Abstract:
The present invention is a pipeline pig for cleaning the interior of a pipeline, the pipeline pig having a longitudinal pig body with forward and rearward elastomeric propulsion members affixed to and supporting the pig body substantially concentrically in a pipeline, the propulsion members functioning to move the pig body through a pipeline by the force of fluid flow and a plurality of spaced apart elastomeric diagonally oriented scrapers radially extending from the pig body, each scraper member having a semi-circular outer peripheral edge configured and dimensioned to engage the interior wall of a pipeline to thereby scrape and clean the interior pipeline wall as the pig is moved through the pipeline and provide additional support for the pig substantially concentrically in a pipeline. Orientation of the scraper enhances scraping effectiveness by slicing through any debris buildup, separating the debris from the inner pipe wall so that it can be pushed out of the pipeline by the pig discs or cups.

Description:
REFERENCE TO PENDING APPLICATIONS 
       [0001]    This application is not based upon any pending domestic or international patent applications. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a mechanical pigging device. Such devices are commonly referred to in the industry simply as “pipeline pigs” or more briefly “pigs”. The invention herein is a type of pipeline pig particularly used for cleaning purposes, that is, for moving through the interior of a pipeline by the force of fluid flow and during such movement to scrape and clean the interior wall of the pipeline. 
       BACKGROUND OF THE INVENTION 
       [0003]    Pipelines have long been used for conducting liquids and gases from one location to another. With the advent of the petroleum industry, pipelines are commonly used for transporting hydrocarbon products and particularly for moving crude oil from field locations to refineries or where crude oil is moved for further delivery, such as by ships, tank cars and so forth. In addition to moving crude oil, pipelines are frequently employed in the petroleum industry for moving natural gas from production areas to gas plants and areas of consumption. 
         [0004]    Whether moving hydrocarbon liquids or gases, there is a tendency for contaminants to adhere to the wall of the pipeline. As an example, crude oil frequently carries with it paraffin contents that tend to deposit on the pipeline interior walls. Further, since most pipelines are made of steel, rust has a tendency to form on interior pipeline walls. 
         [0005]    For these and various other reasons, it is important for efficiency purposes that pipeline walls be periodically cleaned and this is most effectively accomplished by periodically scraping the interior walls of the pipeline. 
         [0006]    The present invention is a scraping pig that is configured to be moved by fluid flow through a pipeline. 
         [0007]    For additional information relating to this invention, reference may be had to the following previously issued United States patents. 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Pat. No. 
                 Inventor 
                 Title 
               
               
                   
               
             
             
               
                 3,576,043 
                 Zongker 
                 Pipeline Pig With Spring-Mounted Scrapers 
               
               
                 4,081,875 
                 Nishino 
                 Scale Removal Device 
               
               
                 4,083,074 
                 Curtis 
                 Multipurpose Pipeline Pig 
               
               
                 4,244,073 
                 Sagawa 
                 Pipeline Pig 
               
               
                 4,603,449 
                 Knapp 
                 Unitized Pig Body For Parafin Removal 
               
               
                 4,907,314 
                 Kershaw 
                 Pipeline Pig 
               
               
                 5,379,475 
                 Sivacoe 
                 Scraper For A Pipe Pig 
               
               
                 5,384,929 
                 Smith 
                 Pig For Use In Cleaning The Interior Wall Of A Pipeline 
               
               
                 5,457,841 
                 Minton 
                 Cleaning Pig For Pipeline Of Varying Diameter 
               
               
                 5,600,863 
                 Curran 
                 Pipe Scraper Assembly 
               
               
                 6,038,725 
                 Knapp 
                 Unicast Paraffin Removing Pipeline Pig Incorporating Multiple 
               
               
                   
                   
                 Diameter and Thickness Discs and Having A Central Bending 
               
               
                   
                   
                 Portion For Turns 
               
               
                 6,065,174 
                 Laymon 
                 Parabolic Scraper For A Pipeline Pig 
               
               
                 6,145,150 
                 Knapp 
                 Multi-Dimensional Pig Including Wiper Disk Permitting Passage 
               
               
                   
