Patent Publication Number: US-2009224533-A1

Title: Support system for flexible pipe

Description:
BACKGROUND OF THE INVENTION: 
     The present invention relates generally to the field of expansion pipe loops, used to compensate for and absorb movement in piping systems and more particularly to an improved support assembly for a flexible pipe loop. 
     In conventional piping installations, there is the inevitable problem of movement of pipes in the installation. Movement of the pipes may be caused by expansion, contraction, building movement, earthquake, explosion, or other factors. Such movement often causes the pipes to leak or break apart. 
     Flexible pipe loops have been employed to compensate for and absorb pipe movements. For example, U.S. Pat. No. 5,195,784 to Richter (1993) and U.S. Pat. No. 5,803,506 to Argersinger (1998) disclose such flexible pipe loops. While the Richter and Argersinger flexible pipe loops have gained a fair amount of acceptance in the industry, these flexible pipe loops each have one or more bends or elbows that typically require block or hanger support when the flexible pipe loop is installed in a horizontal position. Block supports that are typically used to support flexible pipe loop elbows, such as shown in  FIG. 7  of the Argersinger patent, often cannot not be employed in ceilings or walls. Conventional hanger supports for flexible pipe loop elbows are typically connected to the apex or outermost point of each bend in the pipe loop, such as shown in  FIG. 4  of the Richter patent, which causes a bending force on the flexible pipe members, particularly at the connection between the flexible pipe members and the rigid elbows, causing the flexible pipe loop members to sag downward, limiting the effectiveness of the flexible pipe loop to absorb movement. Such sagging also adds stress to the flexible pipe loop, and places stress on the connection between the flexible pipes and the rigid elbows, thereby decreasing the stability and life of the flexible pipe loop. 
     SUMMARY OF THE INVENTION 
     In view of the above-described circumstances, a support system consistent with the present invention is provided for use with a flexible pipe loop installed in a non-vertical orientation in a pipe run so that the flexible pipe loop is inhibited from sagging and reducing the stress on the flexible pipe loop and joints and the effectiveness of the pipe loop to absorb movement in the pipe. 
     The pipe run is divided at a location along its run to form a pair of open ends. The pipe loop includes a pair of oppositely disposed pipe run elbows each having first and second open ends, a pair of flexible tube members each having first and second open ends, and at least one loop elbow having a first open end, a second open end, and an inner bend. The first open end of each pipe run elbow is connected to a respective one of the open ends of the pipe run. The second open end of each pipe run elbow is connected to a respective one of the first open ends of the flexible tube members. The first open end of the at least one loop elbow is connected to a respective one of the second open ends of the pair of flexible tube members, such that the inner bend of the loop elbow is disposed towards the pipe run. The support system comprises a first hanger rod having a first end and a second end. The first end of the first hanger rod is operatively configured to attach to the inner bend of the loop elbow or another point on the loop elbow, such that at least one of the flexible tube members is inhibited from sagging when the second end of the first hanger rod is secured away from the inner bend of the loop elbow and above the pipe run. The loop elbow has a centerline which is displaced away from the pipe run axis, and the hanger rod is attached to the loop elbow at a point that is closer to the pipe run axis than the portion of centerline of the loop elbow that is furthest from the pipe run axis. By moving the connection point between the hanger rod and the loop elbow away from the apex and towards the pipe run, the bending moment on the flexible tube members is reduced. By placing the hanger rod connection point at or close to the joint connection between the flexible tube members and the loop elbow, the bending moment at the joint connection can be reduced nearly to zero. 
     In another implementation, the loop elbow is one of a pair of loop elbows disposed in a spaced-apart opposing relationship and the first open end of each loop elbow is connected to a respective one of the second open ends of the pair of flexible tube members. The pipe loop may include a third flexible tube member connected between and to the second open ends of the pair of loop elbows, such that the inner bend of each loop elbow is disposed towards the pipe run. 
     In this implementation, the support system further includes a second hanger rod having a first end and a second end. The first end of each of the first and second hanger rods is operatively configured to attach to the inner bend of a respective one of the loop elbows or another point closer to the pipe run axis than the portion of the centerline of the loop elbows which is furthest from the pipe run axis, such that the flexible tube members are inhibited from sagging when the second end of each hanger rod is secured above the pipe run and away from the inner bend of the loop elbow that is attached to the respective hanger rod. 
