Patent Publication Number: US-2023136358-A1

Title: System and process for recovering fugitive gas emissions

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/273,119, filed Oct. 28, 2021, and incorporates said provisional application by reference into this document as if fully set out at this point. 
     STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR 
     This application incorporates Slater, D. J.,  TESCorp strikes back against methane , CompressorTech 2 , November 2020, by reference into this document as if fully set out at this point. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention generally relates to a system and process for recovering fugitive gas emissions, and more particularly, systems and processes for recovering wet and dry gas emissions from reciprocating compressor packing boxes, gas-operated control valves and pumps, and other packing systems that leak under normal operating conditions. 
     2. Description of the Related Art 
     Reciprocating compressors in the oil and gas industry commonly emit natural gas (where methane is the main component) during normal operation and during standby under pressure. Reciprocating compressors typically have multiple cylinders, and each cylinder piston rod has a packing case ( FIG.  1   ). Reciprocating compressor maintenance practices may vary, and rod packing vents may be configured. The natural gas emissions from reciprocating compressors can be vented to the environment from the rod packing and blowdowns or as fugitive gases from the various compressor components. Currently, more than 51,000 reciprocating compressors are operating in the U.S. natural gas industry, each with an average of four cylinders, representing over 200,000 piston rod packing systems. These systems contribute over 72.4 billion cubic feet per year of methane emissions to the atmosphere, one of the largest sources of emissions at natural gas compressor stations. 
     All packing systems leak under normal conditions, the amount of which depends on cylinder pressure, fitting and alignment of the packing parts, and amount of wear on the rings and rod shaft. A properly aligned and fitted new packing system may lose approximately 11 to 12 standard cubic feet per hour (scfh). As the system ages, however, leak rates increase from wear on the packing rings and piston rod. Lubricating oil injected into the packing parts can help seal the rings and cups, reduce the wear caused by the operation, and lower heat build-up that accelerates ring wear; however, over the thousands of hours of typical compressor operation, rings wear and leakage increase. The average leakage of large, high-pressure reciprocating compressors ranges from 24 to 150 scfh. 
     One company recently reported measuring emissions of 900 scfh from one compressor rod packing. Under the best conditions, new packing systems properly installed on a smooth, well-aligned shaft can be expected to leak a minimum of about 11.5 scfh. Higher leak rates result from fit, packing parts&#39; alignment, and wear. Leakage typically occurs from four areas: 1) around the packing case through the nose gasket; 2) between the packing cups, which are typically mounted metal-to-metal against each other; 3) around the rings from slight movement in the cup groove as the rod moves back and forth; and/or 4) between the rings and piston rod. Factors other than normal wear can also contribute to emissions, such as faulty installation and damaged components (e.g., cups, rings, gaskets). 
     A recent EPA study released in the Natural Gas STAR Program, “Estimates of Methane Emissions by Segment in the United States,” concerning methane leakage into the environment, stated that methane emissions account for 9.5% of all greenhouse gases ( FIG.  2   ). When based upon CO 2 , these emissions have a comparative effect on the environment that is 25 times that of equivalent CO 2 . The study further found that the energy industry is the second largest source of methane emissions. A 2018 study of these gas emissions, as reported by the EPA, estimated that these methane emissions total approximately 175 million metric tons of carbon dioxide equivalent (MMTCO 2 e) per year to the environment. Of that total, 19% was emitted from the oil and gas industry&#39;s transmission and storage facilities, equating to an emission source of approximately 34 MMTCO 2 e. The breakdown of those emission leaks is 0.68 MMTCO 2 e from gas-operated pneumatic controllers, 15.0 MMTCO 2 e from gas compression equipment seal and packing leaks, 3.1 MMTCO 2 e from centrifugal compressors, and 11.9 MMTCO 2 e from reciprocating compressors. 
     Additionally, the same report indicated that the gas processing industry accounted for an additional 12 MMTCO 2 e of emissions per year to the environment. A similar breakdown of the leaks can also be attributed to 0.68 MMTCO 2 e from gas-operated pneumatic controllers, 15.0 MMTCO 2 e from gas compression equipment, 1.0 MMTCO 2 e from centrifugal compressors, and 1.56 MMTCO 2 e from reciprocating compressors. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention relates to a system and process having an emissions recovery unit that is fluidly coupled to a compressor packing case and other fugitive gas sources, pneumatic pumps, and valves. The system and process maintain a positive pressure in the packing case and then evacuate the gas vapors by producing a vacuum to capture and transport the leaking gas emissions from the packing case to the emissions recovery unit. The system and process pressurize the recovered gas to meet the existing pressure needed to reenter either the first stage of the compressor or the compressor fuel gas systems. As the volumes vary in the packing case, the system and process actuate control valves or operate pumps to maintain a constant vacuum to meet varying flow rates. 