                   
                 Through 
               
               
                 6,276,017 
                 Lino et al. 
                 Multisize Bidirectional Scraping Device 
               
               
                 6,308,363 
                 Lino et al. 
                 Modular Multisize Bidirection Scraping Device 
               
               
                 6,792,641 
                 Laker 
                 Pipeline Pig 
               
               
                 7,000,280 
                 Knapp 
                 Aggressive Pipeline Pig 
               
               
                 2003/0041400 
                 Knapp 
                 Molded Pipeline Pig With Hardness Variations 
               
               
                 2003/0183022 
                 Sapelnikov et al. 
                 Sensors Carrier For In-Tube Inspection Scraper 
               
               
                 2007/0113362 
                 Lino et al. 
                 Structured Foam Pig 
               
               
                 2008/0141474 
                 Kapustin et al. 
                 Device For Cleaning Multidiameter Pipelines 
               
               
                   
               
             
          
         
       
     
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The pipeline pig of this invention is used for cleaning the interior of a pipeline. The pipeline pig is formed by a longitudinal pig body. Forward and rearward elastomeric propulsion members are affixed to and serve to support the pig body substantially concentrically in a pipeline. Further, the propulsion members function to move the pig body through a pipeline by the force of fluid flow. 
         [0009]    A plurality of spaced apart elastomeric scraper members radially extend from the pig body. Each scraper member has a semi-circular outer peripheral edge configured and dimensioned to compressibly engage the interior wall of the pipeline. 
         [0010]    Preferably the scrapers are arranged in at least one plane perpendicular to a longitudinal axis of the pig body. Further the scrapers are configured and dimensioned so that their outer peripheral edges contact the pipeline full circumferential interior. 
         [0011]    The scraper members can be made of a variety of semi-rigid materials, polyurethane being one ideal material. 
         [0012]    The elastomeric propulsion members can be made with spaced apart small diameter holes resulting in some pipeline fluid bypassing the pig to assist in maintaining dislodged debris suspended in the pipeline fluid. 
         [0013]    In one embodiment of the invention the scraper members are each individual members having an inner edge affixed to a longitudinal pig body that may be rigid or flexible. In another embodiment the scraper members are each molded into a central hub ring which is attached to the pig body. 
         [0014]    This invention also includes the arrangement wherein the pig body is a structural member that includes a pair of brackets for each scraper member, the brackets being spaced apart in sets and wherein the inner end of each scraper member is supported between a pair of brackets. 
         [0015]    In a preferred embodiment of the invention a pipeline pig has propulsion members that are each in the form of an elastomeric disc or cup of external diameter substantially equal to the internal diameter of the pipeline. 
         [0016]    This invention provides a self-energized pipeline pig for scraping and cleaning the interior of a pipeline, the pig having a plurality of elastomeric scraper members extending radially from a pig body and propulsion means are secured to the pig body for moving the pig body in the pipeline by the force of fluid flow and in which each scraper member has an outer circumferential end of diameter corresponding closely to that of the pipeline interior. 
         [0017]    Further objects and features of the present invention will be apparent to those skilled in the art upon reference to the accompanying drawings and upon reading the following description of the preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Preferred embodiments of the invention will now be described in further detail. Other features, aspects, and advantages of the present invention will become better understood with regard to the following detailed description, appended claims, and accompanying drawings (which are not to scale) where: 
           [0019]      FIG. 1  is an elevational external view of a pipeline scraping pig of this invention ready to be inserted into a pipeline to move through the pipeline by the force of fluid flow to scrape the internal walls of the pipeline. 
           [0020]      FIG. 2  is an elevational external view taken along the line  2 - 2  of  FIG. 1  showing the forward end of the pipeline scraping pig. 
           [0021]      FIG. 3  is an elevational external view of a scraper member as used as a part of the pipeline pig of this invention. 
           [0022]      FIG. 4  is an external end view of a larger end of a radial elastomeric scraper as used in the pipeline pig of this invention. 
           [0023]      FIG. 5  is an external isometric view of the scraper shaped members as used in formulating the pipeline pig of this invention. 
           [0024]      FIG. 6  is an isometric view of the pipeline pig of  FIG. 1  in a form and shape as it is ready to be positioned within the interior of the pipeline. 
           [0025]      FIG. 7  is an external isometric view showing an alternate embodiment of the invention showing an arrangement for mounting the scraper members in hubs that are secured to the longitudinal pig body. 
           [0026]      FIG. 8  is an isometric view as shown in  FIGS. 6 and 7  but showing still a different method of mounting the scraper member to the longitudinal body. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    It is to be understood that this invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. The phraseology and terminology employed herein are for the purpose of description and not of limitation. 
         [0028]    Elements shown by the drawings are identified by the following numbers: 
         [0000]    
       
