Piston-driven pressure differential systems and methods

Abstract

Piston-driven pressure differential systems and methods are disclosed herein. An example apparatus includes a first cylinder fluidly coupled between a bleed gas source and a first pipe location, a first piston positioned in the first cylinder, and an actuator operatively coupled to the first piston and fluidly coupled between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the second pipe location to drive reciprocal motion of the actuator and the first piston, the reciprocal motion of the first piston to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

Description

PISTON-DRIVEN PRESSURE DIFFERENTIAL SYSTEMS ANDMETHODSRELATED APPLICATION

[0001] This patent claims priority to U.S. Provisional Application No. 63 / 614,292, titled ■‘Piston-Driven Pressure Differential Systems and Methods,’’ filed December 22, 2023. U.S. Provisional Application No. 63 / 614,292 is hereby incorporated by reference in its entirety.FIELD OF THE DISCLOSURE

[0002] This disclosure relates generally to gas pipelines and, more particularly, to piston- driven pressure differential systems and methods.BACKGROUND

[0003] In a natural gas pipeline, gas in a pipe can include methane and / or one or more other constituent gases. In some instances, gas-operated equipment can be implemented on the pipe to utilize pressurized gas from the pipe. The gas is often vented to the atmosphere, which is wasteful and harmful to the environment.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 illustrates an example gas recovery system constructed in accordance with teachings of this disclosure.

[0005] FIG. 2 illustrates a first example drive system that can be used to implement the example gas recovery system of FIG. 1.

[0006] FIG. 3 illustrates a second example drive system that can be used to implement the example gas recovery system of FIG. 1.

[0007] FIG. 4 illustrates a third example drive system that can be used to implement the example gas recovery system of FIG. 1.

[0008] FIG. 5A illustrates an example lever and an example rod that may be implemented in examples disclosed herein.

[0009] FIG. 5B illustrates the pistons and / or the rod of FIG. 5A in a second example position.

[0010] FIG. 5C illustrates the pistons and / or the rod of FIGS. 5 A and / or 5B in a third example position.

[0011] FIG. 6A illustrates an example compressor that may be implemented in the example gas recovery system of FIG. 1.

[0012] FIG. 6B is a perspective view of a second example compressor that may be implemented in examples disclosed herein.

[0013] FIG. 6C illustrates the second example compressor of FIG. 6B with example cover plates removed.

[0014] FIG. 6D is a cross-sectional view of the second example compressor of FIGS. 6A and / or 6B taken along line A-A of FIG. 6C.

[0015] FIG. 6E is a top view of the second example compressor of FIG. 6D.

[0016] FIG. 6F is a cross-sectional view of the second example compressor of FIGS. 6B.6C. 6D, and / or 6E taken along line B-B of FIG. 6C.

[0017] FIG. 6G is a cross-sectional view of the second example compressor of FIGS. 6B, 6C, 6D, 6E, and / or 6F taken along line C-C of FIG. 6C.

[0018] FIG. 6H is a front view of the second example compressor of FIG. 6G.

[0019] FIG. 7 illustrates a fourth example drive system that can be used to implement the example gas recovery system of FIG. 1.

[0020] FIG. 8 is a flowchart representative of an example method to produce the first example drive system of FIG. 2, the second example drive system of FIG. 3, and / or the third example drive system of FIG. 4.

[0021] FIG. 9 is a flowchart representative of an example method to produce the fourth example drive system of FIG. 7.

[0022] FIG. 10 is a flowchart representative of example operations to implement a gas recovery procedure using the second example drive system of FIG. 2.

[0023] In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. The figures are not necessarily to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. Although the figures show layers and regions with clean lines and boundaries, some or all of these lines and / or boundaries may be idealized. In reality’, the boundaries and / or lines may be unobservable, blended, and / or irregular.DETAILED DESCRIPTION

[0024] Buildings, plants, factories, and other facilities commonly use natural gas for various purposes such as heating, power generation, transportation, etc. In some cases, natural gas is transported between two or more locations using gas pipelines. Some pipelines includeone or more gas-operated devices implemented thereon. Some such devices utilize gas pressure from the pipeline to operate, then release the gas (e.g., bleed gas) to the atmosphere. For example, the devices can include bleed devices, which can be flow control devices powered by the pressurized gas to automatically maintain a process condition such as a flow rate, a pressure, a temperature, etc. of the gas in the pipeline. In some cases, the bleed devices are intermittent bleed devices (e.g.. intermittent bleed pneumatic devices) that may intermittently release (e.g., vent, discharge) a portion or all of the gas supplied thereto. Alternatively, some bleed devices continuously vent the supply gas to the atmosphere. Natural gas is composed of methane and / or one or more other constituent gases (e.g., carbon dioxide, water vapor, ethane, propane, etc.) that, when vented to the atmosphere, can be harmful to the environment and may pose a safety concern due to a risk of accidental combustion.

[0025] In recent years, to reduce release of bleed gas to the environment, some gas- powered devices have been replaced with electrically-actuated counterparts. However, electrically-actuated devices are often more expensive than gas-powered devices, and electrical power is often not available at many locations along the pipeline. Alternatively, pneumatically - actuated devices can be used instead of gas-operated devices to reduce and / or eliminate the emission of bleed gas. However, a supply of compressed air is not commonly available along the pipeline, and installation of an air compressor may be costly and / or may require electrical power.

[0026] Examples disclosed herein implement an example gas recovery system that is used to capture bleed gas emitted from one or more gas-operated devices and return the captured gas to a pipeline. In examples disclosed herein, the gas recovery system includes an example drive system which utilizes a pressure differential between two or more locations in the pipeline to drive a first piston. In some examples, the first piston is positioned in a first example cylinder fluidly coupled between a bleed gas source (e.g., the gas-operated device(s)) and a first pipe, and reciprocal motion of the first piston within the first cylinder is used to draw bleed gas from the bleed gas source and / or expel the bleed gas to the first pipe. In some examples, a second example piston is operatively coupled to the first piston and / or fluidly coupled between the first pipe and a second pipe, where a first pressure of the first pipe is greater than a second pressure of the second pipe. In some such examples, the pressure differential between the first and second pipes is used to drive fluid from the second pipe to one or more chambers of the second cylinder, resulting in reciprocal motion of the second piston and, thus, the first piston. Additionally or alternatively, a diaphragm actuator can be operatively coupled to the first piston, wheredeflection of a diaphragm of the diaphragm actuator results in reciprocal motion of the first piston within the first cylinder.

[0027] Examples disclosed herein may reduce an amount of bleed gas vented and / or released to the atmosphere, which reduces risk of harm to the environment and / or reducing waste. Additionally, by utilizing pressure differential between two or more locations of a pipeline to drive the gas recovery system, examples disclosed herein reduce a need for additional pneumatic and / or electncal systems to be installed on a pipeline. In particular, examples disclosed herein can be implemented (e.g., retrofitted) on top of existing gas-operated devices and / or pipeline infrastructure, thus avoiding costs associated with installation of air compressors and / or outfitting of the pipeline with electrical power.

[0028] FIG. 1 illustrates an example gas recovery system (e.g., a differential pressure- driven gas recovery system) 100 constructed in accordance with teachings of this disclosure. In the illustrated example of FIG. 1, the gas recovery' system 100 is fluidly coupled between a first example pipe (e.g., a high-pressure line) 102 and a second example pipe (e.g., a low-pressure line) 104. In this example, the first pipe 102 is pressurized to a first example pressure (e.g.. between 900 pounds per square inch (psi) and 1500 psi), and the second pipe 104 is pressurized to a second example pressure (e.g., between 100 psi and 700 psi), where the second pressure is less than the first pressure.

[0029] In this example, the gas recovery system 100 is fluidly and / or operatively coupled to an example gas source (e.g.. a bleed gas source) 106. In some examples, the gas source 106 corresponds to one or more gas-operated devices that utilize gas pressure from at least one of the first pipe 102 or the second pipe 104 to operate. For example, the gas-operated device(s) can include valves, actuators, and / or other flow control devices that may be operated using the pressurized gas. In some examples, the gas utilized to operate the gas-operated device(s) is then released (e.g., continuously and / or periodically) as bleed gas to the atmosphere. The release of such bleed gas to the atmosphere can be wasteful and harmful to the environment and / or may pose a safety concern due to a risk of accidental combustion.

[0030] In examples disclosed herein, the gas recovery system 100 utilizes a pressure differential between the first pipe 102 and the second pipe 104 to capture and / or compress bleed gas from the gas source 106 and provide the gas to another location (e.g., the first pipe 102 and / or the second pipe 104). In the illustrated example of FIG. 1, the gas recovery' system 100 includes an example drive device 108 fluidly coupled between the first pipe 102 and the second pipe 104. In particular, a third example pipe 110 fluidly couples the drive device 108 to the first pipe 102, and a fourth example pipe 1 12 fluidly couples the drive device 108 to the second pipe104. Further, an example bleed line 114 fluidly couples the gas source 106 to the drive device 108. In this example, an example sensor (e.g.. a sensor device) 116 is operatively coupled between the drive device 108 and the gas source 106.

[0031] In the illustrated example of FIG. 1, the sensor 116 measures and / or detects bleed gas output from the gas source 106. In this example, in response to the sensor 116 detecting the presence of bleed gas from the gas source 106, the sensor 1 16 provides an example control signal 118 to the drive device 108 to turn on and / or shut off the drive device 108 and / or otherwise control flow of gas to the drive device 108. In some examples, based on the control signal 118, the drive device 108 operates to draw bleed gas away from the gas source 106 via the bleed line 114. The drive device 108 can compress the bleed gas and / or provide the bleed gas to the second pipe 104. In some examples, different devices and / or configurations can be used to implement the functionality of the gas recovery system 100 of FIG. 1. For example, the drive device 108 may be implemented using one or more valves and / or pistons. Additionally or alternatively, the drive device 108 may be implemented using one or more nozzles (e.g., Venturi nozzles), one or more diaphragms, one or more turbines, one or more pumps, and / or any other suitable device(s).

[0032] FIG. 2 illustrates a first example drive system 200 that can be used to implement the example gas recover}' system 100 of FIG. 1. In the illustrated example of FIG. 2, the first drive system 200 includes a first example cylinder (e.g.. a first drive cylinder, a first compression cylinder) 202 fluidly and / or operatively coupled between the first and second pipes 102, 104. Further, a second example cylinder (e.g., a second drive cylinder, a second compression cylinder) 204 is implemented on the bleed line 114 and is fluidly and / or operatively coupled between the gas source 106 and the second pipe 104. In this example, a first example piston (e.g.. a piston actuator) 206 is positioned in and / or slidable within the first cylinder 202, and a second example piston 208 is positioned in and / or slidable within the second cylinder 204. An example rod 210 couples (e.g., operatively couples) the first and second pistons 206, 208 such that the first and second pistons 206, 208 move together within the respective cylinders 202. 204.

[0033] In the illustrated example of FIG. 2, a first example valve 212, a second example valve 214, and an example reservoir 216 coupled therebetween are fluidly coupled between the first pipe 102 and the first cylinder 202. In this example, the second valve 214 is fluidly coupled, via a first example inlet line 218, to a first example chamber 220 defined in the first cylinder 202 between the first piston 206 and a first example end 222 of the first cylinder 202. Additionally, the second valve 214 is fluidly coupled, via a second example inlet line 224, to a secondexample chamber 226 defined in the first cylinder 202 between the first piston 206 and a second example end 228 of the first cylinder 202. In this example, the first chamber 220 is fluidly coupled to the second pipe 104 via a first example outlet line 230 and a third example valve 232 implemented along the first outlet line 230, and the second chamber 226 is fluidly coupled to the second pipe 104 via second example outlet line 234 and a fourth example valve 236 implemented along the second outlet line 234.