     Accordingly, it is an object of this invention to provide an improved system and process for recovering fugitive gas emissions. 
     Another object of this invention is to provide a system and process for recovering fugitive gas emission sources that can be captured and restored to the process without emitting them into the atmosphere. 
     A further object of this invention is to provide a system and process for recovering wet and dry gas emissions from reciprocating compressor packing boxes, gas-operated control valves and pumps, pneumatic systems, and other packing systems that leak under normal operating conditions without emitting the gas emissions to the environment. 
     A further object of this invention is to provide a system and process for recovering fugitive gas emissions that allows operators to defer packing system changes over much longer periods of operation, thus reducing maintenance and downtime costs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects and advantages of this invention may be more clearly seen when viewed in conjunction with the accompanying drawing wherein: 
         FIG.  1    is a side-sectional illustration of a typical reciprocating compressor rod packing system. 
         FIG.  2    is a tabular view of emission factors for reciprocating compressor rod packing systems by industry sector as reported by the EPA in the Natural Gas STAR Program, “Estimates of Methane Emissions by Segment in the United States.” 
         FIG.  3    is a schematic illustration of an example of an emission recovery unit fluidly coupled to a reciprocating compressor rod packing system for recovering fugitive gas emissions in accordance with an illustrative embodiment of the invention disclosed herein. 
         FIG.  4    is a perspective view of an example of an emission recovery unit for recovering dry gas emissions in accordance with an illustrative embodiment of the invention disclosed herein. 
         FIG.  5 A  is a top elevation view of the emission recovery unit shown in  FIG.  4   . 
         FIG.  5 B  is a first side elevation view of the emission recovery unit shown in  FIG.  4   . 
         FIG.  5 C  is a front elevation view of the emission recovery unit shown in  FIG.  4   . 
         FIG.  5 D  is a second side elevation view of the emission recovery unit shown in  FIG.  4   . 
         FIG.  6    is a piping and instrument diagram illustrating an example fluid flow through the emission recovery unit shown in  FIGS.  4  and  5   . 
         FIG.  7    is a process flow diagram for dry gas applications using the emission recovery unit shown in  FIGS.  4  and  5   . 
         FIG.  8    is a perspective view of an example of an emission recovery unit for recovering wet gas emissions in accordance with an illustrative embodiment of the invention disclosed herein. 
         FIG.  9 A  is a top elevation view of the emission recovery unit shown in  FIG.  8   . 
         FIG.  9 B  is a first side elevation view of the emission recovery unit shown in  FIG.  8   . 
         FIG.  9 C  is a front elevation view of the emission recovery unit shown in  FIG.  8   . 
         FIG.  9 D  is a second side elevation view of the emission recovery unit shown in  FIG.  8   . 
         FIG.  10    is a piping and instrument diagram illustrating an example fluid flow through the emission recovery unit shown in  FIGS.  8  and  9   . 
         FIG.  11    is a process flow diagram for wet gas applications using the emission recovery unit shown in  FIGS.  8  and  9   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention is susceptible to embodiment in many different forms, there are shown in the drawings and will herein be described in detail some specific embodiments of the invention. It should be understood, however, that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments so described. 
     In general, the invention relates to a system and process for recovering fugitive gas emissions, and more particularly, a system and process for recovering wet or dry gas emissions from reciprocating compressor rod packing systems, gas-operated control valves and pumps, pneumatic systems, and other packing systems that leak under normal operating conditions without emitting the gas emissions to the environment. The inventive system and process allow existing wet or dry gas pipelines, utility compression systems, and pneumatic components to meet and comply with the EPA&#39;s “New Source Performance Standards” (40 CFR § 60, subpart 0000a). As used herein, “dry gas” is pipeline-quality gas that has been processed down to almost pure methane, with less than 7 lbs. water content per 1,000,000 cubic feet (CF), whereas “wet gas” is found in the natural state as produced in the oil field. The inventive system and process can also handle saturated gases that contain natural gas liquids (NGLs) and are water saturated. 
