Abstract:
A housing at each end of a conduit defines a valve seat. A connector is connected to a valve body in each housing and holds the bodies away from the seats until the conduit fails, after which each body moves into contact with the corresponding seat. A compression zone between each body and the corresponding seat is sufficiently large to reduce heat generated thereat from adiabatic compression of the fluid flowing therethrough. In a variation, two heat-dissipating ribs are externally positioned on each housing adjacent the compression zone. In another variation, the connector is a generally helical spring within the conduit and sized to be in contact with an interior wall of the conduit so that the spring provides structural strength thereto. In another variation, a third housing is employed as a one-way check valve.

Description:
FIELD 
     The present disclosure relates to high pressure fluid delivery systems and more particularly to a safety system for a conduit which is part of the high pressure delivery system. 
     BACKGROUND 
     A prevailing problem in high pressure fluid delivery systems such as those used to fill containers with compressed gases such as oxygen, nitrogen, carbon dioxide and the like is the risk that a conduit which is part of the fluid delivery system may fail. Typically, the conduit is constructed as a hose or the like from a hardy flexible material such as treated and reinforced rubber, neoprene, nylon, TEFLON polymer, stainless steel and the like. 
     However, on occasion, a conduit fails by rupturing or splitting. When a hose/conduit ruptures, at least two hazards are present. First, the two pieces of the conduit which result from the rupture are free to whip around wildly under the force of the compressed gases which are being discharged through the ruptured conduit from the container being filled and from the discharge manifold of the fluid supply. Until the conduit can be constrained, substantial risk of injury to personnel and damage to equipment exists. Second, a discharge of gas from the manifold and the container through the ruptured hose/conduit can lead to a costly waste of gas, or even worse, can fill an environment with hazardous fumes. 
     It would therefore be desirable to have a system which would restrain a ruptured high pressure conduit from whipping about, and at the same time would be capable of preventing gases from leaking from the conduit through the rupture. 
     SUMMARY 
     The aforementioned need is satisfied by a safety system for a fluid conduit that has first and second ends. In one variation of the system, a housing is provided at each end of the conduit and defines a valve seat. Each valve seat is normally a first predetermined distance from the other and is movable away from the other when the conduit fails. The housing includes a generally cylindrical portion and a generally tapered portion defining the valve seat, where the cylindrical portion and the tapered portion meeting at a generally transverse plane. 
     A valve body is disposed within each housing such that the valve seats are disposed between the valve bodies. The valve bodies and the valve seats cooperate to define valves. A connector is connected to each of the valve bodies and holds the valve bodies apart a second distance which is greater than the first distance so that each valve body resides generally in the cylindrical portion of the corresponding housing until the conduit fails. A retainer is disposed within each housing and cooperates with the connector to retain the valve bodies against movement to permit fluid to flow through the conduit until the conduit fails. 
     The connector is operative when the conduit fails and the valve seats move away from each other to retain the valve bodies at the second distance so that the valve seats move toward the valve bodies and close the valves, or if the distance between the valve seats does not change, to permit the valve bodies to move toward each other so that the valve bodies move toward the valve seats to close the valves. Each valve body moves a third distance into contact with and past the plane and into the tapered portion of the corresponding housing to close the corresponding valve when the conduit fails. The third distance corresponds to a compression zone between the valve body and the corresponding valve seat and is sufficiently large to reduce heat generated in the compression zone from adiabatic compression of the fluid flowing through the compression zone. 
     In another variation of the system, two heat-dissipating ribs are externally positioned on each housing adjacent the compression zone of the housing to dissipate heat generated thereat. Each rib extends generally circumferentially about the housing and generally radially from the housing. In yet another variation of the system, the connector is a generally helical spring residing within the conduit and sized to be in substantially complete contact with an interior wall of the conduit so that the spring provides structural strength to the conduit. 
