Abstract:
A pipe inspection system and method for accessing and inspecting a feeder tube extending from a larger header pipe at an angle are disclosed. A pipe inspection tool including a head piece and a delivery tube are positioned within the header pipe and aligned with the feeder tube using cameras or other alignment means. The head piece includes a jack that presses the head piece against the interior surface of the header pipe at the feeder tube to create a sufficient seal to deliver a PIG or another pipe inspection device to the feeder tube.

Description:
FIELD OF THE INVENTION 
     The present disclosure is directed to a pipe inspection system for accessing and inspecting a small diameter pipe that branches from a large diameter pipe at an angle. 
     BACKGROUND OF THE INVENTION 
     Many industries rely on piping of various diameters to direct fluids, such as air, water, or oil to and from buildings or refineries. Some of this piping is located in environments that are difficult to access for inspection or repair. A common inspection tool is the pipe inspection gauge, or “PIG,” that can be inserted into a pipe and moved along the interior or the pipe and can have a camera or other telemetry tools on board to inspect the pipe. The pipe geometry itself, however, can make inspection difficult even for a sophisticated PIG. Some angles are not negotiable for PIGs. Also, PIGs are not capable of navigating pipe sections of significantly differing diameters. One approach has been to cut into the pipe and deliver PIGs through the cut or to otherwise inspect the pipes through the cut, and then to patch up the cut. This practice, however, is expensive to perform, takes a facility offline for a relatively long time, and poses the risk that the patch will fail. 
     SUMMARY OF THE INVENTION 
     The present disclosure is directed to a pipe inspection tool for a header pipe having a feeder tube extending from the header pipe. The pipe inspection tool includes a head piece having a tubular body defining a central axis and having a proximal opening at a first end and a distal opening at an angle to the central axis. The distal opening is configured to engage the feeder tube at an interior surface of the header pipe. The inspection tool also includes a camera or another sensing device mounted to the head piece and configured to provide a field of view from a position from within the head piece looking outward through the distal opening. The field of view is centered within the distal opening to facilitate alignment of the feeder tube coupler with the feeder tube. The tool also has one or more jacks coupled to the head piece and configured to press the head piece against the interior surface of the header tube to sealably couple the head piece with the feeder tube. 
     In other embodiments the present disclosure is directed to a method of inspecting a feeder tube extending at an angle from a header pipe by introducing a pipe inspection tool into the header pipe, sealably coupling the pipe inspection tool with the feeder tube, and introducing a PIG to the feeder tube through the inspection tool. 
     The present disclosure is also directed to a pipe inspection tool including a head piece having a longitudinal axis and being sized to fit within a pipe having a first diameter, and a tube coupler carried by the head piece and configured to sealably couple with a tube having a second diameter smaller than the first diameter. The tube coupler is oriented at an angle with respect to the longitudinal axis of the head piece. The inspection tool can also include a means for pressing the tube coupler against an interior surface of the pipe with the tube coupler aligned with the tube. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  depicts a pipe inspection device in position relative to a header pipe and feeder tubes to be inspected by the inspection device according to embodiments of the present disclosure. 
         FIG. 2  illustrates a pipe inspection device having a head piece and a delivery tube according to embodiments of the present disclosure. 
         FIG. 3  is an exploded view of the pipe inspection device of  FIGS. 1 and 2  according to embodiments of the present disclosure. 
         FIG. 4  is a top plan view of the head piece of the pipe inspection tool according to embodiments of the present disclosure. 
         FIG. 5A  is an exploded view of a jack for positioning the head piece relative to the feeder tube to be inspected according to embodiments of the present disclosure. 
