Patent Publication Number: US-2018036756-A1

Title: Coating apparatus and method of coating joint

Description:
FIELD 
     The present disclosure generally relates to an apparatus for coating pipelines and more particularly to an apparatus for spraying joined end portions of adjacent pipe sections with a liquid coating material. 
     BACKGROUND 
     Conventional pipelines are formed by arranging separate lengths or sections of pipe end to end and then joining them together. Typically, central portions of each pipe section are coated with an anticorrosion coating during manufacturing and end portions of the pipe section are left uncoated to allow for joining. Pipe sections in a pipeline are often joined together using girth wells. Adjacent end portions of joined pipe sections should be coated with an anticorrosion coating after they are joined. Conventional liquid coating systems spray a coating around the exposed end portions of joined pipe sections in the field. 
     Coating systems can include a coating apparatus configured to be selectively mounted on a pipeline near an exposed joint surface. Typically, such a coating apparatus includes a frame that mounts a sprayer for spraying a curable liquid toward the joint surface. Frames can include movable frame members that open to install and remove the apparatus from the pipeline and close around the pipe. Operators must be careful when installing and removing the frame from the pipeline. Particularly when removing the frame from the pipeline after coating, it is important to avoid contacting the pipeline and damaging the coating. Certain coating apparatuses are configured to rotate around the pipeline to coat the entire circumference of the pipeline at a joint. In general, it is desirable for the frame to close securely around the pipe before spraying to ensure the coating apparatus stays mounted on the pipe as it rotates. 
     Typically, before or after spraying liquid coating material through a sprayer, flushing fluid is dispensed through the spray nozzle to purge contaminants and buildup. The flushing fluid can adversely affect the quality of the coating if it is allowed to contact the exposed end portions of the joined pipe sections or the recently sprayed on coating. Thus, conventional liquid coating systems orient the spray nozzle away from the pipe sections during flushing. After the sprayer has been flushed, the nozzle is repositioned to spray liquid coating material onto the exposed end portions of the joined pipe sections. Typical liquid coating materials produce overspray that should be removed from the target area during spraying. 
     Coating systems can include process rigs that deliver fluids that form the curable liquid to the coating apparatus. In conventional process rigs, day tanks store one or more components of the curable liquid. The components of the curable liquid are manually poured into the day tanks prior to spraying. As the day tanks are emptied, the operators must refill the day tanks to continue coating. 
     A fluid system connects a process rig to the coating apparatus. Typically, the fluid system will include various indicators of process conditions, such as temperature, pressure, level, and flow indicators. An operator monitors the indicators and adjusts various components of the system to control the process. 
     In general it is desirable for the operator to control the process to achieve desired process conditions during coating. It is thought that certain process temperatures, flow rates, pressures, etc. produce stronger and longer lasting polymeric coatings. An operator will typically attempt to achieve these process conditions each time a joint is coated. At later times, an operator of the pipeline may check the performance of the coatings formed by the coating system. Using conventional coating systems, the operator has no way to cross reference poorly performing coatings against the process conditions at which they were actually formed for purposes of improving future coating processes. 
     SUMMARY 
     In one aspect, a coating apparatus for coating a perimeter surface of a pipeline comprises a mounting frame configured to be selectively mounted on the pipeline. A sprayer is mounted on the mounting frame and configured to deliver fluid along a flow path oriented toward the perimeter surface of the pipeline when the mounting frame is mounted on the pipeline. The sprayer is selectively switchable between operational modes including a preparation mode in which the sprayer delivers a fluid along the flow path to prepare the sprayer for spraying and a spraying mode in which the sprayer sprays the curable liquid along the flow path in a spray pattern. A fluid diverter is secured to the mounting frame and is selectively movable relative the sprayer between a fluid diverting position in which the diverter is positioned in the flow path to divert the fluid delivered from the sprayer away from the perimeter surface of the pipeline when the sprayer is operating in the preparation mode and a non-diverting position in which the diverter is not positioned in the flow path to permit free flow of the curable liquid from the sprayer in the spray pattern when the sprayer is operating in the spraying mode. 
     In another aspect, a coating apparatus for coating a perimeter surface of a pipeline comprises a mounting frame configured to be selectively mounted on the pipeline. A sprayer is mounted on the mounting frame and configured to deliver a fluid along a flow path oriented toward the perimeter surface of the pipeline when the mounting frame is mounted on the pipeline. The sprayer is operable in at least one operational mode to deliver the curable liquid along the flow path in a spray pattern. The coating apparatus is configured to move the sprayer circumferentially around the pipeline when the sprayer is operating in said at least one operational mode to coat the perimeter surface with the curable liquid. A vacuum system is operable to impart a vacuum pressure on a space adjacent the flow path to draw a divertible fluid delivered from the sprayer away from said space. An overspray shroud comprises a wall defining a shroud interior and having a sprayer opening and a vacuum opening formed therein. The overspray shroud and the sprayer are fixed in position relative one another such that the sprayer is oriented to deliver fluid along the flow path through the sprayer opening and the shroud wall is oriented to substantially contain the delivered fluid within the shroud interior. The vacuum system is operatively connected to the vacuum aperture to draw the divertible fluid away from the shroud interior. 
     In another aspect, a method of coating a perimeter surface of a pipeline comprises mounting a sprayer on the pipeline to deliver fluid along a flow path oriented toward the perimeter surface of the pipeline. A fluid diverter is moved to a fluid diverting position in which the diverter is positioned in the flow path. The sprayer is operated in a preparation mode in which fluid delivered to the sprayer to prepare the sprayer for spraying is emitted along the flow path. The fluid delivered by the sprayer operating in the preparation mode is diverted away from the perimeter surface of the pipeline using the diverter positioned in the fluid diverting position. The diverter is moved from the fluid diverting position to a non-diverting position in which the diverter is not positioned in the flow path. The sprayer is operated in a spraying mode in which the sprayer delivers the curable liquid along the flow path in a spray pattern with the diverter positioned in the non-diverting position to coat the perimeter surface of the pipeline. 
     In yet another aspect, a system for coating a perimeter surface of a pipeline comprises a coating apparatus comprising a sprayer configured to spray curable liquid along a flow path. A frame supports the sprayer and is configured to selectively mount the sprayer on the pipeline to orient the sprayer so the flow path is oriented toward the perimeter surface of the pipeline and to move the sprayer relative to the pipeline to coat the perimeter surface of the pipeline with the curable liquid. A rig located remote from the pipeline comprises one or more containers. Each of the one or more containers contains at least one component of the curable liquid. Plumbing fluidly connects the containers to the sprayer. A pump is fluidly connected to the plumbing to pump the at least one component of the curable liquid from the one or more containers through the plumbing to form the curable liquid and to pump the curable liquid through the sprayer, whereby the sprayer sprays the curable liquid along the flow path. A heater is operatively connected to the plumbing to heat at least one component of the curable liquid. A temperature transmitter is operatively connected to the plumbing to sense a temperature of the at least one component of the curable liquid and to produce a temperature signal representative of the sensed temperature. The temperature transmitter is located at the coating apparatus. A controller is operatively connected to the temperature transmitter and the heater to receive the temperature signal from the temperature transmitter and to adjust the heater based on the received temperature signal to adjust the temperature of the at least at least one component of the curable liquid. 
     In still another aspect, in a method of controlling the delivery of curable liquid to a sprayer of a coating apparatus, the coating apparatus is configured to selectively mount the sprayer on a pipeline to spray the curable liquid along a flow path oriented toward a perimeter surface of the pipeline and to move the sprayer relative to the pipeline to coat the perimeter surface with the curable liquid. The method comprises pumping at least one component of the curable liquid from a container located remote from the pipeline through plumbing fluidly connecting the container to the sprayer. A temperature signal representative of a temperature of the at least one component of the curable liquid at the coating apparatus is received. A heater operatively connected to the plumbing based on the received temperature signal is adjusted to adjust the temperature of the at least one component of the curable liquid. 
     In another aspect, in a method of operating a coating apparatus, the coating apparatus comprises a sprayer configured to spray fluid along a flow path and to be selectively switchable between operational modes including a spraying mode in which the sprayer delivers curable liquid along the flow path and a purge mode in which the sprayer delivers a solvent along the flow path to purge the sprayer. The coating apparatus is configured to selectively mount the sprayer on a pipeline to move the sprayer relative to the pipeline while the sprayer is operating in the spraying mode to coat a perimeter surface of the pipeline with the curable polymer. The method comprises detecting a solvent level representative of an amount of solvent in a solvent container from which the sprayer receives the solvent. The detected solvent level is compared to a threshold solvent level. The sprayer is permitted to operate in the spraying mode when the detected solvent level is greater than the threshold solvent level. The sprayer is automatically prevented from operating in the spraying mode when the detected solvent level is less than the threshold solvent level. 
     In yet another aspect, a method of evaluating a polymeric coating formed on each of a plurality of perimeter joint surfaces of a pipeline comprises storing in a database spray process data about one or more spray process conditions for each of the joint surfaces. The spray process data is received from one or more process sensors of a joint coating apparatus configured to spray each of the perimeter joint surfaces with a curable liquid to form the respective polymeric coating. Said one or more process sensors are configured to detect said one or more spray process conditions while the joint coating apparatus sprays each of the perimeter joint surfaces with the curable liquid. The spray process data for each of the perimeter joint surfaces is associated with joint identity data which identifies the respective perimeter joint surface in the database. 
     In still another aspect, a rig for use in delivering a curable liquid to a coating apparatus for coating a perimeter surface of a pipeline comprises a housing defining an interior and having a floor. One or more drums are located within the housing. Each of the one or more drums contains a component of the curable liquid. A drum support comprises a base fixedly mounted on the floor of the housing. The base comprises a tray defining a secondary liquid containment cavity. A liquid-permeable platform is configured to support the one or more drums. The platform is slidably mounted on the base to slide relative to the base between a drum loading position and an operational position. The platform extends outside of the interior of the housing when positioned in the drum loading position to receive the one or more drums thereupon. The platform is positioned above the tray when the platform is in the operational position such that any of the at least one components of the curable liquid contained in the one or more drums that leaks onto the platform passes through the platform and into the secondary liquid containment cavity. 
     In another aspect, a coating apparatus for coating a perimeter surface of a pipeline comprises a mounting frame configured to be selectively mounted on the pipeline. A sprayer has a spray nozzle configured to deliver fluid along a flow path oriented away from the spray nozzle and flaring outwardly in a fan pattern such that the flow path has a width and the width of the flow path increases as a distance of the flow path from the spray nozzle increases. An adjustable sprayer mount mounts the sprayer on the mounting frame for movement relative to the mounting frame. The sprayer mount orients the sprayer so that the flow path is oriented toward the perimeter surface of the pipeline when the mounting frame is mounted on the pipeline and is configured to selectively move the sprayer relative to the mounting frame to adjust a distance between the spray nozzle and the exterior surface of the pipeline to thereby adjust the width of the flow path at a location where the flow path intersects the exterior surface of the pipeline. 
     In yet another aspect, a coating apparatus for coating a perimeter surface of a pipeline comprises a sprayer configured to deliver a curable liquid along a flow path. A mounting frame is connected to and supports the sprayer and is configured to be selectively mounted on the pipeline to orient the sprayer so that the flow path intersects the perimeter surface of the pipeline. The mounting frame comprises a central bracket having a first end portion, a second end portion, and a width extending between the first and second end portions. A first end bracket is pivotally connected to the first end portion of the central bracket to pivot relative the central bracket around a first pivot axis. A second end bracket is pivotally connected to the second end portion of the central bracket to pivot relative the central bracket around a second pivot axis spaced apart from the first pivot axis. The first and second end brackets are selectively pivotable relative the central bracket between a closed position and an open position. In the closed position, the mounting frame is shaped and arranged for extending circumferentially around at least a portion the pipeline to mount the coating apparatus on the pipeline. In the open position, the mounting frame defines an open gap having a width extending along a gap axis that is wider than the pipeline so that the coating apparatus may be removed from the pipeline with the pipeline passing through the gap along a movement axis generally perpendicular to the gap axis without contacting the mounting frame. 
     In still another aspect, a coating apparatus for coating a perimeter surface of a pipeline comprises a sprayer configured to deliver a curable liquid along a flow path. A mounting frame is connected to and supports the sprayer and is configured to be selectively mounted on the pipeline to orient the sprayer so that the flow path intersects the perimeter surface of the pipeline. The mounting frame comprises first and second brackets having interlocking end portions. The first and second brackets are selectively movable relative to one another from an open position in which the interlocking end portions are spaced apart from one another to define an open gap sized and arranged to allow the pipeline to pass through the gap and into the mounting frame and a closed position in which the interlocking ends are positioned adjacent to one another such that the mounting frame is sized and arranged to extend circumferentially around the pipeline to mount the coating apparatus on the pipeline. A locking mechanism comprises a retaining member at the interlocking end portion of the first bracket. A locking member is pivotally connected to the interlocking end portion of the second bracket and is sized and arranged for interlocking engagement with the retaining member. The locking member is selectively pivotable around a pivot axis when the first and second brackets are in the closed position from an unlocked position in which the locking member is spaced apart from the retaining member to a locked position in which the locking member interlockingly engages the retaining member to lock the mounting frame in the closed position. 
     Other objects and features will be in part apparent and in part pointed out hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic elevation of a pipeline; 
         FIG. 1A  is a schematic elevation of a coating system; 
         FIG. 2  is a fluid schematic of the coating system; 
         FIG. 3  is a flowchart illustrating the steps and decision blocks of a method of coating a joint; 
         FIG. 4  is a flow chart illustrating the steps and decision blocks of a method carrying out one of the steps of the method of  FIG. 3 ; 
         FIG. 5  is a perspective of a coating apparatus of the coating system of  FIG. 1  secured to the pipeline; 
         FIG. 6  is a front elevation of the coating apparatus with an overspray shroud wall removed; 
         FIG. 7  is an enlarged perspective of a dispensing subsystem of the coating apparatus including the overspray shroud, a sprayer, and a diverter; 
         FIG. 8  is an enlarged fragmentary cross section illustrating the components shown in  FIG. 7  and depicting the diverter positioned in a fluid diverting position; 
         FIG. 9  is an enlarged fragmentary cross section similar to  FIG. 8  illustrating the diverter positioned in a non-diverting position; 
         FIG. 10  is a perspective of another embodiment of a coating apparatus; 
