. The support element  110  preferably includes three inwardly directing protrusions  120  about the outer circumference of the support element  110 . Preferably, each protrusion  110  is evenly spaced to cooperatively aid in engaging the outer face  64  of either pipe fitting  60   a ,  60   b  ( FIGS. 1A-1C ). In one embodiment, each protrusion extends inwardly approximately at angle θ from the outer circumference of the support element  110 . The angle θ is preferably 8 degrees but can range between 1 and 89 degrees. The degree in which the protrusion  120  is facing provides an amount of restoring force when the protrusion  120  is in mechanical connection with the outer face  64  of either pipe fitting  60   a ,  60   b . That is, while each protrusion  120  flexes outwardly in a radial direction when engaging the outer face  64  of either pipe fitting  60   a ,  60   b , a restoration force is applied in an equal but opposite direction which effectively secures the pipe gasket  100  to either pipe fitting  60   a ,  60   b.    
         [0028]     In another embodiment, each protrusion  120  has a width of between 1 and 49 percent of the outer circumference of the support element  110  and preferably approximately sixteen percent of the outer circumference of the support element  110 .  
         [0029]     The width of the protrusion provides a larger contact/surface area for the engaging the outer face  64  of either pipe fitting  60   a ,  60   b . The width also provides a stable surface area  124  for writing indicia representative of the pipe gasket  100 . The indicia can include, but is not limited to, material identification of the pipe gasket  100 , date and lot code the pipe gasket  100  was made, the type of application of the pipe gasket  100  is approved for, and/or the date the pipe gasket  100  is installed. In yet another embodiment, each protrusion can include an engagement portion or lip  122  for engaging the outer face  64  of either pipe fitting  60   a ,  60   b.    
         [0030]     In other embodiments, the support element  110  can be color-coded. The colors can be pre-assigned to aid with preventive maintenance of the pipe joints for a particular application. For example, a plant&#39;s protocol or the FDA may require replacement of each pipe gasket  100  every two months. As such, a different color can be assigned for each two month period. Quality control can check the color of the support element  110  of each pipe gasket  100  to determine if each pipe gasket  100  is within the plant&#39;s protocol without having to physically open the pipe joint. Further, colors can be assigned for material identification of the pipe gasket  100  and/or the type of application the pipe gasket  100  is approved for.  
         [0031]     As shown in  FIG. 2A , the support element  110  includes a series of holes  112  that allow the seating element  130  to couple through. Such coupling can include cross-linking, bonding, or any other type of coupling known in the art. In a preferred embodiment, the holes  112  are evenly spaced about the inner circumference of the support element  110 . Known pipe gaskets use adhesives that can contaminate the process stream by leaching out or breaking down over time. The present invention eliminates this risk by removing the adhesives.  
         [0032]      FIGS. 3A-3C  show a detailed view of another embodiment of the pipe gasket  100 ′ of the present invention. Each of the elements are essentially the same as the elements as described in  FIGS. 2A-2D . However, sealing element  130  has been replaced with sealing element  130 ′. Sealing element  130 ′ provides a gasket membrane  131 ′ that protects instrumentation from caustic saline solutions. For example, the pipe gasket  100 ′ can be used to couple a pressure gauge to the piping system. The gasket membrane  131 ′ will not interfere with gauge operation or accuracy, the gasket membrane  131 ′ will work with most industry standard instruments, and the gasket membrane  131 ′ will help extend the life of gauges.  
         [0033]     The orientation of the support element  120  provides accurate installation of the pipe gasket  100 ′. As shown in  FIGS. 3B and 3C , the protrusions  120  are on the same side as the gasket membrane  131 ′. Improper installation of the pipe gasket  100 ′ will cause the gasket membrane  131 ′ to fail, thereby allowing potential damage to the gauges.  
         [0034]      FIG. 4  shows a flow diagram of one embodiment of manufacturing a pipe gasket  100  of the present invention. In a first step ( 200 ), the support element  120  is placed in a pipe gasket mold. Next ( 210 ), an uncured sealing element is injected into the pipe gasket mold such that the pressure in the mold allows the uncured sealing element to flow through a plurality of holes in the support element. After which ( 220 ), the uncured sealing element is allowed to cure thereby coupling itself to the support element.  
         [0035]     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.