Abstract:
A system for internally filling a joint or other discontinuity in a pipeline. The system includes a flexible conduit, a fill device removably connected to said flexible conduit, wherein the fill device is constructed and arranged to apply a fill material to an interior surface of said pipeline to fill one or more gaps in the pipeline, and a propulsion unit connected to at least one of the flexible conduit and the fill device that propels the flexible conduit through said pipeline.

Description:
RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part of U.S. Ser. No. 09/337,578, filed Jun. 22, 1999, which is a continuation-in-part of U.S. Ser. No. 09/047,837, filed Mar. 25, 1998, now U.S. Pat. No. 5,913,977, each of which is incorporated herein by reference, and in addition, this application claims priority to Provisional Application 60/323,342, filed Sep. 18, 2001, which is also incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to apparatus and methods for internally treating pipeline or conduit. Particularly, this invention relates to treating, bridging, filling and or sealing pipe joints or other discontinuities in situ in a variety of different types of pipeline or conduit, such as live propane, live natural gas, water or sewer pipeline. Even more particularly, this invention relates to internally, milling, filling and sealing pipe joints or other discontinuities in live propane or natural gas pipeline, and the automation thereof.  
         BACKGROUND OF THE INVENTION  
         [0003]    A dilemma has arisen in the gas and gas transportation industry. Low-moisture gas, such as propane or natural gas, has replaced high-moisture manufactured gas, such as coal gas, as a source of domestic and industrial fuel. Traditionally, and for many decades, coal or other high-moisture gases were fed to customers by underground pipes. Typically, these gas pipelines were constructed of individual lengths of pig or cast iron pipe. These individual lengths of pipe were commonly joined together by bell or lap joints that were sealed with a combination of a filler material and lead or grout.  
           [0004]    Several different types of filler material were used including horsehair, yarn, jute and hemp. It was discovered that, as many municipalities converted from high-moisture manufactured gas to the relatively low-moisture propane or natural gas, the filler material in the pipe joints would dry out. As these filler materials dry out, they decompose and disintegrate, thereby causing gas leaks to appear at the pipe joints.  
           [0005]    The decay of joint filler due to the conversion to low-moisture gas is not unique to the United States. The United Kingdom is experiencing similar decay of their gas pipe joint filler. As a preventative measure, and as an attempt to slow down the decay of filler material, many gas companies in the United Kingdom, and a few in the United States, routinely “fog” their gas lines. Fogging normally involves sending a glycol type product through the gas pipeline to enhance the moisture content of the filler. Another method of maintaining high moisture in the filler involves a process known in the gas industry as humidification. This process requires repeated application of pressurized steam to a gas pipe system.  
           [0006]    Unfortunately, these preventative procedures are only temporary, and can be quite costly. Today, to adequately prevent gas from escaping these types of pipelines, the pipe joints or other discontinuities must be sealed or replaced. Because many of these pipelines are underground and not readily accessible, excavating, removing and replacing an entire length of pipeline having deteriorated pipe joints is drastic and quite costly.  
           [0007]    Other pipeline joints and discontinuities, such as those that exist in water and sewer pipelines, also require periodic treatment to prevent materials from leaking into or out of the pipeline. These leaks are a result of decaying materials such as the material used in the construction of the pipeline, certain types of obstructions or debris which may clog a pipeline, chemical exposure and or crushing due to overburden pressure. Many pipelines require repair to prevent exterior leaking and possible ground water contamination. Additionally, without proper treatment, ground water can infiltrate into the broken pipelines. Further, in water pipelines, obstructions, cracks or other discontinuities can cause areas of reduced water flow, which can result in undesirable bacterial growth.  
           [0008]    Today, to adequately prevent gas or liquid from escaping or penetrating these types of pipelines, the pipe joints or other discontinuities must be sealed or replaced. As described above, because many of these pipelines are also underground and not readily accessible, excavating, removing and replacing an entire length of pipeline having deteriorated pipe joints is drastic and quite costly.  
           [0009]    One method of sealing these pipe joints or discontinuities against gas leaks includes excavating an end of the pipe and having someone climb into the pipe to hand apply a coating compound. This method can be quite expensive and time consuming. Also, this method can be dangerous and is unfeasible for small diameter pipe. Another technique includes inserting a permanent lining throughout the entire length of pipe. Again this is quite costly and may cause an unacceptable reduction in the flow capacity of the pipe. Also, this method requires a large consumption of natural resources to fabricate a lining for an entire length of pipe, when typically only the joints are susceptible to leaking.  
           [0010]    Still another method, such as U.S. Pat. No. 4,178,875 (1979, Moschetti), includes sending a device through the pipe that can remotely detect a joint or other discontinuity that needs repair. A coating material is then sent through attached tubing and is sprayed onto the inner surface of the pipe at the desired location. However, this and the above-mentioned methods are not performed on “live gas pipe” (pipe in which pressurized gas remains flowing). These methods require the gas flow to be shut down for long periods of time. Depending on the customers being serviced by the gas line, it is normally unacceptable to interrupt service for such long periods of time. Another disadvantage of these methods is that they require more than a single excavation when coating long lengths of pipeline.  
           [0011]    Still other methods are known whereby the gas remains live while coating, repairing or sealing is accomplished. U.S. Pat. Nos. 4,582,551 and 4,627,471 (1986, Parkes et al.) disclose a method and device that can remotely seal joints or leaks in a pipe while the gas continues flowing in the pipe. The device is inserted into a pipe whose inner diameter is slightly larger than the outer circumference of the device. The device uses expandable bladders to form a substantially air-free environment, thereby isolating the joint or discontinuity from pressurized gas. The pressurized gas is rerouted through the interior of the device. Anaerobic sealant is then pumped to the device and the sealant is sprayed onto the interior of the pipe at the desired location. The device remains in place long enough to allow the anaerobic sealant to setup. A disadvantage with this device is that it requires an environment free from air and flowing pressurized gas in which to apply sealant. Another disadvantage with these types of devices is that they are limited in their ability to maneuver around comers or other obstacles in the pipeline as they are in close proximity to the interior of the pipe. Still another disadvantage with these devices is that they are slow and time consuming because they require the device to remain in place while the sealant sets.  
           [0012]    Another method of sealing pipe joints in a live gas pipe is taught in U.S. Pat. No. 5,156,886 (1992, Kitson). This method involves inserting a nozzle attached to a hose through a tapping mandrel to a desired location in a live gas pipe, whereby an anaerobic sealant is pumped through the hose to the nozzle. The nozzle sprays the anaerobic sealant onto the interior of the pipe. This method works well on relatively short lengths of pipe. However, as the length of tubing increases, the viscosity of the anaerobic sealant prevents it from reaching the spraying device in adequate quantities. Also, as the length of tubing increases, static electric charges build up in the line due to the friction caused by the sealant rubbing against the interior of the tubing. This can pose serious problems when working in a live gas setting. Another drawback with this device is that the anaerobic sealant tends to pool in the bottom of the pipe upon application. An additional drawback of this method is that it typically requires the presence of some filler to properly seal a leaking joint. Because the above-mentioned preventative or fogging measures were never routinely performed in the United States, much of the filler in United States gas pipe joints has disintegrated, making this method of sealing pipe joints impractical.  