         FIG. 11  is a front elevation of the coating apparatus of  FIG. 10  in the open position; 
         FIG. 12  is a front elevation of the coating apparatus of  FIG. 10  in the closed position; 
         FIG. 13  is an enlarged fragmentary perspective of a locking mechanism of the coating apparatus of  FIG. 10  in the unlocked position; 
         FIG. 14  is an enlarged fragmentary perspective of the locking mechanism in the locked position; 
         FIG. 15  is an enlarged cross section of a sprayer assembly of the coating apparatus of  FIG. 10  and the pipeline; 
         FIG. 16  is an enlarged perspective of the sprayer assembly; 
         FIG. 17  is another enlarged perspective of the sprayer assembly illustrating the sprayer in a different position than  FIG. 16  relative to a mounting frame of the coating apparatus; 
         FIG. 18  is a perspective of a process rig of the coating system; 
         FIG. 19  is a cross section of the process rig taken in the plane of line  19 - 19  of  FIG. 18 ; 
         FIG. 20  is similar to  FIG. 19  but illustrates a drum support and a vessel support of the process rig in loading positions; and 
         FIG. 21  is a perspective of the drum support in the loading position. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a pipeline such as is commonly used for transporting oil and gas is generally indicated at reference number  10 . The pipeline  10  includes separately joined pipe sections  10 A- 10   n  that are arranged end to end to form the pipeline. Central portions of each of the pipe sections  10 A- 10   n  are coated with an anticorrosion coating  12 , but end portions of the pipe sections are uncoated to allow the pipe sections to be joined together to form the pipeline. The thickness of the coating  12  is greatly exaggerated in  FIG. 1  so that coated and uncoated portions of the pipeline are easily distinguished. The uncoated end portions of the pipe sections  10 A- 10   n  are preferably joined together by girth welds at joints  16 . At each of the joints  16 , the uncoated end portions of the pipe sections  10 A- 10   n  define perimeter joint surfaces  14  that extend between adjacent coatings  12 . As shown in  FIG. 1 , the joint surfaces  14  have direct exposure to environmental conditions, which can cause deterioration of the pipeline  10  if the joint surfaces remain uncoated. As shown in  FIG. 1A , a coating system  20  is configured to separately coat each of the exposed perimeter joint surfaces  14  with a polymeric coating to protect the pipeline  10  from environmental conditions. For context, before discussing various aspects of the coating system and joint coating process in further detail, the major components of the coating system  20  and the overall process by which the coating system coats the exposed perimeter joint surfaces  14  of the pipeline  10  will now be briefly summarized. 
     The illustrated coating system  20  includes a crawler  22  fitted with a crane  24 . The crawler  22  is attached to a trailer  26  that supports a rig  30  for processing the components of a curable liquid used to coat the perimeter joint surfaces of the pipeline  10 . The crawler  22  supports a generator  32  that is operatively connected to the rig  30  to provide power to the rig. The rig  30  is operatively connected to a coating apparatus  40 . The crane  24  supports the coating apparatus  40  and is configured to selectively mount the coating apparatus on the pipeline  10  at each of the joint surfaces  14 . As will be discussed in further detail below, the rig  30  is configured to deliver two-components of a curable liquid to the coating apparatus  40 . The rig  30  is also configured to deliver a purging fluid such as a solvent to the coating apparatus  40  to purge residual coating liquid from the coating apparatus after the coating apparatus coats each joint surface  14  with the coating liquid. The coating apparatus  40  is configured to mix the two components to from the curable liquid and to spray the curable liquid over the exposed perimeter joint surfaces  14  of the pipeline  10 . The trailer  26  supports an air compressor  42  that is operatively connected to the coating apparatus  40 . As will be discussed in further detail below, compressed air from the air compressor  42  drives movement of the coating apparatus circumferentially around the pipeline  10  to enable the coating apparatus to spray the curable liquid around the entire circumference of each perimeter joint surface  14 . Although  FIG. 1  illustrates the major components of one embodiment of a suitable coating system  10 , it will be understood that other coating systems can use different components without departing from the scope of the invention. 
     The general process by which the coating system  20  coats the perimeter joint surfaces  14  of the pipeline  10  begins when the crawler  22  moves the coating system to one of the joint surfaces. The crane  24  is used to mount the coating apparatus  40  on the pipeline  10  at the joint surface  14 . A control system executes a control routine to separately deliver the two components of the curable liquid from the rig  30  to the coating apparatus  40  at desired process conditions. The coating apparatus  40  mixes the two components together to form the curable liquid and sprays the curable liquid along a flow path oriented toward the perimeter joint surface  14 . The air compressor  42  delivers compressed air to the coating apparatus  40  that drives rotation of the coating apparatus circumferentially around the pipeline. The coating apparatus  40  sprays the curable liquid as it rotates to coat the entire circumference of the perimeter joint surface  14 . After coating, the process rig  30  delivers solvent (broadly, flushing fluid) to the coating apparatus  40  to flush the curable liquid and keep the coating system from becoming clogged. As will be discussed in further detail below, the coating system  20  includes a solvent collection system that automatically reclaims the fluid sprayed through the coating apparatus during flushing. After flushing, the crane  24  removes the coating apparatus  40  from the pipeline, and the crawler  22  moves the coating system  20  to the next joint surface  14  where the process is repeated. It will be understood that various steps of the above-described coating process may be modified with departing from the scope of the invention. 
     Before describing the structure of certain exemplary embodiments of the rig  30  and coating apparatus  40 , an exemplary embodiment of an automated fluid handling system  50  (broadly, plumbing) that extends from inside the rig onto the coating apparatus will be described in reference to  FIG. 2 . In the illustrated embodiment the fluid system  50  is configured to form the curable liquid from first and second fluid components, which are stored separately in first and second drums  52 A,  52 B located in the rig  30 . For example, the first component stored in the first drum  52 A can be a resin, and the second component stored in the second drum  52 B can be a hardener. When the two components are mixed together at a suitable volumetric ratio and at suitable process conditions (e.g., temperatures), they form a curable liquid configured for coating the joint surfaces  14 . Although the illustrated embodiment uses a two-part curable liquid, it will be understood that other embodiments can use single-component curable liquids or curable liquids mixed together from more than two components without departing from the scope of the invention. 
     As will be discussed in further detail below, the fluid system  50  defines first and second parallel flow paths for conveying the first and second components from the first and second drums  52 A,  52 B to a mixing manifold  54  of the coating apparatus  40 . The mixing manifold  54  mixes the first and second components together to form the curable liquid. Throughout this disclosure, components of the coating system  20  that are operatively connected to the first flow path for processing the first component of the curable liquid will be given a reference numeral ending in the letter ‘A’ and components operably connected to the second flow path for processing the second component will be given a reference numeral ending in the letter ‘B.’ 
     As will be discussed in further detail below, the coating system  20  is configured to switch between several operational modes, including the following: a spray buildup mode in which the process rig  30  builds up a sufficiently large flow of curable liquid in a desired temperature range through the coating apparatus to spray the curable liquid in a desired spray pattern S; a spraying mode in which the coating apparatus sprays the curable liquid to coat a perimeter joint surface  14 ; a recirculation mode in which the coating system  20  recirculates the first and second components of the curable liquid through the fluid system  50 ; and a purge mode in which the coating system delivers a solvent through the coating apparatus to flush residual curable liquid from the coating apparatus. When the coating system  20  is operating in the spray buildup and spraying modes, it pumps the first and second components into the mixing manifold  54 , which mixes the components together to form the curable liquid. The coating system  20  further pumps the curable liquid through a sprayer  55  to spray the perimeter surface  14  of the pipeline. When the coating system  20  is operating in the recirculation mode, it pumps the first and second components through portions of the fluid systems that extend between the rig  30  and coating apparatus  40 . But instead of pumping the first and second components through the mixing manifold  54 , the coating system recirculates the first and second components. As explained below, the process rig  30  pumps a solvent through portions of the coating apparatus  40  that come in contact with the curable liquid when operating in the purge mode. Various aspects of the coating system  20  that carry out the spray buildup and spraying modes will be described before turning to the recirculation and purge modes. 
     In the illustrated embodiment, each of the fluid flow paths includes a pump  56 A,  56 B that pumps the respective component from the drum  52 A,  52 B to a day tank  58 A,  58 B. As will be discussed in further detail below, the drums  52 A,  52 B are replaceable. New drums  52 A,  52 B replace old drums once the old drums are emptied. A level detector (not shown) can be installed in each of the drums  52 A,  52 B to detect emptiness. By comparison, the day tanks  58 A,  58 B are permanently installed in the process rig  30  and are integral and permanent components of the fluid system  50 . Though the illustrated embodiment uses replaceable drums  52 A,  52 B to provide the first and second fluid components to permanent day tanks  58 A,  58 B, it will be understood that day tanks can be filled with the components of the curable liquid without using replaceable drums without departing from the scope of the invention. 
     Even though the drums  52 A,  52 B are replaceable, the fluid system  50  includes automated temperature control for maintaining the temperature of the fluid components contained in the drums. This ensures the drums  52 A,  52 B deliver the first and second fluid components to the day tanks  58 A,  58 B at proper temperatures for further processing. Each drum  52 A,  52 B has a closed loop temperature control system comprising a heater  60 A,  60 B and a temperature transmitter  62 A,  62 B. These temperature control components are preferably refitted onto each new drum  52 A,  52 B as it is installed. The transmitters  62 A,  62 B are configured to sense the temperature of the fluid components in the drums  52 A,  52 B and to provide a representative temperature signal to a controller  70 . The controller  70  adjusts the heaters  60 A,  60 B to maintain the fluid components in the drums  52 A,  52 B at the desired temperatures. In the illustrated embodiment, the controller  70  is a central controller that runs the control logic for several automated systems of the coating system  20 . 
     Throughout this disclosure, various automated processes will be described as being controlled or directed by the central controller  70 . That is, the controller  70  acts as a single control module for many of the automated systems of the coating system  20 . In other embodiments, local controllers can separately control discrete control loops such as the temperature control loops that implement the heaters  60 A,  60 B and transmitters  62 A,  62 B. Alternatively, any of the automated control systems described herein can be replaced with operator control without departing from the scope of the invention. 
     The controller  70  is configured to operate the pumps  56 A,  56 B to deliver fluid from the drums  52 A,  52 B to the day tanks  58 A,  58 B to maintain a desired fluid level in the day tanks. The day tanks  58 A,  58 B preferably include level transmitters (not shown) that measure the level of the fluid component contained in each day tank and transmit a respective level signal to the controller  70 . The controller  70  uses the level signals to adjust the pumps  56 A,  56 B to maintain the desired fluid levels in the day tanks  58 A,  58 B. 
     Like the drums  52 A,  52 B, the day tanks  58 A,  58 B include temperature control for maintaining the fluid components at the desired temperatures. Each day tank  58 A,  58 B has a temperature control system comprising a respective temperature transmitter  72 A,  72 B and heater  74 A,  74 B. The transmitters  72 A,  72 B are configured to sense and provide a temperature signals representing the temperatures of the first and second fluid components to the controller  70 . The controller  70  automatically adjusts the heaters  74 A,  74 B to maintain the fluid components in the day tanks  58 A,  58 B at desired temperatures. 
     Pumps  76 A,  76 B installed in the process rig  30  are configured to pump the fluid components from the day tanks  58 A,  58 B through downstream portions of the fluid system  50 . The pumps  76 A,  76 B pump the first and second components from the day tanks  58 A,  58 B through an umbilical bundle  80  fluidly connecting the process rig to the coating apparatus  40  and further through plumbing at the coating apparatus. The umbilical bundle  80  extends between the rig  30  and the coating apparatus  40  to convey various fluids. In the illustrated embodiment, the umbilical bundle  80  includes a heat trace  82  that can be used to heat the fluids in the umbilical bundle as they flow between the rig  30  and the apparatus  40 . 
     In addition to the pumps  76 A,  76 B, heaters  86 A,  86 B are operatively connected to the first and second flow paths at the process rig  30 . The heaters  86 A,  86 B are configured to heat the first and second components to desired temperatures for mixing them together and spraying the curable liquid. When the fluid system  50  is operating in the spraying mode, the controller  70  controls the operation of the pumps  76 A,  76 B, and heaters  86 A,  86 B to deliver the first and second components of the curable liquid to the mixing manifold  54  at desired temperatures and desired volume ratios. 
     The controller  70  receives several inputs that it uses to control the pumps  76 A,  76 B and heaters  86 A,  86 B. In the illustrated embodiment, a rig pressure transmitter  88 A and a rig temperature transmitter  90 A are operatively connected to the first fluid flow path at the process rig  30 . Likewise, a rig pressure transmitter  88 B and a rig temperature transmitter  90 B are operatively connected to the second fluid flow path at the process rig  30 . The fluid system  50  also includes an apparatus pressure transmitter  92 A and apparatus temperature transmitter  94 A operatively connected to the first fluid flow path at the coating apparatus  40 . Likewise, the fluid system  50  includes an apparatus pressure transmitter  92 B and an apparatus temperature transmitter  94 B operatively connected to the second fluid flow path at the coating apparatus  40 . The pressure transmitters  88 A,  88 B,  92 A,  92 B are configured to sense the pressures of the first and second fluid components at the rig  30  and coating apparatus  40 , respectively. The pressure transmitters  88 A,  88 B,  92 A,  92 B are operatively connected to the controller  70  to transmit pressure signals representative of the sensed pressures to the controller. The temperature transmitters  90 A,  90 B,  94 A,  94 B are configured to sense the temperatures of the first and second fluid components at the rig  30  and coating apparatus  40 , respectively. The temperature transmitters  90 A,  90 B,  94 A,  94 B are operatively connected to the controller  70  to transmit temperature signals representative of the sensed temperatures to the controller. Preferably, the pumps  76 A,  76 B or other flow sensors are also operatively connected to the controller  70  to transmit pumped volume signals representative of a volume of the first and second component pumped through the fluid system  50 . 
     The controller  70  is configured to use the pressure signals, temperature signals, and pumped volume signals to adjust the pumps  76 A,  76 B and heaters  86 A,  86 B to deliver a desired volume of each of the first and second components to the mixing manifold  54  at a desired back pressure and temperature. In a preferred embodiment, the controller  70  uses a proportional-integral-derivative (PID) control scheme to adjust the operation of the pumps  76 A,  76 B and the heaters  86 A,  86 B. The pressure, temperature, and pumped volume signals are inputs that the PID control routine uses to derive outputs that adjust the pumps  76 A,  76 B and heaters  86 A,  86 B. 
     For example, in one or more embodiments, the controller uses the temperature signals to adjust the heaters  86 A,  86 B to control the temperatures of the first and second fluid components at the mixing manifold  54 . In certain embodiments, the controller  70  uses only the temperature signals from the temperature transmitters  94 A,  94 B to control the heaters  86 A,  86 B. The controller can also use the temperature signals from both of the temperature transmitters  90 A,  94 A as inputs in a PID control routine to adjust the heater  86 A to maintain the temperature of the first component. Likewise, the controller can use the temperature signals from one or both of temperature transmitters  90 B,  94 B to adjust the heater  86 B to maintain the temperature of the second component. Transmitters  94 A,  94 B provide temperature information close to the point of application of the spray to the pipeline  10 , where temperature is most critical to the effective application of the coating. Depending upon environmental conditions, there may be a substantial effect upon temperature of the components from the rig  30  to the coating apparatus  40 . However, by also monitoring temperature detected at the transmitters  92 A,  92 B and using their signals in the PID algorithm, temperature can be properly controlled to avoid overheating the components at the rig  30  and damage to the heaters  86 A,  86 B caused by hunting. Although the signals from the rig temperature transmitters  90 A,  90 B and the apparatus temperature sensors  94 A,  94  be can be used in suitable embodiments, it is also thought that suitable control can be achieved using only the apparatus temperature sensors as control inputs. 