[0034] In some examples, the second valve 214 is a three-way valve that can be switched and / or moved between three different positions (e.g., configurations). For example, when the second valve 214 is in a closed position (e.g., a closed configuration), the second valve 214 restricts (e.g., blocks, prevents) fluid flow from the reservoir 216 to the first inlet line 218 and to the second inlet line 224. Further, when the second valve 214 is in a first open position (e.g.. a first open configuration), the second valve 214 enables fluid flow from the reservoir 216 to the first inlet line 218, and restricts fluid flow from the reservoir 216 to the second inlet line 224. Conversely, when the second valve 214 is in a second open position (e.g., a second open configuration), the second valve 214 restricts fluid flow from the reservoir 216 to the first inlet line 218, and enables fluid from flow the reservoir 216 to the second inlet line 224. While the second valve 214 is implemented as a three-way valve in this example, the second valve 214 can be implemented using one or more different valves (e.g., separate valves implemented on the respective inlet lines 218, 224) instead.

[0035] In some examples, the valves 212, 214, 232. 236 are in a closed position prior to initiation of a gas recovery procedure. To initiate the gas recovery procedure, the first valve 212 is opened to enable fluid (e.g., gas) to flow from the first pipe 102 to the reservoir 216. In some examples, the first valve 212 is held in an open position until the reservoir 216 is filled and / or is pressurized to a threshold pressure, where the threshold pressure corresponds to the first pressure in the first pipe 102. Once the reservoir 216 is pressurized to the threshold pressure, the first valve 212 is closed, the fourth valve 236 is opened, and the second valve 214 is switched to the first open position. In such examples, pressurized fluid from the reservoir 216 flows to the first chamber 220 via the first inlet line 218. and a buildup of pressure in the first chamber 220 causes the first piston 206 to move rightward within the first cylinder 202 (e.g.. toward the second end 228 of the first cylinder 202). As the first piston 206 moves rightward, a volume of the gas in the first chamber 220 increases and, thus, a first pressure in the first chamber 220 decreases until the first pressure corresponds to a second pressure in the second chamber 226. In some examples, as the first piston 206 moves rightward in FIG. 2, the first piston 206 pushes the rod 210, and, thus, the second piston 208 rightward in the second cylinder 204. Further, as thefirst piston 206 moves rightward, gas is expelled from the second chamber 226 via the fourth valve 236 and / or the second outlet line 234, and the expelled gas is provided to the second pipe 102.

[0036] In some examples, the first piston 206 reaches a first piston position when the first pressure in the first chamber 220 corresponds to (e.g., is substantially equal to) the second pressure in the second chamber 226. such that the first piston 206 is stationary and / or ceases moving rightward in the first cylinder 202. In such examples, the second valve 214 switches to the closed position, and the first valve 212 is opened to enable refilling and / or re-pressurization of the reservoir 216 with fluid from the first pipe 102. In some examples, when the reserv oir 216 is re-pressurized to the threshold pressure, the first and fourth valves 212, 236 are closed, the third valve 232 is opened, and the second valve 214 is switched to the second open position. In such examples, pressurized fluid from the reservoir 216 flows to the second chamber 226 via the second inlet line 224, and a buildup of pressure in the second chamber 226 causes the first piston 206 to move leftward within the first cylinder 202 (e.g., tow ard the first end 222 of the first cylinder 202).

[0037] As the first piston 206 moves leftw ard in FIG. 2, the first piston 206 pushes the rod 210 and, thus, the second piston 208 leftward in the second cylinder 204. Further, as the first piston 206 moves leftw ard, gas is expelled from the first chamber 220 via the third valve 232 and / or the first outlet line 230, and the expelled gas is returned to the second pipe 102. Further, as the first piston 206 moves leftward in FIG. 2. a volume of the gas in the second chamber 226 increases and, thus, the second pressure in the second chamber 226 decreases until the second pressure corresponds to the first pressure in the first chamber 220. In some examples, the first piston 206 reaches a second piston position when the first pressure in the first chamber 220 corresponds to the second pressure in the second chamber 226, such that the first piston 206 is stationary and / or ceases moving leftward in the first cylinder 202.

[0038] In some examples, by opening and / or closing respective ones of the valves 212, 214, 232, 236 as described above, flow' of gas from the first pipe 102 can be alternated between the first and second chambers 220. 226 to drive reciprocal motion of the first piston 206 in the first cylinder 202. In turn, the resulting reciprocal motion of the second piston 208 in the second cylinder 204 is used to draw bleed gas (e.g., exhaust gas) away from the gas source 106 and provide (e.g., push) the bleed gas to the second pipe 104. In particular, when the second piston 208 moves leftward in the second cylinder 204 in FIG. 2 (e.g., toward a third example end 238 of the second cylinder 204), suction caused by the leftward motion of the second piston 208 draws the bleed gas from the gas source 106 and into a third example chamber 240 of the secondcylinder 204. Conversely, when the second piston 208 moves rightward in the second cylinder 204 in FIG. 2 (e.g.. toward a fourth example end 242 of the second cylinder 204), the second piston 208 causes gas to be expelled from the third chamber 240 and flow to the second pipe 104.

[0039] In the example of FIG. 2, a first example check valve 244A is implemented along the bleed line 114 between the gas source 106 and the second cylinder 204. and second example check valve 244B is implemented along the bleed line 1 14 between the third chamber 240 and the second pipe 104. In some examples, the check valves 244A, 244B restrict backflow of fluid from the second pipe 104 and / or the third chamber 240 toward the gas source 106. While two of the check valves 244A, 244B are used in this example, a different number of check valves may be used instead. In the illustrated example of FIG. 2, by recovering the bleed gas from the gas source 106 and returning the bleed gas to the second pipe 104, the drive system 200 of FIG. 2 can reduce emissions of gas from the gas source 106 to the atmosphere, which reduces waste and / or risk of harm to the environment.

[0040] FIG. 3 illustrates a second example drive system 300 that can be used to implement the example gas recovery system 100 of FIG. 1. In the illustrated example of FIG. 3, the first drive system 200 includes a first example cylinder 302 fluidly coupled between the first and second pipes 102, 104, and a second example cylinder 304 is implemented on the bleed line 114 and fluidly coupled between the gas source 106 and the second pipe 104. In this example, a first example piston (e.g., a first spring-loaded piston, a piston actuator) 306 is positioned in and / or slidable within the first cylinder 302, and a second example piston 308 is positioned in and / or slidable within the second cylinder 304. In the example of FIG. 3, a first example chamber 309 is defined in the first cylinder 302 between the first piston 306 and a first example end 310 of the first cylinder 302, and a second example chamber 312 is defined in the first cylinder 302 between the first piston 306 and a second example end 314 of the first cylinder 302. Further, a third example chamber 316 is defined in the second cylinder 304 between the second piston 308 and a third example end 318 of the second cylinder 304, and a fourth example chamber 320 is defined in the second cylinder 304 between the second piston 308 and a fourth example end 322 of the second cylinder 304. In the example of FIG. 3, an example spring 324 is positioned in the second chamber 312 of the first cylinder 302 and is coupled (e.g., operatively coupled) between the first piston 306 and the second end 314 of the first cylinder 302. An example rod 326 couples (e.g.. operatively couples) the first and second pistons 306, 308 such that the first and second pistons 306. 308 move together within the respective cylinders 302, 304.

[0041] In the illustrated example of FIG. 3, the first chamber 309 of the first cylinder 302 is fluidly coupled to the first pipe 102 via an example inlet line 328, and a first example valve 330 is implemented along the inlet line 328 to control a flow of fluid (e.g., gas) to the first chamber 309. In particular, when the first valve 330 is in a closed position, the closed first valve 330 restricts (e g., blocks, prevents) fluid flow to the first chamber 309, and, when the first valve 330 is in an open position, the first valve 330 enables fluid flow to the first chamber 309. Further, the first chamber 309 is fluidly coupled to the second pipe 104 via an example outlet line 332, and a second example valve (e.g., an overpressure safety valve) 334 is implemented along the outlet line 332. In this example, an example bleed valve 336 couples the first chamber 309 to the outlet line 332.

[0042] In operation, a gas recovery procedure can be initiated by switching the first valve 330 to the open position, which enables fluid to flow from the first pipe 102 to the first chamber 309 via the inlet line 328. In some examples, a buildup of fluid pressure in the first chamber 309 causes the first piston 306 to move rightward within the first cylinder 302 in FIG. 3 (e.g., toward the second end 314 of the first cylinder 302) to compress the spring 324 in the second chamber 312. In some examples, as the first piston 306 moves rightward in FIG. 3, the first piston 306 pushes the rod 326 and, thus, the second piston 308 rightward in the second cylinder 304. In some examples, the first valve 330 is switched to the closed position when the pressure in the first chamber 309 corresponds to a first pressure in the first pipe 102 (e.g., 1300 psi. 1400 psi. 1450 psi. 1500 psi, etc.).

[0043] In some examples, the bleed valve 336 relieves pressure from the first chamber 309 by slowly releasing the fluid from the first chamber 309 into the outlet line 332. In such examples, the fluid released to the outlet line 332 is at a second pressure less than the first pressure in the first chamber 309. In particular, the second pressure corresponds to the pressure in the second pipe 104 (e.g., 40 psi, 50 psi, 55 psi, etc.) in some examples. The fluid from the first chamber 309 then flows to the second pipe 104 and / or mixes with the fluid therein. In the example of FIG. 3, the second valve 334 is a pressure relief valve (e.g., an overpressure safety- valve) that relieves pressure from the outlet line 332 when the pressure of the fluid therein does not satisfy (e.g., is greater than) a threshold pressure. In some examples, the threshold pressure is at or above the pressure in the second pipe 104. In some examples, by relieving and / or preventing excessive pressures in the outlet line 332, the second valve 334 can reduce and / or prevent damage to one or more components of the second drive system 300.

[0044] In some examples, the pressure in the first chamber 309 reduces as the fluid from the first chamber 309 is released to the outlet line 332. In some examples, when the pressure inthe first chamber 309 is less than a spring force of the compressed spring 324, the spring 324 extends and pushes the first piston 306 leftward in the first cylinder 302 toward the first end 310 of the first cylinder 302 and, thus, causes the second piston 308 to move leftward in the second cylinder 304 toward the third end 318 of the second cylinder 304. When the pressure in the first chamber 309 returns to a starting pressure (e.g., 30 psi, 40 psi, 45 psi, 55 psi, etc.) and / or the spring 324 is uncompressed, the first valve 330 can be reopened to enable additional fluid to flow from the first pipe 102 to the first chamber 309.

[0045] In some examples, the above process may be repeated to drive reciprocal motion of the first piston 306 and the second piston 308 in the respective first and second cylinders 302, 304. In some such examples, the reciprocal motion of the second piston 308 can be used to draw bleed gas (e.g.. exhaust gas) away from the gas source 106 and provide (e.g.. push) the bleed gas to the second pipe 104. In particular, when the second piston 308 moves leftward in the second cylinder 304 in FIG. 3 (e.g., toward the third end 318 of the second cylinder 304), suction caused by the leftward motion of the second piston 308 draws the bleed gas from the gas source 106 and into the fourth chamber 320 of the second cylinder 304. Conversely, when the second piston 308 moves rightward in the second cylinder 304 in FIG. 3 (e.g., toward the fourth end 322 of the second cylinder 304), the second piston 308 causes the bleed gas to be expelled from the fourth chamber 320 and flow to the second pipe 104.

