Abstract:
A positive shutoff device is provided for a connection point of a refrigeration system. The connection point includes a manually-actuatable valve that permits charging and testing of the system. The device includes a first fitting engagable with the connection point and having a raised actuator that actuates the manually-actuatable valve when the first fitting engages the connection point, and a shutoff valve having a first end coupled to the first fitting and a second end coupled to a second fitting, the shutoff valve is operable in a closed position to prevent flow therethrough and an open position to permit flow therethrough, so that the refrigeration system may be charged or tested by connecting equipment to the second fitting and opening the shutoff valve, and the connection point may be positively shut off to prevent leakage of refrigerant through the connection point by closing the shutoff valve.

Description:
FIELD 
     The present invention relates to a positive shutoff device for a connection point in a refrigeration system. The present invention relates more particularly to a positive shutoff device for a connection point in a refrigeration system used for refrigerant charging and/or pressure-testing the system, and/or isolation of another type of coolant. 
     BACKGROUND 
     It is well known to provide a refrigeration system for use with one or more temperature controlled storage devices such as a refrigerator, freezer, refrigerated merchandiser, display case, etc. that may be used in commercial, institutional, and residential applications for storing or displaying refrigerated or frozen objects. For example, it is known to provide a refrigeration system having a refrigerant for direct expansion in a single loop operation to provide cooling to heat exchanger such as an evaporator or chiller. It is also known to provide a connection point for readily attaching refrigerant charging equipment and/or pressure testing equipment to charge or pressure test the piping and other components of the system. However, such known connection points tend to leak over time and result in loss of refrigerant from the system and the need for expensive re-charging and pressure testing activities. A positive shutoff device for use with a charging and testing connection point for both new and existing refrigeration systems is provided. 
     SUMMARY 
     The present invention relates to a positive shutoff device for a connection point of a refrigeration system, where the refrigeration system includes a piping network that circulates a refrigerant to a compressor, a condenser, an expansion device, and an evaporator. The connection point includes a manually-actuatable valve defining a passageway to permit charging and pressure-testing of the refrigeration system. The positive shutoff device includes a first fitting engagable with the connection point and having a raised actuator that actuates the manually-actuatable valve when the first fitting engages the connection point, and a shutoff valve having a first end coupled to the first fitting and a second end coupled to a second fitting. The shutoff valve is operable for use in a closed position to prevent flow therethrough and an open position to permit flow therethrough, so that the refrigeration system may be charged or tested by connecting charging or test equipment to the second fitting and positioning the shutoff valve in the open position, and the connection point may be positively shut off to prevent leakage of refrigerant through the connection point by positioning the shutoff valve in the closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a refrigeration system having a connection point and a positive shutoff device, according to an exemplary embodiment. 
         FIG. 2  is a schematic diagram of a positive shutoff device for the connection point on the refrigeration system of  FIG. 1 , according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the FIGURES, a refrigeration system is shown for use with a plurality of temperature controlled storage devices, where the storage devices may have different storage temperature requirements (e.g. “low temperature,” such as approximately −20° F., and “medium temperature,” such as approximately 25° F.). However, the various temperatures of the storage devices, refrigerants and liquid coolants illustrated or described in the various embodiments, are shown by way of example only. A wide variety of other temperatures and temperature ranges may be used to suit any particular application and are intended to be within the scope of this disclosure. 
     Referring to  FIG. 1 , a refrigeration system  10  includes a piping network  14  (e.g. tubing, conduit, piping, etc.) interconnecting a plurality of refrigeration system components shown for example to include a compressor  16 , a condenser (e.g. air-cooled, water-cooled, etc.), a receiver  18  to collect condensed refrigerant, and one or more expansion devices  20 , shown for example as four (4) expansion valves for expanding the liquid refrigerant to a saturated liquid-vapor refrigerant for use in a cooling device  24  (e.g. evaporator in the form of a cooling coil, micro-channel coil, etc.) in a temperature-controlled storage device  26  (e.g. refrigerated display case, etc.). According to the illustrated embodiment, the piping network  14  includes multiple parallel branch lines  28  that supply refrigerant to each of the temperature-controlled storage devices  26  (e.g. four (4) branch lines for four (4) temperature-controlled storage devices), however, any number of branch lines, in any suitable configuration (e.g. series, parallel, series-parallel, etc.) may be used according to any alternative embodiments. The refrigerant is circulated in a closed-loop circuit through the piping network and the refrigeration system components to provide a source of cooling to the cooling devices in the temperature-controlled storage devices. According to other embodiments, the refrigeration system may include a liquid coolant (e.g. water, glycol, etc.) circulated within another loop (e.g. secondary coolant loop, etc.). All such types of refrigeration and/or cooling systems are intended to be within the scope of the disclosure. 
