CASCADE REFRIGERANT LINE SET

CROSS-REFERENCE TO RELATED APPLICATION

[0001]This application claims the benefit of U.S. Provisional Application 63/666,473, filed in the United States Patent and Trademark Office on Jul. 1, 2024.

BACKGROUND

1. Field

[0002]Apparatuses and methods consistent with example embodiments relate to liquid and vapor lines in a refrigeration circuit, and, more specifically, to coaxial liquid and vapor lines in a refrigeration circuit.

2. Description of Related Art

[0003]FIG. 1 illustrates an example refrigeration circuit of the related art. The refrigeration circuit 10 includes a condenser 30, an evaporator 50, a compressor 20, and an expansion valve 40 connected by lines 60. This example circuit 10 constitutes a theoretical Linde circuit, as would be understood by those of skill in the art, in which the condenser 30 expels heat from the system 10, while the evaporator 50 draws a cooling effect into the system 10. The compressor 20 increases the pressure, temperature, and energy of a vapor refrigerant, slightly decreasing its energy and specific volume as the refrigerant transitions from a saturated vapor to a saturated liquid. High pressure refrigerant from the compressor 20 is directed to the condenser 30 in which the saturated vapor refrigerant entering the condenser 30 is transitioned to a saturated liquid refrigerant under constant pressure and temperature conditions. The refrigerant from the condenser 30 passes through the expansion valve 40 which lowers the pressure, such that the refrigerant exits the expansion valve as a liquid-vapor mixture. The expansion valve 40 may be, for example, an electronic expansion valve (EEV). The refrigerant is directed to the evaporator 50 where it absorbs heat, reaches its boiling point, and evaporates, such that low-pressure vapor refrigerant is directed from the evaporator 50 back to the condenser 20. Operations of any one or more of the compressor 20, condenser 30, expansion valve 40, and evaporator 50 may be controlled by a controller (not illustrated) operatively coupled to one or more components of the circuit 10.

[0004]Many refrigeration circuits are installed such that the condenser is on a roof and liquid and vapor lines are required between the outside condenser and the remainder of the circuit, located inside. As a number of units in a building increases, roof space becomes tight, and the requirements for piping from the roof units increase the costs of installation and may limit the number of units that can be installed.

SUMMARY OF EXAMPLE EMBODIMENTS

[0005]Example embodiments may address at least the above problems and/or disadvantages and other disadvantages not described above. Also, example embodiments are not required to overcome the disadvantages described above, and may not overcome any of the problems described above.

[0006]According to an aspect of an example embodiment, a refrigeration circuit may comprise: a condenser; an evaporator; and a line set extending from the condenser to the evaporator and comprising: a gas line comprising: a first end connected to the condenser, and a second end connected to the evaporator; a liquid line comprising a first end connected to the condenser a second end connected to the evaporator, and an interior section, disposed between the first end and the second end and running through an interior of the gas line.

[0007]According to an example implementation, the liquid line may enter the interior of the gas line via a first opening in the gas line and exit from the interior of the gas line via a second opening in the gas line, and the line set may further comprise a first connection unit sealing the first opening in the gas line around the liquid line and a second connection unit sealing the second opening in the gas line around the liquid line.

[0008]According to an aspect of an example embodiment, a refrigeration circuit leak detection system may comprise: the refrigeration circuit, wherein the liquid line extends from the condenser, through a first opening in a sidewall of the gas line, through the interior of the gas line, through a second opening in the sidewall of the gas line, and to the evaporator; a first temperature sensor configured to detect a first temperature of gas in the gas line adjacent to the first opening; a second temperature sensor configured to detect a second temperature of gas in the gas line adjacent to the second opening; and a controller comprising: a non-volatile memory storing instructions thereon, and at least one hardware processor coupled to the memory and configured to execute the instructions and thereby: receive a first detected temperature from the first temperature sensor; receive a second detected temperature from the second temperature sensor; determining a temperature change between the first detected temperature and the second detected temperature; comparing the temperature change to a threshold; and outputting an alert based on the temperature change being greater than the threshold.

[0009]According to an aspect of an example embodiment, a connection unit of a refrigeration line set may comprise: a cap comprising: a tube element configured to be attached around an end of a first liquid line section, and a flange element extending radially outward from the tube element; a line fitting comprising: a first fitting element configured to be attached to the tube element, a second fitting element configured to be attached around an end of a second liquid line section, and a connecting element disposed between the first fitting element and the second fitting element and providing a sealed connection between the first fitting element and the second fitting element.