           [0013]    What is needed is an apparatus and method for coating or sealing the interior of very long lengths of underground pipe or other conduit, either at a joint, another type of discontinuity or along the entire length of the pipe, while the gas in the pipe remains live, that overcomes drawbacks of prior art devices.  
         SUMMARY OF THE INVENTION  
         [0014]    It is an object of the present invention to provide an apparatus and method for coating or sealing the interior of very long lengths of underground pipe or other conduit, either at a joint, another type of discontinuity or along the entire length of the pipe, while the gas in the pipe remains live.  
           [0015]    It is still another object of the present invention to allow for several layers of coating material to be applied at the same site.  
           [0016]    It is a further object of the present invention to provide a rapid coating process, which does not require the coating device to remain in place while the coating material sets.  
           [0017]    It is a further object of the present invention that it can be inserted into a live gas pipe using a variety of methods.  
           [0018]    It is a further object of the present invention that it can maneuver around bends and other obstacles normally found in gas pipe. It is still a further object of the present invention that it applies a polyurethane sealant that will coat the interior of a variety of different pipe surfaces, with or without the presence of pressurized gas, with or without the presence of air or oxygen and that will not pool in the bottom of the pipe upon application.  
           [0019]    It is still a further object of the present invention to provide for repair of several hundred feet of live underground pipe from a single excavation point.  
           [0020]    One or more of these objects is achieved in one aspect of the invention by providing an apparatus and a method for coating or sealing the interior of underground pipes where the apparatus is moved through the pipe while the gas is flowing. The coating device is connected to reservoirs of coating material and is specially designed to operate in the presence of propane or natural gas without incident. In addition, an epoxy-type coating material is utilized that will adhere to a variety of surfaces and that will set-up within a variety of climates, including a pressurized live gas environment. In one embodiment, the sealant material is a 100% solids system that does not rely on evaporation for curing.  
           [0021]    To prevent electric discharge caused by friction, resulting from the individual components of coating material traveling to the coating device, the coating material components can be pumped to the coating device through grounded tubing. This makes the device safer to operate in a live gas environments.  
           [0022]    The device can also include scissor-type expansion legs. These scissor-type legs allow the device to maneuver around corners and bends in the pipe, and to adapt to a wide variety of pipe diameters. Also, the combination of a non-conductive or electrically grounded delivery system with a specially designed pushing system, allow greater lengths of pipe to be sealed or repaired with fewer excavations than known related art devices and techniques.  
           [0023]    Embodiments of the present invention provide an economically feasible method of repair that allows indefinite postponement of the replacement of thousands of miles of gas pipeline, thereby preserving the enormous quantities of natural resources that would be required to fabricate replacement pipe. As many of these pipe joints and other discontinuities are sealed, the loss of natural or propane gas will be greatly reduced, as will the consumption of enormous amounts of glycol and other joint filler preserving compounds.  
           [0024]    Other embodiments of the present invention comprises an automated system for pretreating a section of pipeline, removing an amount of debris there from, filling or bridging a gap, joint or other discontinuity found therein, and sealing the same as described herein.  
           [0025]    A particular aspect of the invention is directed to a system for internally filling a joint or other discontinuity in a pipeline. The system includes a flexible conduit, a fill device removably connected to the flexible conduit, wherein the fill device is constructed and arranged to apply a fill material to an interior surface of said pipeline to fill one or more gaps in the pipeline, and a propulsion unit connected to at least one of the flexible conduit and the fill device that propels the flexible conduit through said pipeline.  
           [0026]    The fill device can include a center carriage and at least one scraper coupled to the center carriage and constructed and arranged to contact an inner surface of the pipeline to move debris on the inner surface. The at least one scraper can be moveably mounted to the center carriage and constructed and arranged to be moveable between a retracted position and an activated position. The at least one scraper can be a plurality of scrapers. The system can further include an entry unit, coupled to the flexible conduit and coupled to the propulsion unit that is constructed and arranged to mate with a live pipeline. The fill device can be constructed and arranged to spray foam for filling gaps in a pipeline, and to spray a sealant to seal a gap in a pipeline. The fill device can be constructed and arranged to spray fill material in the presence of pressurized gas in the pipeline. The fill device can include a carriage having a first end and a second end, a spraying mechanism detachably connected to the first end of the carriage, and a plurality of adjustable legs, each having a first end and a second end, the first end connected to said carriage, and the second end constructed and arranged to contact an inner surface of the pipeline.  
           [0027]    Another aspect of the present invention is directed to a method for internally filling a joint or other discontinuity in a live pipeline. The method includes attaching an insertion duct to the pipeline, inserting a filling unit through the insertion duct into the pipeline, the filling unit having a spraying mechanism to spray foam to fill the joint or discontinuity, orienting the filling unit in the pipeline adjacent to the joint or other discontinuity to be filled using a flexible conduit operatively attached to the filling unit, the conduit being sufficiently rigid to propel the filling unit, and the conduit being sufficiently flexible to maneuver around bends or other obstacles in the pipeline, and spraying an interior of the pipeline at a desired location with the foam. The method can include spraying a sealant over the foam and clearing debris from an area of the pipeline around the joint or discontinuity prior to spraying the foam. Clearing debris can include activating at least one scraper coupled to the filling unit to contact the interior of the pipeline. The method can further include inserting a milling device into the pipeline through the insertion unit, and operating the milling device to treat an area around the joint or discontinuity.  
           [0028]    Yet another aspect of the invention is directed to a system for internally filling a joint or other discontinuity in a pipeline. The system includes a flexible conduit, means, coupled to the flexible conduit, for applying a fill material to an interior surface of said pipeline to fill one or more gaps in the pipeline, and a propulsion unit connected to the flexible conduit that propels the flexible conduit through the pipeline.  
           [0029]    The system can further include means for scraping debris from around the joint or other discontinuity, and means for inserting the means for applying into a live gas pipeline. The system can also include means, coupled to the flexible conduit, for applying a sealant over the fill material in the pipeline, and means for monitoring application of the fill material to the interior surface. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    For a better understanding of the present invention, reference is made to the drawings, which are incorporated herein by reference, and in which:  
         [0031]    [0031]FIG. 1 is a detailed side view of a coating device and semi-flexible containment tube of one embodiment of the present invention showing the device situated inside a section of gas pipe;  
         [0032]    [0032]FIG. 2 is a cross-sectional view of the containment tube showing the different dedicated hoses, rods and tubes required for operation of the coating device shown in FIG. 1;  
         [0033]    [0033]FIG. 3 is a schematic view of an excavation site showing an exposed length of gas pipe and a bypass system that allows the gas to remain flowing in the pipe;  
         [0034]    [0034]FIG. 4 is a schematic view of an excavation site showing a section of gas pipe removed and an end cap placed on an exposed end and a gas bypass system that allows the gas to remain flowing in the pipe;  
         [0035]    [0035]FIG. 5 is a side view of a containment tube-pushing unit of the present invention.  
         [0036]    [0036]FIG. 6 is an enlarged side view of a fly drivewheel and idler wheel from the containment tube-pushing unit shown in FIG. 5.  