         
               
               
             
           
               
                   
               
             
             
               
                 10 
                 Longitudinal pig body 
               
               
                 12 
                 Forward radial circumferential flange 
               
               
                 14 
                 Angular braces 
               
               
                 16 
                 Rearward radial circumferential flange 
               
               
                 18 
                 Forward elastomeric propulsion member 
               
               
                 20 
                 Rearward elastomeric propulsion member 
               
               
                 24 
                 Smaller reinforcing ring 
               
               
                 26 
                 Bolts 
               
               
                 28 
                 Nuts 
               
               
                 32 
                 Smaller reinforcing ring 
               
               
                 36 
                 End plate 
               
               
                 38 
                 Pull eye 
               
               
                 40 
                 Bypass holes 
               
               
                 42 
                 Forward group of scraper members 
               
               
                 44 
                 Rearward group of scraper members 
               
               
                 46 
                 Radial elastomeric scraper 
               
               
                 48 
                 Outer circumferential edge surface 
               
               
                 50 
                 Leading edge surface 
               
               
                 52 
                 Following edge surface 
               
               
                 54 
                 Planar front surface 
               
               
                 56 
                 Planar rear surface 
               
               
                 58 
                 Inner circumferential edge surface 
               
               
                 60 
                 Bolt holes 
               
               
                 62 
                 Bolts 
               
               
                 63 
                 Nuts 
               
               
                 64 
                 Forward bracket 
               
               
                 66 
                 Rearward bracket 
               
               
                 68 
                 Angle braces 
               
               
                 70 
                 Forward hub 
               
               
                 72 
                 Rearward hub 
               
               
                 74 
                 Forward ring 
               
               
                 76 
                 Rearward ring 
               
               
                 78 
                 Bolts 
               
               
                 84 
                 Bevel 
               
               
                   
               
             
          
         
       
     