[0046] In the example of FIG. 3, a first example check valve 342A is implemented along the bleed line 114 between the gas source 106 and the second cylinder 304, and second example check valve 342B is implemented along the bleed line 114 between the second cylinder 304 and the second pipe 104. While two of the check valves 342A, 342B are used in this example, a different number of check valves may be used instead. In some examples, the check valves 342A. 342B restrict backflow of fluid from the second pipe 104 and / or the fourth chamber 320 toward the gas source 106.

[0047] FIG. 4 illustrates a third example drive system 400 that can be used to implement the example gas recover}' system 100 of FIG. 1. The third drive system 400 is substantially similar to the second drive system 300 in the illustrated example of FIG. 3, but further includes a second example spring 402 positioned in the fourth chamber 320 of the second cylinder 304 and coupled (e.g., operatively coupled) between the second piston 308 and the fourth end 322 of the second cylinder 304. In some examples, the second spring 402 can be used in addition to or instead of the first spring 324 in the second chamber 312 of the first cylinder 302. In the illustrated example of FIG. 4, when the first valve 330 is open and fluid flows from the first pipe 102 to the first chamber 309, pressure in the first chamber 309 pushes the first and secondpistons 306, 308 rightward in FIG. 4, thus compressing both the first and second springs 324, 402 in the respective second and fourth chambers 312, 320. Further, when the fluid pressure is released from the first chamber 309 through the bleed valve 336, spring forces from the compressed first and second springs 324, 402 cause the first and second pistons 306, 308 to move leftward in FIG. 4, such that the first and second springs 324, 402 can return to an uncompressed (or less compressed) starting position.

[0048] In some examples, by utilizing both the first and second springs 324, 402, the spring force on the first and second pistons 306, 308 is greater compared to when only one of the first spring 324 or the second spring 402 is used. As such, the first and second pistons 306, 308 can return to the starting position faster and / or at lower pressures in the first chamber 309 compared to when only one of the first spring 324 or the second spring 402 is used. While the first and second pistons 306, 308 are operatively coupled via the rod 326 in this example, in some other examples, force between the pistons 306, 308 may be communicated using another mechanical link and / or hydraulic fluid.

[0049] FIG. 5A illustrates an example lever (e.g., a valve lever) 502 and an example rod 504 that may be implemented in examples disclosed herein. In particular, the lever 502 and rod 504 may be implemented in one or more of the first example drive system 200 of FIG. 2, the second example drive system 300 of FIG. 3, the third example drive system 400 of FIG. 4, the fourth example drive system 700 of FIG. 7, or the example compressor 600 of FIG. 6A. In the illustrated example of FIG. 5 A, the example rod 500 is coupled between first and second example pistons 506, 508. In some examples, the first and second example pistons 506, 508 of FIG. 5A correspond to the pistons 206, 208 of FIG. 2, and the example rod 504 of FIG. 5A corresponds to the rod 210 of FIG. 2. In some examples, the first and second example pistons 506, 508 of FIG. 5 A correspond to the pistons 306, 308 of FIGS. 3 and / or 4, and the example rod 504 of FIG. 5A corresponds to the rod 326 of FIGS. 3 and / or 4. In some examples, the first and second example pistons 506, 508 of FIG. 5 A correspond to the piston 710 and the diaphragm 718 of FIG. 7, and the example rod 504 of FIG. 5A corresponds to the rod 724 of FIG. 7. In some examples, the first and second example pistons 506, 508 of FIG. 5A correspond to the piston 710 and the diaphragm 718 of FIG. 7, and the example rod 504 of FIG. 5A corresponds to the rod 724 of FIG. 7.

[0050] In the illustrated example of FIG. 5 A, the rod 504 includes first and second example flanges 510, 512, and the lever 502 is positioned between the first and second flanges 510, 512. In particular, the rod 504 and / or the pistons 506, 508 are shown in a first position (e.g., a starting position) in which the lever 502 is not in contact with the flanges 51 , 512. In someexamples, the lever 502 is operatively coupled to one or more flow control devices (e.g., the valve 214 of FIG. 2, the valve 330 of FIGS. 3 and / or 4, the plugs 638, 640 of FIG. 6A, and / or the valve 732 of FIG. 7) to control position(s) of the flow control device(s) based on movement of the pistons 506, 508 and / or the rod 504.

[0051] Turning to FIG. 5B, the pistons 506, 508 and / or the rod 504 are shown in a second position (e.g., a leftward position) relative to the pistons 506, 508 and / or the rod 504 in FIG. 5A. In some examples, the pistons 506, 508 and / or the rod 504 move to the second position when a second pressure in the second chamber 226 of FIG. 2 is greater than a first pressure in the first chamber 220 of FIG. 2. For example, the second pressure may be between 900 psi and 1500 psi, and the first pressure may be between 100 psi and 700 psi. In some examples, when the rod 504 is in the second position of FIG. 5B, contact between the second flange 512 and the lever 502 produces a first example moment 514 in a first direction (e.g., a clockwise direction) about an example rotational axis 516 of the lever 502. In some examples, the first moment 514 causes the valve 214 of FIG. 2 to switch to a first position in which the valve 214 enables fluid flow to the first chamber 220 and restricts fluid flow to the second chamber 226. Additionally or alternatively, the first moment 514 can cause the valve 330 of FIGS. 3 and / or 4 and / or the valve 732 of FIG. 7 to move to a first position (e.g., an open position), and / or may adjust a position of the plugs 638, 640 of FIG. 6A (e.g. leftward and / or rightward in FIG. 6A).

[0052] Conversely. FIG. 5C illustrates the pistons 506, 508 and / or the rod 504 in a third position (e.g., a rightward position) relative to the first position shown in FIG. 5A. In some examples, the pistons 506, 508 and / or the rod 504 move to the third position when a second pressure in the second chamber 226 of FIG. 2 is less than a first pressure in the first chamber 220 of FIG. 2, a fourth pressure in the second chamber 312 of FIGS. 3 and / or 4 is less than a third pressure in the first chamber 309 of FIGS. 3 and / or 4, a fifth pressure in the third chamber 626 is greater than a sixth pressure in the second chamber 624 of FIG. 6 A, etc. In the illustrated example of FIG. 5C, when the rod 504 is in the third position of FIG. 5C, contact between the first flange 510 and the lever 502 produces a second example moment 518 in a second direction (e.g., a counterclockwise direction) about the rotational axis 516, where the second direction is opposite to the first direction. In some examples, the second moment 518 causes the valve 214 of FIG. 2 to switch to a second position in which the valve 214 enables fluid flow to the second chamber 226 and / or restricts fluid flow to the first chamber 220. Additionally or alternatively, the second moment 518 can cause the valve 330 of FIGS. 3 and / or 4 and / or the valve 732 of FIG. 7 to move to a second position (e.g., a closed position), and / or may adjust a position of the plugs 638, 640 of FIG. 6A (e.g. leftward and / or rightward in FIG. 6A).

[0053] In some examples, detent features may be used to hold the lever 502 and, thus, the flow control device(s) (e.g., the valve 214 of FIG. 2. the valve 330 of FIGS. 3 and / or 4. the plugs 638, 640 of FIG. 6A, and / or the valve 732 of FIG. 7) in position during a dwell period (e.g., a duration during which the rod 504 moves from the second position of FIG. 5B to the third position of FIG. 5C and / or from the third position to the second position). In some examples, a duration of the dwell period is selected to enable proper functioning (e.g., cycling) of the drive system (e.g., the first example dnve system 200 of FIG. 2, the second example drive system 300 of FIG. 3, the third example drive system 400 of FIG. 4, the fourth example drive system 700 of FIG. 7, or the example compressor 600 of FIG. 6A). In some examples, the duration of the dwell period may be selected based on a pressure and / or flow of the gas through the flow control device(s). In some examples, by holding the lever 502 and, thus, the flow control device(s) in place during the dwell period, the detent features reduce and / or prevent premature switching of the flow control device(s).

[0054] In some examples, the pistons 506, 508 and the rod 504 cycle between the second position of FIG. 5B and the third position of FIG. 5C to alternate the flow of fluid between the first and second chambers 220, 226. The alternating flow is used to adjust pressures in the first and second chambers 220, 226, which, in turn, drives the reciprocal motion of the pistons 506, 508 and the rod 504. As such, the reciprocal motion of the pistons 506, 508 and the rod 504 can be controlled without the use of a separate drive device (e.g., an actuator, a pneumatic switch, etc.) to adjust the position of the valve 214. Further, while the rod 504. the pistons 506. 508, and / or the lever 502 are described in connection with the first drive system of FIG. 2, the rod 504, the pistons 506, 508, and / or the lever 502 can additionally or alternatively be implemented in the second drive system 300 of FIG. 3 and / or the third drive system 400 of FIG. 4 to control the position(s) of one or more valves therein.

[0055] FIG. 6A illustrates an example compressor (e.g., a reciprocating compressor) 600 that may be implemented in the example gas recover}7system 100 of FIG. 1. In the illustrated example of FIG. 6A, the compressor 600 includes a first example cylinder 602 and a second example cylinder 604 coupled together at a first example flanged portion 606 of the compressor 600. The compressor 600 further includes a second example flanged portion 608 coupled to the first cylinder 602 at a first end 610 of the compressor 600, and a third example flanged portion 612 coupled to the second cylinder 604 at a second end 614 of the compressor 600. In the example of FIG. 6A, a first example piston 616 is positioned in and / or slidable within the first cylinder 602. and a second example piston 616 is positioned in and / or slidable within the second cylinder 604. An example rod 620 couples (e g., operatively couples) the first and secondpistons 616, 618. A first example chamber 622 is defined in the first cylinder 602 between the second flanged portion 608 and the first piston 616, a second example chamber 624 is defined in the first cylinder 602 between the first piston 616 and the first flanged portion 606, a third example chamber 626 is defined in the second cylinder 604 between the first flanged portion 606 and the second piston 618, and a fourth example chamber 628 is defined between the second piston 618 and the third flanged portion 612.

[0056] In the illustrated example of FIG. 6A, the first flanged portion 606 includes an example inlet port 630 fluidly coupled to the first pipe 102 of FIG. 1 and an example outlet port 632 fluidly coupled to the second pipe 102. In this example, the inlet port 630 is fluidly coupled to a first example fluid passageway 634 extending through the first flanged portion 606 between the second and third chambers 624, 626. Further, the outlet port 632 is fluidly coupled to a second example fluid passageway 636 extending through the first flanged portion 606 between the second and third chambers 624, 626. In the example of FIG. 6A, a first example plug 638 is disposed in and / or movable within the first fluid passageway 634, and a second example plug 640 is disposed in and / or movable within the second fluid passageway 636. In this example, example check valves 642, 644 are implemented within the respective inlet and outlet ports 630, 632 to restrict backflow from the first fluid passageway 634 to the inlet port 630 and / or from the outlet port 632 to the second fluid passageway 636.

[0057] In the illustrated example of FIG. 6A, the first and second plugs 638, 640 are shown in a first position (e.g., a rightward position) in the respective first and second fluid passageways 634, 636. When in the first position, the first plug 638 engages with the first flanged portion 606 to restrict fluid flow from the inlet port 630 to the second chamber 626 and enable fluid flow from the inlet port 630 to the first chamber 624. Conversely, the second plug 640 in the first position engages with the first flanged portion 606 to restrict fluid flow from the first chamber 624 to the outlet port 632 and enable fluid flow from the second chamber 626 to the outlet port 632. In operation, when the first and second plugs 638, 640 are in the first position of FIG. 6A, fluid from the first pipe 102 flows to the second chamber 624 to increase a pressure in the second chamber 624. As a result of the buildup of pressure in the second chamber 624, the first and second pistons 616, 618 move leftward in FIG. 6A toward the first end 610 of the compressor 600.