[0010]According to an example implementation, the connecting element may be rotatably connected to the first fitting element and to the second fitting element.

[0011]According to an example implementation, the connecting element may be removably connectable to the first fitting element and to the second fitting element.

[0012]According to an example implementation, the connection unit may further: a flange clamp configured to clamp the flange element of the cap to a flange attached around an opening in a gas line.

[0013]According to an aspect of an example embodiment, a refrigeration line set may comprise: a gas line comprising an opening formed through a sidewall thereof; a liquid line comprising: exterior first liquid line section, and interior second liquid line section disposed within the gas line; and the connection unit, wherein: the tube element is attached around the end of the first liquid line section, the flange element is sealed to the sidewall of the gas line around the opening, and the second fitting element is attached around the end of the second liquid line section.

[0014]According to an example implementation, the connection unit may further comprise: a gas line flange fixed to the sidewall of the gas line around the opening, and a flange clamp attaching the flange element to the gas line flange.

[0015]According to an example implementation, the refrigeration circuit may further comprise: a temperature sensor disposed to sense a temperature within the gas line adjacent to the connection unit.

[0016]According to an aspect of an example embodiment, a method of assembling a refrigeration line set may comprise: sealing a cap to an end of an exterior section of a liquid line; sealing a line fitting to an end of an interior section of the liquid line; extending the interior section of the liquid line into a gas line via an opening in a sidewall of the gas line; sealing the cap to the line fitting, thereby connecting the exterior section of the liquid line to the interior section of the liquid line; and sealing the cap to the sidewall of the gas line around the opening therein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]The above and/or other aspects will become apparent and more readily appreciated from the following description of example embodiments, taken in conjunction with the accompanying drawings, in which:

[0018]FIG. 1 illustrates an example refrigeration circuit of the related art;

[0019]FIG. 2 illustrates a path of a combined liquid and gas line set according to an example embodiment;

[0020]FIG. 3 illustrates a first example embodiment of connection units connecting an external portion of a liquid line to a portion of the liquid line internal to a gas line;

[0021]FIGS. 4A and 4B illustrate exploded and assembled views, respectively, of a second example embodiment of a connection unit connecting an external portion of a liquid line to a portion of the liquid line internal to a gas line;

[0022]FIG. 5 is a block diagram of a controller according to an example embodiment; and

[0023]FIG. 6 illustrates an example method of a function of the controller according to an example embodiment.

DETAILED DESCRIPTION

[0024]Reference will now be made in detail to example embodiments which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the example embodiments may have different forms and may not be construed as being limited to the descriptions set forth herein.

[0025]It will be understood that the terms “include,” “including,” “comprise,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0026]It will be further understood that, although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections may not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section.

[0027]As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

[0028]Various terms are used to refer to particular system components. Different companies may refer to a component by different names—this document does not intend to distinguish between components that differ in name but not function.

[0029]Matters of these example embodiments that are obvious to those of ordinary skill in the technical field to which these example embodiments pertain may not be described herein in detail.

[0030]As discussed above, FIG. 1 illustrates an example refrigeration circuit. One or more example embodiments described herein enable a liquid line to be run, coaxially, through the interior of a vapor tube (alternately referred to herein as a gas line), thus decreasing or removing the need for separate line mounting, reducing brazing time, and/or reducing high pressure strength requirements for the liquid line. According to one or more example embodiments, the use of plastic, rubber, or other soft fluid tubing may be used for at least a portion of the liquid line internal to the gas line, thereby reducing the cost of supplies.

[0031]FIG. 2 illustrates routing of a combined liquid and gas line set according to an example embodiment. As shown in FIG. 2, a gas line 101 extends between an outdoor location A and an indoor location B, and gas may pass therethrough from a compressor disposed in the indoor location B to a condenser disposed in the outdoor location A. A liquid line 202 extends between the outdoor location A and the indoor location B, and liquid may pass therethrough from the condenser disposed in the outdoor location A to an expansion valve disposed in the indoor location B. One or more connection units (discussed hereinbelow) may be disposed in the outdoor location A in the region in which the liquid line 202 enters the gas line 101, and likewise, one or more connection units (discussed hereinbelow) may be disposed in the indoor location B in the region in which the liquid line 202 exits the gas line 101.

[0032]In the example embodiment of FIG. 2, the gas line and liquid line extend between the outdoor location A and the indoor location B. However, this is merely an example, the gas and liquid lines may extend entirely within an indoor location or entirely within an outdoor location, or in any positioning as would be understood by one of skill in the art. Benefits of the example embodiments described herein are not limited to only those implementations in which the gas and liquid lines extend between an outdoor location and an indoor location.