     The system and process for recovering fugitive gas emissions from gas compression systems and gas-operated components include an emissions recovery unit  1000  that is designed for either dry gas applications (up to 970 Btu/CF, less than 7 lbs. water per MMCF) ( FIGS.  4  through  7   ) or wet gas applications (up to 2500 Btu/CF) ( FIGS.  8  through  11   ). The system and process can have capacities of up to 1500 scfh and discharge pressures of up to 200 pounds per square inch in gauge (psig). 
     Referring to  FIG.  3   , the emissions recovery unit  1000  is fluidly coupled to an air supply (e.g., customer-supplied process air)  108  and fluidly coupled to a compressor packing case  100 . In addition, the emission recovery unit  1000  can be fluidly coupled to other fugitive gas sources, pneumatic pumps, and valves  110 . The system and process maintain a positive pressure in the packing case  100 , and then evacuate the gas vapors  106  by producing a vacuum (e.g., about 150 psig) to capture and transport the leaking emissions  106  from the packing case  100  to the emissions recovery unit  1000 . The system and process pressurize the recovered gas  106  to meet the existing pressure needed to reenter either the first stage of the compressor  102 A or the compressor fuel gas systems  102 B. The volumes vary as the packing case  100  leakage  106  changes, and in response, the system and process actuate control valves or operate pumps to maintain a constant vacuum to meet varying flow rates. 
     Turning now to  FIGS.  4  through  11   , wherein  FIGS.  4  through  7    illustrate a dry gas emission recovery unit  1000  and  FIGS.  8  through  11    illustrate wet gas emissions recovery unit  1000 , and wherein like numerals of reference designate like elements throughout the several views, the emissions recovery unit  1000  includes a hermetically sealed compressor/motor  1001 / 1101  in fluid communication with an inlet vessel  1401 , a gas/oil separation and stabilization assembly  1616 / 1621 , a heat exchanger assembly  1201 , a back pressure regulator valve  1341  or a condensate blowback vessel  1451  through a series of piping and valve members. Gas fluid flows through the unit  1000  along a gas flow path represented by arrows G, and oil fluid flows through the unit  1000  along an oil fluid flow path represented by arrows O. The inlet vessel  1401  is fluidly connected to the packing case  100 , and the inlet vessel  1401  includes an inlet check valve  1305 , a pressure relief valve  1309 , and a pressure transducer  1502 . The inlet vessel  1401  is also fluidly coupled to an upstream side of the compressor/motor  1001 / 1101 . The compressor  1001  can be an encapsulated scroll compressor  1001 , and the motor  1101  can be a variable frequency drive (VFD) (e.g., a three-phase 480 VAC VFD, 15 hp (11.2 kW) without packing or seal to prevent leaks). 
     A downstream side of the compressor/motor  1001 / 1101  is fluidly coupled to an upstream side to the gas/oil separation and stabilization assembly  1616 / 1621 . The compressor/motor/ 1001 / 1101  forces the recovered gas from the inlet vessel  1401  along the gas flow path G through a discharge temperature transducer  1508  to the gas/oil separation and stabilization assembly  1616 / 1621 , which includes an oil reservoir  1616 , an gas/oil separator  1621 , a temperature transducer  1531 , a low oil level switch  1615 , and an oil drain valve  1624 . For wet gas applications ( FIGS.  8 - 11   ), the gas/oil separation and stabilization assembly  1616 / 1621  further includes a stabilizer temperature transducer  1551  and a stabilizer heater  1552 . The oil reservoir  1616  can include an upper and a lower sight glass  1617 A and  1617 B, and the gas/oil separator  1621  can include a separator filter  1625 . 
     From the gas/oil separator  1621 , the recovered gas flowed through a pressure relief valve  1311  and a differential pressure indicator (“DPI”) gauge  1622 , which may be configured to maintain a gas flow pressure of about 200 psig, into a gas cooler  1204  of the heat exchanger assembly  1201 . Oil from the oil reservoir  116  is pumped through an oil filter  1618  or a DPI gauge  1619 , through a coolant thermostatic valve (e.g., set at about 200° F.), and into a lube oil cooler  1208  of the heat exchanger assembly  1201 . The heat exchanger assembly  1201  also includes a heat exchanger motor  1209  (e.g., a three-phase 480 VAC, ½ hp) that pumps the oil from the oil cooler  1208  along oil flow path O through an oil cooler discharge temperature indicator  1525 , a compressor inlet check valve  1623 , and back to the compressor  1101 . 
     The heat exchanger motor  1209  pumps the gas from the gas cooler  1204  along gas flow path G through a gas cooler discharge temperature indicator  1541  and into the discharge separator  1411 . The discharge separator  1411  can be fluidly coupled to a liquid level control  1412  and a high-pressure liquid level switch  1519 . In addition, the discharge separator  1411  is fluidly coupled to the back pressure regulator  1341  (e.g., set at about 60 psi) along the gas flow path  102  to the discharge check valve  1306  before being flowed back to the compressor packing  100 . The discharge separator  1411  is also fluidly connected to a pressure relief valve  1310  (e.g., set at about 200 psi) and to a condensate blowback vessel  1451  along the condensate flow path  104 . A liquid level control  1452  and a high-pressure liquid level switch  1518  are fluidly coupled to the blowback vessel  1451 , and the condensate flow  104  passes through a condensate control/check valve  1455  before being discharged from the unit  100 . 
