Abstract:
A system and method of locating a conduit, such as an underground conduit is provided. The system includes a tracing device that is adapted to be coupled to a valve. The tracing device includes a bypass member that is movable between a first position and a second position, wherein the bypass member extends through the valve when in the second position. A tracing member is sealingly coupled to the tracing device and extends through the bypass member. An electrical signal is applied to the tracing member and a monitoring device is used to locate an electrical field created by the electrical signal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to a device and method for tracing nonconductive conduit that cannot be seen, such as a conduit located underground, and in particular to a device and method for tracing a pressurized gas conduit. 
         [0002]    Conduits or pipes are used in a variety of applications to either transfer a material, such as a gas or liquid for example, from a first area to a second area. Other applications make use of conduits as a type of shield to protect an object, such as an electrical, telecommunications or other cable for example, from damage. Often, these conduits are located underground, or are arranged within a wall, making it difficult to precisely locate the conduit at a later date. It should be appreciated that if the conduits are made from a ferrous material, various techniques may be used that inject an electrical signal onto an exposed end of the conduit causing an electrical field to be created around the conduit. Various detectors may then be used to detect the electric field and locate the conduit, even if it is buried beneath the ground or within a wall of a building. Once the conduit is located, personnel in the area may take measures to avoid contacting or damaging the conduit. 
         [0003]    One application that makes extensive use of conduits is in the delivery of natural gas from a provider to a residence. Natural gas main conduits are typically installed under a street and have branch connections that couple the gas main to a residence, office building or other facility. Often, the conduits used in a natural gas system are made from nonmetallic-plastic material, such as polyvinyl chloride or polyethylene (PE) for example. The branch natural gas conduits are usually installed underground and have a first valve (sometimes referred to as a curb valve) adjacent the main conduit near the street and a second valve adjacent the gas meter located in or near the residence or building. 
         [0004]    It should be appreciated that it is desirable to avoid contact with the natural gas conduit when personnel are performing tasks such as digging or using power equipment. When plastic natural gas conduits were initially installed in the 1970&#39;s, the gas conduits were installed alongside conduits carrying electrical power lines. When work was to be performed in the area, the personnel located the electrical power lines (using a field detector). Since the personnel knew the natural gas conduits and electrical power conduits were adjacent to each other, the approximate location of the natural gas conduit was also ascertained. 
         [0005]    Unfortunately, over time the conductors carrying the electrical power lines were upgraded, repaired or replaced. In many instances, such as when the electrical service to the residence or building was upgraded for example, the electrical power lines were installed in a different location. As a result, no conductive material was located adjacent to the natural gas conduit, making it difficult to accurately locate the natural gas conduit. In these situations, personnel typically rely on maps that were made at the time of installation to determine the approximate location of the natural gas conduit. Since it is often desirable to know an accurate location of the natural gas conduit, hand-dug holes are often made to locate the conduit. To avoid an inadvertent release of natural gas, these conduits are often depressurized between the curb valve and the meter valve. 
         [0006]    While existing devices and systems for locating hidden conduits are suitable for their intended purposes, a need for improvement remains in providing a device and method of locating conduits without having dig holes or depressurizing the conduit. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0007]    According to one aspect of the invention, a device for locating a nonconductive conduit having a valve is provided. The device includes a first fitting having an end adapted to couple with the valve. A bypass member is having an axial opening is sealingly coupled to the first fitting. The bypass member a first end within the first fitting, the bypass member being movable between a first position and a second position. An end member is operably coupled to a second end of the bypass member. A tracing member is sealingly coupled to the end member and includes a portion arranged partially within the axial opening, the tracing member being movable through the end member and the bypass member. 
         [0008]    According to another aspect of the invention, a method of locating a conduit is provided. The method includes closing a valve coupled to the conduit adjacent a portion of the conduit to be located. A tracing device is coupled to one side of the valve, the tracing device having a bypass member and a tracing member. The valve is opened. The bypass member is moved from a first position to a second position. The tracing member is inserted into the conduit. 
         [0009]    According to yet another aspect of the invention, a tracing device for locating a conduit comprising is provided. The tracing device includes a coupling portion. A bypass member is sealingly coupled to the coupling portion. A fitting is coupled to the bypass member. A tracer member is sealingly coupled to the fitting. 