[0033]The gas line 101 may, for example, be copper or another material, as would be understood by one of skill in the art, which can provide the strength to support the high pressure of the gas in the gas line 101. The gas line 101 includes openings therein, and the one or more connection units attached thereto, in those regions in which the liquid line enters and exits.

[0034]The liquid line 202 includes an exterior line sections that are external to the gas line 101 and an interior line section that extends within the gas line 101. The exterior line sections of the liquid line 202 may be copper or another material, as would be understood by one of skill in the art, which can provide the strength to support the high pressure in the liquid line. The interior line section however, may be made from plastic, rubber, nylon, cross-linked polyethylene, or another comparatively soft and/or flexible material, due to the positioning of the liquid line 202 within the gas line 101 which enables the surrounding gas line 101 to provide the necessary high pressure strength.

[0035]As shown in FIG. 2, first and second temperature sensors 60 may be disposed on the gas line 101 at a first location adjacent to the outdoor location where the liquid line 202 enters the gas line 101 and at a second location adjacent to the indoor location where the liquid line 202 exits the gas line 101. The temperature sensors may be configured to measure a temperature and to output temperature data to a controller (not shown). Such a controller may be a controller of the refrigeration circuit, and the temperature sensors may be operatively coupled to the controller. The sensors may already exist in the refrigeration circuit or may be newly added and may comprise thermocouples. The controller may be a part of an existing controller of the refrigeration circuit, may be a part of another existing controller operatively connected to the refrigeration circuit, such as, for example, a building controller, or may be a controller specific to the line set and either operatively independent of any existing controller or coupled to and cooperative with an existing controller.

[0036]As would be understood by one of skill in the art, a liquid line is the largest and fastest possible source of a leak in a refrigeration circuit. Thus, having a portion of the liquid line 202 internal to the gas line 101 helps protect that portion of the liquid line 202 from damage and may aid in reducing the possibility of a leak.

[0037]In an implementation in which a portion of the liquid line 202 is internal to the gas line 101, there may be up to a fifty percent reduction in an amount of space required for installation per unit. This may be particularly beneficial for use in large, densely populated data centers. The combination of the liquid and gas lines 101 may also contribute to a reduction in installation costs at least with respect to the cost of support components, insulation, and clamps, for example.

[0038]The controller may be a computer 600, as shown in FIG. 5, including a processing unit 601, a system memory 602, and a system bus 603. The system bus 603 couples system components including, but not limited to, the system memory 602 to the processing unit 601. The processing unit 601 can be any of various available processors. Dual microprocessors and other multiprocessor architectures also can be employed as the processing unit 601.

[0039]The system bus 603 can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus or external bus, and/or a local bus using any of a variety of available bus architectures including, but not limited to, Industrial Standard Architecture (ISA), Micro-Channel Architecture (MSA), Extended ISA (EISA), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), Card Bus, Universal Serial Bus (USB), Advanced Graphics Port (AGP), Personal Computer Memory Card International Association bus (PCMCIA), Firewire (IEEE 1394), and Small Computer Systems Interface (SCSI).

[0040]The system memory 602 may include volatile memory and nonvolatile memory.

[0041]A basic input/output system (BIOS), containing basic routines to transfer information between elements within the computer, such as during start-up, may be stored in nonvolatile memory. By way of non-limiting example, nonvolatile memory may include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, or nonvolatile random access memory (RAM) (e.g., ferroelectric RAM (FeRAM). Volatile memory may include random access memory (RAM), which may act as an external cache memory. By way of non-limiting example, RAM is available in many forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), direct Rambus RAM (DRRAM), direct Rambus dynamic RAM (DRDRAM), and Rambus dynamic RAM.

[0042]The computer may also include removable and/or non-removable, volatile and/or non-volatile computer storage media, for example, a disk storage. A disk storage may include, but is not limited to, a magnetic disk drive, floppy disk drive, tape drive, Jaz drive, Zip drive, LS-100 drive, flash memory card, and a memory stick. Disk storage also may include storage media separately or in combination with other storage media including, but not limited to, an optical disk drive such as a compact disk ROM device (CD-ROM), CD recordable drive (CD-R Drive), CD rewritable drive (CD-RW Drive) or a digital versatile disk ROM drive (DVD-ROM). To facilitate connection of the disk storage devices to a system bus, a removable or non-removable interface may be used.