     In another variation, a third housing is positioned in series with the conduit and coupled to one of the first and second housings to permit fluid to flow through the conduit in a first direction and to prevent flow through the conduit in a second direction opposite the first direction. The valve body of the third housing is un-tethered and acts as a one-way check valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary as well as the following detailed description of various embodiments of the present subject matter will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the various embodiments of the subject matter, there are shown in the drawings embodiments that are presently preferred. As should be understood, however, the subject matter considered to be inventive is not limited to the precise arrangements and instrumentalities shown. In the drawings: 
         FIG. 1  is a schematic drawing of an apparatus for filling a cylinder or the like with compressed fluid under high pressure. 
         FIG. 2  is a cut-away view of a hose or other conduit constructed in accordance with one form of the inventive subject matter with the valves therein positioned to permit fluid flow. 
         FIG. 3  is a section view taken along lines  3 - 3  of  FIG. 2 . 
         FIG. 4  is a cut-away view similar to that of  FIG. 2  but showing the valves positioned to block fluid flow. 
         FIG. 5  is a partial cut-away view similar to that of  FIGS. 2 and 4  and shows a valve housing constructed to include a relatively larger compression zone. 
         FIG. 6  is a partial cut-away view similar to that of  FIGS. 2 and 4  and shows a valve housing constructed to include exterior heat-dissipating ribs adjacent the compression zone. 
         FIG. 7  is a cut-away view similar to that of  FIGS. 2 and 4  and shows a conduit constructed to include a spring rather than a cable. 
         FIG. 8  is a partial cut-away view similar to that of  FIGS. 2 and 4  and shows an additional valve housing in-line with a hose such as that of  FIGS. 2 ,  5 , and  6  and acting as a one-way check valve. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Certain terminology may be used in the following description for convenience only and is not considered to be limiting. For example, the words “left”, “right”, “upper”, “lower”, “top”, “bottom”, “front”, and “back” designate directions in the drawings to which reference is made. Likewise, the words “inwardly” and “outwardly” are directions toward and away from, respectively, the geometric center of the referenced object. The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. 
     In  FIG. 1  a delivery system for filling containers with compressed fluids is illustrated as comprising fluid supply  10  such as a reservoir, or fluid compressing means, or the like. The supply  10  may be connected by a discharge manifold  12  to a plurality of containers  14  to which the fluid is to be transferred. 
     Typically, the containers  14  may be gas cylinders which are well known in the art. Conduits  20  which may be elongated flexible members are connected between the discharge manifold  12  and the containers  14 . 
     Typically, the conduits  20  are hoses made of reinforced neoprene, rubber, neoprene, nylon, TEFLON polymer, stainless steel and the like so that they have a high degree of flexibility and are capable of withstanding the high pressures which they encounter from the compressed fluids that move through them. 
     In  FIG. 2  one of the conduits  20  is shown in detail. The conduit  20  includes a housing  22  at one end and an identical housing  24  at its other end. The housings  22  and  24  are connectors which enable the conduit  20  to be connected to other elements in the fluid handling system. Since the two housings are identical, the following detailed description of housing  22  will also suffice as a description of housing  24 . Housing  22  is connected to conduit  20  by a ferrule  26  which cooperates with a complementary elongated cylindrical hollow member  30  that extends from the end wall  32  of the housing  22  and into the passage  34  defined by the conduit  20 . 
     As best seen in  FIG. 2  the housing  22  is an elongated, hollow, cylindrical element which is connected by end wall  32  and member  30  to the conduit  20  and has threads  36  at its other end for connection to another element in the fluid handling system. The housing  22  has an inner wall that includes a valve chamber  38  which is defined by a ledge  40  that faces away from end wall  32  and a tapered valve seat  42  that lies adjacent end wall  32 . The tapered valve seat  42  lies between the ledge  40  and the end wall  32  and faces ledge  40 . 
