Abstract:
A restraint system for use in securing temporary flow lines that include multiple pipe sections, each pair of pipe sections connected together with a fitting or coupling such as a hammer joint coupling. The system includes multiple pluralities of endless loop slings connected end to end with a cow hitch or girth hitch knot. Disconnectable fittings (e.g., shackles) are placed every three or more slings so that easy disassembly is afforded in case of leakage or other failure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/760,956, filed 5 Feb. 2013, which is hereby incorporated herein by reference. 
         [0002]    Priority of U.S. Provisional Patent Application Ser. No. 61/760,956, filed 5 Feb. 2013, which is incorporated herein by reference, is hereby claimed. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0003]    Not applicable 
       REFERENCE TO A “MICROFICHE APPENDIX” 
       [0004]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    1. Field of the Invention 
         [0006]    The present invention relates to devices for restraining, restricting, or arresting movement of temporary piping such as high pressure pipeline or flow lines during a catastrophic failure. More particularly, the present invention relates to a method and apparatus for restraining high pressure pipe and fittings wherein a series of endless loop slings are joined end to end with hitch type connections (such as a cow hitch, sling hitch, lanyard hitch or other like knot) and wherein each of first and second lengths of assembled slings are connected end to end with disconnectable connections (e.g., shackles) that enable service or maintenance of a selected section of the high pressure piping system without disassembly of all of the endless loop slings, and wherein the assembly of slings and connectors is knotted to the pipeline (e.g., with half hitch knots) at selected intervals. 
         [0007]    2. General Background of the Invention 
         [0008]    In the offshore oil and gas industry, temporary high pressure pipelines are often employed at or near a drilling platform or drilling rig or upon a deck of a drilling platform or drilling rig. These high pressure pipelines are assembled using couplings which are also high pressure rated. If one of these sections of pipe or coupling that make up the high pressure flow line fail or leak, the pipe can violently move, potentially causing injury or death to personnel and/or damage to equipment. For example, pipe sections can come completely apart when a failure occurs. 
         [0009]    Patents have issued for restraint systems designed to restrain a flow line or parts thereof. The following are examples of such patents: 
         [0010]    U.S. Pat. Nos. 2,746,773; 5,689,862; 6,481,457 (wherein each of these patents is hereby incorporated herein by reference). 
         [0011]    The &#39;457 patent is directed to a “Safety Restraint Assembly for High Pressure Flow Line”. The patent is owned by S.P.M. Flow Controls, Inc. of Fort Worth, Tex. (hereinafter “S.P.M.”). 
         [0012]    A Society of Petroleum Engineers publication which is identified by the numeral SPE 24619 and entitled “Restraining System to Help Contain Well Flow Lines and Equipment During Rupture for Increased Safety” was said to have been prepared for presentation at the 87th Annual Technical Conferences and Exhibition of the Society of Petroleum Engineers held in Washington, D.C., 4-7 Oct. 1992. 
       BRIEF SUMMARY OF THE INVENTION 
       [0013]    The present invention provides a restraint system for use in securing temporary flow lines that include multiple pipe sections, each pair of sections connected together with a fitting such as a pressure holding coupling (e.g., a hammer union or coupling). 
         [0014]    The present invention thus provides a restraint system for use in securing temporary flowlines that include multiple pipe sections, each pair of pipe sections connected together with fittings. Such temporary piping systems are commonly used in sizes/diameters 2 inch (5.08 centimeters), 3 inch (7.62 centimeters), 4 inch (10.16 centimeters) as examples. The system includes an assembly of polyester round slings, round slings or loop slings (preferably endless loop slings) connected end-to-end, each sling having end portions that are secured to one or more other endless slings. The loops or slings can be synthetic round slings as defined by ASME B30.9. Core yarns of each sling can be of a synthetic fiber. Covers of the slings can be woven from synthetic yarns. The synthetic round slings can be fabricated from core yarns wound together with multiple turns and enclosed in a protective cover(s). The cover and core can be of the same type of material. When the core and cover are of a different type, the thread should be as the same type yarn as the core. Stitching, if used, should be of the type to prevent unraveling. 
         [0015]    Disconnectable fittings join one assembly of multiple slings to another assembly of multiple slings. 