         [0037]    [0037]FIG. 7 is a side view of an entry unit used with embodiments of the present invention;.  
         [0038]    [0038]FIG. 8 shows the entry unit as shown in FIG. 7 attached to a gas pipe with a coating apparatus of the present invention resting within the gas pipe;  
         [0039]    [0039]FIG. 9 is a schematic view of an excavation site showing the entry unit shown in FIG. 7 attached to an exposed end of gas pip;.  
         [0040]    [0040]FIG. 10 is a schematic view of an excavation site showing the containment tube pushing unit shown in FIG. 5 attached to the entry unit as shown in FIG. 7.  
         [0041]    [0041]FIG. 11 is a schematic view of an excavation site showing a split sleeve dresser entry unit of one embodiment of the present invention attached to a gas pipe;  
         [0042]    [0042]FIG. 12 is a schematic view of an excavation site showing the containment tube-pushing unit shown in FIG. 5 attached to the split sleeve dresser shown if FIG. 11;  
         [0043]    [0043]FIG. 13 is a perspective view of a device in accordance with another embodiment of the present invention with scraper blades in an activated state;  
         [0044]    [0044]FIG. 14 is a second perspective view of the device of FIG. 13;  
         [0045]    [0045]FIG. 15 is a perspective view of the device of FIG. 13 with the scraper blades in a retracted position;  
         [0046]    [0046]FIG. 16 is a second perspective view of the device of FIG. 13 with the scraper blades in the retracted position;  
         [0047]    [0047]FIG. 17 is a perspective view of the device of FIG. 13 with extension legs and the scraper blades in an insertion mode;  
         [0048]    [0048]FIG. 18 is a second perspective view of the device of FIG. 13 with the extension legs and the scraper blades in the insertion mode;  
         [0049]    [0049]FIG. 19 is a close-up view of a hinge mechanism of the device of FIG. 13;  
         [0050]    [0050]FIG. 20 is a second close-up view of the hinge mechanism of the device of FIG. 13;  
         [0051]    [0051]FIG. 21 is a third close-up view of the hinge mechanism of the device of FIG. 13;  
         [0052]    [0052]FIG. 22 is a fourth close-up view of the hinge mechanism of the device of FIG. 13;  
         [0053]    [0053]FIG. 23 is a fifth close-up view of the hinge mechanism of the device of FIG. 13;  
         [0054]    [0054]FIG. 24 is a flow chart of a sealing and filling process in accordance with one embodiment of the present invention;  
         [0055]    [0055]FIG. 25 is a cross-sectional view of a pipeline that has been treated using the process of FIG. 24;  
         [0056]    [0056]FIG. 26 is a perspective view of a milling device in accordance with one embodiment of the present invention;  
         [0057]    [0057]FIG. 27 is a second perspective view of the milling device of FIG. 26.  
         [0058]    [0058]FIG. 28 is a third perspective view of the milling device of FIG. 26;  
         [0059]    [0059]FIG. 29 is a fourth perspective view of the milling device of FIG. 26;  
         [0060]    [0060]FIG. 30 is a perspective view of a combination milling and sealing device in accordance with one embodiment of the present invention; and  
         [0061]    [0061]FIG. 31 shows a diagram of a controller coupled to an umbilical in accordance with one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0062]    One embodiment of the present invention will now be described with reference to FIGS.  1 - 12 . Referring now to FIG. 1, a coating device, generally designated by numeral  10 , is shown located resting on an inside surface  12  of a pipe  14 . The coating device  10  is provided with a centering carriage  20 . The centering carriage  20  has a front end  16  and a rear end  18 . A manifold  82  is attached to the rear end  18 . A containment tube  60  is shown attached to manifold  82 . An air motor  38  is mounted inside the front end  16  of centering carriage  20 . Air motor  38  turns a rotating slotted head  40 . A static mixer  50  is fixed to the side of centering carriage  20 . Individual coating material components are sent to the static mixer  50  through intake tubes  86  and  88  where they are thoroughly mixed to produce a coating material  48 . The coating material  48  is then sent through an outlet tube  32  where it is forced into a spray tip  36 . Spray tip  36  then meters an appropriate amount of coating material  48  into rotating slotted head  40 , which centrifugally disperses coating material  48  onto the inside surface  12  of pipe  14 .  
         [0063]    The centering carriage  20  is provided with a plurality of adjustable-length scissor-type expansion legs  22  for support. Each scissor-type expansion leg  22  is attached to a compressed gas powered piston  58 , which is mounted inside the rear end  18  of centering carriage  20 . Wheel assemblies&#39;  28   a  and  28   b  are attached to the ends of the adjustable-length scissor-type expansion legs  22 . The wheel assemblies  28   a  and  28   b  are shown in contact with the inside surface  12  and allow for lateral movement of coating device  10  through pipe  14 . The scissor-type expansion legs  22  are shown having four hinged members  24 ,  26 ,  28 , and  30 . The number of hinged members may be increased or decreased to accommodate different diameters of pipe  14 .  
         [0064]    An illuminating explosion-proof monitoring camera probe  44  is attached to centering carriage  20 , by way of a monitoring probe mount  34 . An explosion-proof camera probe cable  70  is attached at one end to the illuminating explosion-proof monitoring camera probe  44  and at the other end to a control console. The illuminating explosion-proof monitoring camera probe  44 , which is powered by the explosion-proof camera probe cable  70 , is positioned to allow an operator to locate sections of pipe  14  that require treatment by the coating device  10 . The explosion-proof monitoring camera probe  44  lights the inside surface  12  of pipe  14 , and relays images of the inside surface  12  back to the control console.  
         [0065]    As the coating device  10  is progressed laterally through pipe  14  an operator is able to monitor joints or other discontinuities by viewing a monitor on the control console. The operator can remotely control the application of coating material  48  to the inside surface  12  of pipe  14 . Upon discovery of a joint or discontinuity, a specific amount of coating material  48  is metered onto inside surface  12 .  
         [0066]    In one embodiment, a preferred coating material  48  is two-part epoxy-type elastomeric polyurethane sold under the name PLASITE PERMA-THANE 2300. Coating material  48  is capable of filling and coating large joints or other discontinuities. Coating material  48  can be used in a variety of environments including pressurized gas, air or oxygen. Depending upon the desired thickness of coating material  48  required, an operator can reposition coating device  10  and repeat the coating process described above.  
         [0067]    Referring now to FIG. 2, a cross-sectional view of containment tube  60  is shown. Containment tube  60  houses non-conductive sealant component hoses  62  and  64 , compressed gas hoses  66 ,  68  and  78 , sealed explosion-proof camera probe cable  70 , exhaust hoses  72  and  74 , and an optional flexible stabilizing rod  80 . Containment tube  60  serves to protect the various hoses, tubes and rods it surrounds from abrasion. Also, containment tube  60  is flexible enough to maneuver around tight comers and bends in pipe, and is rigid enough to provide for the lateral movement of the coating device  10  in long lengths of pipe. Additionally, containment tube  60  serves to exhaust the gas used to power the air motor  38  and operate the scissor-type expansion legs  22  outside pipe  14 .  