     The controller  70  can also use the volume signals and pressure signals in controlling the pumps  76 A,  76 B. In general, the controller  70  controls the pumps  76 A,  76 B to deliver a desired volumetric ratio of the first and second fluid components to the mixing manifold  54 . In addition, the controller  70  controls the pumps  76 A,  76 B to maintain a desired back pressure in the fluid system  50  so that the curable liquid flows from the sprayer  55  in a desired spray pattern S. The controller  70  may receive user input to control the pumps  76 A,  76 B to deliver the first and second fluid components to the mixing manifold  54  at the desired ratio. The controller  70  preferably uses the pressure signals from one or both of the pressure transmitters  88 A,  92 A to adjust the pump  76 A to maintain a desired back pressure in the first fluid flow path. Likewise, the controller  70  uses the pressure signals from one or both of the pressure transmitters  88 B,  92 B to control the pump  76 B to maintain a desired back pressure in the second flow path. Like the temperature signals, the controller can suitably use the pressure signals from the rig pressure transmitters  88 A,  88 B and those from the apparatus transmitters  92 A,  92 B in a combined control routine that minimizes hunting while accounting for unexpected pressure variation in the fluid system  50  between the pumps  76 A,  76 B and mixing manifold  54 . Alternatively, the controller  70  can use only the pressure signals from the apparatus pressure transmitters  92 A,  92 B in the control routine. 
     The pumps  76 A,  76 B pump the first and second components of the curable liquid through the mixing manifold  54 , which mixes them together to form the curable liquid. The pumps further pump the curable liquid through the sprayer  55  to spray the curable liquid in a spray pattern S. A pressure sensor  96  and a temperature sensor  98  sense the pressure and temperature of the curable liquid and provide representative pressure and temperature signals to the controller  70 . In the illustrated embodiment, the controller  70  does not use these pressure and temperature signals to control the coating system  20 . Rather, the controller provides these and other data about the process to a database  100 . As will be explained in further detail below, the database  100  stores the process data so that a user can later cross reference process conditions against the quality of joint coatings to determine if changes should be made to the process. 
     The coating apparatus  40  is configured to spray the curable liquid over the entire circumference of each perimeter joint area  14 . During the spray buildup mode, the coating apparatus  40  builds up the fan-shaped spray pattern S described in further detail below. Once an operator determines that a desired spray pattern S has been achieved, he or she can provide command to the controller  70  to begin the spraying mode. During the spraying mode, the sprayer sprays the curable liquid in the fan-shaped spray pattern S. As the coating system  20  sprays the curable liquid in the spraying mode, the air compressor  42  drives an air motor  102  on the coating apparatus  40  to rotate the coating apparatus around the pipe. The controller  70  controls the motor  102  to time rotation with spraying to form an even coating of curable liquid over the joint surface  14 . 
     The coating system  20  is configured to minimize overspray as it sprays the curable liquid along the flow path. The process rig  30  includes a cyclonic vacuum separator  104  operatively connected to a fluid diverter  106  positioned adjacent the flow path. The structure and operation of a suitable fluid diverter will be described in further detail below in reference to an exemplary embodiment of the coating apparatus  40 . Generally, however, the separator  104  draws a vacuum through the fluid diverter  106  to draw fluids near the diverter through the vacuum separator. As will be discussed in further detail below, the diverter  106  is selectively movable from a position that intersects the flow path of the spray pattern S to a position adjacent the flow path. Preferably the diverter  106  is positioned in the flow path during the spray buildup mode to block the curable liquid from contacting the joint surface  14  and to draw the curable liquid into the separator  104 . The controller  70  moves out of the flow path during the spraying mode, thereby switching the coating system from the spray buildup mode to the spraying mode. There, the vacuum separator  104  draws overspray away from the joint surface  14  through the diverter  106 . The separator  104  delivers liquid and solid particles from the sprayer  55  into a reclamation vessel  108 . An exhaust fan  110  exhausts gaseous fluids drawn into the separator  104  out of the process rig  30 . 
     The controller  70  is configured to selectively switch the coating system  20  from the spraying mode to the recirculation mode. In the illustrated embodiment, the coating apparatus  40  includes a spray valve  112 A,  112 B and a recirculation valve  114 A,  114 B fluidly connected to the fluid system  50  along each of the first and second flow paths. When the coating system  20  is operating in the spray mode, the spray valves  112 A,  112 B are open and the recirculation valves  114 A,  114 B are closed to allow the first and second fluid components to flow from the day tanks  58 A,  58 B to the mixing manifold  54 . But when the coating system  20  switches to the recirculation mode, the controller closes the spray valves  112 A,  112 B and opens the recirculation valves  114 A,  114 B. Thus, in the recirculation mode, the pumps  76 A,  76 B pump the first and second fluid components from the day tanks  58 A,  58 B, through the umbilical bundle  80  and into the coating apparatus  40 . But instead of flowing into the mixing manifold  54 , the first and second components flow through the open recirculation valves  114 A,  114 B, upstream through the umbilical bundle  80 , and back into the day tanks  58 A,  58 B. The recirculation mode, therefore, creates separate closed loop flow paths for each of the first and second fluid components. Fluid in the recirculation flow paths can be heated by the heaters  74 A,  74 B and  86 A,  86 B to continue to warm the first and second fluid components. Thus, the recirculation mode can be used to heat the first and second fluid components to a desired temperature before entering the spray buildup or spraying modes. 
     In the illustrated embodiment, the process rig  30  includes a solvent tank  116 . The solvent tank  116  is preferably filled with a solvent suitable for flushing curable liquid from the mixing manifold  54  and spray nozzle  55 . The controller  70  is configured to selectively switch the coating system  20  to a purge mode in which the coating system delivers solvent from the solvent tank  116  through the mixing manifold  54  and spray nozzle  55  to flush curable liquid from the fluid system  50 . A solvent pump  118  is configured to pump solvent from the solvent tank  116  to the coating apparatus  40  through a solvent flow path, which extends through the umbilical bundle  80 . The coating apparatus  40  includes first and second solvent valves  120 A,  120 B, which selectively fluidly connect the solvent tank  116  to the end portions of the first and second flow paths, near the mixing manifold. Alternatively, a single solvent valve could be used, which selectively fluidly connects the solvent tank directly to the mixing manifold. The controller  70  is operatively connected to the solvent valves  120 A,  120 B to switch the coating system  20  to the purge mode by opening the solvent valves and closing the spray valves  112 A,  112 B. 
     The controller  70  causes the pump  118  to pump solvent into the coating apparatus. Some of the solvent flows through the first solvent valve  120 A and into the portion of the mixing manifold  54  through which the first component of the curable liquid flows in the spraying mode. Another portion of the solvent flows through the second solvent valve  1206  and into the portion of the mixing manifold  54  through which the second component of the curable liquid flows in the spraying mode. The two portions of the solvent mix in the mixing manifold  54  just as the first and second fluid components do in the spraying mode. The solvent pump  118  continues to pump the mixed solvent through the coating apparatus until it passes through the sprayer  55 . Thus, it can be seen that, during the purge mode, the fluid system  50  fluidly connects the solvent in the solvent tank  116  to the portion of the plumbing that carries the curable liquid so that the solvent pump  116  can pump the solvent through the plumbing to flush the coating system  20  of curable liquid contained therein. 
     As explained in further detail below, the controller  70  is preferably configured to automatically cause the coating system  20  to enter the purge mode after each perimeter joint surface is coated with the curable liquid. In one or more embodiments, the coating apparatus  40  remains mounted on the pipeline  10  with the sprayer  55  oriented toward the perimeter joint surface while the coating system flushes the solvent through the coating apparatus. To prevent the solvent from contacting the freshly coated perimeter joint surface  14 , the coating apparatus  40  is configured to move the fluid diverter  106  into the solvent flow path F. The vacuum separator  104  draws the solvent and flushed curable liquid into the reclamation vessel  108 , and the exhaust fan  110  exhausts gaseous fluids away from the coating system  20 . 
     Generally, it is desirable to flush the coating system  20  of curable liquid contained therein after each use. If curable liquid is not flushed shortly after spraying, it can cure in the fluid system  50  and form obstructions. In the illustrated embodiment, a level sensor  122  is operatively connected to the solvent tank  116  to prevent the coating system  20  from spraying curable liquid when the solvent tank is empty. The level sensor  122  detects a solvent level in the solvent tank to determine an amount of solvent therein. The level sensor  122  is operatively connected to the controller  70  to provide a level signal representative of the detected amount of solvent in the tank  116 . The controller  70  is configured to compare the detected solvent level with a threshold (e.g., a threshold amount of solvent equal to an amount of solvent needed to flush the coating system  20  of curable liquid in the purge mode) before operating the coating system in the spraying mode. If the detected solvent level is greater than the threshold, the controller  70  permits the coating system  20  to operate in the spraying mode. If the detected solvent level is less than the threshold, the controller  70  automatically prevents the coating system  20  from operating in the spraying mode until solvent is added to the tank  116 . For example, the controller can force the coating system  20  into the recirculation mode until the solvent level exceeds the minimum threshold. Moreover, a suitable notification of a low solvent level can be caused to be given by the controller  70 . 
     Referring to  FIG. 3 , an exemplary method  300  of operating the coating system  20  to coat a perimeter joint surface  14  with curable liquid will now be described. The method  300  begins at step  310  when the coating apparatus  40  is mounted on the pipeline at an uncoated perimeter joint surface  14 . Once mounted the coating system  20  stores joint identity data about the joint surface  14  it is about to coat. The joint identity data identifies the joint surface  14  and distinguishes the joint surface from other joint surfaces in the pipeline  10 . Suitable joint identity data include global positioning system coordinates for the joint surface  14 , an applicator identifier such as the name of one or more operators of the coating system  20 , application time that identifies the date and time at which the curable liquid is sprayed onto the joint surface, etc. 
     In addition to storing joint identity data, at step  314  the coating system stores process data on the database  100 . In one or more embodiments, the process data includes temperature data, pressure data, pumped volume data, valve position data, etc. from the various component devices used in the coating system  20  and described above. Preferably, the coating system  20  stores process data continuously throughout the execution of the method  300  at intervals of, for example about ten seconds. The coating system associates the process data with the joint identity data. Then later, the joint coating process conditions can be evaluated by comparing the performance of the joint coatings with the recorded process conditions at which the joints were formed. 
     Preferably, when the coating apparatus  40  is initially mounted on the pipeline  40  at the joint surface  14 , the coating system  20  begins to operate in the recirculation mode. As the coating system  20  operates in the recirculation mode, the coating system checks to determine whether all start conditions have been met at decision block  316 . For example, in one or more embodiments, the coating system checks to ensure there are sufficient amounts of the first and second fluid components in the drums  52 A,  52 B and day tanks  58 A,  58 B. As described above, the coating system  20  also checks to determine whether the solvent level exceeds a minimum threshold at step  316 . The coating system  20  can also, at step  316 , determine whether the first and second fluid components flowing through the fluid system  50  in the recirculation mode are at the desired temperatures and pressures. In certain embodiments, the coating system also determines whether the cyclonic vacuum separator  104  is turned on and whether the coating apparatus  40  is securely mounted on the pipeline  10  before proceeding to the spraying modes. 
     Once the coating system  20  determines that the necessary conditions for spraying have been met at step  316 , it provides an indication to an operator that the system is ready for spraying. At step  318  the operator responds to the indication with a command to begin spraying the perimeter joint surface  14 , and the coating system  20  switches to the spray mode and coats the joint (step  320 ). It is to be understood that switch to the spray mode could be carried out automatically. The joint coating step  320  includes the spray buildup mode, spraying mode, and purge mode and is more fully described below in reference to the method  400  of  FIG. 4 . As the coating system  20  carries out step  320 , it continuously monitors various parameters such as fluid temperature, back pressure, pumped volumes, etc. (decision block  322 ). If the monitored parameters are not properly maintained, the coating system  20  notifies the operator at step  324 . If the system  20  maintains the monitored parameters throughout the joint coating step  320 , at step  326  the joint coating process is completed. The crane  24  removes the coating apparatus  40  from the pipeline  10  and the crawler  22  moves the coating system  20  to the next perimeter joint surface  14 . 
     Referring to  FIG. 4 , an exemplary method of coating a joint  400  is suitable for being run during the joint coating step  320  of the method  300 . Thus, once the coating system  20  receives the start command from the operator, the air motor  102  rotates the coating apparatus  40  around the circumference of the pipe to an initial position (step  402 ). With the fluid diverter  106  positioned in front of the sprayer  55 , the coating system  20  begins to build up the spray pattern S (step  403 ). The coating system  20  sprays the curable liquid with the diverter  106  positioned in front of the sprayer  55  until the pressure in and flow rate through the sprayer achieves the desired spray pattern S (e.g., a fan pattern that has a width that increases along with a distance from the sprayer). Once the desired spray pattern is achieved, the coating system  20  retracts the diverter  106 . With the diverter  106  retracted, the flow path is oriented toward the exposed perimeter joint surface  14  (step  404 ). At step  406  the air motor  102  begins to rotate the coating apparatus  40  around the circumference of the pipeline  10  (step  406 ). 
     At decision block  408 , the coating system determines whether the coating apparatus  40  has rotated around the pipeline  10  a number of rotations required to achieve the desired coating thickness. The coating system  20  continues to spray the curable liquid along the flow path while rotating the apparatus  40  around the pipeline  10  until the desired number of rotations is reached. Then, the coating system  20  stops spraying the curable liquid. After the spraying mode has ended, at step  410 , the coating apparatus rotates to a predefined purge location; and at step  412 , the coating apparatus extends the diverter  106  into the flow path. At step  414 , the coating system  20  switches to the purge mode and pumps solvent through the mixing manifold  54  and sprayer  55  to flush the coating apparatus  40  of curable liquid. Once flushing is complete, the motor  102  rotates the coating apparatus  40  to a home position suitable for removing the coating apparatus from the pipeline  10 . 
     It will be understood that the illustrated coating system  20  has automated many of the steps of the methods  300  and  400  using the controller  70 . Although the controller  70  automatically executes various steps of the coating methods  300 ,  400  in the illustrated embodiment, in other embodiments the steps of the methods can be performed manually without departing from the scope of the invention. Moreover, other embodiments can implement a coating method using different sequences of steps without departing from the scope of the invention. 