         [0016]    The disconnectable fitting is not a part of a sling. 
         [0017]    In one embodiment, the disconnectable fitting can be a shackle. 
         [0018]    In one embodiment, each endless sling is wrapped around the piping system at least one 360° wrap. 
         [0019]    In one embodiment, there are at least three endless loop slings in each assembly. 
         [0020]    In one embodiment, each endless loop sling assembly encircles a pipe section next to a fitting. 
         [0021]    The present invention provides a method for restraining a temporary flow line that includes multiple pipe sections, each pair of sections connected together with a disconnectable coupling. 
         [0022]    The method provides first and second pluralities of connected endless sling loops, each plurality including at least three endless loop slings connected end to end with a cow hitch, girth hitch or sling hitch or other hitch knot. 
         [0023]    The endless loop slings are connected end to end and connecting each plurality to another plurality with a disconnectable connector. 
         [0024]    In one embodiment, the disconnected connector is not a part of an endless sling. 
         [0025]    In one embodiment, the connector is metallic. 
         [0026]    In one embodiment, the connector is a shackle. 
         [0027]    In one embodiment, the connector is a fitting having two parts, one part that disconnects from the other part. 
         [0028]    The present invention provides a restraint system for use in securing temporary flowlines that include multiple pipe sections, each pair of sections connected together with fittings. An assembly of endless loop slings are connected end-to-end, each sling having end portions that are secured to one or more other endless slings. 
         [0029]    Disconnectable fittings join one assembly of multiple endless slings to another assembly of multiple endless slings; 
         [0030]    The disconnectable fitting is not a part of an endless loop sling. 
         [0031]    The assembly of flowlines is connected at intervals to the pipe sections and fittings using knotted connectors. 
         [0032]    In one embodiment, the disconnectable fitting is a shackle. 
         [0033]    In one embodiment, each endless sling is tied to the piping system with half hitch knots. 
         [0034]    In one embodiment, there are between 2 and 12 endless loop slings in each assembly. 
         [0035]    In one embodiment, each endless loop sling assembly is tied to a pipe section next to a fitting. 
         [0036]    The present invention provides a method for restraining a temporary flow line that includes multiple pipe sections, each pair of sections connected together with a disconnectable coupling, the system providing first and second pluralities of connected endless sling loops. 
         [0037]    Each plurality includes at least three endless loop slings connected end to end with a knotted connection. 
         [0038]    The slings are connected end to end connecting each plurality to another plurality with a disconnectable connector. 
         [0039]    The slings are knotted to the flow line at intervals using half hitch or other knotted connections. 
         [0040]    In one embodiment, the disconnected connector is not a part of an endless sling. 
         [0041]    In one embodiment, the connector is metallic. 
         [0042]    In one embodiment, the connector is a shackle. 
         [0043]    In one embodiment, the connector is a fitting having two parts, one part that disconnects from the other part. In one embodiment the two parts are a shackle bow and a shackle pin. 
         [0044]    Anchors can be used to anchor the extreme ends of the slings or loops or round slings. Such an anchor can be a pump truck, well head, immovable object. The connection to the immovable object can be a choke hitch or shackle. 
         [0045]    The polyester round slings are used to form a hitch connection parallel to the piping installation, with hitch connections before and after each pipe connection/swivel and at regular intervals (e.g. five feet (1.524 meters)) on straight joints of pipe. At the end of a run of several slings connected end to end, the last sling is connected to an immovable object such as a well head or other immovable object using a shackle or like structural connector. 
         [0046]    The present invention includes a restraint system for use in securing temporary flowlines that include multiple pipe sections, each pair of sections connected together with one or more fittings. The system can include an assembly of multiple endless loop slings connected end-to-end, one sling having end portions, an end portion secured to one or more of said other slings with a cow hitch knot connection. A plurality of disconnectable fittings can each join one assembly of multiple slings to another assembly of multiple slings. The disconnectable fitting is not a said sling. The slings can be attached to the assembly of pipe sections and fittings with knots at spaced apart positions. 