         [0068]    The non-conductive sealant component hoses  62  and  64  provide the individual coating material components to the intake tubes  86  and  88 , respectively. The compressed gas hose  66  provides compressed gas for manipulating piston  58 , which controls the expansion and contraction of the scissor-type expansion legs  22 . Compressed gas hose  68  is used for powering air motor  38 , which in turn powers slotted spray head  40 . The sealed explosion-proof probe cable  70  is used for powering, lighting and receiving information from explosion-proof monitoring probe  44 . Exhaust hose  72  exhausts the compressed and other gases outside pipe  14 . Compressed gas hose  78  supplies compressed gas for purging any unused sealant  48  from the coating device  10 . The optional flexible stabilizing rod  80  provides for additional rigidity within containment tube  60  and allows for additional lateral force to be applied to the coating device  10 .  
         [0069]    Referring now to FIG. 3, a schematic view of an excavated section of live gas pipe  14 , having a first section  202  and a second section  204  is shown. Tap holes  212  and  214  are drilled in sections  202  and  204  respectively. Next, a temporary bypass  210  is connected between drilled holes  212  and  214  to allow the gas to remain flowing in pipe  14  while a section is removed to allow for the insertion of coating device  10 . The temporary by-pass  210  is equipped with a pressure gauge  216  and a shut-off valve  218 .  
         [0070]    Holes  222  and  224  are drilled, tapped and plugged in section  202  and holes  226  and  228  are drilled, tapped and plugged in section  204  of the excavated section of live gas pipe  14 , between the drilled holes  212  and  214 . The plugs are then removed from the drilled holes  222 ,  224 ,  226  and  228 , and inflatable bladders  232 ,  234 ,  236  and  238  are inserted through the drill holes  222 ,  224 ,  226  and  228  respectively.  
         [0071]    Inflatable bladders  232  through  238  are inflated to create a gas impermeable seal within pipe  14 . Depending upon the pressure and the direction of the gas flowing in pipe  14 , fewer or additional inflatable bladders may be employed to control the flow of gas in pipe  14 . Opening the shut-off valve  218  diverts the flow of gas in pipe  14  through the temporary by-pass  210 . With inflatable bladders  232 ,  224 ,  226  and  238  still inflated, a length of pipe located between inflatable bladders  234  and  236  is removed.  
         [0072]    Referring now to FIG. 4, the now exposed end  206  of section  202  is shown sealed off with cap  248 . Inflatable bladders  232  and  234  may then be removed without allowing gas to escape from pipe  14 . The gas in pipe  14  continues to flow through temporary by-pass  210 .  
         [0073]    Referring now to FIG. S a pushing unit  150  is shown. FIG. 5 shows pushing unit  150  having a first end  156 , a second end  158 , and an outside surface  160 . Pushing unit  150  controls the movement of containment tube  60  in pipe  14 , which in turn controls the lateral movement of coating device  10 . A power mechanism  154  is attached to outside surface  160 . A control mechanism  152  is operatively connected to power mechanism  154  and controls the rate at which power mechanism  154  operates. Containment tube  60  is shown entering pushing unit  150  through first end  156  and exiting pushing unit  150  through second end  158 . A plurality of flywheels  162  are powered by power mechanism  154  and operate to maneuver containment tube  60  through pushing unit  150  and into and out of pipe  14 .  
         [0074]    [0074]FIG. 6 shows an enlarged side view of a single flywheel  162 , having a curved inner surface for receiving containment tube  60 .  
         [0075]    Referring now to FIG. 7 a side view of a preferred insertion duct  240  is shown. Insertion duct  240  has a first end  242  and a second end  244 . Insertion duct  240  is fitted with a gate-valve  246  in second end  244 . Gate valve  246  closes to form a gas impermeable seal about containment tube  60 , which permits containment tube  60  to pass through it while preventing gas from escaping from pipe  14 . Insertion duct  240  is shown having a preferred curve shape. This design facilitates the insertion of containment tube  60  and coating device  10  into pipe  14  and allows for a smaller section of pipe  14  to be removed. A straight or other shaped insertion duct may also be used.  
         [0076]    Referring now to FIG. 8 insertion duct  240  is shown attached to a section of gas pipe  14 . Coating apparatus  10 , as shown in FIG. 1, is shown situated in pipe  14 .  
         [0077]    Referring now to FIG. 9, second end  244 , of insertion duct  240 , is shown bolted or otherwise fastened to the now exposed end  208  of pipe  14 .  
         [0078]    Referring now to FIG. 10, second end  158 , of pushing unit  150 , is shown attached to first end  242  of insertion duct  240 . Prior to bolting or otherwise fastening pushing unit  150  to insertion duct  240 , containment tube  60  is inserted through pushing unit  150  and attached to coating device  10 . Coating device  10 , attached to containment tube  60 , is then inserted into first end  242  of insertion duct  240 , through gate-valve  246  and into pipe  14 . Second end  158  of pushing unit  150  is then secured to first end  242  of insertion duct  240 . After pushing unit  150  is secured to insertion duct  240  inflatable bladders  236  and  238  are deflated and removed and drill holes  226  and  228  are plugged.  
         [0079]    An operator can then laterally relocate coating device  10  hundreds of feet down pipe  14  away from section  204  to a desired location with control unit  152 . Control unit  152  adjusts the rate of speed of power mechanism  154 , which in turn controls the speed of flywheels  162 . Flywheels  162  feed containment tube  60  into pipe  14 , which laterally moves coating device  10 . The operator can then monitor the inside surface  12  of pipe  14  using the images sent back along explosion-proof camera probe cable  70  from the explosion-proof monitoring camera probe  44 .  
         [0080]    Once a joint or other discontinuity has been located the operator may then remotely apply coating material  48 . The operator controls the thickness of coating material applied to inside surface  12  by controlling both the rate of lateral movement of coating device  10  and by controlling the flow rate of the individual sealant components. When the operator has finished coating and sealing a section of pipe  14  with coating material  48 , the static mixer  50 , the spray tip  36 , the outlet tube  32  and the rotating slotted head  40  may be purged of coating material  48  by forced compressed gas provided by compressed gas purging line  78 .  
         [0081]    Once the desired length of pipe  14  leading away from section  204  is sealed, pushing unit  150 , insertion duct  240  and coating device  10  are removed in reverse order as above-described and an end cap  248  is placed over exposed end  208 .  
         [0082]    To seal the length of pipe  14 , leading away from exposed end  202 , drill holes  236  and  238  are unplugged and inflatable bladders  236  and  238  are reinserted and inflated. End cap  248  is removed from section  202  of pipe  14  and insertion duct  240  is mounted to exposed end  206  in its place. Coating apparatus  10  is then inserted into section  202  and pushing unit  150  is attached to insertion duct  240 . The inspection and treating procedure is the same as described above.  
         [0083]    Referring now to FIGS. 11 and 12, a second method is revealed for inserting coating device  10  into live gas pipe  14 . FIG. 11 depicts an excavated section of live gas pipe  14 . A two-piece split-sleeve dresser  110 , having a first end  102  and a second end  104 , is put in place and bolted around the outer circumference  24  of a section of live gas pipe  14 . Angled sections  106  and  108 , containing gate valves  126  and  128  respectively, are then attached to an outer surface  120  of the split-sleeve dresser  110 .  