     Although the valve members of the system and process in the PI&amp;D of  FIGS.  6  and  10    are illustrated as pressure relief valves, relief valves, and check valves, the invention is not so limited and other types of valves may be used, including but not limited to, gate valves, globe valves, solenoid valves, hydraulic valves, motor-operated valves, powered valves, butterfly valves, flap valves, or any other form of shut-off valves to control or stop the flow of the air or gas through the piping of the emission recovery unit  1000 . 
     In addition, the emissions recovery unit  1000  may be mounted on a skid or mobile unit  1701  to access hard-to-reach reciprocating compressor rod packing systems, such as in a gas or power plant that requires the skid or mobile unit able to fit on elevators or in an oil or gas field, pipeline exchange or storage hub. An optional weather-proof enclosure  1702  can protect the unit  1000 , which as noted, can have a compact (e.g., 4×4 ft. (1.2×1.2 m)) footprint for ease of installation and utilization of space. The system and process for removing emissions can be a self-contained system that is automated with sensing capabilities for taking lubricant measurements or the like. 
     If programmable logic is used, such logic may execute on a commercially available processing platform or a special-purpose device. One of ordinary skill in the art may appreciate that embodiments of the disclosed subject matter can be practiced with various computer system configurations, including multi-core multi-processor systems, minicomputers, mainframe computers, computers linked or clustered with distributed functions, as well as pervasive or miniature computers that may be embedded into virtually any device. For example, a controller  1501  for automatic operation and capacity control. The control panel  1501  of the emission recovery unit  1000  can be an assembled PLC control panel per NEC Class I, Group D, Division II and include a customer interface and local fault annunciation. The control panel  1501  can contain control logic to properly operate and safeguard the unit  1000  during operation. In addition, the emission recovery unit  1000  can include various operational instruments, such as a high/low suction pressure transducer  1502 , a high/low discharge pressure transducer  1503 , a high discharge temperature transducer  1508 , a condensate level controller level switch  1518 , and a stabilizer oil temperature controller  1551  and PLC control, and other suitable instrumentation depending upon the particular application. 
     Moreover, the system and process disclosed herein can be implemented using a “smart application”-type software, allowing the system and process to be operated remotely by a tablet or smartphone. For example, the system and process may be implemented in a computer system using hardware, software, firmware, tangible computer-readable media having instructions stored thereon, or a combination thereof and may be implemented in one or more computer systems or other processing systems. 
     For instance, at least one processor device and a memory may be used to implement the above-described embodiments. A processor device may be a single processor, a plurality of processors, or combinations thereof. Processor devices may have one or more processor “cores.” 
     Various embodiments of the inventions may be implemented in terms of this example computer system. After reading this description, it will become apparent to a person skilled in the relevant art how to implement one or more of the inventions using other computer systems and/or computer architectures. Although operations may be described as a sequential process, some of the operations may be performed in parallel, concurrently, and/or in a distributed environment and with program code stored locally or remotely for access by single or multi-processor machines. In addition, in some embodiments, the order of operations may be rearranged without departing from the spirit of the disclosed subject matter. 
     The processor device may be a special-purpose or a general-purpose processor device or maybe a cloud service wherein the processor device may reside in the cloud. As will be appreciated by persons skilled in the relevant art, the processor device may also be a single processor in a multi-core/multi-processor system, such system operating alone or in a cluster of computing devices operating in a cluster or server farm. The processor device is connected to a communication infrastructure, for example, a bus, message queue, network, or multi-core message-passing scheme. 