     Having described the coating system  20  at a system level, reference is now made to  FIG. 5 , which depicts various aspects of an exemplary coating apparatus  40  in greater detail. The coating apparatus  40  is shown mounted on the pipeline  10  to coat the exposed perimeter surface  14  of the pipe sections  10 A,  10 B across the girth weld  16 . The coating apparatus  40  includes a mounting frame  512  configured to be selectively mounted on the joined end portions of the pipe sections  10 A,  10 B for rotation about the longitudinal axis of the pipeline  10 . The mounting frame  512  includes first and second brackets  512 A,  512 B that are selectively pivotable about a hinged connection  514  from an open position (not shown) to a closed position in which the brackets are shaped and arranged for extending around the circumference of the pipeline  10 . The coating apparatus includes two pairs of drive wheels  516 ,  518  and the air motor  102 . The air motor  102  receives compressed air routed from the air compressor  42  through a pneumatics control box  520 . The air motor  102  uses the compressed air to drive rotation of the drive wheels  516 ,  518  to rotate the coating apparatus  40  circumferentially around the pipeline  10 . Other types of drive motors can also be used without departing from the scope of the invention. The drive wheels  516 ,  518  and a third pair of wheels  522 , which are not driven, contact the exterior of the pipeline  10  to guide the apparatus  40  on the pipeline as it rotates. 
     In a preferred embodiment, the coating apparatus  40  can rotate at least one complete revolution around the circumference of the pipeline. In an exemplary embodiment, the controller  70  communicates with the drive motor  102  to automatically direct the motor to rotate the coating apparatus  40  around the pipeline  10 . The coating apparatus  40  sprays a curable liquid on the exposed perimeter surface  14  of the pipeline  10  as the apparatus rotates to coat the joined end portions of the pipe sections  10 A,  10 B. 
     Referring to  FIGS. 5 and 6 , the sprayer  55  is mounted on the mounting frame  512  and configured to deliver fluid along the flow path F toward the exposed perimeter surface  14  of the pipeline  10 . In one suitable embodiment, the sprayer is a GRACO AL Series Automatic Sprayer, available from GRACO Inc. of Minneapolis, Minn. In other embodiments, the coating apparatus uses other sprayers without departing from the scope of the invention. As shown in  FIG. 5 , a shroud  532  substantially surrounds the spray pattern S to prevent overspray. In  FIG. 6 , the shroud  532  has been partially broken away to reveal a flow path F of the spray and show more of the sprayer  55 . 
     Referring to  FIGS. 7-9 , the overspray shroud  532  includes a shroud wall surrounding the flow path F and defining a shroud interior. The shroud  532  has an open bottom (as the shroud is oriented in  FIGS. 4-6 ) that permits spray to pass out of the shroud onto the pipeline  10 . The shroud wall  532  defines a sprayer opening  533  and a vacuum/diverter opening  535 . The overspray shroud  532  and the sprayer  55  are fixed in position relative one another such that the sprayer is oriented to deliver fluid along the flow path F through the sprayer opening  533 . The wall of the shroud  532  is shaped and arranged to substantially contain the delivered fluid within the shroud interior. The sprayer opening  533  is aligned with the sprayer  55  and flow path F so that the sprayer delivers fluid along the flow path through the sprayer opening. As will be discussed in further detail below, the vacuum/diverter opening  535  is sized to receive the diverter  106  for selectively obstructing fluid flow along the flow path F. Likewise, the vacuum/diverter opening  535  is shaped and arranged to couple the shroud interior to a vacuum pressure that draws overspray out of the interior of the shroud. The terms “vacuum opening” and “diverter opening” will be used interchangeably to refer to the vacuum/diverter opening  535  throughout this disclosure. 
     As shown in  FIGS. 5 and 6  mounting bracket  534  fixedly mounts the sprayer  55  on the second mounting frame  512 . When the coating apparatus  40  is mounted on the pipeline  10 , the sprayer  55  does not move relative to the apparatus. Moreover, when the coating apparatus  40  is mounted on the pipeline  10 , the flow path F is oriented in a fixed direction relative to the apparatus and moves conjointly with the apparatus. As will be discussed below, the sprayer  55  is configured to selectively switch between different operational modes in which the sprayer delivers different types of fluid along a flow path F. In each of the operational modes, the flow path F is oriented toward the exposed perimeter surface  14  of the pipeline  10 . But in different operational modes, the sprayer  55  can, in some embodiments, deliver fluids along the flow path F in different dispensing patterns. For example, in at least one operational mode, the sprayer  55  delivers fluid along the flow path F in a spray pattern S in which the delivered fluid fans out across the entire axial length of the perimeter surface  14  between the coatings  12  ( FIG. 1 ) so that the pipe sections are continuously coated after spraying is complete. 
     Preferably, the shroud  532  is shaped and arranged to be spaced apart from the fluid the sprayer  55  delivers along the flow path F. Thus in the illustrated embodiment, the shroud  532  is shaped like a long and narrow box to allow for substantially unobstructed spray of the coating liquid along the flow path F in a wide, fan-like spray pattern which spans the length of the exposed perimeter surface  14  of the pipeline  10 . As discussed above, the sprayer  55  may require a fan buildup mode to build sufficient fluid flow to achieve the desired spray pattern. In addition to the spray pattern, it is understood that the sprayer  55  can deliver fluids along the flow path F with different dispensing patterns. 
     Referring again to  FIGS. 5-6 , the sprayer  55  is configured to deliver different types of fluid along the flow path F depending on the operational mode. As discussed above, the apparatus  40  includes the mixing manifold  54  for mixing together fluids of different types before delivering them through the sprayer  55 . In the drawings, the coating apparatus  40  is shown with the hoses that connect the mixing manifold  54  and sprayer  55  removed for clarity. The mixing manifold  54  is operatively connected to a plurality of fluid sources, such as the day tanks  58 A,  58 B and solvent tank  116 . The mixing manifold  54  can also be connected to other fluid sources without departing from the scope of the invention. As discussed above, the process rig  30  pumps curable liquid components and solvent through the mixing manifold  54  and sprayer  55 . In other embodiments, it is contemplated that the coating apparatus could, instead, use a local pump system and/or local fluid containers without departing from the scope of the invention. 
     As discussed above, the spraying system is configured to switch between several operational modes, including a spraying mode. The coating apparatus  40  is configured to operate in the spraying mode to deliver the curable liquid in a spray pattern along the flow path F to coat the exposed perimeter joint surface  14  of the pipeline  10 . As the sprayer  55  sprays the curable liquid, the motor  120  drives apparatus  40  in rotation around the circumference of the pipeline  10  so that the sprayer delivers a substantially uniform coating over the exposed perimeter surface  14 . In a preferred embodiment, the controller  70  sequences the operation of the sprayer  55  in the spraying mode with the operation of the drive motor  102  to cover the exposed perimeter surface  14  with a substantially uniform coating of curable liquid material, which cures to form an anticorrosion coating on the pipeline  10 . 
     Operational modes other than the spraying mode in which fluid flows through the sprayer  55  can generally be referred to as “preparation modes” because they each are used to prepare the coating apparatus for operating in the spraying mode at some future time. For example, in the purge mode, the coating system  20  prepares the sprayer  55  for spraying by flushing residual curable liquid from the sprayer. Likewise, in the spray buildup mode, the coating system  20  prepares the sprayer  55  for spraying by building up a fan pattern suitable for coating the joint surface  14  with the curable liquid. In either of these uses of the preparation mode, the sprayer  55  delivers fluid, such as solvent or curable liquid that is not used in coating the pipeline  10  along the flow path F. Because the sprayer  55  is fixed in position relative to the mounting frame  512 , the sprayer directs the fluid toward the perimeter surface  14  of the pipeline  10  in the preparation mode just as in the spraying mode. The application of fluid to the perimeter surface  14  of the pipeline  10  either before or after spraying the pipeline with the curable liquid can damage the resulting coating. As discussed below, in the preparation mode, the coating apparatus  40  is configured to divert the fluid away from the exposed surface  14  of the pipeline  10  to prevent damage to the coating. 
     Referring to  FIGS. 8 and 9 , the fluid diverter  106  is configured to divert fluid dispensed along the flow path F in the preparation mode. The fluid diverter  106  is movably secured to the mounting frame  512 . In the illustrated embodiment, the fluid diverter  106  is movable relative to the sprayer  55  between a fluid diverting position ( FIG. 8 ) and a non-diverting position ( FIG. 9 ). In the fluid diverting position, the diverter  106  intersects in the flow path F to divert the fluid away from the perimeter surface  14  of the pipeline  10 . The controller  70  preferably automatically positions the fluid diverter  106  in the fluid diverting position when the sprayer  55  operates in the preparation mode. In the non-diverting position shown in  FIG. 9 , the diverter  106  is spaced apart from the flow path F to permit free flow of fluid from the sprayer toward the exposed perimeter surface  14 . The controller  70  preferably automatically positions the diverter  106  in the non-diverting position when the sprayer  55  operates in the spraying mode to permit free flow of the curable liquid to the perimeter surface  14 . 
     In the illustrated embodiment, the diverter  106  is movable along a diverter movement axis A between the fluid diverting and non-diverting positions. It will be understood, that a fluid diverter may be movable in other ways (e.g., by pivoting, etc.) without departing from the scope of the invention. The diverter movement axis A extends transverse (e.g., generally perpendicular) to the flow path F. The diverter  106  extends through the diverter opening  535  in the side wall of the shroud  532  and moves along the movement axis A through the opening between the fluid diverting and non-diverting positions. In both the fluid diverting and non-diverting positions, the inner axial end of the diverter  106  is positioned within the interior of the shroud  532 . 
     In the illustrated embodiment, the coating apparatus  40  includes a diverter guide  552  oriented parallel to the diverter movement axis A. The diverter guide  552  defines a guide channel, and a slide  554  is slidingly received in the guide channel. The diverter  106  is mounted on the slide  554  and is thereby received in the diverter guide  552  for movement along the diverter movement axis A. In the illustrated embodiment, a mounting bracket  556  fixedly mounts the diverter guide  552  on the overspray shroud  532 . A pneumatic cylinder  558  ( FIG. 7 ) that is mounted on the shroud  132  operatively connects the diverter  106  to the diverter guide  552  to move the diverter through the diverter guide along the diverter movement axis A between the fluid diverting and non-diverting positions. Preferably, the controller  70  is operatively connected to the pneumatic cylinder  558  to time actuation of the cylinder to automatically position the diverter  106  in the fluid diverting position during the preparation mode and in the non-diverting position during the spraying mode. 
     Although a diverter can have any suitable shape without departing from the scope of the invention, the illustrated diverter  106  is tube-shaped. The diverter  106  has inner and outer axial ends and an annular side wall  551  extending along a longitudinal axis oriented parallel to the diverter movement axis A. The side wall  551  of the diverter  106  defines a lumen  553 . An inner axial end wall  560  bounds an inner end of the lumen  553 , and the lumen extends through the open outer axial end of the diverter  106 . As shown in  FIG. 6 , an aperture  562  is formed in the side wall of the diverter  106  adjacent the inner axial end wall  560 . When the diverter  106  is positioned in the fluid diverting position as shown in  FIG. 8 , the aperture  562  is positioned in the flow path F and opposes the sprayer  55  such that the fluid delivered from the sprayer is delivered through the aperture and into the lumen  553 . Thus, in the fluid diverting position, the illustrated diverter  106  collects diverted fluid in the interior lumen  553 . 
     Referring again to  FIGS. 8 and 9 , in a preferred embodiment, the diverter  106  is operatively connected to the cyclonic vacuum separator  104  (broadly, a vacuum system), which is adapted to draw a vacuum through the interior lumen  553  of the tube. The vacuum system  104  can be a vacuum pump or other apparatus that is mounted on the mounting frame  512  or is located remote from the pipeline  10 . The vacuum system  104  is preferably operatively connected to the open outer end of the diverter  106  to impart a vacuum pressure on the interior lumen  553 . When the diverter  106  is positioned in the fluid diverting position and the sprayer  30  is operating in the preparation mode, the vacuum pressure is operative to draw the diverted fluid through the tube. The fluid flows along a first portion of the fluid flow path F, through the aperture  562 , and into the diverter lumen  553 , where the vacuum pressure draws the fluid out of the diverter  106  and into the vacuum system  104 . As discussed above, the vacuum separator  104  deposits liquid and solid particles in a reclamation vessel  108  and the exhaust fan  110  exhausts gaseous fluids away from the coating system  20 . 
     In a preferred embodiment, the vacuum system  104  is also operative to draw any overspray of curable liquid away from the interior of the shroud  532  during the spraying mode. As discussed above and illustrated in  FIG. 6 , when the cylinder  558  moves the diverter  106  to the non-diverting position, the inner axial end of the tube extends through the diverter opening  535  in the shroud  532  and into the shroud interior. Preferably, the diverter  106  is shaped and arranged in the non-diverting position so that the aperture  562  is located within the interior of the shroud  532 . The vacuum system  104  is operative to draw overspray of the curable liquid through the aperture  562 , into interior lumen  553  of the diverter  106 , and away from the shroud interior. The vacuum separator  104  deposits liquid and solid particles in the reclamation vessel  108  and the exhaust fan  110  exhausts gaseous fluids away from the coating system  20 . 
     As can be seen, the illustrated embodiment employs a dual purpose diverter  106  that functions to draw in overspray during the spraying mode. It will be understood that in other embodiments, the vacuum system may impart a vacuum pressure on a space adjacent the flow path to draw in overspray in other ways without departing from the scope of the invention. 
     A method of using the coating apparatus  40  that highlights the implementation of the diverter  106  will now be briefly described. The crane  22  mounts the apparatus  40  on the pipeline  10  so that the sprayer  55  is oriented toward the perimeter surface  14  of the pipeline. The controller  70  automatically directs the pneumatic cylinder  558  to move the diverter  106  to the fluid diverting position ( FIG. 8 ). The controller  124  then operates the sprayer  55  in the fan buildup mode to build up a fan-shaped spray pattern. In the fan buildup mode, the diverter  106  diverts the flushing fluid away from the perimeter surface  14  of the pipeline  10  and the vacuum system  104  draws the diverted fluid away from the coating apparatus. After completion of the preparation mode, the controller  70  directs the pneumatic cylinder  558  to move the diverter  106  from the fluid diverting position to the non-diverting position ( FIG. 9 ). With the diverter  106  in the non-diverting position, the controller  70  switches the coating system  20  to the spraying mode and sprays the curable liquid over the perimeter joint surface  14  as the coating apparatus  40  rotates. During the spraying mode, the vacuum system  104  draws a vacuum through the diverter  106 , to remove overspray during spraying. After the spraying mode is complete, the controller  70  returns the diverter  106  to the diverting position and operates the sprayer  55  in the purge mode to flush curable liquid out of the sprayer. During the purge mode, the vacuum separator  104  draws the sprayed solvent through the diverter  106  and away from the perimeter joint surface  14 . 
     As can be seen, the illustrated coating apparatus  40  sprays an exposed surface of a pipeline  10  in a controlled manner. The apparatus  40  functions in multiple fluid delivery modes to ensure uniform spraying of curable liquid when the exposed pipeline surface  14  is being coated. The movable diverter  106  allows flushing fluids to be diverted away from the surface  14  of the pipeline  10  without moving of the sprayer  55 . Moreover, the diverter  55  functions in two capacities to dispose of flushing fluids and gaseous fumes associated with the curable coating material. 
     Referring to  FIG. 10  another embodiment of a coating apparatus suitable for use in the coating system  20  is generally indicated at reference number  1040 . The coating apparatus  1040  is similar in many respects to the coating apparatus  40 . Features of the coating apparatus  1040  that correspond with features of the coating apparatus  40  are given the same reference number, plus  1000 . 