     Other systems, methods, features, and advantages of the present invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of the present invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings: 
         FIG. 1  shows a perspective view of an exemplary support system for a flexible pipe loop consistent with the present invention, where the flexible pipe loop is installed in a horizontal position in a pipe run and is supported from above; 
         FIG. 2  shows a perspective view of another exemplary flexible pipe loop consistent with the present invention, where the flexible pipe loop is installed in a horizontal position in a pipe run and is supported from above; and 
         FIG. 3  shows a perspective partial view of another exemplary support system for the flexible pipe loop of  FIG. 2 . 
         FIG. 4  shows a perspective view of an exemplary support system for another flexible pipe loop consistent with the present invention, where the flexible pipe loop is installed in a horizontal position in a pipe run and is supported from below. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     In  FIG. 1 , there is illustrated a support system  100  for a flexible pipe loop  10  consistent with the present invention, where the flexible pipe loop  10  is installed in a horizontal or non-vertical position in a pipe run  12  extending along a longitudinal axis  14 . As discussed further below, the support system  100  inhibits the flexible pipe loop  10  from sagging when the flexible pipe loop is installed in a non-vertical orientation. The pipe run  12  is divided along its length to form a pair of open ends  16 , which are attached to the pipe loop  10 . The pipe run  12  may be supported by hanger supports or pipe guides  18 . 
     As shown in  FIG. 1 , the pipe loop  10  comprises a pair of oppositely disposed pipe run elbows  20 , each having a first open end  22  configured to mate with one of the open ends  16  of the divided pipe  12 , a second open end  24 , and a bend  26  (e.g., 30 degrees, 45 degrees, or as shown, 90 degrees) between the two ends  22  and  24 . Other angles for the bend  26  could also be used. The first open end  22  of each pipe run elbow  20  may have an end fitting to be secured to the open end  16  of the pipe  12 , such as by flanges with threaded fasteners (not shown in figures), male or female pipe threads, weld nipples, swivel unions, slip-on and stub-&amp;-lap-joint flanges, sanitary fittings, flared tube fittings, grooved fittings, or other specially designed connectors, all known in the plumbing art. 
     The pipe loop  10  also includes a pair of flexible tube members  30  each having a first open end  32  and a second open end  34 . The first open end  32  of each tube member  30  is connected to a respective one of the second open ends  24  of the pipe run elbows  20 . 
     The pipe loop  10  further includes at least one loop elbow  36  having a first open end  38 , a second open end  40 , and an inner bend  42 . In the embodiment shown in  FIG. 1 , the first open ends  38  of the loop elbows  36  are connected to a respective one of the second open ends  34  of the pair of flexible tube members  30 , such that the inner bend of the loop elbow is disposed towards the pipe run  12 . In the implementation shown in  FIG. 1 , the inner bend  42  of the loop elbows  36  is 90 degrees and the second open ends  40  of the loop elbows  36  are connected to an open end  44  of a third flexible or rigid tube member  46 . The flexible tube members  30  each may comprise an inner corrugated hose and an outer braided cover or may comprise other types of flexible tubes, such as rubber tubes or corrugated hose with no outer braid cover. By use of such a construction, the flexible tube members  30  will permit and absorb movement of the pipe  12  along the x-axis, the y-axis, and the z-axis shown in  FIG. 1 , while imparting no thrust load to the pipe. Pipe run elbow  20  and loop elbow  36  may each be made from copper, stainless steel, bronze, or alloys of these or other metals, which may add a significant amount of weight to the pipe loop  10 . 
     The loop elbows  36  have a centerline which is displaced away from the pipe run axis  14 . In the embodiment of  FIG. 1 , the centerline of the loop elbows  36  is at its furthest distance from the pipe run axis  14  at the connection of the loop elbows with the tube member  46 . The centerline at that point is the same as a centerline of the tube member  46 , and is identified in  FIG. 1  with reference number  50 . 
     The support system  100  constructed in accordance with the present invention functions to counterbalance the loop elbows  36  and inhibit the flexible tube members  30  from sagging. The support system  100  includes a first hanger rod  110  having a first end  112  and a second end  114 . The first end  112  of the first hanger rod  110  is operatively configured to attach to the inner bend  42  of the loop elbow  36 , such that at least one of the flexible tube members  30  is inhibited from sagging when the second end  114  of the first hanger rod is secured away from the inner bend  42  of the loop elbow and above the pipe run  12 . 
     The first end  112  of the first hanger rod  110  may be secured to a tab  116  extending inwardly (towards the pipe run axis  14 ) from the inner bend  42  of the loop elbow  36 . The first hanger rod  110  may be secured to the tab  116  with fasteners  118 , such as nuts engaging with a threaded portion of the hanger rod. 
     In the implementation shown in  FIG. 1 , the second end of the first hanger rod  110  is mounted to a structure  122  above the pipe run, such as a ceiling or a side wall. 