         [0084]    [0084]FIG. 12 shows pushing unit  150  attached to angled section  106 . Pushing unit  150  controls the lateral movement of coating device  10  in the same manner as described above. Once the desired length of pipe  14  has been treated and inspected using coating device  10 , then the coating device may be removed from pipe  14 .  
         [0085]    Prior to the attachment of pushing unit  150 , a drilling unit is mounted to a faceplate  132  of angled section  106 . Gate valve  126 , located within angled unit  106 , is opened as the drilling unit drills a hole  142  (not shown) through the two-piece split-sleeve dresser  110  and into pipe  14 , at the point where angled section  106  and split sleeve dresser  110  intersect. Hole  142  is large enough to allow coating device  10 , attached to containment tube  60 , to be inserted into pipe  14 . Gate valve  126  is then closed and the drilling unit is removed.  
         [0086]    Containment tube  60  is threaded through pushing unit  150  and attached to coating device  10 . Coating device  10  is then inserted into angled section  106 . Second end  158  of pushing unit  150  is then bolted or otherwise fastened to face plate  132  of angled section  106 . An inflatable packing gland  138  is then inserted into pushing unit  150  and is positioned around containment tube  60 , to form a gas impermeable seal. Inflatable packing gland  138  prevents gas from escaping pipe  14  while allowing containment tube  60  to pass through hole  142  into pipe  14 . Once inflatable packing gland  138  is in place, gate valve  126  is opened and coating device  10  is pushed through hole  142  and into pipe  14 .  
         [0087]    A length of gas pipe section leading away from split sleeve dresser end  104 , may be inspected and treated in the same manner as described above. First, an operator relocates the coating device  10  the desired distance down pipe  14 . The operator then maneuvers the coating device  10  back to the split sleeve dresser  110  inspecting and coating joints or other discontinuities along the way. After the section of pipe leading away from split sleeve dresser end  104  has been treated, the coating device  10  is returned to angled section  106 . Gate valve  126  is closed and the pushing unit  150  is removed. A cap  136  (not shown) is then bolted or otherwise fastened to face plate  132 .  
         [0088]    In order to inspect and treat the section of gas pipe extending away from split sleeve dresser end  102 , a hole  144  (not shown) similar to hole  142 , is cut into pipe  14 , within angled section  108  and through the two-piece split-sleeve dresser  110 . Hole  144  is large enough to allow coating device  10 , attached to containment tube  60 , to be inserted into pipe  14 . Coating device  10  is then inserted through angled section  108  through hole  144  and into pipe  14 . After the section of gas pipe extending away from split sleeve dresser end  102  has been inspected and treated, and coating device  10  has been removed, a cap  146  (not shown) is secured to face plated  134 . After both sections of pipe  14 , leading away from the split sleeve dresser  110  have been inspected and treated, and angled sections  106  and  108  have been capped, the split sleeve dresser  110  is left in place and the excavation is filled in.  
         [0089]    Depending upon the amount of build up of debris on inside surface  12  of pipe  14 , a cleaning device may be attached to containment tube  60  and fed through pipe  14  using the same methods as described above to recondition the pipe. Preferred cleaning devices are self-centering, powered by compressed air, and are explosion proof. After reconditioning, the cleaning device is removed to allow for the insertion of coating device  10 .  
         [0090]    In embodiments described above, a self-propelled coating device is inserted in pipeline to seal discontinuities in pipelines. The embodiments described above are particularly useful for sealing relatively small discontinuities in pipelines. As will now be described, in additional embodiments of the present invention, apparatus and processes are provided that are particularly useful for filling larger dimension and unique gaps. At seams in pipelines, relatively large gaps can form. When multiple coats of sealant are applied to large gaps, an effect known as telegraphing can occur where the crack gets deeper without the sealant ever filling it or bridging across it. In embodiments of the invention described below, prior to the application of sealant to a gap, a filler is applied to the gap, allowing the sealant to smoothly bridge the gap. Further, in embodiments described below, using apparatus of the present invention, debris can be removed from a pipeline prior to the application of filler and/or sealant for the purpose of exposing the pipe wall in order to provide a surface for adhesion and sealing.  
         [0091]    Referring to FIGS. 13 and 14, a debris mover and gap-bridging device  310  in accordance with one embodiment of the present invention will now be described. The device  310  may be coupled to a containment tube (also referred to herein as an umbilical) and propulsion device, like those described above, to allow the device  310  to be inserted into and propelled through a pipeline. The device  310  includes a centering carriage  320  having a front end  316  and a rear end  318 . The manifold of a containment tube, like manifold  82  described above, couples to the rear end  318 . The device also includes three adjustable-length scissor-type expansion legs  322 , a spray head  336 , blade actuators  331 , a laser  335 , a camera  337 , and scraper blades  339 ,  341  and  343 . In addition, as understood by those skilled in the art, control cables (not shown for clarity) extend from the umbilical to devices mounted on device  310  for monitoring and controlling the devices.  
         [0092]    The expansion legs  322  are similar to expansion legs  22  described above and operate in the same manner to provide support for device  310  in a pipeline and to center the device in the pipeline. As in the previous embodiments, the expansion legs are retractable to facilitate insertion of the device into a pipeline. The expansion legs are shown in an expanded state in FIGS. 13 and 14 and in a retracted state in FIGS. 17 and 18.  
         [0093]    The spray head is coupled to the centering carriage  320  using a motor/rotary union  317  that in one embodiment provides for 360-degree rotation of the spray head in a single rotational direction. In other embodiments, the motor/rotary union can reciprocate, rotating in one direction and then the other. The laser  335  and camera  337  are mounted to the spray head. The camera is coupled through the containment tube to a controller mounted outside of the pipeline to provide an operator with images of the interior of a pipeline, and the laser, also controlled by the controller, is used to provide illumination of the interior of the pipeline. Electrical signals and power for the spray head are provided though a slip-ring built into the rotary union.  
         [0094]    Each of the scraper blades  339 ,  341  and  343  are coupled to two of the expansion legs using first hinges  346  for one end of the blades and second hinges  348  for the other end of the blades. The first hinges  346  are coupled to one of the actuators  331  though a piston. The actuators use the pistons to move the scraper blades between a folded position shown in FIGS. 15 and 16 and the activated state shown in FIGS. 13 and 14. In the embodiment shown in FIGS.  13 - 16 , each of the scraper blades includes two rows of teeth  358  mounted on a frame  360 . The scraper blades are sized such that in the activated state, the three blades combine to form a substantially circular scraper having an outer diameter that is approximately equal to the inner diameter of a pipeline. In one embodiment, the material used to make the blades is stainless steel spring steel, and the blades are manufactured by cutting the tooth pattern from flat stock stainless steel, and then bending up the teeth and spring tempering the blades.  