         [0010]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0011]    The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0012]      FIG. 1  is a side plan view illustration, partially in section of a device for inserting a tracer member into a conduit; 
           [0013]      FIG. 2  is a side plan view illustration, partially in section of the device of  FIG. 1  coupled to a closed valve; 
           [0014]      FIG. 3  is a side plan view illustration, partially in section, of the device of  FIG. 1  coupled to an open valve; 
           [0015]      FIG. 4  is a schematic illustration of the device of  FIG. 1  coupled to a gas conduit system with a tracer member extended into a conduit; and, 
           [0016]      FIG. 5  is a flow chart illustrating a method of locating a conduit that is not visible. 
       
    
    
       [0017]    The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Embodiments of the present invention provide advantages in allowing the location of a nonvisible nonconductive conduit, such as a conduit located beneath the ground or within a wall for example. Other embodiments of the invention provide further advantages in inserting a tracer member, such as a wire for example, into a pressurized conduit. 
         [0019]    Referring to  FIG. 1 , an exemplary tracing device  20  for locating nonconductive or nonferrous conduits is illustrated. The tracing device  20  includes a first fitting  22  having a coupling portion  24  that is sized and configured to couple with a desired conduit, such as a natural gas conduit for example. In the exemplary embodiment, the coupling portion  24  has a 1-inch (25.4 millimeter) diameter and is threaded to be received in an outlet of a valve. The first fitting  22  has a substantially hollow interior portion  26 . A compression fitting  28  is coupled to an end of the first fitting opposite the coupling portion  24 . The compression fitting  28  includes an opening  32  that extends therethrough. As will be discussed in more detail below, the opening  32  is sized to allow a bypass member  34  to fit therein. 
         [0020]    A seal  30  is disposed within the fitting  22 ,  28  assembly. In the exemplary embodiment, the seal  30  is a self-sealing polychloroprene seal/gasket material, such as Neoprene® manufactured by E.I. du Pont de Nemours and Company. As will be discussed in more detail, the seal  30  inhibits gas from a pressurized conduit from flowing through the tracing device  20  when the tracing device  20  is coupled to the conduit while simultaneously providing a sliding seal for the bypass member  34  to move within the opening  32  and interior portion  26 . It should be appreciated that the seal  30  may be disposed on one end of the compression fitting  28 , as illustrated for example, or may also be arranged within the compression fitting  28  or the first fitting  22 . 
         [0021]    The bypass member  34  is movably coupled to the compression fitting  28 . In the exemplary embodiment, the bypass member  34  is movable in an axial direction  36  within the opening  32  and interior portion  26  between a first position and a second position. When in the first position, an end  38  of the bypass member  34  is positioned adjacent to or within the interior portion  26 . The bypass member  34  includes an opening  40  that extends generally axially along the length of the bypass member  34 . As will be discussed in more detail below, the opening  40  is sized to allow a tracer member  42  to pass therethrough. In the exemplary embodiment, the bypass member  34  has a rectangular cross-section. In one embodiment, the rectangular cross-section is sized to fit within a generally rectangular opening within a valve body opening. In another embodiment, the bypass member  34  has a width of 0.25 inches (6.35 millimeters) and a height of 0.5 inches (12.7 millimeters). In other embodiments, the bypass member  34  has a cross-section, such as a circular or oval cross-section for example, that is sized and shaped to fit within and through an opening in a valve body. 
         [0022]    On an end  44  opposite end  38  of bypass member  34 , a second fitting  46  is fixedly coupled to the bypass member  34 . A member  48  is coupled to the second fitting  46  opposite the bypass member  34 . The member  48  and second fitting  46  each have an opening  56  sized to allow the tracer member  42  to pass therethrough. A cap or third fitting  50  is coupled to the end of the bypass member  34 . The third fitting  50  includes an opening  54  sized to allow the tracer member  42  to pass into the member  48 . A second seal  60  is arranged in the opening  56 . In the exemplary embodiment, the second seal  60  is a self-sealing neoprene gasket. As will be discussed in more detail below, the second seal allows the tracer member  42  to pass while inhibiting the flow of pressurized gas or fluid from an attached conduit. 
         [0023]    It should be appreciated that the arrangement of the second fitting  46 , member  48  and third fitting  50  is exemplary and the claimed invention should not be so limited. These fittings  46 ,  48 ,  50  may be combined in other configurations, such as single integrated member for example, that allow the tracer member  42  to pass into the opening  40  of bypass member  34  while inhibiting the flow of the gas or fluid in the conduit the tracing device  20  is coupled. 
         [0024]    In the exemplary embodiment, the tracing member  42  is a coiled wire member having sufficient length, such as between 120-240 feet (36.6-76.2 meters) to extend the desired length of the conduit that the operator desires to locate. The tracing member  42  is electrically conductive and in the exemplary embodiment is made from antenna wire. In one embodiment, the tracing member  42  is a copper coated steel wire. 