[0058] In the illustrated example of FIG. 6A, the second flanged portion 608 includes a third example fluid passageway 646 that operatively couples the gas source 106 to the second pipe 104 of FIG. 1. Further, the third flanged portion 612 includes a fourth example fluid passageway 648 that operatively couples the gas source 106 to the second pipe 104. In thisexample, the third fluidly passageway 646 is fluidly coupled to the first chamber 622 via a first example port 650, and the fourth fluid passageway 648 is fluidly coupled to the fourth chamber 628 via a second example port 652. In this example, example check valves 654A, 654B are implemented along the third fluid passageway 646 to restrict backflow from the second pipe 104 and / or the first chamber 622, and example check valves 656A, 656B are implemented along the fourth fluid passageway 648 to restrict backflow from the second pipe 104 and / or the fourth chamber 628.

[0059] In some examples, as the first and second pistons 616, 618 move leftward in FIG. 6A, fluid from the third chamber 626 is expelled via the second fluid passageway 636 and the outlet port 632 to the second pipe 104. Further, a pressure of the fluid in the second chamber 624 reduces as a volume of the fluid in the second chamber 624 expands. In such examples, as the first and second pistons 616, 618 move leftward in FIG. 6A, fluid is expelled from the first chamber 622 to the second pipe 104 via the first port 650 and the third fluid passageway 646. Additionally, bleed gas from the gas source is drawn and / or pulled into the fourth chamber 628 via the fourth fluid passageway 648 and the second port 652.

[0060] In some examples, the first and second pistons 616, 618 move leftward in FIG. 6A until reaching a first piston position (e.g., a leftmost position) in which the first piston 616 contacts the second flanged portion 608, the second piston 618 contacts one(s) of the plugs 638, 640, and / or a first pressure in the first chamber 622 corresponds to a second pressure in the second chamber 624. In some such examples, when the first and second pistons 616. 618 reach the first piston position, the plugs 638, 640 move to a second position (e.g., a leftward position) within the respective fluid passageways 634, 636. In some examples, the plugs 638, 640 are moved and / or actuated based on a signal (e.g., a pneumatic signal). In some examples, the second piston 618 contacts the plugs 638, 640 to push the plug 638. 640 leftward to the second position. When in the second position, the first plug 638 engages with the first flanged portion 606 to enable fluid flow from the inlet port 630 to the second chamber 626 and restrict fluid flow from the inlet port 630 to the first chamber 624. Conversely, the second plug 640 in the second position engages with the first flanged portion 606 to enable fluid flow from the first chamber 624 to the outlet port 632 and restrict fluid flow from the second chamber 626 to the outlet port 632.

[0061] When the first and second plugs 638, 640 are in the second position, fluid from the first pipe 102 flows to the third chamber 626 to increase a pressure in the third chamber 626. As a result of the buildup of pressure in the third chamber 626, the first and second pistons 616, 618 move rightward in FIG. 6A toward the second end 614 of the compressor 600. In someexamples, as the first and second pistons 616, 618 move rightward in FIG. 6 A, fluid from the second chamber 624 is expelled via the second fluid passageway 636 and the outlet port 632 to the second pipe 104, and the bleed gas previously pulled into the fourth chamber 628 is expelled from the fourth chamber 628 to the second pipe 104 via the second port 652 and the fourth fluid passageway 648. Additional bleed gas from the gas source is drawn and / or pulled into the first chamber 622 via the third fluid passageway 646 and the first port 650. In some examples, the first and second pistons 616, 618 move rightward in FIG. 6A until reaching a second piston position (e.g., a rightmost position) in w hich the first piston 616 contacts one(s) of the plugs 638, 640, the second piston 618 contacts the third flanged portion 612, and / or a third pressure in the third chamber 626 corresponds to a fourth pressure in the fourth chamber 628.

[0062] In some examples, the plugs 638, 640 return to the first position when the first and second pistons 618, 618 reach the second piston position. As a result, the above process is repeated to drive reciprocal motion of the pistons 616, 618 within the respective cylinders 602, 604. In such examples, the reciprocal motion of the pistons 616, 618 causes bleed gas to be pulled from the gas source 106 to the first and fourth chambers 622, 628, and further causes the pulled bleed gas to be expelled from the first and fourth chambers 622, 628 and provided to the second pipe 104. Accordingly, the compressor 600 of FIG. 6A enables recovery of bleed gas from the gas source, which reduces an amount of bleed gas released and / or vented to the atmosphere.

[0063] FIG. 6B is a perspective view of a second example compressor 660 that may be implemented in examples disclosed herein. In the illustrated example of FIG. 6B, the second compressor 660 includes first and second example cylinders 662A, 662B coupled to a first example flanged section 664A positioned therebetween. Further, the first and second cylinders 662A, 662B are coupled to second and third example flanged sections 664B, 664C at respective ends of the second compressor 660. In the illustrated example of FIG. 6B, example cover plates 666A, 666B are coupled (e.g., bolted) to respective surfaces of the first flanged section 664A. Further, the second compressor 660 includes first and second openings 668A, 668B extending through the first cover plate 666A and / or the first flanged section 664A, and third and fourth example openings 668C. 668D positioned in respective ones of the second and third flanged sections 664B, 664C.

[0064] FIG. 6C illustrates the second example compressor 660 of FIG. 6B with the cover plates 666 A, 666B removed. In the illustrated example of FIG. 6C, the first and second openings 668A, 668B extend into the first flanged section 664A. In some examples, the first flanged section 664 receives drive fluid (e.g., high-pressure fluid) from a first location (e.g., the first pipe102 of FIG. 1) via the first opening 668 A, and the drive fluid is expelled from the first flanged section 664 to a second location (e.g., the second pipe 104 of FIG. 1) via the second opening 668B. In the illustrated example of FIG. 6C, an example rod 670 is positioned in and movable within the first flanged section 664. In some examples, based on a position of the rod 670, the rod 670 can direct the flow of drive fluid between the first and second cylinders 662A, 662B.

[0065] FIG. 6D is a cross-sectional view of the second example compressor 660 of FIGS. 6A and / or 6B taken along line A-A of FIG. 6C. In the illustrated example of FIG. 6D, the second compressor 660 includes a first example piston 672A positioned in and / or slidable within the first cylinder 662A, and a second example piston 672B positioned in and / or slidable within the second cylinder 662B. In this example, the first and second pistons 672A, 672B are operatively coupled via an example shaft 674 extending through the first flanged section 664A, such that the first and second pistons 672A, 672B move together in the respective first and second cylinders 662A, 662B. In this example, a first example chamber 676A is defined in the first cylinder 662 A between the first flanged section 664A and the first piston 672A, and a second example chamber 676B is defined between the second flanged section 664B and the first piston 672A. Further, a third example chamber 676C is defined in the second cylinder 662B between the first flanged section 664A and the second piston 672B, and a fourth example chamber 676D is defined in the second cylinder 662B between the third flanged section 664C and the second piston 672B. In some examples, the second flanged section 664B includes a first inlet port 678A, and the third flanged section 664C includes a second inlet port 678B, where the first and second inlet ports 678A, 678B are fluidly coupled to the gas source 106 of FIG. 1 to receive bleed gas therefrom.

[0066] In the illustrated example of FIG. 6D, the pressure differential between the first pipe 102 and the second pipe 104 can be used to drive operation of the second compressor 660. For example, when the rod 670 is in a first rod position, the rod 670 enables drive fluid from the first pipe 102 to enter the first flanged section 664A (e.g. , via the first opening 668A of FIG. 6B and / or 6C) and flow to the first chamber 676A. In such examples, the drive fluid applies pressure on the first piston 672A and causes the first piston 672A to slide toward the second flanged section 664B. In some examples, the first piston 672A compresses fluid (e.g., bleed gas) in the second chamber 676B and expels the compressed fluid from the second chamber 676B via the third opening 668C of the second flanged section 664B. Further, when the first piston 672A moves toward the second flanged section 664B, the second piston 672B moves toward the first flanged section 664A and causes drive fluid to be expelled from the third chamber 676C to the second pipe 104 via the second opening 668B of FIG. 6C. In such examples, the movement ofthe second piston 672B toward the first flanged section 664A draws additional bleed gas into the fourth chamber 676D via the second inlet port 678B.

[0067] Conversely, when the rod 670 is in a second rod position, the rod 670 enables drive fluid from the first pipe 102 to flow to the third chamber 676C. In such examples, the drive fluid applies pressure on the second piston 672B and causes the second piston 672B to slide toward the third flanged section 664C. In some examples, the second piston 672B compresses fluid (e.g., bleed gas) in the fourth chamber 676D and expels the compressed fluid from the fourth chamber 676D via the fourth opening 668D of the third flanged section 664C. Further, when the second piston 672B moves toward the third flanged section 664C, the first piston 672A moves toward the first flanged section 664A and causes drive fluid to be expelled from the first chamber 676A to the second pipe 104 via the second opening 668B of FIG. 6C. In such examples, the movement of the first piston 672A toward the first flanged section 664A draws additional bleed gas into the second chamber 676B via the first inlet port 678A.

[0068] In some examples, the rod 670 can move between the first and second rod positions to alternate the flow of drive fluid between the first and third chambers 676A, 676C, thus driving reciprocal motion of the first and second pistons 672A, 672B within the respective first and second cylinders 662A, 662B. As a result, the second compressor 660 draws bleed gas from the gas source 106, compresses the bleed gas, and / or provides the compressed bleed gas to the second pipe 104, thus reducing an amount of bleed gas to be vented to the atmosphere.

[0069] FIG. 6E is a top view of the second example compressor 660 of FIG. 6D. In the illustrated example of FIG. 6E, the rod 670 is in the second rod position in which the rod 670 contacts a first inner surface 679A of the first flanged section 664A. In some examples, when the rod 670 is in the second rod position of FIG. 6E. drive gas is provided to the third chamber 676C via a second example fluid passageway 680B in the first flanged section 664A. and drive gas is expelled from the first chamber 676A via a first example fluid passageway 680A. Conversely, the rod 670 is in the first rod position when the rod 670 contacts a second inner surface 679B of the first flanged section 664A. In some examples, when the rod 670 is in the first rod position, drive gas is provided to the first chamber 676A via the first fluid passageway 680A, and drive gas is expelled from the third chamber 676C via the second fluid passageway 680B. In some examples, the rod 670 remains in the second rod position of FIG. 6E until the first piston 672A of FIG. 6D contacts an example pin 682 positioned in the first flanged section 664A. In this example, the rod 670 is positioned and / or oriented along a first direction, and the pin 682 is positioned and / or oriented along a second direction different from (e.g., perpendicular to) the first direction.

[0070] FIG. 6F is a cross-sectional view of the second example compressor 660 of FIGS . 6B. 6C, 6D, and / or 6E taken along line B-B of FIG. 6C. In the illustrated example of FIG. 6F, the pin 682 is shown in a first pin position in which the pin 682 protrudes from a first example surface 684A of the first flanged section 664A and is substantially flush with a second example surface of the first flanged section 664A. In some examples, when the pin 682 is in the first pin position of FIG. 6F, the pin 682 enables drive gas to be routed to the rod 670 of FIG. 6E such that the rod 670 moves to and / or is held in the second rod position of FIG. 6E. In some examples, when the first piston 672A of FIG. 6D contacts the pin 682, the first piston 672A pushes the pin 682 to a second pin position in which the pin 682 protrudes from the second surface 684B and is substantially flush with the first surface 684A. In some examples, when the pin 682 is in the second pin position, the pin 682 enables drive gas to be routed to the rod 670 such that the rod 670 moves to the first rod position. In some examples, the pin 682 enables the rod 670 to move between the first and second rod positions and, thus, cause reciprocal motion of the first and second pistons 672A, 672B without the use of pneumatic and / or electrical control signals.