     Piping network  14  also includes a connection point  30  (e.g. pipe stub, branch, fitting, etc.), for use in connecting (e.g. temporarily, etc.) various equipment associated with set-up, operation or maintenance of the refrigeration system. For example, connection point  30 , may be used to connect charging equipment (not shown) for charging the refrigerant system  10  with a refrigerant, such as R404A, carbon dioxide (CO2), or other suitable refrigerant. Alternatively, the connection point may be used on a liquid coolant line for charging, testing and/or draining the liquid coolant line. Connection point  30  is shown to be located on a “liquid” portion of the refrigeration system (i.e. on the piping network  14  between the receiver and the expansion device(s)), however, the connection point may be provided at any suitable location on the piping network. Connection point  30  may also be used for connecting other equipment, such as testing equipment (e.g. pressure testing equipment, etc.) for testing and/or monitoring the pressure and/or leak-tightness of the refrigeration system. Connection point may also serve as a location for draining a liquid coolant or recapturing a refrigerant contained within the piping network. Connection point  30  typically serves as part of a pressure boundary for the piping network  14  and is intended to provide a location where charging and/or testing equipment can be readily connected and disconnected without a significant loss of refrigerant from the refrigeration system  10 . However, typical connection points often use equipment that tends to leak slowly over extended periods of time, or may fail suddenly, which causes or contributes to a degradation or loss of refrigerant charge in the refrigeration system. 
     According to one embodiment shown in more detail in  FIG. 2 , connection point  30  includes a fitting  32  having a first end  34  that connects (e.g. by a threaded connection, soldering, brazing, etc.) to the piping network  14  and a second end  36  that connects to the positive shutoff device  50 . Fitting  32  is shown to include a manually-actuatable valve  38  (e.g. a poppet-type valve such as a Schrader valve, etc.) disposed within an internal passageway of fitting  32  to provide controlled access to the piping network  14  of the refrigeration system (e.g. for charging, testing, depressurizing, etc.). Manually-actuatable valve  38  includes a movable valve stem  40  that can be moved (e.g. depressed, shifted, shuttled, etc.) against a spring force (or a force from refrigerant pressure within the piping network, or the like) to provide a clearance for a flow path within the internal passageway of the fitting  32 . 
     Referring further to  FIG. 2 , a positive shutoff device  50  for the connection point  30  of the refrigeration system  10  is shown according to an exemplary embodiment. Positive shutoff device  50  is shown to include a first fitting  60 , a shutoff valve  70 , and a second fitting  80 . First fitting  60  (e.g. a female flare fitting, such as a ¼ inch, ⅜ inch or other suitable size female flare fitting or other type of fitting of a suitable size) has a first end  62  that connects to second end  36  of fitting  32  of the connection point  30 , and a second end  64  that couples or connects to a first end  72  of the shutoff valve  70 , in a substantially leak-tight manner (e.g. by threaded connection with a suitable thread sealant or the like, etc.). According to one embodiment, first fitting  60  includes an internal region  66  having a raised actuator segment  68  (e.g. actuator, “Schrader depressor”, etc.). As the internal region  66  of first fitting  60  receives the second end  36  of fitting  32 , the raised actuator segment  68  engages (e.g. contacts, etc.) and moves valve stem  40  to actuate the manually actuatable valve  38  of the connection point  30  (i.e. opens the passageway within fitting  32  of connection point  30 ). According to alternative embodiments, the first fitting may be provided without a raised actuator segment, such as for applications where fitting  32  is provided without an internal manually actuatable valve, or where the shutoff valve is provided with a suitable projection that is operable to engage the valve stem  40 . 
     Referring further to  FIG. 2 , the shutoff valve  70  includes a first end  72  and a second end  74 , and is operable (e.g. manually actuatable, etc.) between a first position (e.g. closed, etc.) and a second position (e.g. open, etc.). According to one embodiment, shutoff valve is a manually-actuatable ball-type valve, such as are commercially available from JB Industries of Aurora, Ill. The first end  72  of shutoff valve  70  connects to the second end  64  of the first fitting  60  in a substantially leak-tight manner (e.g. by threaded connection with a suitable thread sealant or the like, etc.). Thus, when shutoff valve  70  is coupled to first fitting  60 , and first fitting  60  is coupled to the fitting  32  of connection point  30 , access to the pressure boundary of the piping network  14  is controlled by manually actuating the shutoff valve  70  between the open position (where the flow path is through the open shutoff valve  70 , the first fitting  60 , and the passageway within fitting  32  via the depressed valve stem  40  of the manually-actuatable valve  30 ), and the closed position, where the pressure boundary of the piping network  14 , includes the shutoff valve  70 . According to other embodiments, the shutoff valve may be another type of valve, such as a globe valve, gate valve, needle valve, control valve, or other valve capable of providing a positive shutoff and maintaining a pressure boundary for the system. 