         [0095]    When the expansion legs are in the retracted state, as shown in FIGS. 17 and 18, the scraper blades become further bent to allow the device  310  to be inserted into pipelines using an insertion tube having a diameter smaller than the diameter of the pipeline. In one embodiment of the present invention, an insertion device having a diameter of 12 inches is used for pipelines having inner diameters from 16 to 24 inches, so the device  310  is collapsible to a diameter much smaller than the pipeline for which it is designed for use. The thin stainless steel used for the frame  360  and separable teeth  358  allows the scraper blades to have sufficient rigidity when activated yet be flexible enough to bend inward with the retraction of the expansion legs. The flexibility of the scraper blades is also advantageous in the activated states in that it allows the scraper blades to bend with the expandable legs to adjust for non-uniform pipes.  
         [0096]    The operation of the activators  331  and associated hinges  346 ,  348  for moving the scraper blades will now be discussed with reference to FIGS.  19 - 23 , which provide partial, close-up views of the activators and hinges. In FIG. 19, the device  310  is in the insertion mode with the legs in the retracted state and the scraper blades retracted and bent, in FIG. 20, the device  310  is in the travel state with the legs extended and the blades retracted, and in FIG. 21, the device  310  is in the scrape mode with the legs extended and the scraper blades in the activated state. With reference to FIG. 19, each actuator  331  is coupled to a piston  362 , which in turn is rotatably coupled at a first pivot point  370  to a first section  366  of one of the first hinges  346 . The first section  366  of the first hinge  346  is coupled to a second section  368  of the first hinge  346  at a second pivot point  372 . Each scraper blade is coupled to the second section  368  of the first hinge. The first hinge  346  is coupled to the leg  322  using a mounting block  364 . The first hinge is coupled to the mounting block  364  using a screw  371 , which also functions as a third pivot point for the first hinge. Each mounting block  364  supports the first hinge for one scraper blade and the second hinge for an adjacent scraper blade. Each of the second hinges (as best seen in FIG. 22) includes a first section  376  and a second section  378 . The second hinges are substantially identical to the first hinges, except that the second hinges are not coupled to an actuator through a piston.  
         [0097]    The actuators and hinges operate to control the scrapers as follows. The actuators  331  are coupled to the controller outside of the pipeline through air lines (not shown). The actuators have a retracted position and an extended position, and in one embodiment of the invention, the actuators are implemented using an air cylinder actuator, such as that manufactured by Festo Corporation of Hauppauge, N.Y., under part no. DZF-1/2-1-A-PA. In the insertion state and in the retracted/travel state of the device  310 , the actuators are in the retracted position as shown in FIGS. 19 and 20, while in the activated state of the device  310 , the actuators are in the extended position. In the insertion state, the combination of the flexibility of the scrapers and the tension on the scrapers caused by the folding of the expansion legs, causes the scrapers to be retracted and bent, so that the device can be inserted into a pipeline. In this state, as shown in FIG. 19, the first section  366  of hinge  346  is rotated to be substantially parallel with the piston  362 , and the second section  368  of the hinge  346  is rotated to be substantially parallel with the first section  366 .  
         [0098]    When the expansion legs are moved to the travel state, as shown in FIG. 20, this causes the second hinge section  368  to rotate at pivot point  372 , and also causes a slight rotation of the first hinge section  366  at point  370 . The amount of rotation that occurs is dependent on the dimensions of each of the parts, but in embodiments of the invention, when the legs are extended, the scrapers still remain retracted until the actuator is actuated. When the actuator is controlled to move to the extended position, then the piston  362  extends causing the hinge  346  to move. The force caused by the movement of the piston causes the first section  366  of the hinge to rotate at pivot point  370  and causes the second section of the hinge  368  to rotate at pivot point  372 , as shown in FIG. 21, thereby causing the scraper blade  339  to move to the extended position. In the embodiment shown, the hinge  346  rotates  90  degrees at pivot point  370 . The design of the hinges and scrapers provides for rotation of each of the scrapers using only one actuator. Rotation of the second hinges  348  are caused by the translation of the scrapers due to the extension of the pistons, as shown in FIG. 22. As shown in FIG. 23, the mounting block  364  has a stop  380  that limits the movement of the first section  366  when pushed by the piston  362 . The stop  38  is positioned to keep the second section, and therefore the scraper, perpendicular to the centerline of the device  310 . Further, during the scraping action by the scrapers on the inside wall of a pipeline, the stop  380  maintains the scraper substantially perpendicular to the centerline.  
         [0099]    The spray head  336  is configured to spray a two-part, expandable, urethane foam  360  degrees within a pipeline to fill gaps in the pipeline. In one embodiment, the spray head includes a plural-component air purge spray gun available from Gusmer Corporation of Lakewood, N.J. under the trade name GAP. In the embodiment shown in the drawings, the gun is mounted at a right angle to the centerline of the carriage to cause the foam to be sprayed on the walls of the pipe. In other embodiments, the spray gun is mounted along the centerline, and a right angle adapter is added to the output of the spray gun to cause the material to contact the inner surface of a pipe. In one embodiment, the material used with the spray head is a two part foam that is supplied to the spray head through the umbilical using two separate feed hoses, and the spray gun is designed to receive the two feed hoses and mix the final compositions within the gun. In one embodiment, the material used is available from Preferred Foam Products of Trenton, N.J., under part no. 9800-2506.  
         [0100]    Operation of the device  310  will now be described with reference to FIG. 24, which shows a process  400  of the present invention. When it is desired to fill and seal seams and other gaps in a pipeline, then at stage  402  of the process, the device  310  is first inserted into the pipeline. For a live gas pipeline, one of the procedures described above for device  10  can be used to insert device  310  into the pipeline. In one embodiment, the front of the carriage having the spray head is inserted first. After insertion of the device  310 , at stage  404 , the device is propelled some distance down the pipeline. In one embodiment, the device is propelled using the containment tube pushing unit described above, under the control of the controller. The distance that the device is propelled may be determined either based on characteristics of the pipeline, i.e. an end of the pipeline is reached, or based on the length of the umbilical cable. While propelled down the length of the pipeline, the laser and camera can be used to locate gaps to be treated.  
         [0101]    Once the device reaches the end, the propulsion system begins bringing the device back toward the insertion point, stage  406 , treating each of the seams and/or gaps along the way. When a seam is reached, stage  408 , the scraper blades are activated just prior to the seam, and debris is removed from the area just before and after the seam. Depending on the amount and type of debris at a seam, as determined by images generated by the camera, the device may be moved back and forth several time to fully scrape all debris around the seam, stage  410 .  
         [0102]    Once the debris has been removed, at stage  412 , the device is moved further towards the insertion point to align the spray head with the seam. The laser and the camera are used to properly align the spray head with the seam. After alignment, at stage  414  filler material is provided to the spray head while the spray head is rotated 360 degrees to apply filler to the seam. After full rotation, the device is slowly moved so that the spray head provides a coat of filler material from a point just on one side of the seam to a point just on the other side of the seam so that the filler material completely bridges the seam. After a coat of material has been sprayed on, at stage  416 , the camera is used to view the seam to determine if further coats of material are needed. If a determination is made that further coats are needed, then stages  414  and  416  are repeated. Once the seam has been sufficiently filled, the device  310  moves to the next seam and continues to repeat this process  420 , until the device has returned to the insertion point and is removed from the pipeline.  