     Like the coating apparatus  40 , the coating apparatus  1040  includes a mounting frame  1512  configured to selectively mount a sprayer  1055  on the pipeline  10  so that a flow path F ( FIG. 15 ) intersects an exposed perimeter joint surface  14  of the pipeline. A mixing manifold  1054  is mounted on the frame  1512  and is configured to be fluidly connected to the process rig  30  like the mixing manifold  54 . The manifold  1054  is configured to mix the first and second components together to form the curable liquid and to provide the curable liquid to the sprayer  1055 . A drive motor  1102  is mounted on the mounting frame  1512  and operatively connected to the air compressor  42 . The drive motor  1102  drives rotation of wheels  1518 , which are all driven wheels in certain embodiments. The wheels  1518  contact the pipeline  10  to rotate the coating apparatus  1040  around the pipeline as the sprayer  1055  sprays the curable liquid over the exposed perimeter joint surface  14 . 
     Unlike the mounting frame  512 , the mounting frame  1512  includes a central bracket  1512 A and first and second end brackets  1512 B,  1512 C pivotally secured to the central bracket. Each of the brackets  1512 A,  1512 B,  1512 C comprises parallel plate members. Bracing rods extend between the parallel plate members and fix the parallel plate members in spaced apart relationship. The central bracket  1512 A has a first end portion near the first end bracket  1512 B, a second end portion near the second end bracket  1512 C, and a width extending between the first and second end portions. The first end bracket  1512 B has a pivoting end portion pivotally connected to the first end portion of the central bracket  1512 A at a pivoting connection  1514 B. The first end bracket  1512 B also has a width that extends from the pivoting end portion to an opposite interlocking end portion. The second end bracket  1512 C has pivoting end portion pivotally connected to the second end portion of the central bracket  1512 A at a pivoting connection  1514 C. The second end bracket  1512 C also has a width that extends from the pivoting end portion to an opposite interlocking end portion adjacent the interlocking end portion of the first end bracket  1512 B. 
     The first and second end brackets  1512 B,  1512 C are connected to the central bracket  1512 A to pivot about first and second pivot axes A 1 , A 2 , respectively. As shown in  FIGS. 11 and 12 , the first and second end brackets  1512 B,  1512 C are selectively pivotable about the first and second pivot axes A 1 , A 2  relative the central bracket  1512 A between an open position ( FIG. 11 ) and a closed position ( FIG. 12 ). As will be discussed in further detail below, when the first and second end brackets  1512 B,  1512 C are in the closed position, the interlocking end portions are configured for selective interlocking engagement to secure the mounting frame  1512  on the pipeline  10 . 
     As shown in  FIG. 10 , the coating apparatus  1040  is configured to pivot between the open and closed positions under pneumatic power. Two pneumatic cylinders  1515  are operatively connected to the mounting frame  1512  between the central bracket  1512 A and the first end bracket  1512 B to pivot the first end bracket between the open and closed positions. Two other pneumatic cylinders  1515  are operatively connected to the mounting frame  1512  between the central bracket  1512 A and the second end bracket  1512 C to pivot the second end bracket between the open and closed positions. The controller  70  is preferably operable connected to the pneumatic cylinders  1515  to drive the cylinders to open and close the mounting frame  1512  in response to operator commands. 
     Referring to  FIG. 11 , in the open position, the mounting frame  1512  defines an open gap  1517 . The open gap  1517  has a width W 1  extending along a gap axis A 3  that is wider than the pipeline  10 . Thus, in the open position, the coating apparatus  1040  may be installed on or removed from the pipeline  10 , whereby the pipeline passes through the gap  1517  without contacting the frame. More specifically, the pipeline  10  can pass through the gap  1517  without contacting the frame  1512  by moving the coating apparatus  1040  along a gap movement axis A 4  perpendicular to the gap axis A 3 . By using three brackets  1512 A,  1512 B, and  1512 C and two pivoting connections  1514 B,  1514 C, the mounting frame  1512  can be pneumatically opened to have a wide pipeline receiving gap  1517 . As a result, when removing the coating apparatus  1040  from the pipeline  10  after the perimeter joint surface  14  is coated with the curable liquid, it is less likely that the mounting frame  1512  will contact the pipeline and damage the coating material. 
     Referring to  FIG. 12 , in the closed position, the mounting frame  1512  is shaped and arranged for extending circumferentially around the pipeline  10  to mount the coating apparatus  1040  on the pipeline. In the illustrated embodiment, the mounting frame  1512  extends around the entire circumference of the pipeline. The interlocking end portions of the first and second end brackets  1512 B,  1512 C are positioned adjacent one another opposite the central bracket  1512 A. Though the illustrated embodiment is shaped and arranged to extend substantially around the entire circumference of the pipeline in the closed position, it will be understood that other mounting brackets can extend around less than the entire circumference of a pipeline without departing from the scope of the invention. As shown in  FIG. 12 , the mounting frame  1512  is preferably shaped and arranged to automatically position the drive wheels  1518  in contact with the pipeline  10  when the mounting frame  1512  is closed around the pipeline. This ensures the drive motor  1102  can drive rotation of the coating apparatus  1040  around the pipeline during spraying. 
     Referring to  FIGS. 13 and 14 , the illustrated coating apparatus  1040  includes a locking mechanism  1511  configured to selectively lock the mounting frame  1512  is in the closed position. The locking mechanism  1511  includes a retaining shaft  1521  (broadly, a retaining member) that is fixed to the interlocking end portion of the first end bracket  15126 . In the illustrated embodiment, the retaining shaft  1521  extends between the plate members forming the first end bracket  1512 B. In other embodiments retaining members can have other configurations without departing from the scope of the invention. The locking mechanism  1511  also includes plurality locking hooks  1523  (each, broadly a locking member). The locking hooks  1523  are configured to lockingly engage the retaining shaft to secure the mounting frame  1512  in the closed position on the pipeline  10 . The locking hooks  1523  are pivotally connected to the interlocking end portion of the second end bracket  1512 C. In the illustrated embodiment the locking hooks  1523  are spaced apart along a pivoting shaft  1525  extending between the two plate members forming the second end bracket  1512 B. The pivoting shaft  1525  is pivotally mounted on the mounting frame  1512  to pivot about a pivot axis A 5 . The pivoting shaft  1525  and the retaining shaft  1521  extend along parallel axes in the illustrated embodiment. 
     The locking hooks  1523  are selectively pivotable around the pivot axis A 5  from an unlocked position ( FIG. 13 ) in which the locking hooks are spaced apart from the retaining shaft  1521  to a locked position ( FIG. 14 ) in which the locking hooks lockingly engage the retaining shaft. Each of the locking hooks  1523  has hook end and an opposite free end. Each hook end is sized and arranged for interlockingly engaging the retaining shaft  1521 . In the illustrated embodiment, the locking hooks  1523  are fixedly mounted on the pivoting shaft  1525 , and the pivoting shaft is configured to pivot around the pivot axis A 5 , which is collocated with the central longitudinal axis of the pivoting shaft. Alternatively, the locking hooks could be pivotally mounted on the pivot shaft to pivot around a pivot axis without departing from the scope of the invention. The pivot shaft could also be pivotally mounted on one or more pivot arms that pivot about a pivot axis spaced apart from the central longitudinal axis thereof without departing from the scope of the invention. 
     A pneumatic cylinder  1527  is operatively connected to an attachment shaft  1529  that is attached to the free ends of the locking hooks  1523 . When the pneumatic cylinder  1527  is actuated, it drives the attachment shaft  1529  and locking hooks  1523  in rotation about the pivot axis A 5  to pivot the hooks between the locked and unlocked positions. Preferably, the controller  70  is operatively connected to the pneumatic cylinder  1527  to selectively actuate the cylinder to move the locking hooks  1523  about the pivot axis A 5  between the locked and unlocked positions. 
     As shown in  FIG. 15 , the sprayer  1055  is configured to spray the curable liquid toward the perimeter joint surface  14  along a flow path F that widens as the curable liquid travels away from the sprayer. The sprayer  1055  has a spray nozzle  1057 . The sprayer  1055  delivers the curable liquid along the flow path F so the fluid flow is oriented away from the spray nozzle  1057 . The flow path F has a spray pattern that flares outwardly in a fan pattern such that the flow path has a width W 2 . The width W 2  of the flow path F increases as a distance D of the flow path from the spray nozzle  1057  increases. As a result of the fan pattern of the flow path F, the sprayer  1055  is capable of coating different widths of the pipeline  10  with the curable liquid depending on the distance between the spray nozzle  1057  and perimeter surface  14 . In the illustrated embodiment, the coating apparatus  1040  is configured to adjust the distance D between the spray nozzle  1057  and the perimeter surface  14  to adjust the width W 2  of the pipeline  10  the coating apparatus sprays with the curable liquid. 
     Referring to  FIGS. 16 and 17 , the illustrated coating apparatus includes an adjustable sprayer mount  1611 . The sprayer mount  1611  mounts the sprayer  1055  and shroud  1532  on the mounting frame  1512  for movement relative to the mounting frame. The sprayer mount  1611  orients the sprayer  1055  so that the flow path F is oriented toward the perimeter surface  14  of the pipeline  10  when the mounting frame is mounted on the pipeline ( FIG. 15 ). Moreover, as shown by comparison of  FIGS. 16 and 17 , the sprayer mount  1611  is configured to selectively move the sprayer  1055  relative to the mounting frame  1512  to adjust the distance D between the spray nozzle  1057  and the exterior surface of the pipeline to thereby adjust the width Ws of the flow path F at the location where the flow path intersects the exterior surface  14  of the pipeline. 
     In the illustrated embodiment, the sprayer mount comprises a threaded shaft  1613  and a pair of threaded guide collars  1615  threadably mated to the threaded shaft. The threaded shaft  1613  is mounted on the mounting frame  1512  for rotation relative to the mounting frame, but is prevented from moving in translation relative to the mounting frame along its longitudinal axis. The guide collars  1615  are threaded onto the shaft  1613  and fixedly mounted on the overspray shroud  1532 . The sprayer  1055  is also fixedly mounted on the overspray shroud  1532 . An adjustment knob  1617  is fixed to the free end of the shaft  1613  to allow a user to rotate the threaded shaft. The threaded shaft  1613  rotates in the guide collars  1615 , which causes the guide collars to translate relative the shaft along its longitudinal axis. The shroud  1532  and sprayer  1055  move conjointly with the guide collars  1615  and relative to the perimeter joint surface  14  of the pipeline  10 . 
     Thus, a user can adjust the distance D between the spray nozzle  1057  and the perimeter joint surface  14  and thereby adjust the width Ws of the spray pattern S at the joint surface by rotating the knob  1617 . Although the illustrated embodiment uses a threaded shaft mounted on the mounting frame and threaded collars monted on the sprayer assembly to form the movable sprayer mount, it will be understood that other embodiments can use other movable sprayer mounts to adjust the width of the sprayed-on coating without departing from the scope of the invention. Moreover, it is also contemplated that the distance adjustment could be automated without departing from the scope of the invention. 
     In the illustrated embodiment, the sprayer  1055  and shroud  1532  are supported as they move relative to the mounting frame  1512 . The coating apparatus  1040  includes non-threaded support shafts  1619  oriented parallel to the threaded shaft  1613 . The support shafts  1519  are mounted on the base frame  1512 . Each of the support shafts  1619  is slidably received in a pair of non-threaded support collars  1621  that is fixed to the shroud  1532 . As the guide collars  1615  translate relative to the threaded shaft  1613 , the support collars  1621  slide along the support shafts  1619  to support the shroud  1532  as it moves. 
     Referring to  FIG. 18 , aspects of an exemplary embodiment of the process rig  30  will now be described. The process rig  30  includes a housing  1802  that has a front end  1803 , a rear end  1804 , and a floor  1805 . The housing  1802  defines a process rig interior  1808 . The process rig interior  1806  receives various components of the fluid system  50 , such as the day tanks  52 A,  52 B, pumps  76 A,  76 B (not shown in  FIG. 18 ), and associated plumbing. 
     Referring to  FIG. 19 , the process rig housing  1802  is also configured to receive the replaceable fluid component drums  52 A,  52 B. Conventionally, the components of a curable liquid are manufactured and stored in large drums (e.g.,  55 -gallon drums) that are difficult to transport and store. The term “drum” will refer to any suitable movable container for storing one or more components of a curable liquid. Rather than pouring the first and second fluid components from the drums  52 A,  52 B into the day tanks  58 A,  58 B, the illustrated process rig  30  includes drum fittings  1810 A,  1810 B that can be fitted over the open top ends of new drums as they are replaced. The fittings  1810 A,  1810 B fluidly connect the drums  52 A,  52 B to the fluid system  50  so that the pumps  56 A,  56 B can pump the first and second fluids into the day tanks  58 A,  58 B. Once the pumps  56 A,  56 B pump out all of the fluid contained in one of the drums  52 A,  52 B, the empty drum can be removed and a new drum can be installed. As explained below and illustrated by comparison of  FIGS. 19 and 20 , the process rig  30  includes a movable drum support  1820 , which simplifies the process of replacing the drums  52 A,  52 B. 
     As shown in  FIG. 21 , the illustrated drum support  1820  comprises a base  1822  and a movable platform  1824 . The base  1820  is fixedly mounted on the floor  1805  of the process rig housing  1802  near the front end  1803 . The base  1820  includes an outer base frame  1826  and an inner tray  1828 . The base frame  1826  supports guide rails  1830  that guide movement of the platform  1824  relative to the base  1822 . The tray  1828  defines a secondary liquid containment cavity  1832  for receiving any liquid that is spilled from either of the drums  52 A,  52 B in use ( FIG. 19 ). 
     The platform  1824  is configured to support the drums  52 A,  52 B. The platform  1824  includes an outer frame  1840 , which is slidably mounted on the base  1822 . The platform  1824  rotatably mounts guide rollers (not shown) that are received in the guide rails  1830 . As the platform  1824  slides relative to the base  1822 , the guide rollers roll along the guide rails  1830  to guide the movement of the platform. Preferably, the platform  1824  is liquid-permeable. In the illustrated embodiment, the platform comprises a metal grate  1842  that is supported by the frame  1840 . The platform  1824  permits any liquid that leaks or spills from the drums  52 A,  52 B to pass through the metal grate. 
     The platform  1824  is slidably mounted on the base to slide relative to the base between a drum loading position ( FIG. 20 ) and an operational position ( FIG. 19 ). In the drum loading position, the platform  1824  extends out of the front end  1803  of the process rig housing  1802 . In some embodiments, the interior  1805  of the process rig  30  is small. Because of the small size, it can be difficult to load the oftentimes bulky drums  52 A,  52 B into the process rig  30 . By extending the platform  1824  outside the process rig in the drum loading position, the drums  52 A,  52 B can be more easily removed from and loaded onto the drum support  1820 . Once new drums are positioned on the platform  1824 , the platform can slide relative to the base  1822  to the operational position. In the operational position, the drums  52 A,  52 B are positioned in the interior  1805  of the rig housing  1802 . Moreover, the platform  1824  is positioned over the base  1822 . As a result, any liquid that spills or leaks from the drums  52 A,  52 B falls through the grate  1842  and into the secondary liquid containment cavity  1832 . The tray  1830 , therefore, provides secondary containment of the components of the curable liquid in the event of a leak or spill. 
     Referring again to  FIGS. 19 and 20 , the process rig  30  also includes a movable reclamation vessel support  1850  for supporting the reclamation vessel  108 . In certain embodiments, the reclamation vessel  108  can be removed and replaced after it is filled. Thus, like the drums  52 A,  52 B, it is desirable to provide for easy loading and unloading of the reclamation vessel. The illustrated reclamation vessel support  1850  is substantially the same as the drum support  1820 . The vessel support  1850  includes a base  1852  that is mounted on the floor  1805  of the housing  1802  near the rear end  1804 . The base  1852  includes a tray that defines a secondary containment cavity. A movable, liquid-permeable platform  1854  is slidably mounted on the base to slide between a vessel loading position ( FIG. 20 ) and an operational position ( FIG. 19 ). In the vessel loading position, the platform  1854  extends out of the rear end  1804  of the housing  1802  so that the reclamation vessel  108  can be replaced outside of the housing. In the operational position, the platform  1854  is positioned within the interior  1805  of the housing  1802  over the base  1852 . Any liquid that spills or leaks from the secondary containment vessel falls through the liquid permeable platform  1854  and into the secondary containment cavity defined by the base  1852 . 
     OTHER STATEMENTS OF THE INVENTION 
     The following are statements of the invention described in the present application. Although not currently presented as claims, they constitute applicant&#39;s statement of invention(s) believed to be patentable and may subsequently be presented as claims.
         A. A system for coating a perimeter surface of a pipeline comprising:       

