Abstract:
A freeze resistant manifold includes a plurality of conduits, junction, and expansion device. Each conduit of the plurality of conduits includes a respective first end in fluid communication with a respective second end. The junction is defined by each of the respective first ends of the plurality of conduits in direct fluid communication with a remainder of the first ends of the plurality of conduits. The expansion device includes a housing, plug, and linear actuator. The housing has a first housing end and a second housing end. The first housing end is in fluid communication with the junction. The plug is disposed between the first housing end and the second housing end. The plug has a substantially fluid-tight, sliding engagement with an inner wall of the housing. The linear actuator is to urge the plug towards the first housing end with a predetermined amount of force. The plug is held proximal to the first housing end by the linear actuator in response to a fluid pressure in the junction being less than a predetermined normal working pressure. The plug is moved towards the second end in response to the fluid pressure in the junction exceeding the predetermined normal working pressure.

Description:
FIELD OF THE INVENTION 
       [0001]    The disclosure generally relates to a manifold, and more particularly to a freeze resistant manifold assembly and system. 
       BACKGROUND OF THE INVENTION 
       [0002]    Pipes or other such conduits for conveying fluids are often subject to temperature extremes. In some instances, these temperature extremes may cause damage to the conduits and/or other components of a fluid supply system such as tanks, fittings, manifolds, and the like. Where possible, insulation and/or auxiliary heating/cooling systems may help protect the fluid supply system and the fluid therein. Unfortunately, insulation is typically bulky or otherwise impractical in some instances and heating/cooling systems require energy input and may not be sufficiently reliable for some applications. 
         [0003]    Accordingly, it is desirable to provide a manifold assembly and system capable of overcoming the disadvantages described herein at least to some extent. 
       SUMMARY OF THE INVENTION 
       [0004]    The foregoing needs are met, to a great extent, by the present invention, wherein in some embodiments a freeze resistant assembly and system is provided. 
         [0005]    An embodiment of the present invention relates to a freeze resistant manifold. The freeze resistant manifold includes a plurality of conduits, junction, and expansion device. Each conduit of the plurality of conduits includes a respective first end in fluid communication with a respective second end. The junction is defined by each of the respective first ends of the plurality of conduits in direct fluid communication with a remainder of the first ends of the plurality of conduits. The expansion device includes a housing, plug, and linear actuator. The housing has a first housing end and a second housing end. The first housing end is in fluid communication with the junction. The plug is disposed between the first housing end and the second housing end. The plug has a substantially fluid-tight, sliding engagement with an inner wall of the housing. The linear actuator is to urge the plug towards the first housing end with a predetermined amount of force. The plug is held proximal to the first housing end by the linear actuator in response to a fluid pressure in the junction being less than a predetermined normal working pressure. The plug is moved towards the second end in response to the fluid pressure in the junction exceeding the predetermined normal working pressure. 
         [0006]    Another embodiment of the present invention pertains to a fluid supply system for an aircraft. The fluid supply system includes a fluid storage tank, main line to draw a fluid from the storage tank, first fixture, first supply line to supply the fluid to the first fixture, second fixture, second supply line to supply the fluid to the second fixture, and freeze resistant manifold. The freeze resistant manifold includes a junction and expansion device. The junction is to directly fluidly connect the main line to the first supply line and the second supply line. The expansion device includes a housing, plug, and linear actuator. The housing has a first housing end and a second housing end. The first housing end is in fluid communication with the junction. The plug is disposed between the first housing end and the second housing end. The plug has a substantially fluid-tight, sliding engagement with an inner wall of the housing. The linear actuator is to urge the plug towards the first housing end with a predetermined amount of force. The plug is held proximal to the first housing end by the linear actuator in response to a fluid pressure in the junction being less than a predetermined normal working pressure. The plug is moved towards the second end in response to the fluid pressure in the junction exceeding the predetermined normal working pressure. 
         [0007]    There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
         [0008]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
         [0009]    As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a simplified view of an interior of an aircraft showing a fluid supply system suitable for use with an embodiment of the invention. 
           [0011]      FIG. 2  is a perspective view of a manifold according to an embodiment of the invention. 
           [0012]      FIG. 3  is a cross sectional view  3 - 3  of the manifold according to  FIG. 2 . 
