Abstract:
A hose having an upstream end and a downstream end, each of the upstream and downstream ends including a connecting member to connect the hose arrangement to, for example, the high side or the low side of an air conditioning or refrigeration unit, or to a manifold. An intermediate access fitting is provided along the length of the hose, such as a T-shaped fitting, and provides a port to enable the hose arrangement to be connected to a device conveniently and without the necessity of adapters. Also disclosed is a method of evacuating or dehydrating an air conditioning or refrigeration system using the hose.

Description:
BACKGROUND 
       [0001]    Mechanical air conditioning and refrigeration is accomplished by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system. Charging or recharging an air conditioning or refrigeration system with refrigerant is done through the low side suction intake fitting with the use of manifold gauges and service hoses. Low-pressure vapor refrigerant is compressed and discharged from a compressor as a high temperature, high-pressure, “superheated” vapor or liquid. The high-pressure refrigerant flows to a condenser, where it is changed to a low temperature, high-pressure liquid. It then flows through a filter dryer to a thermal expansion valve or TXV. The TXV meters the correct amount of liquid refrigerant into an evaporator. As the TXV meters the refrigerant, the high-pressure liquid changes to a low pressure, low temperature, saturated liquid/vapor. This saturated liquid/vapor enters the evaporator and is changed to a low pressure, dry vapor. The low pressure, dry vapor is then returned to the compressor. The cycle then repeats. 
         [0002]    The manifold commonly has three refrigeration lines or hoses connected thereto. One line is connected through the manifold to a low pressure gauge and is used in servicing the low pressure side (suction side) of a refrigeration/air conditioning system. A second line is connected through the manifold to a high pressure gauge and is used in servicing the high pressure side (discharge side) of a refrigeration/air conditioning system. A third line is connected to a port which commonly connects the ports in the manifold leading to the high and low pressure lines. The third line is used for connection to a refrigerant source or some other pressurized source, or a vacuum source. 
         [0003]    Flow control is performed by means of high pressure and low pressure valves at the manifold. Whenever any of the aforementioned three lines are connected to a refrigeration or air conditioning system, the lines can be bled to purge the air from the lines so as to avoid contamination of the refrigeration system with air (and moisture in that air). 
         [0004]    The presence of moisture in an air conditioning or refrigeration system can result in freeze-ups and corrosion, as even trace amounts of water (e.g., water vapor) can react with the refrigerant and form acids that can damage the system. A vacuum pump or the like can be connected to the system to pull a vacuum in an effort to eliminate moisture (and air) from the system. Preferably an accurate gauge (e.g., a micron gauge) is used to monitor the extent of the vacuum created, as the compound gauges of the manifold assembly are not accurate enough to effectively measure vacuum. 
         [0005]    However, setting up a vacuum pump and connecting it to the system can be time consuming and difficult, particularly in a confined space. The service ports of many air conditioning and refrigeration systems are located in a tight space where there is inadequate room to connect a gauge. In addition, even where there is adequate room, other hoses need to be disconnected. 
         [0006]    It therefore would be desirable to facilitate the connection of a vacuum pump or other equipment to an air conditioning or refrigeration unit. 
         [0007]    Other objects a advantages of the present invention and advantageous features thereof will become apparent as the description proceeds herein. 
       SUMMARY 
       [0008]    Problems of the prior art have been addressed by the embodiments disclosed herein, which relate a hose arrangement or assembly having an upstream end and downstream end. Each of the upstream and downstream ends may include a connecting member to connect the hose arrangement to, for example, the high side or the low side of an air conditioning or refrigeration unit, or to a manifold. In certain embodiments, the hose arrangement includes an intermediate access fitting, such as a T-shaped fitting, located along the length of the hose at a position anywhere between the upstream and downstream ends. In certain embodiments, the intermediate access fitting provides a port to enable the hose arrangement to be connected to a device (e.g., be in fluid communication with a device such as a measuring device) conveniently and without the necessity of adapters, and without having to disconnect other hoses. 