[0043]A function of the controller is to monitor temperature data received from the temperature sensors and, based on the temperature data, determine whether there is a change in temperature which may indicate a leak, and output information including, but not limited to an alert.

[0044]FIG. 6 illustrates an example method of the function of the controller. The controller receives data from the temperature sensors (S101). Using the data from the temperature sensors, the controller monitors a temperature drop between the sensors to determine if there is a change in the temperature drop that is greater than a predetermined threshold (S102). If there is a change greater than the predetermined threshold (S102—YES), this may indicate liquid leaking into the gas line, and the controller may output an alert (S103). If there is no change greater than the predetermined threshold, the controller continues to receive the data (S101) and monitor the temperatures (S102).

[0045]The liquid in the liquid line runs in a direction opposite to the direction in which the gas in the gas line runs. Therefore, if there is a leak in the liquid line leaking into the gas line, the leaked liquid will cool the vapor as it flows by, and this change in temperature may be detected by the temperature sensors. The predetermined threshold may be set such that any change in the temperature that is not otherwise accounted for by the environment will cause the controller to output an alert.

[0046]The alert(s) output from the controller may be output to any of a variety of different apparatuses, including, but not limited to, an existing controller of the refrigeration circuit, an existing building or system controller (not shown), and a user interface which may be part of or directly connected to the controller, part of or directly connected to an existing controller of the refrigeration circuit, part of or directly connected to an existing building or system controller, or a separate user interface. A user interface to which the alert(s) are output may include one or more of a display screen, a speaker, and one or more visual outputs including, but not limited to light emitting diodes (LEDs). The alert(s) may all be output to a same apparatus or to different apparatuses. The outputting may be executed via a hardware wired connection, or wirelessly.

[0047]FIG. 3 illustrates a first example embodiment of connection units connecting, through an opening in a wall of a gas line, an exterior line section of a liquid line to an interior line section of the liquid line. FIG. 3 illustrates a gas line 101; a liquid line including an exterior line section 202a disposed at least partially external to the gas line, and an interior line section 202b, disposed within the gas line; and a first example embodiment of connection units 300 and 350 connecting these lines. As would be understood by one of skill in the art, these connection units 300 and 350 may be disposed at any location at which the liquid line enters the gas line and/or at any location at which the liquid line exits the gas line. As discussed above with respect to FIG. 2, these locations may be, respectively, indoor and outdoor locations. However, this example embodiment is not limited thereto. The example connection units described herein may be used at any location or locations where a liquid line enters or exits a gas line.

[0048]The exterior line section 202a of the liquid line extends through an opening 303 in the gas line 101, and an end of the exterior line section 202a of the liquid line is thus positioned within the gas line 101. A first connection unit 300 provides a connection between the opening 303 in the gas line 101 and the exterior line section 202a of the liquid line. A second connection unit 350 is disposed within the gas line 101. The second connection unit 350 connects the end of the exterior line section 202a of the liquid line to an end of an interior line section 202b of the liquid line.

[0049]The first connection unit 300 may provide an air-tight seal between the exterior of the exterior line section 202a of the liquid line and the opening 303 in the gas line. The first connection unit includes a first fitting 301 including a flange 304 connected around the opening 303 in the gas line 101. The first fitting 301 also includes a first tube 305 attached to the exterior line section 202a of the liquid line. The flange 304 may be fixed to the gas line 101 via soldering or brazing and may provide an air-tight seal to the gas line 101. The first fitting 301 may be made from copper, brass, steel, stainless steel, or another material as would be understood by one of skill in the art. The first fitting 301 also includes an opening 306 running therethrough, through the first tube 305 and the flange 304, and the exterior line section 202a of the liquid line extends through the opening 306. The first tube 305 of the fitting 301 may be crimped around the exterior line section 202a of the liquid line with heat reacting glue forming a seal between the interior of the tube 305 and an outer circumference of the exterior line section 202a. Alternately, the first tube 305 of the first fitting 301 may be brazed or soldered around the outer circumference of the exterior line section 202a, may be compressed around the exterior line section 202a, may be connected with an Army-Navy (AN) fitting, via pipe threads, or by welding, thereby sealing an interior of the first tube 305 around the outer circumference of the exterior line section 202a. Of course, the first tube 305 may be sealed around the outer circumference of the exterior line section 202a in another air-tight manner, as would be understood by one of skill in the art.