         [0047]    In one embodiment, the disconnectable fitting can be a shackle. 
         [0048]    In one embodiment, the knot can include a wrap of a said sling around the piping system at least one 360° wrap. 
         [0049]    In one embodiment, each sling assembly can include three or more endless loop slings in each assembly. 
         [0050]    In one embodiment, the said knot can secure each endless loop sling assembly to the pipe section encircling the pipe multiple times next to a said fitting. 
         [0051]    In one embodiment, each sling assembly can include a sling that connects to two other side slings with first and second spaced apart cow hitch knots. 
         [0052]    In one embodiment, there can be multiple spaced apart fittings and the assembly of endless loop slings encircles a pipe section multiple times in between two of said spaced apart fittings. 
         [0053]    In one embodiment, the assembly of endless loop slings can encircle a said fitting multiple times and on opposing sides of said fitting. 
         [0054]    In one embodiment, the slings can be of differing lengths. 
         [0055]    In one embodiment, the slings can be of differing thicknesses. 
         [0056]    The present invention includes a method for restraining a temporary flow line that includes multiple pipe sections, each pair of sections connected together with a disconnectable coupling. The method includes providing first and second sling assemblies, each assembly comprising multiple endless sling loops connected to one another. Each sling assembly can include at least three endless loop slings connected end to end, one of the endless loop slings being a middle sling that connects at spaced apart positions with a girth hitch knot joining one said sling to another said sling. The endless loop slings can be connected end to end connecting each plurality to another plurality with a disconnectable connector. The slings can be attached to the assembly of pipe sections and fittings with knots. 
         [0057]    In one embodiment, the disconnectable connector is not a part of an endless sling. 
         [0058]    In one embodiment, the connector can be metallic. 
         [0059]    In one embodiment, the connector can be a shackle. 
         [0060]    In one embodiment, the connector can be a fitting having two parts, one part that disconnects from the other part. 
         [0061]    The present invention includes a restraint system for use in securing temporary flowlines that include multiple pipe sections, each pair of sections connected together with fittings. The system can have multiple assemblies of endless loop slings connected end-to-end, each assembly defined by one sling having an end portion that is secured to one or more other endless slings with a cow hitch knot. Disconnectable fittings can join one said assembly of multiple endless slings to another assembly of multiple endless slings, wherein the disconnectable fitting is not a said endless loop sling. The system further includes attaching the assemblies to the flowlines at intervals using a combination of knotted connectors that each encircle the flowline. 
         [0062]    In one embodiment, the disconnectable fitting can be a shackle. 
         [0063]    In one embodiment, each endless sling can be tied to the piping system at with half hitch knots. 
         [0064]    In one embodiment, there can be between 2 and 12 endless loop slings in each assembly. 
         [0065]    In one embodiment, each endless loop sling assembly can be tied to a pipe section next to a fitting. 
         [0066]    The present invention includes a method for restraining a temporary flow line that includes multiple pipe sections, each pair of sections connected together with a disconnectable coupling. The method includes providing multiple assemblies of connected endless sling loops. Each plurality can include at least three endless loop slings connected end to end with each sling attached to another said sling with a girth hitch knot. The assemblies can be connected end to end, one assembly connecting to another assembly with a disconnectable connector. The method can include knotting the slings to the flow line at intervals. 
         [0067]    In one embodiment, the disconnectable connector is not a part of an endless sling. 
         [0068]    In one embodiment, the connector can be metallic. 
         [0069]    In one embodiment, the connector can be shackle. 
         [0070]    In one embodiment, the connector can be a fitting having two parts, one part that disconnects from the other part. 
         [0071]    In one embodiment, the slings can be of differing lengths. 
         [0072]    In one embodiment, the slings can be of differing diameters. 
         [0073]    In one embodiment, the slings can be of a polyester material. 
         [0074]    In one embodiment, the slings can be of a synthetic fiber material. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0075]    For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