[0071] FIG. 6G is a cross-sectional view- of the second example compressor 660 of FIGS. 6B, 6C, 6D, 6E, and / or 6F taken along line C-C of FIG. 6C. In the illustrated example of FIG. 6G, the rod 670 is positioned in the first flanged section 664A along a transverse direction 686A of the second compressor 660. and the pin 682 is positioned in the first flanged section 664 along a longitudinal direction 686B of the second compressor 660. As such, the pin 682 is substantially perpendicular to the rod 670 in this example. In the example of FIG. 6G, the first flanged section 664A further includes first and second example fluid outlets 688A, 688B and an example fluid inlet 689. In some examples, the first and second fluid outlets 688A, 688B are fluidly coupled to the second opening 668B of FIG. 6B and / or 6C to expel fluid thereto, and the fluid inlet 689 is fluidly coupled to the first opening 668A of FIGS. 6B and / or 6C to receive fluid therefrom. In this example, the first flanged section 664A further includes an example channel 690 in an example surface 691 of the first flanged section 664 A. In some examples, the channel 690 enables exhaust fluid from both the first and second example fluid outlets 688 A, 688B to flow to the second opening 668B and, thus, to the second pipe 104.

[0072] FIG. 6H is a front view- of the second example compressor 660 of FIG. 6G. In the illustrated example of FIG. 6C, the rod 670 is in the second rod position in which the rod 670 contacts the first inner surface 679A of the first flanged section 664A. In this example, when the rod 670 is in the second rod position, the fluid inlet 689 fluidly couples the first opening 668A to the second fluid passageway 680B and, thus, to the third example chamber 676C of FIGS. 6Dand / or 6E. Further, when the rod 670 is in the second rod position, the first fluid outlet 688A fluidly couples the first fluid passageway 680A and, thus, the first chamber 676A of FIGS. 6D and / or 6E to the second opening 668B. As a result, drive fluid can be provided to the third chamber 676C and / or can be expelled from the first chamber 676A when the rod 670 is in the second rod position.

[0073] In some examples, the rod 670 moves to the first rod position in which the rod 670 contacts the second inner surface 679B of the first flanged section 664A. In such examples, when the rod 670 is in the first rod position, the fluid inlet 689 fluidly couples the first opening 668A to the first fluid passageway 680A and, thus, to the first example chamber 676A of FIGS. 6D and / or 6E. Further, when the rod 670 is in the first rod position, the second fluid outlet 688B and the channel 690 fluidly couple the second fluid passageway 680A and, thus, the third chamber 676C of FIGS. 6D and / or 6E to the second opening 668B. As a result, drive fluid can be provided to the first chamber 676 A and / or can be expelled from the third chamber 676C when the rod 670 is in the first rod position.

[0074] FIG. 7 illustrates a fourth example drive system 700 that can be used to implement the example gas recovery system 100 of FIG. 1. In the illustrated example of FIG. 7, the fourth drive system 700 includes an example Venturi (e.g., a Venturi feature, a fluid constrictor) 702 implemented along and / or positioned at the first pipe 102. For example, the Venturi 702 includes an example pipe section 704 coupled between example nozzles 706, 708. where a diameter of the pipe section 704 is less than a diameter of the first pipe 102. In the example of FIG. 7, as fluid flows through the pipe section 704, the reduction in diameter from the first pipe 102 to the pipe section 704 causes the fluid to reduce in pressure and / or increase in velocity'. As a result, the fluid in the pipe section 704 is at a first pressure (e.g., 1300 psi, 1350 psi. 1400 psi. etc.) less than a second pressure (e.g., 1450 psi, 1500 psi. 1550 psi. etc.) in the first pipe 102. In some examples, the pressure differential between the first pipe 102 and the pipe section 704 can be used to drive reciprocal motion of an example piston 710 positioned in and / or slidable within an example cylinder 712. In this example, the cylinder 712 is implemented along an example bleed line 714 fluidly coupled between the gas source 106 and the first pipe 102.

[0075] In the illustrated example of FIG. 7, the fourth drive system 700 includes an example diaphragm actuator (e.g., a double-acting diaphragm actuator) 716 operatively coupled to the piston 710. In particular, the diaphragm actuator 716 includes an example diaphragm 718 defining first and second example chambers 720, 722 in the diaphragm actuator 716. In this example, the diaphragm 718 is operatively coupled to the piston 710 via an example rod 724, such that deflection of the diaphragm 718 results in corresponding movement of the piston 710in the cylinder 712. A first example fluid line 726 fluidly couples the pipe section 704 to the first chamber 720 of the diaphragm actuator 716. and a second example fluid line 728 fluidly couples the first chamber 720 to the first pipe 102. Additionally, a third example fluid line 730 fluidly couples the second chamber 722 of the diaphragm actuator 716 to the first pipe 104. In this example, an example valve (e.g., a flow valve) 732 is implemented along the first fluid line 726 to control the flow of fluid between the pipe section 704 and the diaphragm actuator 716. For example, the valve 732 can move between an open position in which the valve 732 enables fluid flow between the pipe section 704 and the diaphragm actuator 716 and a closed position in which the valve 732 restricts fluid flow between the pipe section 704 and the diaphragm actuator 716. In the example of FIG. 7, the bleed line 714 is fluidly coupled to the first pipe 102 on a first side (e.g., a downstream side) of the Venturi 702 and the diaphragm actuator 716 is fluidly coupled to the first pipe 102 on a second side (e g., an upstream side) of the Venturi 702 opposite the first side.

[0076] In some examples, the diaphragm 718 can deflect and / or flex (e.g., from a starting position of the diaphragm 718 shown in FIG. 7) based on a pressure differential between the first and second chambers 720, 722. For example, the diaphragm 718 deflects in a first direction 734 (e.g., toward the cylinder 712, upward in FIG. 7) when a first pressure in the first chamber 720 is greater than a second pressure in the second chamber 722. Conversely, the diaphragm 718 deflects in a second direction 736 (e.g., away from the cylinder 712, downward in FIG. 7) when the first pressure in the first chamber 720 is less than the second pressure in the second chamber 722. In the illustrated example of FIG. 7, repeatedly opening and closing the valve 732 can be used to vary a pressure in the first chamber 720 of the diaphragm actuator 716, thus causing the diaphragm 718 to deflect in the first and second directions 734, 736 in an alternating manner.

[0077] In the illustrated example of FIG. 7, the deflection of the diaphragm 718 in the first and second directions 734, 736 results in corresponding motion (e.g., reciprocal motion) of the piston 710 within the cylinder 712. In some examples, the reciprocal motion of the piston 710 is used to drive recovery of bleed gas from the gas source 106. For example, bleed gas from the gas source 106 is drawn (e.g., pulled) into the cylinder 712 when the piston 710 moves in the second direction 736, and the bleed gas is expelled (e.g., pushed) from the cylinder 712 into the first pipe 102 via the bleed line 714 when the piston 710 moves in the first direction 734. In this example, check valves 738, 740 are implemented along the bleed line 714 to restrict backflow from the first pipe 102 to the cylinder 712 and / or from the cylinder 712 to the gas source 106.

[0078] FIG. 8 is a flowchart representative of an example method 800 to produce the first example drive system 200 of FIG. 2, the second example drive system 300 of FIG. 3, and / or the third example drive system 400 of FIG. 4. Although the example method is described with reference to the flowchart illustrated in FIG. 8, many other methods may alternatively be used. For example, the order of execution of the blocks may be changed, and / or some of the blocks described may be combined, divided, re-arranged, omitted, eliminated, and / or implemented in any other way. Further, in some examples, additional processing operations can be performed before, between, and / or after any of the blocks represented in the illustrated example.

[0079] The example method 800 of FIG. 8 begins at block 802, at which a first example cylinder is fluidly coupled between the first and second pipes 102, 104 of FIG. 1. In some examples, the first cylinder corresponds to the first cylinder 202 of FIG. 2 and / or the first cylinder 302 of FIGS. 3 and / or 4. In some examples, the first and second pipes 102, 104 are fluidly coupled to the first chamber 309 of the first cylinder 302 of FIGS. 3 and / or 4, and / or to both the first and second chambers 220, 226 of the first cylinder 202 of FIG. 2. In such examples, fluid (e.g.. gas) from the first pipe 102 can flow to the first cylinder 202 of FIG. 2 and / or the first cylinder 302 of FIGS. 3 and / or 4, and the fluid can be evacuated and / or expelled from the first cylinder 202 of FIG. 2 and / or the first cylinder 302 of FIGS. 3 and / or 4 to the second pipe 104.

[0080] At block 804. a second example cylinder is fluidly coupled between the example gas source 106 and the second pipe 102 of FIG. 1. In some examples, the second cylinder corresponds to the second cylinder 204 of FIG. 2 and / or the second cylinder 304 of FIGS. 3 and / or 4. In some examples, the first and second pipes 102, 104 are fluidly coupled to the third chamber 240 of the second cylinder 204 of FIG. 2, and / or to the fourth chamber 320 of the second cylinder 304 of FIGS. 3 and / or 4. In such examples, bleed gas from the gas source 106 can flow to the second cylinder 204 of FIG. 2 and / or the second cylinder 304 of FIGS. 3 and / or 4, and the bleed gas can be evacuated and / or expelled from the second cylinder 204 of FIG. 2 and / or the second cylinder 304 of FIGS. 3 and / or 4 to the second pipe 102.

[0081] At block 806. one or more example valves are fluidly coupled between the first pipe 102 and the first cylinder and / or between the second pipe 104 and the first cylinder. For example, the first and second valves 212, 214 are fluidly coupled between the first pipe 102 and the first and second chambers 220, 226 of the first cylinder 202 of FIG. 2, and the third and fourth valves 232, 236 are fluidly coupled between the second pipe 104 and respective ones of the first and second chambers 220. 226. Additionally or alternatively, the first valve 330 is fluidly coupled between the first pipe 102 and the first chamber 309 of the first cylinder 302 ofFIGS. 3 and / or 4, and the second valve 334 is fluidly coupled between the second pipe 104 and the first chamber 309. In some examples, opening and / or closing of one(s) of the valves 212. 214, 232, 236, 330, 334 can be used to control fluid flow to and / or from the first cylinder 202 of FIG. 2 and / or the first cylinder 302 of FIGS. 3 and / or 4.

[0082] At block 808, a first example piston of the first cylinder is operatively coupled to a second example piston of the second cylinder. For example, the first piston 206 positioned in and / or slidable within the first cylinder 202 of FIG. 2 is operatively coupled (e.g., via the rod 210) to the second piston 208 positioned in and / or slidable within the second cylinder 204 of FIG. 2. Additionally or alternatively, the first piston 306 positioned in and / or slidable within the first cylinder 302 of FIGS. 3 and / or 4 is operatively coupled (e.g., via the rod 326) to the second piston 308 positioned in and / or slidable within the second cylinder 304 of FIGS. 3 and / or 4. In some examples, differential pressure between the first pipe 102 and the second pipe 104 drives reciprocal motion of the first piston 206 within the first cylinder 202 of FIG. 2 and, as a result, drives corresponding reciprocal motion of the second piston 208 within the second cylinder 204 of FIG. 2. In some examples, differential pressure between the first pipe 102 and the second pipe 104 drives reciprocal motion of the first piston 306 within the first cylinder 302 of FIGS. 3 and / or 4 and, as a result, drives corresponding reciprocal motion of the second piston 308 within the second cylinder 304 of FIGS. 3 and / or 4. In such examples, the reciprocal motion of the second piston 208 within the second cylinder 204 of FIG. 2 and / or the reciprocal motion of the second piston 308 within the second cylinder 304 of FIGS. 3 and / or 4 is used to draw bleed gas from the gas source 106 and pump the bleed gas to the second pipe 104, thus reducing an amount of bleed gas to be vented from the gas source 106.