         [0103]    In one embodiment of the present invention, multiple coats of filler material are provided at each gap with a first coat acting as an insulator between the pipe, which is often relatively cool, and the insulating material, which in one embodiment is applied at a temperature of approximately 120 degrees Fahrenheit. The first insulation coat allows the remaining coat(s) to properly cure and maintain a foam-like consistency.  
         [0104]    After the device  310  is removed from the pipeline, the device  10 , described above, may be inserted into the pipeline to provide sealant over the filler material to completely seal a gap. FIG. 25 shows a section of pipeline  450  having a gap  452  at a joint between a first pipe section  453  and a second pipe section  454 . The pipeline  450  been treated using the process described above. A layer of filler material  457  is shown filling the gap in the pipe and a layer of sealant  456  covers the filler material and extends past the filler material in the pipe. Also shown in FIG. 25 is a gasket  458  and filler  460 . The gasket  458  and filler  460  are representative of typical sealing materials used to seal gas pipes at the time of initial installation of a pipeline, and these typically degrade over time.  
         [0105]    In the embodiment described above, separate fill and sealant devices are provided. In another embodiment, the fill device may be configured to spray both the fill material and the sealant using one spray head or using two separate spray heads on the same device. In the situation where one spray head is used, after the fill process is complete, the lines and the spray head can be purged from the controller, and sealant can be sent to the device instead of fill material. In still other embodiments, only one material may be used to both fill and seal a gap.  
         [0106]    In embodiments of the present invention, in addition to removing debris using scrapers as described above, it may also be desirable to provide a more thorough cleaning or scraping of the interior of a pipe to ensure that the sealant properly seals the pipe. In another embodiment of the present invention, a milling device  510  is provided that can be inserted into a pipeline in the same manner as the devices  10  and  310  described above. The milling device  510 , which will now be described with reference to FIGS.  26 - 29  provides a milling operation on each side of a gap prior to the application of filler and sealer. Debris generated by the milling operation can be removed from the area to be treated using the scraper described above. In addition, in some embodiments of the invention, gas nozzles that eject jets of pressurized air (or a compatible gas in gas lines) can be used to clear debris. Still further, debris can also be cleared during a purge operation of the spray head during which gas is ejected from the head.  
         [0107]    The milling device  510 , in one embodiment of the present invention, is mounted on the centering carriage  320  of the device  310  and includes the expansion legs  322  and the motor/rotary union  317  of the device  310 . In addition, the milling device  510  includes a support bracket  512  that supports a piston  514  mounted to a telescoping assembly  516 . The piston is extendable under control of the controller to move the telescoping assembly towards the inner wall of a pipeline where milling is to occur.  
         [0108]    The telescoping assembly  516  includes a milling tool motor  518 , a chain sprocket  520 , a drive chain  522 , a base plate  524 , a side plate  526 , a milling tool  528 , and a control foot  530 . The milling tool motor  518  is mounted to the side plate  526  and is controlled by the controller, located outside of the pipeline and coupled to the milling tool motor through control lines. The chain sprocket  520  is coupled to the drive chain  522  and to the milling tool  528 , such that the milling tool is driven by the milling tool motor. The control foot, the chain sprocket and the milling tool are coupled to the base plate  524 .  
         [0109]    During operation, the piston  514  is extended under control of the motor until the milling tool contacts the inside surface of the pipeline. The motor is then turned on, and the inside of the pipeline, where sealant is to be applied, is ground down using the milling tool. The motor/rotary union  317  rotates the support bracket, and accordingly the milling tool  360 , degrees. The control foot is adjustable to set a depth of the cut by the milling tool in the pipeline. When a set depth is reached during a milling operation, the curved outer surface of the control foot contacts the inner surface of the pipeline to prevent the milling device from cutting deeper into a pipeline. In addition, many old pipes are oval rather than round in cross-section, and the foot acts as a restraint and allows the milling device to follow the nonuniform curvature of a pipe&#39;s circumference. As with devices  10  and  310 , the milling device  510  can be inserted into a pipeline, moved down the pipeline, and then treat surfaces of the pipeline as the milling device returns to the insertion point.  
         [0110]    In certain embodiments of the present invention, the sealing operations dictate that it would be more convenient, and increase quality if the joint filling and sealing operation immediately follow the debris moving operation. The reason this is important is the in situ robots would otherwise have to drive over the cleaned area and could drag a significant amount of the umbilical along with it thus depositing debris that had previously been moved from an area back into the cleaned area. Therefore having a debris mover on the in situ robot performing the sealing service is a great advantage.  
         [0111]    In one embodiment of the present invention, which will now be described with reference to FIG. 30, a combination multifunctional device  610  is provided. The device  610  includes a spray and debris moving device  612 , a milling device  614  and a tractor robot  616 . The spray and debris moving device may be implemented using device  310 , described above, modified to spray both fill and sealant, as also described above. The milling device  614  is similar to milling device  510 , except that the carriage and support bracket in the device are designed to receive the umbilical and allow it to pass through to the device  612 .  
         [0112]    The tractor robot  616  is used to pull the umbilical through the pipeline and to push devices  612  and  614  through the pipeline. The tractor robot is used with the device  610  to push the device through a pipeline in place of the push rod system described above for the other embodiments. The tractor robot provides additional propulsion that is useful when pushing the heavier combined device and can increase the range that the device can be pushed down the pipeline. In other embodiments, the device  610  may be implemented in conjunction with the push rod system so that the tractor robot is not needed.  
         [0113]    The tractor robot includes a centering chassis  622 , a front end  624 , a back end  626 , three wheel assemblies  628 , each of which is coupled to the centering chassis using folding brackets  630 , that can fold down to allow insertion of the tractor robot. The back end  626  receives an umbilical coupled to the controller located outside of the pipe line, and passes the umbilical out of the front end  624  to device  614 . The tractor robot can be propelled using a hydraulic motor or electric motor mounted in the center of the tractor robot and coupled to the wheels through flexible drive shafts mounted in or adjacent the folding bracket. In another embodiment, high-power miniature motors can be mounted directly in the wheel assemblies. Further, in still another embodiment, each set of wheels can be replaced by a track assembly.  
         [0114]    The device  610  is inserted into a pipeline and moved some distance down the pipeline. The insertion into the pipeline can be accomplished using embodiments of the invention described above, except that an extension tube may be needed for the entry system due to the length of the combined system. Specifically, referring to FIG. 10 for example, an extension tube can be inserted between insertion duct  240  and the end  158  of the pushing unit. Similarly, the insertion duct  240  could be altered to have more of a bend radius and extended. Alternatively, the excavation hole could be made larger with the tap holes moved further from the end of the pipe to provide length of pipe to insert device  610 . While moved down the pipeline, the milling tool and the scrapers are maintained in the travel mode, and are not in contact with the pipeline. The device  610  is then moved back to the insertion point, and at each gap that is to be filled, the milling tool first operates on both sides of the gap to provide a smooth surface for the sealant. Next, the scrapers on device  612  clear any debris from the area around the gap. The spray head on device  612  then sprays filler into the gap, and after spraying the filler, sprays sealant across the gap. Once all gaps have been filled and sealed, the device  610  is removed from the pipeline.  