     a coating apparatus comprising:
         a sprayer configured to spray curable liquid along a flow path; and   a frame supporting the sprayer and configured to selectively mount the sprayer on the pipeline to orient the sprayer so the flow path is oriented toward the perimeter surface of the pipeline and to move the sprayer relative to the pipeline to coat the perimeter surface of the pipeline with the curable liquid;       

     a rig located remote from the pipeline comprising one or more containers, each of the one or more containers containing at least one component of the curable liquid; 
     plumbing fluidly connecting the containers to the sprayer; 
     a pump fluidly connected to the plumbing to pump the at least one component of the curable liquid from the one or more containers through the plumbing to form the curable liquid and to pump the curable liquid through the sprayer whereby the sprayer sprays the curable liquid along the flow path; 
     a heater operatively connected to the plumbing to heat at least one component of the curable liquid; 
     a temperature transmitter operatively connected to the plumbing to sense a temperature of the at least one component of the curable liquid and to produce a temperature signal representative of the sensed temperature, the temperature transmitter being located at the coating apparatus; and 
     a controller operatively connected to the temperature transmitter and the heater to receive the temperature signal from the temperature transmitter and to adjust the heater based on the received temperature signal to adjust the temperature of the at least at least one component of the curable liquid.
         B. A system as set forth in claim A wherein the temperature transmitter comprises a first temperature transmitter and the temperature signal produced by the first temperature transmitter comprises a first temperature signal, the system further comprising a second temperature transmitter operatively connected to the plumbing to sense the temperature of the at least one component of the curable liquid to produce a second temperature signal representative of the temperature sensed by the second temperature transmitter, the second temperature transmitter being located remote from the sprayer frame.   C. A system as set forth in claim B wherein the controller is operatively connected to the second temperature transmitter to receive the second temperature signal and is configured to adjust the heater based on the first temperature signal and the second temperature signal.   D. A system as set forth in claim C wherein the rig comprises first and second containers storing first and second components of the curable liquid, respectively, the plumbing defining first and second fluid flow paths and comprising a mixing manifold located at the coating apparatus and fluidly connected to the sprayer, the first fluid flow path extending from the first container to the mixing manifold to convey the first component of the curable liquid to the mixing manifold and the second fluid flow path extending from the second container to the mixing manifold to convey the second component of the curable liquid to the mixing manifold, the mixing manifold being configured to mix the first and second components of the curable liquid to form the curable liquid.   E. A system as set forth in claim D wherein the pump, heater, first temperature sensor, and second temperature sensor are connected to plumbing along the first fluid flow path.   F. A system as set forth in claim E wherein the pump and heater comprise a first pump and first heater, respectively, the system further comprising a second pump, second heater, and third temperature sensor operatively connected to the plumbing along the second fluid flow path.   G. A system as set forth in claim F wherein the controller is operatively connected to the second heater and to the third temperature sensor to receive a third temperature signal from the third temperature sensor and to adjust the second heater based on the third temperature signal.   H. A system as set forth in claim A further comprising a pressure transmitter operatively connected to the plumbing to sense a pressure of the at least one component of the curable liquid and to produce a pressure signal representative of the sensed pressure.   I. A system as set forth in claim H wherein the controller is configured to receive the pressure signal and to adjust the pump based on the pressure signal to adjust the pressure of the at least one component of the curable liquid toward a pressure for spraying the curable liquid.   J. A system as set forth in claim H wherein the pressure transmitter is located at the coating apparatus.   K. A system as set forth in claim J wherein the pressure transmitter comprises a first pressure transmitter and the pressure signal produced by the first pressure transmitter comprises a first pressure signal, the system further comprising a second pressure transmitter operatively connected to the plumbing to sense the pressure of the at least one component of the curable liquid to produce a second pressure signal representative of the pressure sensed by the second pressure transmitter, the second pressure transmitter being located remote from the sprayer frame, the controller being operatively connected to the second pressure transmitter to receive the pressure signal and is configured to adjust the pump based on the first pressure signal and the second pressure signal.   L. A system as set forth in claim A wherein the plumbing includes one or more recirculation valves configured to selectively fluidly disconnect the one or more containers from the sprayer and wherein the plumbing is configured to recirculate the at least one component of the curable liquid when the one or more recirculation valves fluidly disconnects the one or more containers from the sprayer.   M. A system as set forth in claim L wherein the one or more recirculation valves are operatively connected to the controller and the controller is configured to selectively actuate the one or more recirculation valves based on the temperature signal.   N. A system as set forth in claim L wherein the one or more recirculation valves are located at the coating apparatus.   O. A method of controlling the delivery of curable liquid to a sprayer of a coating apparatus, the coating apparatus being configured to selectively mount the sprayer on a pipeline to spray the curable liquid along a flow path oriented toward a perimeter surface of the pipeline and to move the sprayer relative to the pipeline to coat the perimeter surface with the curable liquid, the method comprising:       