     The embodiment of  FIG. 1  shows a second hanger rod  124  which supports the other loop elbow  36  and may be secured to that loop elbow in the same manner as described above with respect to the first hanger rod  110 . 
     In this embodiment, the connection of the hanger rod  110  to the support connection comprising the tab  116  is positioned closer to the pipe run axis  14  than the centerline  50  of the loop elbows  36  at the centerline&#39;s furthest distance from the pipe run axis. 
       FIG. 2  shows a perspective view of another exemplary support system  200  for another flexible pipe loop  202  consistent with the present invention, where the flexible pipe loop  202  is installed in a horizontal or non-vertical position in a pipe run  12 . The flexible pipe loop  202  includes a pair of oppositely disposed pipe run elbows  20  with first open ends  22  connected to the pipe  12  as described for the pipe loop  10 . The pipe loop  202  also includes a pair of flexible tube members  30  with first open ends  32  connected to the second open ends  24  of the pipe run elbows  20 . The pipe loop  202  further includes a single loop elbow  204 . An inner bend  206  of the loop elbow  204  shown in  FIG. 2  is 180 degrees facing towards the pipe run  12 . However, the inner bend  206  may be between 10 to 180 degrees when the bends of the pipe run elbows  20  vary from the 90 degree bends illustrated. An open end  38  of each loop elbow  204  is connected to a respective one of the second open ends  34  of the pair of flexible tube members  30 . 
     The support system  200  includes at least one hanger rod  110  attached to the inner bend  206  of one of the loop elbows  204  as described above for pipe loop  10 . The first end  112  of the first hanger rod  110  is operatively configured to attach to the inner bend  206  of a respective loop elbow  204 , such that the flexible tube members  30  are inhibited from sagging when the second end  114  of each hanger rod  110  is secured above the pipe run  12  and away from the inner bend  206  of the loop elbow  204  that is attached to the hanger rod  110 . 
     In this embodiment, the connection of the hanger rod  110  to the support connection comprising the tab  116  is positioned closer to the pipe run axis  14  than the centerline  50  of the loop elbow  204  at the centerline&#39;s furthest distance from the pipe run axis. 
       FIG. 3  shows a perspective view of another exemplary support system  300  for the flexible pipe loop  202  in  FIG. 2 . The support system  300  includes a hanger rod  302 , which may be configured similar to the hanger rod  110  in  FIG. 1 . In the implementation shown in  FIG. 3 , the hanger rod  302  is attached to a support connection in the form of a strap  304 . The strap  304  is secured to the loop elbow  204  at a position closer to the pipe run axis  14  than the centerline  50  of the loop elbow  204  at the centerline&#39;s furthest distance from the pipe run axis. As shown, the strap  304  may extend across legs of the loop elbow away from the bend in the elbow and towards, or at, the first open ends  38  of the loop elbow to engage the loop elbow at at least two points. Although the strap  304  is illustrated as being attached to a top side of the loop elbow  204 , it may also be attached, such as by welding or soldering, to the lower side of the loop elbow. The strap  304  may be configured as a flat plate, as shown, or in other forms, such as a round rod, a beam having a substantial thickness, or even a strap that wraps around the lower sides of the loop elbow. 
       FIG. 4  shows a perspective view of another exemplary support system  400  for another flexible pipe loop  402  consistent with the present invention, where the flexible pipe loop  402  is installed in a horizontal or non-vertical position in a pipe run  12 . The flexible pipe loop  402  includes a pair of oppositely disposed pipe run elbows  20  connected to the pipe  12  as described for the pipe loop  10 . The pipe loop  402  also includes a pair of flexible tube members  30  connected to the pipe run elbows  20 . The pipe loop  402  further includes a loop elbow  404 . The inner bend  406  of the loop elbow  404  shown in  FIG. 4  is 180 degrees. However, the inner bend  406  may be between 10 to 180 degrees and the pipe run elbows may have an inner bend  26  between 5 degrees and 90 degrees. The loop elbow  404  is connected to the pair of flexible tube members  30 . 
     The support system  400  includes at least one support rod  410  attached to a support member  412  which may be in the form of a tab or strap that is secured to each loop elbow  404  at a position closer to the pipe run axis  14  than the centerline  50  of the loop elbow  404  at the centerline&#39;s furthest distance from the pipe run axis. In this embodiment, the pipe loop  402  is supported from below rather than from above as in the previous figures. In all other respects, the support system  400  may take on the various embodiments as described above. 
     While various embodiments of the present invention have been described, it will be apparent to those of skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. Accordingly, the present invention is not to be restricted except in light of the attached claims and their equivalents.