         FIG. 5B  is orthogonal side and front views of the jack of  FIG. 5B  in an assembled state. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a pipe inspection tool  100  according to embodiments of the present disclosure. The inspection tool  100  includes a head piece  110  and a delivery tube  120 . The inspection tool  100  is used to inspect a header pipe  10  having feeder tubes  12  extending from the header pipe  10  at an angle. In general, the feeder tubes  12  have a smaller diameter than the header pipe  10 . The systems and methods of the present disclosure can be used in a variety of environments involving pipes of different diameter, some of which are commonly referred to as header pipes and feeder tubes, and some of which are not necessarily referred to as such. For purposes of clarity and brevity, the terms “header pipe” and “feeder tube” are used to refer to a large diameter pipe and a smaller diameter pipe, respectively without loss of generality. The feeder tubes  12  can extend from the header pipe  10  at virtually any angle; in this embodiment, the angle is approximately 90°. The tool  100  can be introduced to the header pipe  10  and aligned with the feeder tube  12 . The head piece  110  is then pressed against the interior surface of the header pipe  10  with a hydraulic or mechanical jack to form a seal with the feeder tube  12 . A PIG can then be delivered through the delivery tube  120 , through the head piece  110 , and into the feeder tube  12 . 
       FIG. 2  illustrates an inspection tool  100  according to embodiments of the present disclosure, including a head piece  110  and a delivery tube  120 . The head piece  110  includes a tube coupler  130  on a side of the head piece  110 . The head piece  110  can have a longitudinal axis parallel with the delivery tube  120 , and the tube coupler  130  can be oriented at an angle relative to the longitudinal axis of the head piece  110 , such as a 90° angle. The tube coupler  130  can be shaped to conform to an interior surface of the header pipe  10  shown in  FIG. 1 . In some embodiments, the tube coupler  130  can have a curved surface configured to conform to a curved surface such as the inner surface of the header pipe  10 . In other embodiments the tube coupler can have a curved shape of a different radius, or even a flat profile, depending on the shape of the surface to which the tube coupler  130  is to engage. 
     The tube coupler  130  can be made of a resilient member to facilitate forming a seal. In one version, the tube coupler includes a resilient gasket configured to form a seal between the head piece and an opening of a feeder tube within the header pipe. 
     The head piece  110  can also include a jack  140  configured to press the tube coupler  130  against the interior surface of the header pipe  10 . The jack  140  can include bumpers  142  shaped to engage the interior surface of the header pipe  10  opposite the tube coupler  130 . In embodiments in which the inspection tool  100  is for use within a cylindrical header pipe  10 , the radius of the bumpers  142  and the tube coupler  130  can be the same. In other embodiments the bumpers  142  and the tube coupler  130  can be designed to engage with structures having disparate shapes and surface characteristics and can therefore be modified accordingly. 
     The feeder tubes may be located at any distance from an access point in the larger header pipe. Accordingly, the delivery tube  120  may be made to be variable in length, accommodating a number of segments coupled together to form the delivery tube. In addition, the delivery tube may attach to the headpiece in a location that leaves the delivery tube positioned centrally within the header pipe  10 . In this situation, particularly with longer delivery tube runs, it is desirable to include supports for the delivery tube. 
     As seen in  FIG. 2 , the inspection tool  100  includes supports  150  that can help to maintain the position of the head piece  110  and the delivery tube  120  within the header pipe  10 . The supports  150  can comprise arms that extend radially from the head piece  110  or the delivery tube  120  or both. The supports  150  can include casters that can roll or slide along the interior surface of the header pipe  10 . In some versions, the supports may be remotely operable to cause them to selectively raise and lower the height of the delivery tube and the headpiece. The supports can extend from the delivery tube  120  or the head piece  110  in any direction to support the head piece  110  within the header pipe  10 . In different installations the feeder tubes  12  extend from the header pipe  10  in different directions. In some embodiments the supports  150  can be built for a specific installation. In other embodiments the inspection tool  100  can include supports  150  extending in various directions and therefore capable of use with feeder tubes  12  extending in any direction. For example, the inspection tool  100  can include three supports  150 , each spaced apart angularly by 120° around the tool, or four supports  150 , each spaced apart angularly by 90°. This may be desirable in installations where the direction of the feeder tube  12  is not known, or for when an installation has multiple feeder tubes extending at different angles from the header pipe  10 . 