     pumping at least one component of the curable liquid from a container located remote from the pipeline through plumbing fluidly connecting the container to the sprayer; 
     receiving a temperature signal representative of a temperature of the at least one component of the curable liquid at the coating apparatus; and 
     adjusting a heater operatively connected to the plumbing based on the received temperature signal to adjust the temperature of the at least one component of the curable liquid toward.
         P. A method as set forth in claim O wherein the step of receiving the temperature signal comprises receiving a first temperature signal, the method further comprising receiving a second temperature signal representative of a temperature of the at least one component of the curable liquid adjacent the container, and wherein the step of adjusting the heater comprises adjusting the heater based on the first temperature signal and the second temperature signal.   Q. A method as set forth in claim O further comprising receiving a pressure signal representative of a pressure of the at least one component of the curable liquid at the coating apparatus.   R. A method as set forth in claim O further comprising adjusting a rate at which the at least one component of the curable liquid is pumped from the container based on the pressure signal.   S. A method a set forth in claim O further comprising actuating at least one recirculation valve to fluidly disconnect the at least one container from the sprayer and to recirculate the at least one component of the curable liquid through the heater.   T. A method of operating a coating apparatus, the coating apparatus comprising a sprayer configured to spray fluid along a flow path and to be selectively switchable between operational modes including a spraying mode in which the sprayer delivers curable liquid along the flow path and a purge mode in which the sprayer delivers a solvent along the flow path to purge the sprayer, the coating apparatus being configured to selectively mount the sprayer on a pipeline to move the sprayer relative to the pipeline while the sprayer is operating in the spraying mode to coat a perimeter surface of the pipeline with the curable polymer, the method comprising:       