     The computer system also includes a main memory, for example, random access memory (RAM), and may also include a secondary memory. The secondary memory may include, for example, a hard disk drive or a removable storage drive. The removable storage drive may include a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, a Universal Serial Bus (USB) drive, or the like. The removable storage drive reads from and/or writes to a removable storage unit in a well-known manner. The removable storage unit may include a floppy disk, magnetic tape, optical disk, etc., which is read by and written to by the removable storage drive. As will be appreciated by persons skilled in the relevant art, the removable storage unit includes a computer usable storage medium having stored therein computer software and/or data. 
     The computer system (optionally) includes a display interface (which can include input and output devices such as keyboards, mice, etc.) that forwards graphics, text, and other data from communication infrastructure (or from a frame buffer not shown) for display on a display unit. 
     In alternative implementations, the secondary memory may include other similar means for allowing computer programs or other instructions to be loaded into the computer system. Such means may include, for example, the removable storage unit and an interface. Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, PROM, or Flash memory) and associated socket, and other removable storage units and interfaces which allow software and data to be transferred from the removable storage unit to computer system. 
     The computer system may also include a communication interface. The communication interface allows software and data to be transferred between the computer system and external devices. The communication interface may include a modem, a network interface (such as an Ethernet card), a communication port, a PCMCIA slot, and card, or the like. Software and data transferred via the communication interface may be in the form of signals, which may be electronic, electromagnetic, optical, or other signals capable of being received by the communication interface. These signals may be provided to the communication interface via a communication path. Communication path carries signals, such as over a network in a distributed computing environment, for example, an intranet or the Internet, and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link, or other communication channels. 
     In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage unit, removable storage unit, and a hard disk installed in the hard disk drive. The computer program medium and computer usable medium may also refer to memories, such as main memory and secondary memory, which may be memory semiconductors (e.g., DRAMs, etc.) or cloud computing. 
     Computer programs (also called computer control logic) are stored in the main memory and/or the secondary memory. The computer programs may also be received via the communication interface. Such computer programs, when executed, enable the computer system to implement the embodiments as discussed herein, including but not limited to machine learning and advanced artificial intelligence. In particular, the computer programs, when executed, enable the processor device to implement the processes of the embodiments discussed here. Accordingly, such computer programs represent controllers of the computer system. Where the embodiments are implemented using software, the software may be stored in a computer program product and loaded into the computer system using the removable storage drive, the interface, the hard disk drive, or the communication interface. 
     Moreover, embodiments of the disclosure may be practiced with other computer system configurations, including hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframe computers, and the like. Embodiments of the disclosure may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. 
     Embodiments of the inventions also may be directed to computer program products comprising software stored on any computer useable medium. Such software, when executed in one or more data processing devices, causes a data processing device(s) to operate as described herein. Embodiments of the inventions may employ any computer-useable or readable medium. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, and optical storage devices, MEMS, nanotechnological storage device, etc.). 
     The description of the invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “front,” “rear,” “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly” etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the machine be constructed or the process to be operated in a particular orientation. Terms, such as “connected,” “connecting,” “attached,” “attaching,” “join” and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece. 
     The benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. The operations of the methods described herein may be carried out in any suitable order or simultaneously where appropriate. Additionally, individual blocks may be added or deleted from any of the methods without departing from the spirit and scope of the subject matter described herein. Aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples without losing the effect sought. 
     The above description is given by way of example only, and various modifications may be made by those skilled in the art. The above specification, examples, and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this specification. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Part/Reference Nos. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1001 
                 Compressor first stage 
               