         [0025]    The tracing device  20  may be coupled to a valve  62  as illustrated in  FIG. 2 . The valve  62  may be any be any type of valve, such as a ball valve for example. The valve  62  includes an output end  64  that includes a coupling feature  66  that allows the first fitting  22  to be sealing coupled to the valve  62 . The valve  62  further has a valve member, such as ball valve  68  for example, with an opening  70  therethrough that allows a fluid to pass when the valve  62  is in an open position  FIG. 3 ), and prevents the flow of fluid when the valve  62  is in a closed position ( FIG. 2 ). 
         [0026]    An exemplary embodiment of an application that may use the tracing device  20  is the delivery of natural gas as illustrated in  FIG. 4 . In some circumstances, it may be desirable to locate an underground conduit  72 , such as when the ground is going to be excavated in the area for example. The conduit  72  connects a main supply conduit  73  to a meter  74  adjacent to a residence or building  75 . Generally, a curb valve  77  is positioned between the main supply conduit  73  and the building  75  to allow service to be shut off for maintenance or repairs. Generally, the main supply conduit  73  is positioned under or adjacent to the street and the curb valve  77  is accessible via a service box (not shown). 
         [0027]    In order to locate the underground conduit  72 , a valve  62  located adjacent the meter  74  is moved to a closed position to prevent the flow of gas from the conduit  72  to the meter  74 . With the valve  62  closed, a portion  76  of the conduit between the valve  62  and the meter  74  may be disconnected from the valve  62 . The tracing device  20  is then coupled to the open side of valve  62  as illustrated in  FIG. 2 . It should be appreciated that with the tracing device  20  coupled to the valve  62 , the valve  62  may be opened without gas flowing into the environment. 
         [0028]    With the valve  62  opened, the opening  70  of the valve  62  is generally aligned with the axis of the conduit  72  and the tracing device  20 . The service personnel may then move the bypass member  34  to a second position ( FIG. 4 ) allowing the end  38  to pass through the opening  70  and into conduit  72 . Once the bypass member  34  is moved to the second position, the service personnel may insert the tracing member  42  through the tracing device  20  and into the conduit  72  without interference from the internal components of the valve  62 . As the service personnel insert the tracing member  42 , the tracing member  42  will travel within the conduit  72 . In testing, the tracing member  42  was inserted and the underground conduit  72  was detected over a length of 150 feet (45.7 meters) and it is contemplated that greater than 250 feet of underground conduit may be located in this manner. 
         [0029]    Once a desired length of the tracing member  42  has been inserted, the service personnel couple a device capable of producing an electrical current or signal on the tracing member  42 , often referred to as the “transmitter”. A monitoring device  78  may then detect the electric current. In the exemplary embodiment, the monitoring device  78  is a RD4000 manufactured by Radiodetection Ltd. Once the monitoring device  78  locates the signal from the current injected on the tracing member  42 , the location of the conduit  72  may be marked on the ground. 
         [0030]    Referring now to  FIG. 5 , a method  80  of determining the location of an underground nonconductive conduit, such as a natural gas conduit. The method  80  starts in block  82  and proceeds to block  84  where a desired valve on one end of the conduit is located and closed. In the exemplary embodiment the valve may be located above ground, such as a valve  62  arranged adjacent the residence  75  for example, or below ground in a service box for example. With the valve closed, the method  80  proceeds to block  86  where the conduit downstream from the valve is uncoupled. 
         [0031]    Once the conduit is detached, the tracing device  20  is coupled to the valve with the bypass member  34  in the first or retracted position in block  88 . The valve is opened in block  90  and the bypass member  34  is moved in block  92  to the second position wherein the bypass member  34  passes through the valve. As discussed herein, with the bypass member  34  in the extended position, the tracing member  42  may be inserted in block  94  and it will pass through the valve without becoming entangled with the inner features of the valve. The trace member  42  is extended into the conduit a length substantially the length of the conduit that the service personnel desire to locate. 
         [0032]    Next, the method  80  proceeds to block  96  where the service personnel use a monitoring device to locate and mark (e.g. with paint or flags) the position of the conduit. As discussed above, the process of locating the position of the conduit includes the injecting of a signal or electrical current on the tracing member  42 . Once the conduit is located, the tracing member  42  is with drawn in block  98  and the bypass member  34  in moved to the first position in block  100 . With the bypass member  34  moved, the valve is free to be closed and is closed in block  102 . The tracing device  20  is removed in block  104  and downstream conduit is reconnected and the valve opened once again in block  106 . 
         [0033]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.