[0050]As shown in FIG. 3, the exterior line section 202a of the liquid line may extend through an entirety of the first fitting 301 and into the gas line 101 and may be connected to the interior line section a 202b of the liquid line by means of a second connection unit 350. The second connection unit may include a second fitting 351 made from copper, brass, stainless steel, aluminum, phenolic, or another material as would be understood by one of skill in the art. The second fitting includes a second tube 353 connected to an interior end of the exterior line section 202b of the liquid line, and a crimp end 352 connected to an end of the interior line section 202b of the liquid line. The second fitting 351 also includes an opening 354 running therethrough, through the second tube 353 and the crimp end 352, providing communication for passage of liquid between an interior of the exterior line section 202a of the liquid line and an interior of the interior line section 202b of the liquid line. The second tube 353 of the second fitting 351 may be soldered or glued to the interior line section 202a of the liquid line. The crimp end 352 of the second fitting 351 may be crimped around an end of the interior line section 202b with a low heat transfer coefficient (HTC) heat/pressure glue providing a seal between the second fitting 351 and the interior line section 202b. The glue provides heat resistance and aids in preventing the interior line section 202b from melting during attachment. Any other means of attachment may be used that can withstand the chemicals used in the refrigerant, as would be understood by one of skill in the art.

[0051]As also illustrated in FIG. 3, one or more centering rings 501 may be disposed between an outer circumference of the interior line section 202b and an inner circumference of the gas line 101 to aid in holding the interior line section 202b within the gas line 101. Any number of centering rings 501 may be used and positioned, as needed, along the length of the interior line section 202b. The centering rings 501 may be any material that can withstand the chemical (most refrigerants are not very interactive). A strong plastic such as polypropylene As would be understood by one of skill in the art, one or more centering elements 501 may also be used in conjunction with the gas line 101 and liquid line 202 discussed with respect to the connection units of FIGS. 4A and 4B. Any one of more of the centering elements 501 may be a centering ring forming an unbroken ring around the interior line section 202b of the liquid line. Alternately, any one or more of the centering elements 501 may be positioned, in one or more positions between the outer circumference of the interior line section 202b and the inner circumference of the gas line 101 without entirely encircling the interior line section 202b. For example, a centering element 501 may be disposed between a lower, inner surface of the gas line 101 under a lower, outer surface of the interior line section 202b, thereby supporting a weight of the interior line section 202b within the gas line 101.

[0052]Installation of the combined gas/liquid line set of the example embodiment of FIG. 3 may be accomplished by forming first and second openings 303 in the gas line 101. An end of the exterior line section 202a of the liquid line may be connected to the interior line section 202b of liquid line via the connection unit 350. One or more centering elements 501 may be threaded onto the interior line section 202b of liquid line or may be positioned along the interior line section 202b of the liquid line or within the gas line 101. The interior line section 202b of the liquid line, e.g. having centering elements 501 attached thereto and/or therearound, may be threaded into the gas line 101 through a first opening 303. The interior line section 202b of the liquid line may be run through the gas line 101 and to a region of, or entirely out of, another opening 303 in the gas line 101. Once the interior line section 202b of the liquid line has been extended through the gas line 101, tension may be applied to the interior line section 202b of the liquid line. The first opening 303 in the gas line 101 may be sealed by attaching and affixing the connection unit 300. A second end of the interior line section 202b of the liquid line may be attached, via a second connection unit 350 to an end of another exterior line section 202a of the liquid line. The second opening 303 in the gas line 101 may be sealed by attaching and affixing a second connection unit 300.

[0053]FIGS. 4A and 4B illustrate exploded and assembled views, respectively, of a second example embodiment of a connection unit connecting an exterior line section of a liquid line to an interior line section of the liquid line internal to a gas line. FIGS. 4A and 4B illustrate a gas line 101; a liquid line 202, including an exterior line section 202a, external to the gas line 101, and an interior line section 202b disposed within the gas line 101; and an example embodiment of a connection unit 400 connecting these lines. As would be understood by one of skill in the art, the connection unit 400 may be disposed at any location where the liquid line 202 enters the gas line 101 and/or at any location where the liquid line 202 exits the gas line. As discussed above with respect to FIG. 2, these locations may be, respectively, indoor and outdoor locations. However, this example embodiment is not limited thereto. The example connection units described herein may be used anywhere a liquid line 202 enters or exits a gas line 101 in any locations where it would be desirable to run the liquid line through the gas line 101.