     detecting a solvent level representative of an amount of solvent in a solvent container from which the sprayer receives the solvent 
     comparing the detected solvent level to a threshold solvent level; 
     permitting the sprayer to operate in the spraying mode when the detected solvent level is greater than the threshold solvent level; and 
     automatically preventing the sprayer from operating in the spraying mode when the detected solvent level is less than the threshold solvent level.
         U. A method of evaluating a polymeric coating formed on each of a plurality of perimeter joint surfaces of a pipeline, the method comprising:       

     storing in a database spray process data about one or more spray process conditions for each of the joint surfaces, the spray process data being received from one or more process sensors of a joint coating apparatus configured to spray each of the perimeter joint surfaces with a curable liquid to form the respective polymeric coating, said one or more process sensors being configured to detect said one or more spray process conditions while the joint coating apparatus sprays each of the perimeter joint surfaces with the curable liquid; and 
     associating in the database the spray process data for each of the perimeter joint surfaces with joint identity data which identifies the respective perimeter joint surface.
         V. A method as set forth in claim U further comprising storing joint identity data in the database for each of the plurality of perimeter joint surfaces when the joint coating apparatus sprays the respective perimeter joint surface with the curable liquid.   W. A method as set forth in claim U wherein the joint identity data for each of the plurality of perimeter joint surfaces comprises at least one of global positioning system coordinates, an applicator identifier, and an application time for the respective perimeter joint surface.   X. A method as set forth in claim U wherein the process data comprises at least one of a process temperature, process pressure, and process ratio.   Y. A system for monitoring polymeric coating formed on each of a plurality of perimeter joint surfaces of a pipeline comprising:       

     a database configured to store spray process data about one or more spray process conditions for each of the joint surfaces, the spray process data being received from one or more process sensors of a joint coating apparatus configured to spray each of the perimeter joint surfaces with a curable liquid to form the respective polymeric coating, said one or more process sensors being configured to detect said one or more spray process conditions while the joint coating apparatus sprays each of the perimeter joint surfaces with the curable liquid; and 
     a processor executing instructions to associating in the database the spray process data for each of the perimeter joint surfaces with joint identity data which identifies the respective perimeter joint surface.
         AA. A rig for use in delivering a curable liquid to a coating apparatus for coating a perimeter surface of a pipeline, the rig comprising:       

     a housing defining an interior and having a floor; 
     one or more drums located within the housing, each of the one or more drums containing a component of the curable liquid; 
     a drum support comprising:
         a base fixedly mounted on the floor of the housing, the base comprising a tray defining a secondary liquid containment cavity; and   a liquid-permeable platform configured to support the one or more drums, the platform being slidably mounted on the base to slide relative to the base between a drum loading position and an operational position, the platform extending outside of the interior of the housing when positioned in the drum loading position to receive the one or more drums thereupon, the platform being positioned above the tray when the platform is in the operational position such that any of the at least one components of the curable liquid contained in the one or more drums that leaks onto the platform passes through the platform and into the secondary liquid containment cavity.   AB. A rig as set forth in claim AA wherein the liquid permeable platform comprises a metal grate.   AC. A rig as set forth in claim AA further comprising a reclamation vessel configured to receive reclaimed curable liquid from a reclamation system of the coating apparatus.   AD. A rig as set forth in claim AC wherein the rig further comprises a reclamation vessel support comprising:       

     a base fixedly mounted on the floor of the housing, the base comprising a tray defining a secondary liquid containment cavity; and 
     a liquid-permeable platform configured to support the reclamation vessel, the platform of the reclamation vessel support being slidably mounted on the base of the reclamation vessel support to slide relative to the base of the reclamation vessel support between a vessel loading position and an operational position, the platform of the reclamation vessel support extending outside of the interior of the housing when positioned in the vessel loading position to receive the reclamation vessel thereupon, the platform of the reclamation vessel support being positioned above the tray of the reclamation vessel support when the platform of the reclamation vessel support is in the operational position such that any of the curable liquid that leaks onto the platform passes through the platform and into the secondary liquid containment cavity.
         AE. A rig as set forth in claim AD wherein the housing has a front end and a rear end, the base of the drum support being mounted on the floor adjacent the front end of the housing and the base of the reclamation vessel support being mounted on the floor adjacent the rear end of the housing.   AF. A coating apparatus for coating a perimeter surface of a pipeline, the coating apparatus comprising:       

     a mounting frame configured to be selectively mounted on the pipeline; 
     a sprayer having a spray nozzle configured to deliver fluid along a flow path oriented away from the spray nozzle and flaring outwardly in a fan pattern such that the flow path has a width and the width of the flow path increases as a distance of the flow path from the spray nozzle increases; 
     an adjustable sprayer mount mounting the sprayer on the mounting frame for movement relative to the mounting frame, the sprayer mount orienting the sprayer so that the flow path is oriented toward the perimeter surface of the pipeline when the mounting frame is mounted on the pipeline and being configured to selectively move the sprayer relative to the mounting frame to adjust a distance between the spray nozzle and the exterior surface of the pipeline to thereby adjust the width of the flow path at a location where the flow path intersects the exterior surface of the pipeline.
         AG. A coating apparatus for coating a perimeter surface of a pipeline, the coating apparatus comprising:       

     a sprayer configured to deliver a curable liquid along a flow path; and 
     a mounting frame connected to and supporting the sprayer and configured to be selectively mounted on the pipeline to orient the sprayer so that the flow path intersects the perimeter surface of the pipeline, the mounting frame comprising:
         a central bracket having a first end portion, a second end portion, and a width extending between the first and second end portions,   a first end bracket pivotally connected to the first end portion of the central bracket to pivot relative the central bracket around a first pivot axis, and   a second end bracket pivotally connected to the second end portion of the central bracket to pivot relative the central bracket around a second pivot axis spaced apart from the first pivot axis,   the first and second end brackets being selectively pivotable relative the central bracket between a closed position and an open position,   in the closed position, the mounting frame being shaped and arranged for extending circumferentially around at least a portion the pipeline to mount the coating apparatus on the pipeline, and   in the open position, the mounting frame defining an open gap having a width extending along a gap axis that is wider than the pipeline so that the coating apparatus may be removed from the pipeline with the pipeline passing through the gap along a movement axis generally perpendicular to the gap axis without contacting the mounting frame.   AH. A coating apparatus as set forth in claim AG wherein each of the first and second end brackets comprises a first end portion, second end portion, and width extending between the first and second end portions, the first end portion of the first end bracket being pivotally attached to the first end portion of the central bracket and the first end portion of the second end bracket being pivotally attached to the second end portion of the central bracket.   AU. A coating apparatus as set forth in claim AH wherein the second end portions of the first and second end brackets are positioned adjacent one another when the first and second end brackets are positioned in the closed position.   AJ. A coating apparatus as set forth in claim Al further comprising a retaining member fixed to the first end bracket and a locking member movably attached to the second end bracket configured to selectively move relative the second end bracket to engage the retaining member and thereby lock the mounting frame in the closed position.   AK. A coating apparatus as set forth in claim AG wherein the central bracket and first and second end brackets are shaped and arranged to extend substantially around the entire circumference of the pipeline in the closed position.   AL. A coating apparatus as set forth in claim AG further comprising a drive wheel mounted on the mounting frame for rotation about a drive axis, the mounting bracket being shaped and arranged to automatically position the drive wheel in contact with the pipeline when the mounting frame is mounted on the pipeline in the closed position.   AM. A coating apparatus for coating a perimeter surface of a pipeline, the coating apparatus comprising:       

     a sprayer configured to deliver a curable liquid along a flow path; 
     a mounting frame connected to and supporting the sprayer and configured to be selectively mounted on the pipeline to orient the sprayer so that the flow path intersects the perimeter surface of the pipeline, the mounting frame comprising first and second brackets having interlocking end portions, the first and second brackets being selectively movable relative to one another from an open position in which the interlocking end portions are spaced apart from one another to define an open gap sized and arranged to allow the pipeline to pass through the gap and into the mounting frame, and a closed position in which the interlocking ends are positioned adjacent to one another such that the mounting frame is sized and arranged to extend circumferentially around the pipeline to mount the coating apparatus on the pipeline; and 
     a locking mechanism comprising:
         a retaining member at the interlocking end portion of the first bracket; and   a locking member pivotally connected to the interlocking end portion of the second bracket sized and arranged for interlocking engagement with the retaining member, the locking member being selectively pivotable around a pivot axis when the first and second brackets are in the closed position from an unlocked position in which the locking member is spaced apart from the retaining member to a locked position in which the locking member interlockingly engages the retaining member to lock the mounting frame in the closed position.       

     AN. A coating apparatus as set forth in claim AM wherein the locking member comprises at least one hook member comprising a hook end sized and arranged for interlockingly engaging the retaining member in the locked position.
         AO. A coating apparatus as set forth in claim AN wherein the retaining member comprises a retaining shaft extending along an axis oriented generally parallel to the pivot axis.   AP. A coating apparatus as set forth in claim AN wherein the locking mechanism further comprises a pivoting shaft pivotally attached to the interlocking end portion of the second bracket, the at least one hook being fixedly mounted on the pivoting shaft for pivoting therewith around the pivot axis.   AQ. A coating apparatus as set forth in claim AN wherein the at least one hook member comprises a free end opposite the hook end and the locking mechanism further comprises a pneumatic cylinder operatively connected the free end of the at least one hook member and the second bracket to pivot the hook member around the pivot axis.   AR. A coating apparatus as set forth in claim AM wherein the first bracket comprises first and second bracket members spaced apart along the pivot axis and the second bracket comprises first and second bracket members spaced apart along the pivot axis, the retaining shaft extending between the first and second bracket members of the first bracket and locking member comprising a pivot shaft extending along the pivot axis between the first and second bracket members of the second bracket and a plurality of hook members connected to the pivot shaft in spaced apart relationship along the pivot axis.       

     Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. 
     As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.