           [0013]      FIG. 4  is a view of detail B of an expansion device in a working pressure conformation according to  FIG. 3 . 
           [0014]      FIG. 5  is a view of detail B of the expansion device in an overpressure conformation according to  FIG. 3 . 
           [0015]      FIG. 6  is a side view of the manifold according to  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    The invention will now be described with reference to the drawing figures, in which like numerals refer to like parts throughout.  FIG. 1  is a simplified view of a fluid supply system  10  disposed in an aircraft  12 . The aircraft  12  and other vehicles are particularly suitable for embodiments of the invention due to the relatively close tolerances, power savings, and reliability of the various embodiments of the invention. As shown in  FIG. 1 , the fluid supply system  10  includes a supply tank  14 , fixture  16 , fixture  18 , main line  20 , supply lines  22  and  24 , and manifold  26 . 
         [0017]    The fluid supply system  10  provides fluid for the aircraft  12  and/or users of the aircraft  12 . In a particular example, the fluid supply system  10  stores and provides water for the fixtures  16  and  18 , such as a faucet and toilet. Under typical working pressures, the fluid supply system  10  may be pressurized from about 35 pounds per square inch (psi) (24,607 kilogram per square meter (kg/m 2 )) to about 50 psi (35,153 kg/m 2 ). As is generally known, water expands as the temperature approaches the freezing point (32° F./0° C.). This expansion, if not accounted for, may raise the pressure to more than 5000 psi (351,500 kg/ 2 ). 
         [0018]    The supply tank  14  stores and supplies fluid for the fluid supply system  10 . In a particular example, the supply tank  14  is configured to store water. To store and supply water, the supply tank  14  generally includes a conventional overfill preventor device that prevents the supply tank  14  from being filled more than a predetermined fill amount. The predetermined fill amount is typically about 80% of the total tank volume which allows for about 20% head volume for the freezing water to expand into. 
         [0019]    The fixtures  16  and  18  provide control of a flow of the fluid. For example, the fixture  16  may include a faucet with a valve to control the flow of the fluid therethrough. In another example, the fixture  18  may include a toilet, also having a valve, to initiate, control, and stop the flow of the fluid. In other examples, the fixture  16  and/or  18  may include a plumbed coffee brewing device and the like. 
         [0020]    The main line  20  and supply lines  22  and  24  convey the fluid from the fluid supply tank  14  to the fixtures  16  and  18 . The main line  20  and supply lines  22  and  24  are conventionally fabricated from a relatively flexible material. The flexibility of the material allows the main line  20  and supply lines  22  and  24  to stretch about 10-20% and accommodate the expansion of water that freezes therein. 
         [0021]    The manifold  26  connects the main line  20  to the supply lines  22  and  24 . As used herein, the term, “manifold” refers to a device or arrangement of conduits to redistribute a flow of fluid. Typically, a manifold may redistribute a flow of the fluid from a single inlet to a plurality of outlets or vise versa. In the particular example shown in  FIG. 1 , the manifold  26  connects the main line  20  (the inlet) to the supply lines  22  and  24 . However, in general, the manifold  26  may connect one or more conduits to any suitable number of outlets. 
         [0022]    The manifold  26  may be fabricated from one or more suitable materials. Examples of suitable materials include metals, polymers, resins, composites, and the like. In addition, as shown herein, the manifold  26  includes components, each of which may be made from one or more suitable materials. As described herein with respect to the particular components, suitable materials may include: various metals and particularly aerospace metals and metal alloys; elastomers; polymers such as cross-linked polyethylene and various plastics and resins; composites such as fiber reinforced plastics; and the like. 