[0054]The connection unit 400 includes a sanitary flange 404 attached to an opening 403 in the gas line 101; a sanitary cap 408 connected to the exterior line section 202a of the liquid line and to the sanitary flange 404; and a line fitting 401 connecting the sanitary cap 408 to the interior line section 202b of the liquid line. The opening 403 in the gas line may be an exit nipple, and the sanitary flange 404 may be made from stainless steel which may be welded, soldered, or brazed to the opening 403 in the gas line 101. The sanitary cap 408 includes a tube element 406 and a flange element 405 extending radially outward from the tube element 406. The sanitary cap 408 may be attached to the tube element 406 by hand tightening using a screw with a handle attached thereto. The flange element 405 is connected to the sanitary flange 404. As shown in FIG. 4B, the connection unit 400 may also include a flange clamp 407 which holds the sanitary flange 404 to the flange element 405 and seals the sanitary flange 404 to the flange element 405. The clamp 407 may be made from stainless steel. The sanitary flange 404 may alternately or additionally be sealed to the flange element 405 of the cap 408 by a rubber gasket disposed therebetween and the clamp 407 holding the two parts together. The cap 408 also includes an opening therethrough providing communication for liquid between the interior line section 202b of the liquid line and an interior of the line fitting 401. The line fitting 401 includes a first fitting element 409, a second fitting element 402, and a connecting element 410 connecting the first fitting element 409 to the second fitting element 402. The connecting element 410 may enable the first fitting element 409 and the second fitting element 402 to be rotatably connected to each other. Alternately, the first fitting element 409, the second fitting element 402, and the connecting element 410 may be fixed to each other, may be formed from a single, uniform piece, or may be removably attached to each other in any of various other ways, as would be understood by one of skill in the art. The second fitting element 402 is connected to the tube element 406 of the cap 408 by welding, brazing, or soldering, for example. The first end 409 of the line fitting 401 may be crimped onto an end of the interior line section 202b, and a low HTC heat/pressure glue may provide a seal between the first end 409 of the line fitting 401 and the interior line section 202b of the liquid line. Alternately the first end 409 of the line fitting 401 may be attached to the interior line section 202b of the liquid line via a barbed fitting and a hose clamp.

[0055]Installation of the combined gas/liquid line set of the example embodiment of FIGS. 4A and 4B may be accomplished by forming first and second openings 403 in the gas line, and attaching, for example by welding, soldering, or brazing a sanitary flange 404 to each of the first and second openings 403. A sanitary cap 408 is attached to an end of an exterior line section 202a of the liquid line adjacent to a first opening 403 in the gas line 101, and may be attached via welding, brazing, or soldering, for example. Another sanitary cap 408 may be attached to an end of another exterior line section 202a of the liquid line adjacent to a second opening 403 in the gas line 101. A section of the interior line portion 202b of the liquid line is determined to be an appropriate length for running through the gas line 101 from the first opening 403 to the second opening 403. A first end 409 of a first line fitting 401 is attached to a first end of the exterior line section 202b of the liquid line, and a first end 409 of a second line fitting 401 is attached to a second end of the interior line section 202b of the liquid line. The first and second line fittings 401 may be attached, respectively, to the first and second ends of the interior line section 202b of the liquid line by being crimped therearound with a low HTC heat/pressure glue disposed therebetween and providing a seal. Any one or more centering rings 501 may be disposed on the interior line section 202b of the liquid line before or after the first and second line fittings 401 are attached thereto. The interior line section 202b of the liquid line may be inserted into the gas line 101 through the first opening 403 and threaded through the gas line 101 to the second opening 403. Once the interior line section 202b of the liquid line is in position, the second end 402 of the first line fitting 401 may be attached to the sanitary cap 408 attached to the exterior line section 202a of the liquid line adjacent to the first opening 403, and the flange element 405 of the sanitary cap 408 may be connected to the sanitary flange 404. A flange clamp 407 may be used to hold the sanitary flange 404 to the flange element 405 and provide a seal therebetween. Once the connection unit 400 is assembled at the first opening 403 and fixed to the exterior line section 202a and the interior line section 202b of the liquid line, tension may be applied to the interior line section 202b of the liquid line via the second opening 403. With the tension applied, the second end 402 of the second line fitting 401 may be attached to the sanitary cap 408 attached to the exterior line section 202a of the liquid line adjacent to the second opening 403, and the flange element 405 of the sanitary cap 408 may be connected to the sanitary flange 404. Again, a flange clamp 407 may be used to hold the sanitary flange 404 to the flange element 405 and provide a seal therebetween.

[0056]It may be understood that the example embodiments described herein may be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example embodiment may be considered as available for other similar features or aspects in other example embodiments.

[0057]While example embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.