           [0076]      FIG. 1  is a perspective view of a preferred embodiment of the apparatus of the present invention illustrating one of the loop sling portions thereof; 
           [0077]      FIG. 2  is an elevation view illustrating a part of the method of the present invention; 
           [0078]      FIG. 3  is an elevation view illustrating a part of the method of the present invention; 
           [0079]      FIG. 4  is an elevation view illustrating a part of the method of the present invention; 
           [0080]      FIG. 5  is a fragmentary view illustrating a connection used to join one endless loop sling to another endless loop sling as part of the method of the present invention; 
           [0081]      FIG. 6  is an fragmentary view illustrating a part of the method of the present invention; 
           [0082]      FIG. 7  is an elevation view illustrating a part of the method of the present invention; 
           [0083]      FIG. 8  is an elevation view illustrating a part of the method of the present invention; 
           [0084]      FIG. 9  is a fragmentary elevation view illustrating a connection of one loop sling to another loop sling using a shackle; 
           [0085]      FIG. 10  is a fragmentary elevation view illustrating a connection of one loop sling to another loop sling using a shackle; 
           [0086]      FIG. 11  is a fragmentary elevation view illustrating a connection of one loop sling to another loop sling using a shackle; 
           [0087]      FIG. 12  is a fragmentary elevation view illustrating a connection of one loop sling to another loop sling using a shackle; 
           [0088]      FIG. 13  is a fragmentary elevation view illustrating a connection of one loop sling to another loop sling using a shackle; 
           [0089]      FIG. 14  is a partial perspective view illustrating the method of the present invention, illustrating an anchor at one end portion of a sling assembly; 
           [0090]      FIG. 15  is a partial perspective view illustrating the method of the present invention, illustrating an anchor at one end portion thereof; and 
           [0091]      FIG. 16  is a partial view of a preferred embodiment of the apparatus of the present invention illustrating a sling assembly as used with the method of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0092]      FIGS. 1-16  show a preferred embodiment of the apparatus of the present invention designated generally by the numeral  10  in  FIGS. 2-4 . Restraint system  10  is used to secure a high pressure flow line or pipeline  11  that can be comprised of a plurality of pipe sections  12 ,  13  and fittings  14  (e.g., couplings, valves, elbows, tees or other fittings). 
         [0093]    Two (2) pipe sections  12 ,  13  are usually connected at fitting  14 . However, the term “fitting” as used herein should be construed broadly to include anything that can be part of a piping system or flowline. “Fitting” as used herein includes but is not limited to an elbow, tee, reducer, valve, coupling, hammer union, union, as examples. In such a high pressure flow line  11 , multiple pipe sections are typically connected end to end with fittings, unions or couplings. The flow line  11  can include multiple straight sections  12 ,  13  of pipe and elbow or bend sections, tee fittings, couplings, unions, and the like. Such temporary high pressure flow lines, fittings and pipe joints are well known in the art. 
         [0094]    A fitting  14  (e.g., a coupling such as a hammer union  14 , which is commercially available) can be used to join a pair of pipe sections  12 ,  13  together (see  FIGS. 2 and 8 ). Such hammer unions, couplings or like fittings  14  are known in the art and commercially available. Coupling or fitting  14  can provide a hammer nut  15  having projections  16  which can be pounded with a hammer to insure a tight seal for the connection of coupling or fitting  14  when it is used to join two pipe sections  12 ,  13  together. An example of a hammer union and seal arrangement can be seen in U.S. Pat. No. 6,764,109 entitled “Hammer Union and Seal Therefor”. U.S. Pat. No. 6,764,109 is hereby incorporated herein by reference. 
         [0095]    In  FIGS. 5-6 , there can be seen a knotted connection, such as a cow hitch or girth hitch knot  18  that joins one endless loop sling  17 A to another endless loop sling  17 B and to a third sling  17 C (see  FIG. 16 ). The slings  17  can be connected end to end as seen in  FIG. 16  to form a sling assembly  29  (e.g., two or three or four slings). Each sling  17  has ends  31 ,  32  and center  33 . Every few slings, the connection is with a shackle  23  or other disconnectable connector. The knot  18  of  FIGS. 5-6  and  16  can be perfected to connect two slings  17 A,  17 B together by forming a first loop  20  and passing it through a second loop  21  as indicated by arrow  19  and pulling the first loop  20  through the second loop  21  until knot  18  is formed as indicated by arrow  22 . The assembled slings  17 A,  17 B connected with knot  18  can be seen in  FIGS. 5-6  and  16 . 