         [0023]      FIG. 2  is a perspective view of the manifold  26  according to an embodiment of the invention. As shown in  FIG. 2 , the manifold  26  includes a plurality of fittings  28 ,  30 , and  32  disposed at respective ends of a plurality of conduits  34 ,  36 , and  38 . The conduits  34 ,  36 , and  38  are joined at a junction  40 . The fittings  28 ,  30 , and  32  are to connect the manifold  26  to the main line  20  and supply lines  22  and  24 . In a particular example, the main line  22  (shown in  FIG. 1 ) is secured to the manifold  26  at the fitting  28  and the supply lines  22  and  24  (shown in  FIG. 1 ) are secured to the manifold  26  at the fittings  30  and  32 , respectively. The main line  22  and supply lines  22  and  24  may be secured to the fittings  28 - 32  in any suitable manner. Examples of suitable attachment methods include threaded engagement, adhesives, welding, friction or compression fit, flange-type fitting, other such mechanical fastening, or the like. In addition, in this or other embodiments, the fittings  28 - 32  and/or conduits  34 - 38  may be optional. For example, the fittings  28 - 32  may be directly joined to form the junction  40  or the main line  22  and supply lines  22 - 24  may be directly joined to form the junction  40 . 
         [0024]    The manifold  26  also includes an expansion device  42  disposed or joined at the junction  40 . The expansion device  42  includes a housing  44 , end cap  46 , and guide rod  48 . The guide rod  48  is optional and, if included, may extend out of the end cap  46  through a witness port  50 . As described herein, the expansion device  42  provides an expandable chamber or volume into which water and/or ice can expand. It is an advantage of embodiments of the invention, that by locating the expansion device  42  at or near the junction  40 , expanding fluid that may have otherwise damaged the fittings  28 - 32  or junction  40  may be directed into or otherwise allowed to expand into the expansion device  42 . 
         [0025]      FIG. 3  is a cross sectional view  3 - 3  of the manifold according to  FIG. 2 . As shown in  FIG. 3 , the expansion device  42  includes a plug  52  disposed in the housing  44 . The plug  52  may move within the housing  44  to provide volume for expanding fluid to flow into. In a particular example, the plug  52  is in sliding engagement with a housing bore  54 . The plug  52  may provide a substantially fluid-tight sliding seal within the housing bore  54 . The substantially fluid-tight sliding seal is generally sufficient to limit or prevent fluid from flowing between the plug  52  and the housing bore  54 . More particularly, the plug  52  may include one or more O-rings  56  captured by one or more corresponding annular grooves  58  disposed in the plug  52 . The O-ring  56  may include one or more of elastomers such as synthetic resinous fluorine-containing polymers, silicone and fluorosilicones, nitrile, butyl, urethane, and the like. 
         [0026]    In a specific example shown in  FIG. 3 , the plug  52  includes one annular groove  58  disposed at or near an end of the plug  52  that is proximal to the junction  40 . This proximal end of the plug  52  includes a plug face  60  in fluid communication with the junction  40 . The fittings  28 - 32  and conduits  34 - 38  are also in fluid communication with the junction  40  and to each other via the junction  40 . It is an advantage of this embodiment of the invention that the close proximity of the annular groove  58  and O-ring  56  to the junction  40  reduces infiltration of fluid between the housing  44  and the plug  52 . 
         [0027]    Fluid pressure in the junction  40  exerts a force F fluid  upon the plug face  60  to urge the plug  52  to slide in the housing bore  54  in direction C. Opposing the F fluid  is a linear actuator  62  urging the plug  52  in direction D. The linear actuator  62  exerts a force F actuator  upon the plug  52 . The linear actuator  62  includes any suitable device for exerting the F actuator  upon the plug  52 . Suitable examples include springs, pneumatic actuators, and the like. In a particular example, the linear actuator  62  includes a helically wound spring as shown in  FIG. 3  The F actuator  is based upon a variety of factors such as, for example: working pressure of the fluid supply system  10 ; maximum recommended pressure of the fluid supply system  10 ; manufacturers specification; empirical data; and the like. In a particular example, the F actuator  may be in a range of about 35 psi (24,607 kg/m 2 ) to about 500 psi (351,534 kg/m 2 ). More particularly, the F actuator  may be in a range of about 60 psi (42,184 kg/m 2 ) to about 200 psi (140,613 kg/m 2 ). 