[0083] At block 810, one or more example springs are positioned in at least one of the first cylinder or the second cylinder. For example, the first example spring 324 of FIGS. 3 and / or 4 is positioned in the second chamber 312 of the first cylinder 302 of FIGS. 3 and / or 4 and is operatively coupled between the first piston 306 and the second end 314 of the first cylinder 302. Additionally or alternatively, the second example spring 402 of FIG. 4 is positioned in the fourth chamber 320 of the second cylinder 304 of FIGS. 3 and / or 4 and is operatively coupled between the second piston 308 and the fourth end 322 of the second cylinder 304. In some examples, the first spring 324 and / or the second spring 402 facilitate return of the first piston 306 and the second piston 308 to a leftward position in the respective first and second cylinders 302, 304 of FIGS. 3 and / or 4.

[0084] FIG. 9 is a flowchart representative of an example method 900 to produce the fourth example drive system 700 of FIG. 7. Although the example method is described withreference to the flowchart illustrated in FIG. 9, many other methods may alternatively be used. For example, the order of execution of the blocks may be changed, and / or some of the blocks described may be combined, divided, re-arranged, omitted, eliminated, and / or implemented in any other way. Further, in some examples, additional processing operations can be performed before, between, and / or after any of the blocks represented in the illustrated example.

[0085] The example method 900 of FIG. 9 begins at block 902, at which the example Venturi 702 of FIG. 7 is positioned along an example pipe (e.g., the first example pipe 102 of FIG. 1). For example, example nozzles 706, 708 are coupled to the first pipe 102, and an example pipe section 704 is coupled between the nozzles 706, 708 to produce the Venturi 702 of FIG. 7. In some examples, as fluid in the pipe 102 flows through the Venturi 702, the Venturi 702 causes a pressure of the fluid to drop and / or causes a velocity of the fluid to increase. As a result, the fluid in the pipe section 704 of the Venturi 702 is at a first pressure less than a second pressure of the fluid in the pipe 102.

[0086] At block 904, the example cylinder 712 is fluidly coupled between the example gas source 106 and the first pipe 102. For example, the cylinder 712 is implemented along the example bleed line 714 fluidly coupled between the gas source 106 and afirst portion of the first pipe 102 on a first side of the Venturi 702. In some examples, bleed gas from the gas source 106 can flow to the cylinder 712 and / or the bleed gas can flow from the cylinder 712 to the first pipe 102.

[0087] At block 906. the example piston 710 of FIG. 7 is positioned in the example cylinder 712. For example, the piston 710 is positioned in and / or slidable within the cylinder 712 along the first and second directions 734, 736 of FIG. 7. In some examples, reciprocal motion of the piston 710 within the cylinder 712 can be used to draw' bleed gas from the gas source 106 into the cylinder 712 and pump the bleed gas from the cylinder 712 into the first pipe 102.

[0088] At block 908, the example diaphragm actuator 716 of FIG. 9 is fluidly coupled between the Venturi 702 and the first pipe 102. For example, the first chamber 720 of the diaphragm actuator 716 is fluidly coupled to the pipe section 704 of the Venturi 702 and is further fluidly coupled to a second portion of the first pipe 102 on a second side of the Venturi 702 (e.g.. opposite the first side). Further, the second chamber 722 of the diaphragm actuator 716 is fluidly coupled to the second portion of the first pipe 102. In some examples, the first chamber 720 is fluidly coupled to the first pipe 102 at a first location, and the second chamber 722 is fluidly coupled to the first pipe 102 at a second location upstream relative to the first location.

[0089] At block 910, the example valve 732 of FIG. 7 is fluidly coupled between the Venturi 702 and the diaphragm actuator 716. For example, valve 732 is implemented along the first fluid line 726 between the first chamber 720 of the diaphragm actuator 716 and the pipe section 704 of the Venturi 702. In some examples, by repeatedly opening and closing the valve 732, a relative pressure between the first and second chambers 720, 722 of the diaphragm actuator 716 can be adjusted to cause deflection of the diaphragm 718 (e.g., along the first and second directions 734, 736 of FIG. 7).

[0090] At block 912, the example diaphragm actuator 716 is operatively coupled to the example piston 710. For example, the example rod 724 of FIG. 7 operatively couples the diaphragm 718 of the diaphragm actuator 716 to the piston 710. such that deflection of the diaphragm 718 results in corresponding movement (e.g., reciprocal motion) of the piston 710 within the cylinder 712, and, thus, causes bleed gas to be drawn from the gas source 106 and provided to the first pipe 102.

[0091] FIG. 10 is a flowchart representative of example operations 1000 to implement a gas recovery procedure using the second example drive system 200 of FIG. 2. Although the example method is described with reference to the flowchart illustrated in FIG. 10, many other methods may alternatively be used. For example, the order of execution of the blocks may be changed, and / or some of the blocks described may be combined, divided, re-arranged, omitted, eliminated, and / or implemented in any other way. Further, in some examples, additional processing operations can be performed before, between, and / or after any of the blocks represented in the illustrated example. The operations 1000 begin with the example valves 212, 214, 232, 236 of FIG. 2 in a closed position.

[0092] At block 1002, the first example valve 212 is opened to enable fluid flow from the first example pipe 102 to the example reservoir 216 of FIG. 2. For example, the first valve 212 moves to an open position in which the fluid can flow therethrough from the first pipe 102 to the reservoir 216. In some examples, the first valve 212 can be opened manually (e.g., by an operator) and / or automatically (e.g., by a pneumatic and / or electrical signal from a control system operatively coupled to the first valve 212).

[0093] At block 1004, the fluid pressure in the reservoir 216 is evaluated based on an example threshold (e.g., a pressure threshold). In some examples, the threshold corresponds to a pressure of the fluid in the first pipe 102. In response to the fluid pressure in the reservoir 21 not satisfying the threshold (e.g., block 1004 returns a result of NO), control returns to block 1004 until the fluid pressure satisfies the threshold. In response to the fluid pressure in thereservoir 216 satisfying the threshold (e.g., block 1004 returns a result of YES), control proceeds to block 1006.

[0094] At block 1006, the first valve 214 is closed. For example, the first valve 214 moves to the closed position to restrict further fluid flow from the first pipe 102 to the reservoir 216. In some examples, the first valve 212 can be closed manually (e.g., by an operator) and / or automatically (e.g., by a pneumatic and / or electrical signal from a control system operatively- coupled to the first valve 212).

[0095] At block 1008, the fourth example valve 236 is opened and the second example valve 214 switches to the first open position to enable fluid flow from the reservoir 216 to the first example chamber 220 of the first cylinder 202. For example, the second and fourth valves 214, 236 can be opened manually (e.g., by an operator) and / or automatically (e.g., by a pneumatic and / or electrical signal from a control system operatively coupled to the second and fourth valves 214, 236). For example, fluid flows from the reservoir 21 to the first chamber 220, and pressure buildup in the first chamber 220 causes the first piston 206 to move in a first direction (e.g., rightward in FIG. 2) toward the second end 228 of the first cylinder 202. As a result, the first piston 206 pushes the second piston 208 toward the fourth end 242 of the second cylinder 204, which expels bleed gas from the third chamber 240 of the second cylinder 204 toward the second pipe 104.

[0096] At block 1010, a position of the first piston 206 is evaluated based on a first piston position. For example, the first piston 206 is in the first piston position when a first pressure in the first chamber 220 corresponds to a second pressure in the second chamber 226, and / or when the first piston 206 is stationary' and / or is no longer moving in the first direction (e.g., rightward in FIG. 2). In response to the first piston 206 not reaching the first piston position (e.g., block 1010 returns a result of NO), control returns to block 1010 until the first piston 206 reaches the first piston position. Alternatively, in response to the first piston 206 reaching the first piston position (e.g., block 1010 returns a result of YES), control proceeds to block 1012.

[0097] At block 1012, the fourth valve 236 is closed. For example, the fourth valve 236 moves to the closed position to restrict fluid flow from the second chamber 226 of the first cylinder 202 to the second pipe 104. In some examples, the fourth valve 236 can be closed manually (e.g., by an operator) and / or automatically (e.g., by a pneumatic and / or electrical signal from a control system operatively coupled to the fourth valve 236).

[0098] At block 1014, the third example valve 232 is opened and the second example valve 214 switches to the second open position to enable fluid flow from the reservoir 216 to thesecond example chamber 226 of the first cylinder 202. For example, the second and third valves 214, 232 can be closed manually (e.g.. by an operator) and / or automatically (e.g.. by a pneumatic and / or electrical signal from a control system operatively coupled to the second and third valves 214, 232). In some examples, fluid flows from the reservoir 216 to the second chamber 226, and pressure buildup in the second chamber 226 causes the first piston 206 to move in a second direction (e.g.. leftward in FIG. 2) toward the first end 222 of the first cylinder 202. As a result, the first piston 206 pulls the second piston 208 toward the third end 238 of the second cylinder 204, which draws bleed gas from the gas source 106 to the third chamber 240 of the second cylinder 204.

[0099] At block 1016, a position of the first piston 206 is evaluated based on a second piston position. For example, the first piston 206 is in the second piston position when a first pressure in the first chamber 220 corresponds to a second pressure in the second chamber 226, and / or when the first piston 206 is stationary' and / or is no longer moving in the second direction (e.g., leftward in FIG. 2). In response to the first piston 206 not reaching the second piston position (e.g., block 1016 returns a result of NO), control returns to block 1016 until the first piston 206 reaches the second piston position. Alternatively, in response to the first piston 206 reaching the second piston position (e.g., block 1016 returns a result of YES), control proceeds to block 1018.

[0100] At block 1018, one or more of the valves 212, 214, 232, 236 are closed. For example, the second and fourth valves 214, 236 are moved to the closed position to restrict fluid flow to the first cylinder 202 and / or to the second pipe 104. In some examples, the second and fourth valves 214, 236 can be closed manually (e.g., by an operator) and / or automatically (e.g., by a pneumatic and / or electrical signal from a control system operatively coupled to the second and fourth valves 214, 236).

[0101] At block 1020, the operator and / or the control system determines whether to continue evacuation of bleed gas from the gas source 106. In response to a determination that the evacuation of the bleed gas is to continue (e.g., block 1020 returns a result of YES), control returns to block 1002. Alternatively, in response to a determination that the evacuation of the bleed gas is not to continue (e.g., block 1020 returns a result of NO), control ends.