         [0096]    Once two or more slings  17  are connected end to end as seen in  FIGS. 7 and 16 , an assembly of such slings  17  (e.g., three slings  17 A,  17 B,  17 C connected end-to-end) is connected to another assembly of slings (e.g., three slings  17 A,  17 B,  17 C connected end-to-end) with a disconnectable connector such as a shackle  23 . Shackle  23  has two separable parts, bow  24  and pin  25 . Such shackles are commercially available. In this fashion, if a leak is detected, only two shackles  23  next to or on opposing sides of the leak need be disconnected as opposed to all of the slings  17 . This feature enables the disassembly of only a few slings instead of the dozens or even hundreds of slings that might be employed to restrain a high pressure pipeline or piping system. 
         [0097]    The assemblies of slings  17 A,  17 B,  17 C (e.g., three slings per assembly) are knotted to the pipe  11  and fittings  14  at selected intervals using half hitch or other knots (see  FIGS. 2-4  and  7 - 16 ). In  FIG. 2 , an anchor  27  is provided that can be part of an immovable object such as wellhead  26 . In order to install the restraint system  10  of the present invention on a high pressure flow line  11 , pipeline or piping system, one end portion of a sling assembly  29  is attached to anchor  27  of wellhead  26 .  FIGS. 2 and 3  illustrate such an attachment. A half hitch or cow hitch knot  18  can be used to attach an assembly of slings  17 A,  17 B,  17 C as shown in  FIG. 16  to the anchor  27  shown in  FIGS. 2 and 3 . End  31  is looped through the center of end  32  as illustrated by arrows  30  in  FIG. 2 . The knotted connection to anchor  27  is designated by the numeral  34  in  FIG. 3 . 
         [0098]    Once an assembly of slings  17 A,  17 B,  17 C is connected to anchor  27  at connection  34 , arrows  38  illustrate that the assembly  29  of slings is connected to the high pressure flow line  11  at intervals. At each connection to the pipeline  11 , a knot can be used such as a hitch or half hitch knot  35 . In  FIG. 3 , two half hitch or hitch knots  35  are used, one on each side of fitting  14  which fitting is an elbow in  FIG. 3 . For a length of pipe or section of pipe  12  or  13 , half hitch or hitch knots  36  can be used at intervals (e.g., every five (5) feet (1.524 meters)) designated by the numeral  28  in  FIG. 3 . In  FIG. 3 , two more hitches or half hitch knots  37  are used on opposing sides of a fitting  14  which is a hammer union. 
         [0099]    In FIGS.  4  and  7 - 9 , the installation of an assembly  29  of endless loop slings  17 A,  17 B,  17 C can be seen. Assembly  29  attaches to piping system  11  wherein knots  35 ,  36  and  37  having been completed. Once a first sling assembly  29  of for example two or three or more slings is affixed to the piping system  11  as shown in  FIGS. 3 and 4 , one sling assembly  29  of a plurality of slings  17  is then attached to another sling assembly  29  of a plurality of slings  17  using shackles as shown in  FIG. 16 . In this fashion, only one or two shackles  23  need be disconnected should a leak occur. User&#39;s could then repair the damaged pipe section  11  or  12  or the damaged fitting  14  and then attach a sling assembly or assemblies  29  with shackles  23 . 
         [0100]      FIGS. 10-13  show an alternate method of attaching one loop sling  17 A to another loop sling  17 B using shackle  23 . In  FIGS. 10-13 , a first loop sling  17 A is connected to a second loop sling  17 B by routing the first loop sling  17 A through the open center  33  of the second loop sling  17 B as illustrated by arrow  39  in  FIG. 10 . An end  31  of the loop sling  17 A is then fastened to the sling  17 A using shackle  23  as shown in  FIGS. 11-13 . 
         [0101]      FIGS. 14 and 15  show an alternate anchoring arrangement wherein the anchor  41  connects to the piping system or pipe line  11  at connection  42 . In  FIGS. 14 and 15 , fitting  14  such as a hammer union is closely spaced to connection  42 . A sling assembly  29  or sling  17  is connected to the pipe line  11  on opposing sides of the fitting or hammer union  14  with a shackle  23  connecting one portion of the sling  17  or sling assembly  29  to another portion of the sling or sling assembly  17 ,  29  in order to perfect an attachment of the sling assembly  29  to the pipe line  11  itself for providing an anchor at one end portion of the sling assembly  29 . The sling assembly is attached to the piping system or pipe line  11  using hitch knots or half hitch knots  35 ,  36 ,  37  as with the embodiment of  FIG. 4 . 
         [0102]    The following is a list of parts and materials suitable for use in the present invention: 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 PARTS LIST: 
               