     The inspection tool  100  can also include a spool coupler  160  attached to the delivery tube  120  opposite the head piece  110 . The spool coupler  160  can couple the delivery tube  120  to a conventional PIG delivery device (not shown) or another suitable inspection system. The spool coupler  160  can be coupled directly to the head piece  110  if the feeder tube  12  is near an opening in the header pipe  10 . 
       FIG. 3  is an exploded view of the head piece  110  of the pipe inspection tool  100  according to embodiments of the present disclosure. The head piece  110  can be made of a first pipe section  111  that is oriented generally parallel with the central longitudinal axis of the head piece  110 . As shown, the first pipe section  111  is cylindrical in shape and therefore the longitudinal axis extends through the center of the cylinder. The first pipe section  111  can be coupled to a second pipe section  112 . The first and second pipe sections may be integrally formed as one continuous tube, or may be formed as separate sections joined together. In either case, the first pipe section includes a first, proximal opening at one end that is sized and configured to receive a PIG, as discussed below. Within the head piece, the internal channel forms an angle, preferably curved, to direct the moving pig from a first path of travel aligned with the longitudinal axis to a second path of travel angularly offset by the orientation of the second pipe section. The second pipe section forms a second, distal opening through which the PIG may travel, ultimately allowing it to enter a header pipe. 
     The shape of the second pipe section  112  is chosen based on the angle at which the feeder tube  12  extends from the header pipe  10 . In the embodiment shown, the angle is 90°, but virtually any other angle is possible. The second pipe section  112  can be an elbow junction. The head piece  110  can also include a third pipe section  113  that extends from the second pipe section  112  to accommodate a longer reach if desirable. The feeder tube coupler  130  is shown coupled to the third pipe section  113 . The feeder tube coupler  130  and the third pipe section  113  can be bolted, welded, or otherwise attached to the second pipe section  112 . The fluid circuit for delivering the PIG to the feeder tube  12  includes the first pipe section  111 , the second pipe section  112 , and the feeder tube coupler  130 . If necessary, the circuit can also include a delivery tube  120  and a third pipe section  113 . 
     The head piece  110  can include a support section  114  coupled to the second pipe section  112 . The support section  114  can be generally parallel with the first pipe section  111  and, the primary function is to provide a surface for attaching a hydraulic jack, as described below. In one version, the support section can be configured as a pipe section having roughly the same diameter as that of the first pipe section  111 . In a preferred version, the support section  114  is not in fluid communication with the fluid circuit of the head piece  110  and therefore serves only as a support shelf. Alternatively, the support section  114  can be in selective fluid communication with the fluid circuit by a valve (not shown) between the second pipe section  112  and the support section  114 . When the valve is closed the support section  114  does not communicate fluidly with the fluid circuit, but the valve can be opened to release pressure or to permit the PIG to pass through the head piece  110 . Supports  150  can be mounted to the support section  114  or to other portions of the head piece  110 . The support section  114 , the first pipe section  111 , and the third pipe section  113  can form a T-shaped structure. 
     The head piece  110  can include a sensing device, such as one or more cameras  116   a - c , mounted at various positions. In other embodiments the sensing device can be an ultrasound device or a mechanical sensing device, or any other suitable sensing device. The cameras  116   a - c  can be oriented in any suitable direction to allow the operator to observe the interior of the header pipe  10  in order to align the feeder tube coupler  130  to the feeder tube  12 . In some embodiments, one of the cameras  116   a  can be placed at a center of the angled tube and oriented to look outwardly from the feeder tube coupler  130  to more easily align the feeder tube coupler  130  with the feeder tube  12 . As best seen in  FIG. 3 , a camera  116   a  can be mounted through a channel  117  passing through a portion of the second pipe section  112 . In this configuration, the camera  116   a  is mounted substantially flush with or recessed slightly below the interior sidewall of the first pipe section  111 , oriented to view the image diametrically opposite and through the opening of the second pipe section  112  without significantly obstructing the path through the head piece  110 . Other cameras  116   b ,  116   c  can be mounted elsewhere around the head piece  110  to assist with maneuvering the head piece  110  within the header pipe and with locating the feeder tube  12 . 