[0102] In some examples, first means for receiving fluid can be implemented by the second cylinder 204 of FIG. 2, the second cylinder 304 of FIGS. 3 and / or 4, the first cylinder 602 of FIG. 6A, the first cylinder 662A of FIGS. 6B and / or 6D, and / or the cylinder 712 of FIG. 7. In some examples, second means for receiving fluid can be implemented by the first cylinder 202 of FIG. 2, the first cylinder 302 of FIGS. 3 and / or 4, the second cylinder 604 of FIG. 6B, thesecond cylinder 662B of FIGS. 6B and / or 6D, and / or the first chamber 720 of FIG. 7. In some examples, first means for expelling fluid can be implemented by the second piston 208 of FIG.2, the second piston 308 of FIGS. 3 and / or 4, the second piston 508 of FIGS. 5 A, 5B, and / or 5C, the first piston 616 of FIG. 6A, the first piston 672A of FIG. 6D, and / or the piston 710 of FIG. 7. In some examples, second means for expelling fluid can be implemented by the first piston 206 of FIG. 2, the first piston 306 of FIGS. 3 and / or 4. the first piston 506 of FIGS. 5A, 5B, and / or 5C, the second piston 618 of FIG. 6A, and / or the second piston 672B of FIG. 6D. In some examples, first means for biasing can be implemented by the second spring 402 of FIG. 4. In some examples, second means for biasing can be implemented by the first spring 324 of FIGS. 3 and / or 4.

[0103] “Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc., may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and / or” when used, for example, in a form such as A, B, and / or C refers to any combination or subset of A, B. C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, or (7) A with B and with C. As used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B.

[0104] As used herein, singular references (e.g.. “a”, “an”, “first”, “second”, etc.) do not exclude a plurality. The term “a” or “an” object, as used herein, refers to one or more of thatobject. The terms “a” (or “an’'), “one or more”, and “at least one” are used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements, or actions may be implemented by, e.g., the same entity or object. Additionally, although individual features may be included in different examples or claims, these may possibly be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and / or advantageous.

[0105] As used herein, unless otherwise stated, the term “above” describes the relationship of two parts relative to Earth. A first part is above a second part, if the second part has at least one part between Earth and the first part. Likewise, as used herein, a first part is “below” a second part when the first part is closer to the Earth than the second part. As noted above, a first part can be above or below a second part with one or more of: other parts therebetween, without other parts therebetween, with the first and second parts touching, or without the first and second parts being in direct contact with one another.

[0106] As used in this patent, stating that any part (e.g., a layer, film, area, region, or plate) is in any way on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, indicates that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween.

[0107] As used herein, connection references (e.g., attached, coupled, connected, and joined) may include intermediate members between the elements referenced by the connection reference and / or relative movement between those elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and / or in fixed relation to each other. As used herein, stating that any part is in “contact” with another part is defined to mean that there is no intermediate part between the two parts.

[0108] Unless specifically stated otherwise, descriptors such as “first,” “second,” “third,” etc., are used herein without imputing or otherwise indicating any meaning of priority, physical order, arrangement in a list, and / or ordering in any way, but are merely used as labels and / or arbitrary names to distinguish elements for ease of understanding the disclosed examples. In some examples, the descriptor “first” may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as “second” or “third.” In such instances, it should be understood that such descriptors are used merely for identifying those elements distinctly within the context of the discussion (e.g., within a claim) in which the elements might, for example, otherwise share a same name.

[0109] As used herein, “approximately’' and “about'’ modify their subjects / values to recognize the potential presence of variations that occur in real world applications. For example, “approximately” and “about” may modify dimensions that may not be exact due to manufacturing tolerances and / or other real world imperfections as will be understood by persons of ordinary skill in the art. For example, “approximately” and “about” may indicate such dimensions may be within a tolerance range of + / - 10% unless otherwise specified herein.

[0110] From the foregoing, it will be appreciated that example systems, apparatus, articles of manufacture, and methods have been disclosed that capture bleed gas from a gas source (e.g., one or more gas-operated devices) and return the captured bleed gas to a pipeline. Examples disclosed herein implement a piston positioned in a cylinder along a bleed line between the gas source and a pipe, where reciprocal motion of the piston is used to draw bleed gas from the bleed gas source and / or expel the bleed gas to the pipe. Further, an actuator is operatively coupled to the piston and fluidly coupled between the first pipe location and a second pipe location, where a pressure differential between the first and second pipe locations is used to drive the actuator and, thus, the reciprocal motion of the piston. In some examples, the actuator corresponds to at least one of a second piston or a diaphragm actuator. Advantageously, the disclosed systems, methods, apparatus, and articles of manufacture reduce emission of bleed gas into the atmosphere, which reduces environmental harm, economic waste, and / or risk of accidental combustion compared to venting of the bleed gas.

[0111] Example piston-driven pressure differential systems and methods are disclosed herein. Further examples and combinations thereof include the following:

[0112] Example 1 includes an apparatus comprising a first cylinder fluidly coupled between a bleed gas source and a first pipe location, a first piston positioned in the first cylinder, and an actuator operatively coupled to the first piston and fluidly coupled between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the second pipe location to drive reciprocal motion of the actuator and the first piston, the reciprocal motion of the first piston to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

[0113] Example 2 includes the apparatus of example 1, wherein the actuator includes a second piston positioned in a second cylinder, the first piston operatively coupled to the second piston via a rod extending through a first end of the first cylinder and a second end of the second cylinder.

[0114] Example 3 includes the apparatus of example 2, further including at least one of (a) a first spring positioned in the first cylinder and coupled between the first piston and a third end of the first cylinder, the third end opposite the first end, or (b) a second spring positioned in the second cylinder and coupled between the second piston and the second end of the second cylinder, the at least one of the first spring or the second spring to bias the first piston and the second piston away from the third end of the first cylinder.

[0115] Example 4 includes the apparatus of example 2, further including a first flange and a second flange coupled to the rod between the first cylinder and the second cylinder, a lever positioned between the first flange and the second flange, the lever to contact the first flange when the first and second pistons move to a first position, the lever to contact the second flange when the first and second pistons move to a second position, and a flow control device operatively coupled to the lever, the flow control device to control flow of fluid from the second pipe location to the second cylinder based on the contact between the lever and the first and second flanges.

[0116] Example 5 includes the apparatus of example 2, further including a first flanged portion coupled between the first end of the first cylinder and the second end of the second cylinder, the first flanged portion including an inlet port fluidly coupled to the first pipe location, an outlet port fluidly coupled to the second pipe location, a first fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the first fluid passageway to fluidly couple the inlet port to the first and second cylinders, a second fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the second fluid passageway to fluidly couple the outlet port to the first and second cylinders, a first plug positioned in and movable in the first fluid passageway to selectively control fluid flow from the first pipe location to the first and second cylinders via the inlet port, and a second plug positioned in and movable in the second fluid passageway to selectively control fluid flow from the first and second cylinders to the second pipe location via the outlet port.

[0117] Example 6 includes the apparatus of example 5, further including a second flanged portion coupled to a third end of the first cylinder, the third end opposite the first end, the second flanged portion including a third fluid passageway fluidly coupled between the bleed gas source and the first pipe location, a fluid port fluidly coupled between the third fluid passageway and the first cylinder, a first check valve positioned in the third fluid passageway between the bleed gas source and the fluid port, the first check valve to restrict backflow from the first cylinder to the bleed gas source, and a second check valve positioned in the third fluidpassageway between the fluid port and the first pipe location, the second check valve to restrict backflow from the first pipe location to the first cylinder.

[0118] Example 7 includes the apparatus of example 2, wherein the rod is a first rod, further including a flanged portion coupled between the first and second cylinders, the flanged portion including a first surface facing the first cylinder, a second surface facing the second cylinder, a first opening fluidly coupled to the first pipe location, a second opening fluidly coupled to the second pipe location, and a second rod positioned in the flanged portion and oriented along a first direction, the second rod movable between a first rod position and a second rod position, the first opening fluidly coupled to the first cylinder and the second opening fluidly- coupled to the second cylinder when the second rod is in the first rod position, the first opening fluidly coupled to the second cylinder and the second opening fluidly coupled to the first cylinder when the second rod is in the second rod position.

[0119] Example 8 includes the apparatus of example 7, further including a pin positioned in the flanged portion and oriented along a second direction different from the first direction, the pin movable between (a) a first pin position in which the pin protrudes from the first surface and is substantially flush with the second surface and (b) a second pin position in which the pin protrudes from the second surface and is substantially flush with the first surface, contact between the pin and the first and second pistons to switch the pin between the first pin position and the second pin position, the pin to cause the second rod to move to the first rod position when the pin is in the first pin position, the pin to cause the second rod to move to the second rod position when the pin is in the second pin position.

[0120] Example 9 includes the apparatus of example 1, wherein the actuator includes a first chamber fluidly coupled between the second pipe location and a Venturi positioned at the first pipe location, a second chamber fluidly coupled to the second pipe location, and a diaphragm positioned between the first chamber and the second chamber, the diaphragm operatively coupled to the first piston via a rod, the diaphragm to deflect based on a difference between a third pressure in the first chamber and a fourth pressure in the second chamber, the deflection of the diaphragm to move the first piston.

[0121] Example 10 includes a method comprising fluidly coupling a first cylinder between a bleed gas source and a first pipe location, positioning a first piston in the first cylinder, operatively coupling an actuator to the first piston, and fluidly coupling the actuator between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the second pipe location to drive reciprocal motion of the actuator andthe first piston, the reciprocal motion of the first piston to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

[0122] Example 11 includes the method of example 10, wherein the actuator includes a second piston positioned in a second cylinder, further including operatively coupling the first piston to the second piston via a rod extending through a first end of the first cylinder and a second end of the second cylinder.

[0123] Example 12 includes the method of example 11, further including at least one of (a) positioning a first spring in the first cylinder between the first piston and a third end of the first cylinder, the third end opposite the first end, or (b) positioning a second spring in the second cylinder between the second piston and the second end of the second cylinder, the at least one of the first spring or the second spring to bias the first piston and the second piston away from the third end of the first cylinder.

[0124] Example 13 includes the method of example 11, further including coupling a first flange and a second flange to the rod between the first cylinder and the second cylinder, positioning a lever between the first flange and the second flange, the lever to contact the first flange when the first and second pistons move to a first position, the lever to contact the second flange when the first and second pistons move to a second position, and operatively coupling a flow control device to the lever, the flow control device to control flow of fluid from the second pipe location to the second cylinder based on the contact between the lever and the first and second flanges.

[0125] Example 14 includes the method of example 11, further including coupling a first flanged portion between the first end of the first cylinder and the second end of the second cylinder, the first flanged portion including an inlet port fluidly coupled to the first pipe location, an outlet port fluidly coupled to the second pipe location, a first fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the first fluid passageway to fluidly couple the inlet port to the first and second cylinders, a second fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the second fluid passageway to fluidly couple the outlet port to the first and second cylinders, a first plug positioned in and movable in the first fluid passageway to selectively control fluid flow from the first pipe location to the first and second cylinders via the inlet port, and a second plug positioned in and movable in the second fluid passageway to selectively control fluid flow from the first and second cylinders to the second pipe location via the outlet port.

[0126] Example 15 includes the method of example 14, further including coupling a second flanged portion to a third end of the first cylinder, the third end opposite the first end. the second flanged portion including a third fluid passageway fluidly coupled between the bleed gas source and the first pipe location, a fluid port fluidly coupled between the third fluid passageway and the first cylinder, a first check valve positioned in the third fluid passageway between the bleed gas source and the fluid port, the first check valve to restrict backflow from the first cylinder to the bleed gas source, and a second check valve positioned in the third fluid passageway between the fluid port and the first pipe location, the second check valve to restrict backflow from the first pipe location to the first cylinder.

[0127] Example 16 includes the method of example 11, wherein the rod is a first rod, further including coupling a flanged portion coupled the first and second cylinders, the flanged portion including a first surface facing the first cylinder, a second surface facing the second cylinder, a first opening fluidly coupled to the first pipe location, a second opening fluidly coupled to the second pipe location, and a second rod positioned in the flanged portion and oriented along a first direction, the second rod movable between a first rod position and a second rod position, the first opening fluidly coupled to the first cylinder and the second opening fluidly coupled to the second cylinder when the second rod is in the first rod position, the first opening fluidly coupled to the second cylinder and the second opening fluidly coupled to the first cylinder when the second rod is in the second rod position.