         [0028]      FIG. 4  is a view of detail B of the expansion device  42  in a working pressure conformation according to  FIG. 3 . As shown in  FIG. 4 , the expansion device  42  includes a stop  64  to impede or prevent the plug  52  from extending out from the housing  44  and into the junction  40 . In a particular example, the stop  64  includes an annular bearing surface  66  disposed in the housing bore  54  and opposing annular bearing surface  68  disposed on the plug  52 . The stop  64  is to arrest movement of the plug  52  in direction D in response to the plug  52  achieving a predetermined position in the housing  44 . For example, in response to F actuator &gt;F fluid , the plug  52  is urged in direction D until the annular bearing surface  66  bears upon the annular bearing surface  68 . It is an advantage of this and other embodiments that the stop  64  prevents the O-ring  56  from extending into the junction  40 , loosing contact with the housing bore  54 , and allowing fluid to flow into the expansion device  42  from the junction  40 . 
         [0029]    It is another advantage of this and other embodiments of the invention that the guide rod  48  provides an indication of the fluid pressure and the witness port  50  provides an indication of the functionality of the expansion device  42 . For example, the guide rod  48  may include an indicator  70 , indicating that the fluid pressure is at or below a predetermined operating pressure. In a particular example, the indicator  70  may include green coloring, symbols, numbering, and/or lettering sufficient to convey the fluid pressure is at or below the predetermined operating pressure. As shown in  FIG. 5 , the guide rod  48  may include one or more additional indicators that the predetermined operating pressure is exceeded. 
         [0030]    The expansion device  42  may further include an adjustable or threaded portion  72  to mate the housing  44  to the end cap  46 . By rotating the end cap  46  relative to the housing  44 , the end cap  46  may advance or withdrawal the end cap  46  along the housing  44 . In this manner, the linear actuator  62  may be compressed or expanded, respectively, which may increase or reduce, respectively, the F actuator . If the end cap  46  is withdrawn sufficiently, the end cap  46  may be removed to disassemble the expansion device  42  for service, for example. 
         [0031]      FIG. 5  is a view of detail B of the expansion device  42  in an overpressure conformation according to  FIG. 3 . As shown in  FIG. 5 , the fluid pressure in the junction  40  has urged the plug  52  in direction C. In response to this movement, a chamber  74  is generated in the housing  44 . Also shown in  FIG. 5 , the guide rod  48  may include additional indicators  76 - 80  of the predetermined operating pressure being exceeded. For example, the indicator  76  may include yellow coloring, symbols, numbering, and/or lettering sufficient to convey the fluid pressure is above the predetermined operating pressure. The indicator  78  may include orange coloring, symbols, numbering, and/or lettering sufficient to convey the fluid pressure is substantially above the predetermined operating pressure. The indicator  80  may include red coloring, symbols, numbering, and/or lettering sufficient to convey the fluid pressure has exceeded a predetermined maximum pressure. In this regard, in response to the plug  52  being advanced into the housing  44  such that the O-ring  56  moves past the annular bearing surface  66 , the fluid may flow past the O-ring  56 , into a chamber  82 , and out of the witness port  50 . 
         [0032]    It is an advantage of this and other embodiments of the invention that the witness port  50  provides an indicator of the working condition of the expansion device  42 . For example, in response to a worn or otherwise damaged O-ring  56  and/or housing bore  54 , fluid may seep into the chamber  82  and out the witness port  50 . 
         [0033]      FIG. 6  is a side view of the manifold  26  according to  FIG. 2 . As shown in  FIG. 6 , the conduit  34 /fitting  28  includes a central axis E, the conduit  36 /fitting  30  includes a central axis F, the conduit  38 /fitting  32  includes a central axis G, and the expansion device  42  includes a central axis H. In an embodiment of the invention, the central axes E, F, G, and H intersect the junction  40  at a central point  84 . In general, the central point  84  occupies a volume within the junction  40 . For example, the central point  84  may be defined within about a cubic centimeter of volume. In another example, the central point  84  may be defined within about a cubic millimeter of volume. It is an advantage of this and other embodiments of the invention that freezing, partially frozen, and/or frozen fluid may flow or advance towards the expansion device  42  by virtue of the location of the central point  84  disposed within the junction  40  and the direct flow path or access to the chamber  74  from the junction  40 . 
         [0034]    In addition, the expansion device  42  may include one or more optional lock cables  86  to lock rotation of the end cap  46  relative to the housing  44 . If included, the lock cables  86  reduce or prevent the end cap  46  from rotating relative to the housing  44 . In this manner, the expansion device  42  may be prevented from accidental disassembly. 
         [0035]    The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.