         [0029]    Referring to the drawings and first to  FIGS. 1 and 6 , a first embodiment of the invention is illustrated.  FIG. 1  is an external elevational view of a completed pig with diagonally oriented scrapers while  FIG. 6  is an external isometric view of the pig. As shown in  FIGS. 1 and 6 , a basic element of the pipeline scraping pig of this invention is a longitudinal pig body  10 . At a forward end of the longitudinal pig body  10  there is a forward radial circumferential flange  12  structurally supported by angular braces  14 . The forward radial circumferential flange  12  that extends around the parameter of longitudinal pig body  10  and angular braces  14  are preferably welded to the exterior of pig body  10 . 
         [0030]    In like manner, there is a rearward radial circumferential flange  16  that is affixed and radially extends from a rearward end of pig body  10 , the rearward radial circumferential flange  16  also being supported by angular braces  14  that can be welded to the exterior of longitudinal pig body  10 . 
         [0031]    Supported on the exterior of the forward end of pig body  10  is a forward elastomeric propulsion member  18 . The propulsion member  18  may be an integral toroidal elastomeric plate member positioned on the exterior of a forward end of longitudinal pig body  10 . 
         [0032]    In like manner a rearward radial circumferential elastomeric propulsion member  20  is mounted on the rearward end of longitudinal pig body  10 . 
         [0033]    Referring again to  FIGS. 1 and 6  there is shown at the forward end of longitudinal pig body  10  a smaller diameter toroidal reinforcing ring  24 , preferably made of metal and retaining the elastomeric propulsion member  18 . Bolts  26 , the heads of which are seen in  FIGS. 1 and 6 , extend through the smaller reinforcing ring  24 , the forward elastomeric propulsion member  18  and the forward radial circumferential flange  12 . Bolts  26  are retained by nuts  28 . 
         [0034]    The rearward elastomeric propulsion member  20  is secured to pig body  10  in substantially the same way as the forward elastomeric propulsion member is secured, that is, by the provision of a smaller reinforcing ring  32 . Bolts  26 , the heads of which are seen in  FIG. 1  and nuts  28  seen in  FIGS. 1 and 6  retain the rearward elastomeric propulsion member  20  extending radially of pig body  10 . 
         [0035]    The internal passageway of longitudinal pig body  10  (best formed of a length of pipe) is closed as seen in  FIGS. 6 and 8  by an end plate  36  which typically might be a circular plate welded to or within the forward end of pig body  10 . A pull eye  3   8  having a forward open loop is secured, such as by welding, to end plate  36 . While not seen in the drawings, the rearward end of longitudinal pig body  10 , when made of pipe as is the preferred embodiment, is open ended. 
         [0036]    The diameters of forward elastomeric propulsion member  18  and rearward elastomeric propulsion member  20  are configured and dimensioned to closely fit the interior of the pipeline for which the pig is designed so that when the pig is positioned in a pipeline the propulsion members substantially close fluid flow through the pipeline to ensure that as fluid moves in the pipeline the pipeline scraping pig is moved by the fluid flow to traverse the interior of a pipeline. The elastomeric propulsion members can be made with spaced apart small diameter holes resulting in some pipeline fluid bypassing the pig to assist in maintaining dislodged debris suspended in the pipeline fluid. 
         [0037]    As seen in  FIGS. 1 and 6 , a most important part of the pipeline scraping pig of this invention is a plurality of spaced apart elastomeric scrapers radially extending from the pig body. In the arrangement illustrated in  FIGS. 1 and 6  the diagonally oriented scrapers are arranged in a forward group generally indicated by the numeral  42  and a rearward group generally indicated by the numeral  44 . Each group includes a number of spaced apart radial diagonally oriented scrapers  46 . In the illustration, in  FIGS. 1 and 6  each of groups  42  and  44  include eight radially extending diagonally oriented scrapers  46 . Each diagonally oriented scraper  46  functions like a plow to shave off debris from a pipeline interior wall. 
         [0038]      FIGS. 3 ,  4  and  5  show in detail the configuration of each of the radially extending diagonally oriented scrapers  46 . Each scraper  46  is formed of an elastomeric sheet of material, such as polyurethane, of sufficient thickness to be substantially rigid and yet free to flex as necessary to accommodate deviations in the internal configurations of a pipeline and yet, each provides an outer circumferential edge surface  48 . Each scraper therefore has, in addition to the outer circumferential edge surface  48 , a leading longitudinal edge surface  50  and a following longitudinal edge surface  52 . Each radial diagonally oriented scraper  46  has a planar front surface  54  and a planar rear surface  56 . At the end opposite of the outer circumferential edge surface  48 , each scraper is defined by an inner circumferential edge surface  58  that abuts against the exterior of pig body  10  as the radial diagonally oriented scrapers are mounted to the pig body. Adjacent the inner circumferential edge surface  58  and extending between the planar front and rear surfaces  54 ,  56  of each elastomeric scraper  46  has a pair of bolt holes  60 . These bolt holes  60  receive bolts  62  by which the radial diagonally oriented scrapers  46  are retained on pig body  10 . Each of bolts  62  is retained by a nut  63 . 