[0128] Example 17 includes the method of example 16. further including positioning a pin in the flanged portion and orienting the pin along a second direction different from the first direction, the pin movable between (a) a first pin position in which the pin protrudes from the first surface and is substantially flush with the second surface and (b) a second pin position in which the pin protrudes from the second surface and is substantially flush with the first surface, contact between the pin and the first and second pistons to switch the pin between the first pin position and the second pin position, the pin to cause the second rod to move to the first rod position when the pin is in the first pin position, the pin to cause the second rod to move to the second rod position when the pin is in the second pin position.

[0129] Example 18 includes an apparatus comprising first means for receiving fluid fluidly coupled between a bleed gas source and a first pipe location, first means for expelling fluid positioned in the first means for receiving fluid, and means for actuating operatively coupled to the first means for expelling fluid and fluidly coupled between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the secondpipe location to drive reciprocal motion of the means for actuating and the first means for expelling fluid, the reciprocal motion of the first means for expelling fluid to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

[0130] Example 19 includes the apparatus of example 18, wherein the means for actuating includes second means for expelling fluid positioned in second means for receiving fluid, the first means for expelling fluid operatively coupled to the second means for expelling fluid via a rod extending through a first end of the first means for receiving fluid and a second end of the second means for receiving fluid.

[0131] Example 20 includes the apparatus of example 19, further including at least one of (a) first means for biasing positioned in the first means for receiving fluid and coupled between the first means for expelling fluid and a third end of the first means for receiving fluid, the third end opposite the first end, or (b) second means for biasing positioned in the second means for receiving fluid and coupled between the second means for expelling fluid and the second end of the second means for receiving fluid, the at least one of the first means for biasing or the second means for biasing to bias the first means for expelling fluid and the second means for expelling fluid away from the third end of the first means for receiving fluid.

[0132] The following claims are hereby incorporated into this Detailed Description by this reference. Although certain example systems, apparatus, articles of manufacture, and methods have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all systems, apparatus, articles of manufacture, and methods fairly falling within the scope of the claims of this patent.

Claims

What Is Claimed Is:

1. An apparatus comprising: a first cylinder fluidly coupled between a bleed gas source and a first pipe location; a first piston positioned in the first cylinder; and an actuator operatively coupled to the first piston and fluidly coupled between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the second pipe location to drive reciprocal motion of the actuator and the first piston, the reciprocal motion of the first piston to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

2. The apparatus of claim 1, wherein the actuator includes a second piston positioned in a second cylinder, the first piston operatively coupled to the second piston via a rod extending through a first end of the first cylinder and a second end of the second cylinder.

3. The apparatus of claim 2, further including at least one of (a) a first spring positioned in the first cylinder and coupled between the first piston and a third end of the first cylinder, the third end opposite the first end, or (b) a second spring positioned in the second cylinder and coupled between the second piston and the second end of the second cylinder, the at least one of the first spring or the second spring to bias the first piston and the second piston away from the third end of the first cylinder.

4. The apparatus of claim 2, further including: a first flange and a second flange coupled to the rod between the first cylinder and the second cylinder; a lever positioned between the first flange and the second flange, the lever to contact the first flange when the first and second pistons move to a first position, the lever to contact the second flange when the first and second pistons move to a second position; and a flow control device operatively coupled to the lever, the flow control device to control flow of fluid from the second pipe location to the second cylinder based on the contact between the lever and the first and second flanges.

5. The apparatus of claim 2, further including a first flanged portion coupled between the first end of the first cylinder and the second end of the second cylinder, the first flanged portion including: an inlet port fluidly coupled to the first pipe location; an outlet port fluidly coupled to the second pipe location;a first fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the first fluid passageway to fluidly couple the inlet port to the first and second cylinders; a second fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the second fluid passageway to fluidly couple the outlet port to the first and second cylinders; a first plug positioned in and movable in the first fluid passageway to selectively control fluid flow from the first pipe location to the first and second cylinders via the inlet port; and a second plug positioned in and movable in the second fluid passageway to selectively control fluid flow from the first and second cylinders to the second pipe location via the outlet port.

6. The apparatus of claim 5, further including a second flanged portion coupled to a third end of the first cylinder, the third end opposite the first end, the second flanged portion including: a third fluid passageway fluidly coupled between the bleed gas source and the first pipe location; a fluid port fluidly coupled between the third fluid passageway and the first cylinder; a first check valve positioned in the third fluid passageway between the bleed gas source and the fluid port, the first check valve to restrict backflow from the first cylinder to the bleed gas source; and a second check valve positioned in the third fluid passageway between the fluid port and the first pipe location, the second check valve to restrict backflow from the first pipe location to the first cylinder.

7. The apparatus of claim 2, wherein the rod is a first rod, further including a flanged portion coupled between the first and second cylinders, the flanged portion including: a first surface facing the first cylinder; a second surface facing the second cylinder; a first opening fluidly coupled to the first pipe location; a second opening fluidly coupled to the second pipe location; and a second rod positioned in the flanged portion and oriented along a first direction, the second rod movable between a first rod position and a second rod position, the first opening fluidly coupled to the first cylinder and the second opening fluidly coupled to the second cylinder when the second rod is in the first rod position, the first opening fluidly coupled to thesecond cylinder and the second opening fluidly coupled to the first cylinder when the second rod is in the second rod position.

8. The apparatus of claim 7, further including a pin positioned in the flanged portion and oriented along a second direction different from the first direction, the pin movable between (a) a first pin position in which the pin protrudes from the first surface and is substantially flush with the second surface and (b) a second pin position in which the pin protrudes from the second surface and is substantially flush with the first surface, contact between the pin and the first and second pistons to switch the pin between the first pin position and the second pin position, the pin to cause the second rod to move to the first rod position when the pin is in the first pin position. the pin to cause the second rod to move to the second rod position when the pin is in the second pin position.

9. The apparatus of claim 1, wherein the actuator includes: a first chamber fluidly coupled between the second pipe location and a Venturi positioned at the first pipe location; a second chamber fluidly coupled to the second pipe location; and a diaphragm positioned between the first chamber and the second chamber, the diaphragm operatively coupled to the first piston via a rod, the diaphragm to deflect based on a difference between a third pressure in the first chamber and a fourth pressure in the second chamber, the deflection of the diaphragm to move the first piston.

10. A method comprising: fluidly coupling a first cylinder between a bleed gas source and a first pipe location; positioning a first piston in the first cylinder; operatively coupling an actuator to the first piston; and fluidly coupling the actuator between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the second pipe location to drive reciprocal motion of the actuator and the first piston, the reciprocal motion of the first piston to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

11. The method of claim 10, wherein the actuator includes a second piston positioned in a second cylinder, further including operatively coupling the first piston to the second piston via a rod extending through a first end of the first cylinder and a second end of the second cylinder.

12. The method of claim 11, further including at least one of (a) positioning a first spring in the first cylinder between the first piston and a third end of the first cylinder, the third endopposite the first end, or (b) positioning a second spring in the second cylinder between the second piston and the second end of the second cylinder, the at least one of the first spring or the second spring to bias the first piston and the second piston away from the third end of the first cylinder.

13. The method of claim 11, further including: coupling a first flange and a second flange to the rod between the first cylinder and the second cylinder; positioning a lever between the first flange and the second flange, the lever to contact the first flange when the first and second pistons move to a first position, the lever to contact the second flange when the first and second pistons move to a second position; and operatively coupling a flow control device to the lever, the flow control device to control flow of fluid from the second pipe location to the second cylinder based on the contact between the lever and the first and second flanges.

14. The method of claim 11, further including coupling a first flanged portion between the first end of the first cylinder and the second end of the second cylinder, the first flanged portion including: an inlet port fluidly coupled to the first pipe location; an outlet port fluidly coupled to the second pipe location; a first fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the first fluid passageway to fluidly couple the inlet port to the first and second cylinders; a second fluid passageway extending between the first end of the first cylinder and the second end of the second cylinder, the second fluid passageway to fluidly couple the outlet port to the first and second cylinders; a first plug positioned in and movable in the first fluid passageway to selectively control fluid flow from the first pipe location to the first and second cylinders via the inlet port; and a second plug positioned in and movable in the second fluid passageway to selectively control fluid flow from the first and second cylinders to the second pipe location via the outlet port.

15. The method of claim 14, further including coupling a second flanged portion to a third end of the first cylinder, the third end opposite the first end, the second flanged portion including: a third fluid passageway fluidly coupled between the bleed gas source and the first pipe location;a fluid port fluidly coupled between the third fluid passageway and the first cylinder; a first check valve positioned in the third fluid passageway between the bleed gas source and the fluid port, the first check valve to restrict backflow from the first cylinder to the bleed gas source; and a second check valve positioned in the third fluid passageway between the fluid port and the first pipe location, the second check valve to restrict backflow from the first pipe location to the first cylinder.

16. The method of claim 11, wherein the rod is a first rod, further including coupling a flanged portion coupled the first and second cylinders, the flanged portion including: a first surface facing the first cylinder; a second surface facing the second cylinder; a first opening fluidly coupled to the first pipe location; a second opening fluidly coupled to the second pipe location; and a second rod positioned in the flanged portion and oriented along a first direction, the second rod movable between a first rod position and a second rod position, the first opening fluidly coupled to the first cylinder and the second opening fluidly coupled to the second cylinder when the second rod is in the first rod position, the first opening fluidly coupled to the second cylinder and the second opening fluidly coupled to the first cylinder when the second rod is in the second rod position.

17. The method of claim 16. further including positioning a pin in the flanged portion and orienting the pin along a second direction different from the first direction, the pin movable between (a) a first pin position in which the pin protrudes from the first surface and is substantially flush with the second surface and (b) a second pin position in which the pin protrudes from the second surface and is substantially flush with the first surface, contact between the pin and the first and second pistons to switch the pin between the first pin position and the second pin position, the pin to cause the second rod to move to the first rod position when the pin is in the first pin position. the pin to cause the second rod to move to the second rod position when the pin is in the second pin position.

18. An apparatus comprising: first means for receiving fluid fluidly coupled between a bleed gas source and a first pipe location; first means for expelling fluid positioned in the first means for receiving fluid; andmeans for actuating operatively coupled to the first means for expelling fluid and fluidly coupled between the first pipe location and a second pipe location, a first pressure of the first pipe location less than a second pressure of the second pipe location, a pressure differential between the first pipe location and the second pipe location to drive reciprocal motion of the means for actuating and the first means for expelling fluid, the reciprocal motion of the first means for expelling fluid to draw bleed gas from the bleed gas source and pump the bleed gas to the first pipe location.

19. The apparatus of claim 18, wherein the means for actuating includes second means for expelling fluid positioned in second means for receiving fluid, the first means for expelling fluid operatively coupled to the second means for expelling fluid via a rod extending through a first end of the first means for receiving fluid and a second end of the second means for receiving fluid.

20. The apparatus of claim 19, further including at least one of (a) first means for biasing positioned in the first means for receiving fluid and coupled between the first means for expelling fluid and a third end of the first means for receiving fluid, the third end opposite the first end, or (b) second means for biasing positioned in the second means for receiving fluid and coupled between the second means for expelling fluid and the second end of the second means for receiving fluid, the at least one of the first means for biasing or the second means for biasing to bias the first means for expelling fluid and the second means for expelling fluid away from the third end of the first means for receiving fluid.

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