     According to the illustrated embodiment, shutoff valve  70  is shown with a manually-actuatable handle  76 , however, according to other alternative embodiments, the shutoff valve may be provided with another type of actuator, such as a solenoid, motor, pneumatic, hydraulic, or other type of remotely actuatable actuator. Such a remote actuator may be used to facilitate remote or automatic charging of the refrigeration system, such as upon a degradation of refrigeration system below a predetermined pressure setpoint as monitored by a suitable pressure sensing device (not shown) configured to provide a signal to actuate the shutoff valve to an open position and to return the shutoff valve to a closed position upon restoration of the pressure of the refrigerant or coolant in the refrigeration system to a predetermined pressure. Such a remotely actuatable charging system may be configured for use with an existing system as a retrofit feature by connecting to an existing fitting and using a signal from an existing pressure sensing device, or may be provided as a feature of a new refrigeration system. 
     Referring further to  FIG. 2 , second fitting  80  of the positive shutoff device  50  is shown according to an exemplary embodiment. Second fitting  80  (e.g. a male flare fitting, such as a ¼ inch male flare fitting or other type of fitting of a suitable size) has a first end  82  that couples or connects to the second end  74  of the shutoff valve  70 , and a second end  84  configured to couple to charging and/or testing equipment (not shown), in a substantially leak-tight manner (e.g. by threaded connection with a suitable thread sealant or the like, quick-disconnect, etc.). Second fitting  80  is shown to include a manually-actuatable valve  86  (e.g. a poppet-type valve such as a Schrader valve, etc.) disposed within an internal passageway of second fitting  80  to provide controlled access to the piping network  14  of the refrigeration system (e.g. for charging, testing, depressurizing, etc.) when the shutoff valve  70  is in the open position. Manually-actuatable valve  86  includes a movable valve stem  88  that can be moved (e.g. depressed, shifted, shuttled, etc.) against a spring force (or a force from refrigerant pressure within the piping network  14  up through the shutoff valve  70 , or the like) to provide a clearance for a flow path within the internal passageway of the second fitting  80 . An end of valve stem  88  is disposed proximate the second end  84  of the second fitting  80  and is configured to be engaged (e.g. moved, shifted, shuttled, etc.) by contact with charging and/or testing equipment when such equipment is connected to the second end  84  of the second fitting  80  for charging and/or testing the refrigeration system. 
     According to alternative embodiments, manually actuatable valve  38  may be omitted and the pressure boundary maintained by shutoff valve  70  and manually actuatable valve  86 . Alternatively, manually actuatable valve  86  may be omitted and the pressure boundary maintained by shutoff valve  70  and manually actuatable valve  38 . 
     According to any exemplary embodiment, the positive shutoff device for a connection point of a refrigeration system includes a shutoff valve disposed between a first fitting that engages and opens a passageway to the piping network, and a second fitting that engages with (and opens in response to) connection of charging and/or testing equipment. The first and second fittings and the shutoff valve may be preassembled as a single integrated unit configured to be coupled directly to a connection point of a new or existing refrigeration system. According to an alternative embodiment, a second fitting may be omitted from the positive shutoff device, in the event that such a fitting is included as a part of the charging and/or testing equipment. The positive shutoff device for a connection point of a refrigeration system may be installed as new equipment on original installations of refrigeration systems, or may be provided as a retrofit or enhancement to connection points of existing refrigeration systems. The positive shutoff device for a connection point of a refrigeration system is intended to minimize or eliminate the typical leakage that tends to occur with conventional connection points on refrigeration systems, and is easily and conveniently installed, and provides positive shutoff and isolation of the pressure boundary of the piping network by effectively moving the pressure boundary of the piping network from the connection point to the manual shutoff valve. The presence of the manually actuatable valve in the second fitting also enhances the leak-tightness of the system by preventing refrigerant leakage from the system in the event that the shutoff valve is inadvertently or unintentionally opened without charging or testing equipment coupled thereto. 
     It is important to note that the construction and arrangement of the elements and embodiments of the positive shutoff device for a connection point of a refrigeration system provided herein are illustrative only. Although only a few exemplary embodiments of the present invention have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible in these embodiments (such as variations in features such as components, valves, and fittings; variations in valve, fitting and thread sizes, structures, shapes, dimensions and proportions of the components of the system, use of materials, etc.) without materially departing from the novel teachings and advantages of the invention. According to other alternative embodiments, the positive shutoff device for a connection point of a refrigeration system may be used with any device using a refrigerant or other coolant for transferring heat from one space to be cooled to another space or source designed to receive the rejected heat and may include commercial, institutional or residential refrigeration systems. Further, it is readily apparent that variations of the positive shutoff device for a connection point of a refrigeration system and its components and elements may be provided in a wide variety of types, shapes, sizes and performance characteristics, or provided in locations external or partially external to the refrigeration system. For example, components of a cooling system may be provided as rack-mounted system, or as a custom-installed hard-piped system, or may be provided as a modular unit or package. Accordingly, all such modifications are intended to be within the scope of the invention. 
     The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any means-plus-function clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating configuration and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the inventions as expressed in the appended claims.