     The head piece  110  includes one or more jacks  140  having bumpers  142  that engage the header pipe  10  opposite to the feeder tube coupler  130  to press the feeder tube coupler  130  to the interior surface of the header pipe  10  to sealably couple the head piece  110  to the feeder tube  12 . The head piece  110  can include hydraulic lines  144  to supply hydraulic pressure to the jacks  140 . Hydraulic jacks are one example mechanism that can be used to achieve the necessary pressure to seal the feeder tube coupler  130  to the feeder tube  12 . In other embodiments an inflatable bladder can be used. In still other embodiments the head piece  110  can attach to the interior surface of the header pipe  10  and pull the feeder tube coupler  130  toward the feeder tube  12 . The header pipe  10  or the feeder tube  12  can be built to include a mechanism to facilitate the attachment, such as a threaded hole or a clip or some other mechanism means by which the head piece  110  can attach to the header pipe  10 . Attaching and pulling may be desirable in cases where the header pipe  10  is much larger than the feeder tube  10  such that an opposite surface is not readily available for the jacks  140  to engage. 
     There are many factors that determine how much pressure is necessary to create a proper seal to the feeder tube  12 . In some embodiments, such as header/feeder pipes used by oil refineries, the pressure in the header pipe can be up to 600 psi. So in order to create an adequate seal to the feeder tube  12 , the feeder tube coupler  130  must withstand the required pressure with an appropriate safety margin to create a seal adequate to deliver a PIG or other inspection devices through into the feeder tube and back. 
       FIG. 4  is a top plan view of the head piece  110  according to embodiments of the present disclosure. In this embodiment, there are four cameras  116 : one camera  116   a  positioned at the center of the second pipe section  112  and feeder tube coupler  130 , one camera  116   b  positioned in line with the longitudinal axis of the head piece  110 , and two cameras  116   c  spaced laterally from the center camera  116   a . Other camera positions are possible, and any suitable number of cameras can be used based on the particular needs of a given installation.  FIG. 4  also shows the hydraulic lines  144  for the jacks  140 . The lines can be connected to a valve  143  having a purge port  145  to distribute the hydraulic pressure to the jacks  140 . The head piece  110  can have two jacks  140  positioned on either side of the feeder tube coupler  130 . In other embodiments, the head piece  140  can include a single jack  140  aligned with the feeder tube coupler  130 , or offset therefrom. In still further embodiments, the head piece  110  can include three or more jacks  140 . 
       FIG. 5A  is an exploded illustration of a jack  140  for the pipe inspection tool  100  according to embodiments of the present disclosure. The jack  140  can include first and second endplates  146   a ,  146   b , first and second tube engaging members  147   a ,  147   b , bumpers  142 , and extendible arms  148 .  FIG. 5B  shows front and side views of these same components in an assembled configuration with the tube couplers  147   a ,  147   b  bolted together, and with the arms  148  coupled to the end plates  146   a ,  146   b . The first tube engaging member  147   a  can be attached to the first end plate  146   a  via a connecting member  149 . The arms  148  can be fixedly attached to the end plates  146   a ,  146   b , and can pass through holes in the tube engaging members  147   a ,  147   b . The bumper  142  can be fixed to the second end plate  146   b . When the jack  140  is actuated the arms  148  extend and cause the second end plate  146   b  to move away from the second tube engaging member  147   b  to press the feeder tube coupler  130  against the feeder tube  12 . The jack  140  can be hydraulic and can receive pressurized fluid from the lines  144  shown in  FIG. 4  through a port  151 . The pressure necessary to create the seal between the feeder tube coupler  130  and the feeder tube  12  can be provided by other equivalent mechanisms, such as an inflatable bladder, solenoid, scissor jack, or another mechanical or electromechanical device. 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, in place of cameras to position the head piece other telemetry equipment can be used, including sonar or a mechanical sensor. Also, the angle at which the feeder tube extends from the header pipe can be virtually any angle. The environment in which the inspection tool of the present disclosure is used can be any environment having a pipe or other component that is difficult to access and where PIGs cannot be used. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.