         [0039]    Each of the radial diagonally oriented scrapers  46  is secured to pig body  10  to extend radially therefrom whereby a plane of each scraper is at an angle of between 15° and 75° relative to a plane of a longitudinal axis of pig body  10 . As shown in  FIGS. 1 and 6 , the inner end of each of the radial scrapers is secured between a forward bracket  64  and a rearward bracket  66 . There is a set of brackets for each scraper. Each of the brackets  64 ,  66  has an arcuate inner surface that conforms to the external circumferential surface of pig body  10 . Each of the brackets  64 ,  66  has two openings therein. The bolts  62  and nuts  63  serve to clamp the brackets  64  to the exterior of each of the elastomeric scrapers  46 . 
         [0040]    The inner arcuate edge of each of bracket  66  can be secured to pig body  10  such as by welding. Further, to rigidly secure the radial extension of each of the elastomeric scrapers, each rearward bracket  66  has an angular brace  68  which is also preferably welded to the exterior of pig body  10 . 
         [0041]    The diagonally oriented scrapers  46  are dimensioned to be oversized for the dimensions of the interior wall of a pipeline for which the scraper pig is intended to be used. Thus the scrapers have outwardly extending memory and act like an oversized spring to cause their outer circumferential edge surface  48  to firmly engage a pipeline interior wall surface. In this way the pipeline scraping pig of this invention is self-energized. 
         [0042]      FIG. 7  shows an alternate embodiment of the invention which is different than  FIGS. 1 and 2  only in the way the radial diagonally oriented scrapers  46  are mounted to the exterior of pig body  10 . In  FIG. 7  a pair of integral hubs and scrapers are employed for securing the diagonally oriented scrapers to the pig body. Specifically, there is a forward hub  70  and a rearward hub  72 . Hubs  70  and  72  are cylindrical and of external diameter greater than the external diameter of pig body  10 . Each of the hubs  70 ,  72  are mounted between a forward ring  74  and a rearward ring  76 , each of the rings having spaced apart bolts. By means of bolts  78  extending through rings  74  and  76  are secured to hubs  70  and  72 . The internal circumference of each of the rings  74  and  76  is configured to engage the external circumferential surface of pig body  10 . 
         [0043]      FIG. 8  shows another alternate embodiment that is different from the structures illustrated in  FIGS. 1 and 6  only in the method of securing the radial diagonally oriented scrapers  46  to the pig body. In the arrangement of  FIG. 8 , the body  10  and diagonally oriented scrapers  46  may be one integral molded part or fabricated from a tubular body and diagonally oriented scrapers. 
         [0044]    Various means of securing the diagonally oriented scrapers to longitudinal pig body  10  are illustrated in  FIGS. 6 ,  7  and  8 . These illustrations are exemplary of the fact that the diagonally oriented scraper  46  may be attached to the pig body in a variety of ways. Any method of extending diagonally oriented scrapers radially of a pig body and at an angle to a plane of the axis of the pig body would be within the scope of this invention. 
         [0045]    The arrangement of this invention provides a pig with pipeline cleaning self-energized diagonally oriented scrapers. The pig as described herein, when placed in a pipeline having fluid flow therethrough, will move through the pipeline by the force of the fluid flow. The outer circumferential edge surfaces  48  of each of the radial elastomeric scrapers engages the interior surface of the pipeline and scrapes loose encrustations, paraffin and other debris that tends to collect in the pipeline. The scraped debris is moved forward by the movement of the pig through the pipeline and by the force of fluid flow. 
         [0046]    The pig functions to provide rotational energy by the provision wherein the rate of fluid flow exceeds the rate of movement of the scraping pig. This is accomplished by the propulsion members  18  and  20  have bypass holes  40  therethrough which permits a certain percent of the pipeline fluid to flow past the scraping pig as the scraping pig is moved through the pipeline. The flow rate of the pipeline fluids being greater than the pig means that the movement of fluid against the diagonally oriented scrapers imparts rotary motion so the cleaning pig not only propelled through the pipeline but is concurrently rotated within the pipeline to augment cleaning action. 
         [0047]    The essence of the invention is a pipeline pig having diagonally oriented scrapers each having an outer edge that engages the interior surface of a pipeline as the pig is moved through the pipeline and wherein the scraping action is obtained by the diagonally oriented radially scrapers having outer edges that scrape against the interior surface as the cleaning pig is moved by fluid flow through the pipeline. A unique aspect of the invention is the provision of a pipeline cleaning pig that moves laterally through the pipeline and provides diagonally oriented scrapers to augment cleaning action wherein the outward force on the scraper is accomplished without any mechanical elements. 
         [0048]    While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be limited only by the scope of the attached claims, including the full range of equivalency to which each element thereof is entitled.