         [0009]    Also disclosed is a method of evacuating or dehydrating an air conditioning or refrigeration system. In certain embodiments, a method comprises connecting a first end of a first hose to the low side of an air conditioning or refrigeration system and the second end of the first hose to a manifold; connecting a first end of a second hose to the high side of an air conditioning or refrigeration system and the second end of the second hose to the manifold; and connecting the first end of a third hose to a vacuum pump and the second end of the third hose to the manifold. A suitable gauge, such as a micron gauge (an electronic vacuum gauge), may be attached to the intermediate access port of the first hose. The vacuum pump is activated, the manifold valves are opened, and vacuum is pulled on the air conditioning or refrigeration unit and measured through the intermediate access port by the pressure gauge. No adapters or the like are necessary to attach the pressure gauge as was previously required. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a cross-sectional view of a hose arrangement in accordance with certain embodiments; 
           [0011]      FIG. 2  is a side view of a hose arrangement in accordance with certain embodiments; and 
           [0012]      FIG. 3  is a view, in partial cross-section, of a conventional, refrigeration service apparatus including three-port manifold with pressure gauges. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Turning now to  FIGS. 1 and 2 , there is shown in cross-section a refrigeration service hose  10  in accordance with certain embodiments. One or more of such service hoses  10  may be used in servicing refrigeration and air conditioning systems to check the charge pressure of the refrigerant, in the system, to add refrigerant to the system, to check the performance of the compressor (particularly the compressor valves), to test the expansion valve, and for various other service procedures. Typically hose  10  provides a sealed connection between a manifold gauge set and an HVAC or refrigeration system, such as connecting a service valve (e.g., the low side or high side of the system to be serviced), with a pressure gauge, refrigerant source, pressurized gas source or vacuum source. 
         [0014]    Hose  10  is a flexible elongated member having an internal bore permitting fluid communication between opposite free ends of the hose. In certain embodiments, it is typically composed of a seamless nylon inner tube that provides a barrier layer, surrounded by synthetic braided reinforcement layer (e.g., rubber) which is further surrounded by a thermoplastic cover, which results in relatively dense, gas-proof and liquid-proof conduit. Such hoses are typically from three to six feet in length, although any length hose could be used without departing from the scope of the embodiments disclosed herein. They are rated for high pressure use, e.g., 800 psi working pressures. 
         [0015]    Hose  10  may include at one free end thereof a connector  100  that includes hose nut  101  having internal threads  90  and is adapted to form a liquid-tight and gas-tight connection with the threaded exterior of a one-way refrigeration service valve (not shown), for example, such as a Schraeder valve. In certain embodiments, within hose nut  101  there is a valve depressor  205  that is biased by biasing member  106  towards the free end of the hose nut  101 . In certain embodiments, the valve depressor  105  Is positioned to depress the core of a Schraeder service valve upon connection of nut  101  to the valve, thereby opening the valve. In the embodiment shown, the connector  100  is a low loss anti-blowback fitting, such as that disclosed in U.S. Publ. No 2014/0265317, the disclosure of which is hereby incorporated by reference. Such a fitting traps refrigerant in the hose  10  and helps reduce environmental contamination. Those skilled in the art will appreciate that other connectors can be used and are within the spirit, and scope of the embodiments disclosed herein. 
         [0016]    In certain embodiments, nipple  103  may be integrally attached to hose  10  at eight-sided crimped ferrule  107 , which renders the connection gas-tight and liquid-tight. In certain embodiments, nipple  103  may include a bend, such as 45°, for ease in installation in tight or hard to reach areas. 
         [0017]    Another connector shown generally at  200  is similarly attached at the opposite free end of hose  10 , as shown. Thus, hose nut  201  having internal threads  190  is adapted to form a liquid-tight and gas-tight connection with the threaded exterior of a manifold port ( FIG. 3 ), for example. In certain embodiments, the connector  200  includes a straight hose nipple  203  and a neoprene sleeve  204  to facilitate the liquid and gas-tight connection. The nipple  203  may be attached to hose  10  with eight-sided crimp ferrule  207 . 