               
                 1101 
                 Motor 
               
               
                 1201 
                 Heat exchanger assembly 
               
               
                 1204 
                 First stage aftercooler 
               
               
                 1208 
                 Lube oil cooler 
               
               
                 1209 
                 Heat exchanger motor 
               
               
                 1227 
                 Coolant thermostatic valve 
               
               
                 1303 
                 Automatic bypass valve 
               
               
                 1305 
                 First stage check valve 
               
               
                 1306 
                 Discharge check valve 
               
               
                 1309 
                 Relief valve for 1401 
               
               
                 1310 
                 Relief valve for 1411 
               
               
                 1311 
                 First-stage relief valve 
               
               
                 1315 
                 Instrument control regulator 
               
               
                 1317 
                 Discharge Isolation Valve 
               
               
                 1318 
                 Bleed Valve for 1401 
               
               
                 1319 
                 Isolation Valve for 1401 
               
               
                 1321 
                 First-stage isolation valve 
               
               
                 1324 
                 Compressor inlet flex line 
               
               
                 1325 
                 Compressor discharge flex line 
               
               
                 1327 
                 Pressure instrumentation isolation valve 
               
               
                 1329 
                 Control valve for scrubber/1451 
               
               
                 1330 
                 Control valve for 1000/1451 
               
               
                 1331 
                 Regulator for 1000/1451 
               
               
                 1332 
                 Purge valve for 1451 
               
               
                 1341 
                 Back pressure regulator 
               
               
                 1401 
                 Inlet vessel 
               
               
                 1407 
                 Condensate Pump 
               
               
                 1411 
                 Discharge separator 
               
               
                 1412 
                 Liquid level control for 1411 
               
               
                 1413 
                 Dump valve discharge separator for 1411 
               
               
                 1416 
                 Sight glass for 1411 
               
               
                 1451 
                 Condensate blowback vessel 
               
               
                 1452 
                 Liquid level control for 1451 
               
               
                 1453 
                 Control valve for 1451 
               
               
                 1454 
                 Manual dump valve for 1451 
               
               
                 1455 
                 Condensate control/check valve for 1451 
               
               
                 1456 
                 Liquid level sight gauge for 1451 
               
               
                 1457 
                 Solenoid valve for 1407/Liquid transfer controller for 1451 
               
               
                 1458 
                 Vapor transfer controller for 1451 
               
               
                 1501 
                 Control panel 
               
               
                 1502 
                 Inlet pressure transducer 
               
               
                 1503 
                 Discharge pressure transducer 
               
               
                 1505 
                 Blowdown pressure transducer 
               
               
                 1508 
                 Discharge temperature transducer 
               
               
                 1518 
                 Liquid level switch for 1451 
               
               
                 1519 
                 Liquid level switch for 1411 
               
               
                 1525 
                 Oil cooler discharge temperature indicator 
               
               
                 1531 
                 Compressor discharge temperature gauge 
               
               
                 1541 
                 Gas cooler discharge temperature indicator 
               
               
                 1551* 
                 Stabilizer temperature transducer 
               
               
                 1552* 
                 Stabilizer heater 
               
               
                 1553 
                 Blowdown/scrubber solenoid valve 
               
               
                 1554 
                 Blowdown/ERU solenoid valve 
               
               
                 1555 
                 Discharge isolation valve/ERU solenoid valve 
               
               
                 1615 
                 Low oil level switch for 1616 
               
               
                 1616 
                 Oil reservoir 
               
               
                 1617A/B 
                 Sight glass for 1616 
               
               
                 1618 
                 Compressor oil filter 
               
               
                 1619 
                 Differential pressure indicator (“DPI”) gauge for 1618 
               
               
                 1621 
                 Gas/oil separator 
               
               
                 1622 
                 DPI gauge for 1621 
               
               
                 1623 
                 Compressor inlet oil check valve 
               
               
                 1624 
                 Drain valve for 1616 
               
               
                 1625 
                 Filter element for 1621 
               
               
                 1626 
                 Needle valve for scavenge line from 1616/1625 
               
               
                 1627 
                 Sight glass for scavenge line from 1616/1625 
               
               
                 1628 
                 Check valve for scavenge line from 1616/1625 
               
               
                 1701 
                 Skid 
               
               
                 1702 
                 Enclosure 
               
               
                   
               
               
                 *FIGS. 8-11 only.