         [0115]    In embodiments of the present invention described above, a foam filler material is used to fill gaps. The foam expands when setting up (curing) thus spreading into the gap to be filled as opposed to sagging out of it as with typical non-foaming coatings.  
         [0116]    In embodiments of the present invention, various spray tips may be used on spray heads for applying the gap bridging foam or other gap filling material. In one embodiment of the present invention, a fan tip is used. In certain other embodiments, the fan tip may be rotated with respect to the center line of the pipeline so that a wider area of material may be laid down with a single pass of the spray head.  
         [0117]    Other advantages include having a debris mover with different scrapers for different debris, enhancement of the mixing champers on the spray guns to accommodate both foam and sealant and continuous rotation of the spray nozzle or continuous rotation of the spray gun.  
         [0118]    The gas sealing operation of the present invention is designed to address the issue or problem of filling bell joint seams (gaps). Other pipe sealing applications, such as epoxy coating water pipes and grouting sewer pipes, may well benefit from this processes and apparatus of the present invention. Certainly any situation where a robot was required to inspect and/or fill a gap would consist of a potential commercial application for embodiments of the invention.  
         [0119]    In the present invention, a debris mover and a milling device work mostly in conjunction with the gap filler but both would certainly be beneficial for any service robot in a piping system which was required to perform both a debris or sediment moving operation in conjunction with the service being performed albeit—pipe wall inspection, tapping, etc.  
         [0120]    In embodiments of the present invention described above, a controller outside of the pipeline is described as controlling a number of operations of the devices inserted in a pipeline. The controller is shown in FIG. 31. In embodiments of the present invention, the controller includes various automation sensors, components, computers and software coupled with custom programming that oversees and assists in the control and application of a pipe sealing system. In one embodiment, the controller can be incorporated in a truck or trailer to facilitate moving the controller to different excavation sites. The controller automates many of the functions and aspects identified above increasing and enhancing safety, reliability, repeatability and process balance control that are both mundane and require a high skill level. In embodiments of the present invention, the controller provides a means to log entities seen through video cameras on the robot in the pipe system and conveniently save this data for future use in an electronic computer readable format as well as document the work performed by electronic video capture of before and after photos of the areas sealed. Since these operations are performed in the field, the controller also facilitates the quick transportation of the job specific data to a home office, or other facility, by e-mail since the data is in an electronic format. The home office can then quickly produce reports for distribution and archive as well as billing information in a more efficient manner than otherwise conceivable.  
         [0121]    According to one embodiment of the present invention, the controller includes sensors, transducers, motion control devices, a control computer, custom developed programming and a MMI (man-machine interface). The sensors and transducers monitor the state of the process providing data to the control program. The motion control devices send position data to the control program and receive motion instruction data from the control program allowing the control program to know the position of a driving element such as a motor as well as move the driving element a specified amount. The MMI interfaces with the operator and displays information and data from the control program on it&#39;s screen, provides the interface for data and command input to the control program and also flashes warning signals indicating a problem or inappropriate requested action. The control computer processes the inputs and outputs, runs the computer program, and writes the appropriate data to an electronic storage device. The custom developed programming contains the code that performs all the desired functions of the automation.  
         [0122]    In embodiments of the present invention, transducers, associated with the controller, can be located at desired points in the system and can transmit information to a remote indicator or control computer or a combination of both. By transmitting the sensor information to the controller&#39;s computer, the computer can then compare the information and detect and alarm a condition much quicker and more effectively than a human could manually. Since weight of the entire system is also a concern, by displaying the sensor input information on the MMI system components are eliminated or otherwise combined into one device vs. many thus minimizing the weight of the entire system.  
         [0123]    Embodiments of the present invention rely on precise motion control for the most effective application of the sealant to the pipe walls, and the automation provided by the controller enhances this process significantly and is much more effective than previously utilized manual systems. Many different factors such as pipe size, ambient conditions, substrate conditions etc. influence the operating parameters of the process and different recipes (or condition dependent operational parameters) can be stored in the controller to provide a reference for the operator to address each condition. This process is significantly streamlined with the automation, and quality control is enhanced by virtue of the automation systems ability to monitor the process more effectively than a human. Further, the controller reviews and controls, on a continual basis, flow rates, heat rates, application speeds, timing issues etc. Automation performs this task more efficiently than a human and minimizes the operator&#39;s requirements for this aspect of the process.  
         [0124]    By utilizing the controller, system quality control is enhanced in a way that is otherwise not available without significant human intervention susceptible to human error. Also the skill level requirements of an operator have been significantly reduced with the automation. Since the process of sealing pipelines deals with potential disruption of utilities and often requires supervision and labor by the owners of the utilities, anything that can reduce the amount of time to perform the service minimizes the efforts and disruption.  
         [0125]    A desired and or required aspect of the sealing services is to provide a document of the work performed. Prior to the present invention, this was typically accomplished utilizing video tape. Video tape is an effective means of documentation, however it requires sitting through the viewing of the tape and fast forwarding to the relative information and or editing the tape to overlay with text identification information. The automation system of embodiments of the present invention has the capability to capture snap shots and video while simultaneously overlaying description information critical for documentation purposes. Manual editing or editing of the video while the service is performed is labor intensive and detracts from the service or requires additional labor.  
         [0126]    The controller in embodiments of the present invention may also be used to perform inspection services of the pipe line. Further, in embodiments of the invention, global positioning systems can be used to detect, map and or record the exact position of the robot or other device within a pipeline.  
         [0127]    A feature of the present invention is the streamlining of the process, which significantly reduces human requirements and significantly increases safety, and quality control. By streamlining the entire process with automation not only is on site labor reduced but documentation and billing procedures are streamlined, further saving costs and minimizing human error aspects. The clients of the process benefit by receiving the information more quickly and in a more user friendly format at a reduced cost than would have otherwise been deliverable (it would have cost more to process the information to be presented to the client). From a troubleshooting aspect, since the system has the capability to log operational data, one can review the operational parameters after the fact and effectively recreate the scenario, which lead to a problem, or failure, which could only have been available if someone had manually logged information on a continual basis during system operation. Embodiments of the invention facilitate the combination of inspection and rehabilitation services into one operation.  
         [0128]    Because the available technology in complimentary industries seems to be limited, the automation system could be of use for other manufacturing industries, which rely on sealant application system performance and quality control issues or could benefit by streamlining their operations. In addition, certain embodiments of the present system may be utilized for natural gas distribution systems, but could be applied to a whole host of other pipelines, including but not limited to propane, water and or sewer pipelines.  
         [0129]    In embodiments of the present invention described above, spray heads are used to spray foam and sealant in live gas pipes. In some embodiments, particularly useful for high velocity gas lines or water lines, it may be desirable to install a bladder or tape around the area to be filled or sealed, prior to the sealing or filling process, to prevent the high velocity gas or water from misdirecting the sealant or foam.  
         [0130]    Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting. The invention&#39;s limit is defined only in the following claims and the equivalents thereto.