         [0018]    Hose  10  includes intermediate access fitting  300 . In certain embodiments, the intermediate access fitting  300  is in fluid communication with the interior of the hose via hose splice member  301 . The intermediate access fitting  300  may include external threads  302  for coupling to internal threads  303  of the hose splice member  301 . Splice member  301  may be attached to the hose  10  with crimped hose ferrules  305 ,  306 . Other ways of providing an intermediate access fitting  300  in a hose  10  are within the scope of the embodiments disclosed herein. 
         [0019]    In certain embodiments, the access fitting  300  receives a one-way valve  310 , such as a Schraeder valve. Actuation of the valve by a device (not shown) such as a measuring device (e.g., a micron gauge) results in fluid communication between the hose  10  and the device. The valve normally closed, so that the hose  10  can be used in conventional applications with no leakage through the intermediate access fitting. A cap  309  may be coupled to the access fitting  300  such as with internal threads  311  that mate with external threads  312  on the access fitting  300 . The cap may be tethered to the access fitting  300  with strap  313 . 
         [0020]    The access fitting  100  may be used for purposes other than connection to a measuring device. For example, it can be used to charge or remove refrigerant from a system, inject die into a system, purge nitrogen into a system, etc. 
         [0021]    Although the particular location of the intermediate access fitting  300  along the length of the hose is not particularly limited, in certain embodiments the access fitting  300  is positioned closer to connector  100  (e.g., the connector that attaches to the access port of a refrigeration or air conditioning unit) than connector  200  (e.g., the connector that attaches to a manifold). So positioning the intermediate access fitting  300  allows connection of an external device such as a measuring device (e.g., a micron gauge) at a location closer to the access port of the air conditioning or refrigeration unit, which can be more convenient for the technician. In certain embodiments, the intermediate access fitting  300  is positioned about 12 inches from connector  100 . 
         [0022]      FIG. 3  illustrate a conventional manifold  400  that includes low pressure port  81 , high pressure port  83 , and common port  82  which is capable of communicating with the other two ports  81  and  83  when valves  33  and  34  are in the open positions. Low pressure or compound gauge  32  is threaded to manifold  30  and communicates with port  81  when handle  85  is actuated to open low pressure valve  33 , thereby unseating seal  36 . The low pressure side is used to measure the refrigerant pressure on the low pressure side of refrigeration or air conditioning system. Connector  100  leading from hose  10  on the low pressure side is threaded to the low pressure service valve of the air conditioning or refrigeration unit. 
         [0023]    A second hose can be connected to common port  82 , and leads to a refrigerant source or vacuum source to which it is connected for charging or evacuating a system. 
         [0024]    High pressure port  83  communicates with high pressure valve  34 , when high pressure valve  34  is opened by turning handle  86 . Similarly to the low pressure hose  10 , a high pressure hose can be connected to a high pressure service valve and is used, for example, to measure the pressure output of the compressor to determine the adequacy of the compressor&#39;s valves. 
         [0025]    In certain embodiments, hose  10  can be used to carry out a method of evacuating or dehydrating an air conditioning or refrigeration system. For example, a first end of a first hose  10  may be connected to the low side of an air conditioning or refrigeration system (not shown) and the second end of the first hose to the low pressure port  81  of manifold  400 . Similarly, a first end of a second hose may be connected to the high side of an air conditioning or refrigeration, system and the second end of the second hose to the high pressure port  83  of manifold  400 . The first end of a third hose may be connected to an external device such as a vacuum pump (not shown) and the second end of the third hose to the common port  82  of manifold  400 . A suitable pressure gauge, such as a micron gauge, can be attached to the intermediate access port of the first hose. The vacuum pump is activated, the manifold valves are opened, and vacuum is pulled on the air conditioning or refrigeration unit and measured through the intermediate access port by the pressure gauge. When the vacuum pressure gauge reaches a predetermined level for a predetermined amount of time, indicating a suitable vacuum has been achieved, the vacuum pump can be turned off. No separate adapters or the like are necessary to attach the pressure gauge as was previously required. 
         [0026]    Although the manifold depicted in  FIG. 3  is a so-called “three port” manifold, those skilled in the art will appreciate that other manifolds, such as a “four port” manifold, can be used. In a four port manifold, two intermediate hoses are employed instead of one.