             
          
           
               
                   
                 PART NUMBER 
                 DESCRIPTION 
               
               
                   
                   
               
               
                   
                 10 
                 restraint system 
               
               
                   
                 11 
                 high pressure flow line/pipe line 
               
               
                   
                 12 
                 pipe section 
               
               
                   
                 13 
                 pipe section 
               
               
                   
                 14 
                 coupling/hammer union/fitting/elbow/tee 
               
               
                   
                 15 
                 hammer nut 
               
               
                   
                 16 
                 projection 
               
               
                   
                 17 
                 endless loop sling 
               
               
                   
                 17A 
                 first loop sling 
               
               
                   
                 17B 
                 second loop sling 
               
               
                   
                 17C 
                 third loop sling 
               
               
                   
                 18 
                 cow hitch knot/girth hitch knot/sling hitch 
               
               
                   
                   
                 knot/knotted connection 
               
               
                   
                 19 
                 arrow 
               
               
                   
                 20 
                 first loop 
               
               
                   
                 21 
                 second loop 
               
               
                   
                 22 
                 arrow 
               
               
                   
                 23 
                 shackle/disconnectable connector 
               
               
                   
                 24 
                 bow 
               
               
                   
                 25 
                 pin 
               
               
                   
                 26 
                 wellhead 
               
               
                   
                 27 
                 anchor 
               
               
                   
                 28 
                 distance 
               
               
                   
                 29 
                 sling assembly 
               
               
                   
                 30 
                 arrow 
               
               
                   
                 31 
                 loop end portion 
               
               
                   
                 32 
                 loop end portion 
               
               
                   
                 33 
                 open center 
               
               
                   
                 34 
                 connection to anchor 
               
               
                   
                 35 
                 hitch or half hitch knot 
               
               
                   
                 36 
                 hitch or half hitch knot 
               
               
                   
                 37 
                 hitch or half hitch knot 
               
               
                   
                 38 
                 arrow 
               
               
                   
                 39 
                 arrow 
               
               
                   
                 41 
                 anchor 
               
               
                   
                 42 
                 connection 
               
               
                   
                   
               
             
          
         
       
     
         [0103]    All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise. 
         [0104]    The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.