     As explained above, member  30  cooperates with the ferrule  26  to clamp the conduit  20  between them so that the housing  22  is securely connected to the conduit  20  for the receipt of and transmission of fluid under high pressure. It also serves as a cable guide as will be explained herein. A valve body  44  is disposed in the valve chamber  38 . Preferably, the valve body  44  includes an elongated, cylindrical member  46  having a tapered end  48  and a rear wall  50 . The taper at end  48  corresponds to the taper of the valve seat  42  so that they can cooperate to prevent the flow of fluid when they are in engagement with each other. A distal end  52  extends from the rear wall  50  of the valve body  40  and comprises an elongated stem-like member  54  of relatively small diameter relative to the elongated, cylindrical member  46 . Stem-like member  54  extends away from the valve seat  40 . 
     Each of the valve bodies  44  and stem-like members  54  include a longitudinally extending, axial passage  56  of relatively small diameter through which a relatively stiff cable  58  or other suitable flexible and bendable member of predetermined length can be received. The valve body  44  may be connected to the cable  58  by swaging, welding, or other suitable means so that the cable  58  cannot separated from the valve body  44  under the strong forces which will be present should the conduit  20  rupture. 
     Referring to  FIGS. 2 and 3 , valve body retainers  60  and  62  are provided in housings  22  and  24  respectively. Since the two retainers  60  and  62  are identical the following detailed description of retainer  60  will also suffice as a description of retainer  62 . Referring to  FIG. 3 , retainer  60  is a disc that includes a generally annular central member  64  having a plurality of arms  66  extending radially outwardly from it. The center of the annular member  64  comprises an aperture  68 . Retainers  60  and  62  are disposed on ledges  40  in each housing  22  and  24 . Each retainer is fixed on the ledge by being force fit, clamped, welded or secured by any suitable means that will hold it in place for a reason that will become apparent. The distance between the retainers  60  and  62  is about the same as the distance between the rear walls  50  of the valve bodies  44 . 
     As best seen in  FIG. 2  the member  30  and the stiffness of the cable  58  cause the valve bodies  44  to lie with their rear walls  50  against their respective retainers  60  and  62  with their respective stems  54  extending through the apertures  68 . Under normal operating conditions, compressed fluids flow through conduit  20 , through the fluid passages  70  defined by the space between the arms  66  on each retainer  60  and  62  and the inner wall of the housings  22  and  24 , and through the opening between each valve seat  42  and its respective valve body  44 . Since the cable  58  is confined by the wall of conduit  20 , and is long enough arid sufficiently stiff to keep the valve bodies in engagement with the retainers  60  and  62 , as is apparent from  FIG. 2 , neither valve body can move within its chamber since such movement is blocked by the retainer at the other end of the conduit. 
     Should the conduit  20  fail by either splitting or by rupture, the valve bodies  44  and valve seats  42  will move into engagement with each other thereby stopping the flow through the conduit  20  at each of its ends as seen in  FIG. 4 . Accordingly, not only will discharge from the supply manifold be stopped, but also discharge from the container being filled will be stopped. 
     If the supply  10  or one of the containers  14  should fall during filling, the conduit  20  may fail. In this case the ends of the conduit will move with the item to which they are connected. Therefore, the valve seats  42  will be drawn away from each other and into engagement with their respective valve bodies  44  since the cable  58  will be drawn taut by the movement the conduit ends away from each other. 
     If the supply  10  and containers  14  are fixed, they will not be displaced when the conduit fails. In this case the valve bodies  44  will be urged into engagement with their respective valve seats  42  due to the pressure differential across the valve bodies  44  in that there is still high pressure fluid in the supply  10  and container  14  bearing against the valve bodies  44 . When conduit  20  fails, cable  58  is released from its confinement within the conduit and can flex to permit the valve bodies  44  to move toward the valve seats  42 . Further, because the cable  58  extends through the conduit  20 , it will serve as a guide for a ruptured conduit, thereby preventing the ends of the conduit from being whipped about by the discharging fluid. Still further, even if the cable were to fail as a result of the rupture, fluid flow will still be stopped at each end of the conduit since the cable  58  will not be holding the valve bodies  44  apart. It is significant to note that the advantages of the inventive subject matter are achieved by a structure that is entirely within the conduit. Thus, there is no external apparatus that might be inadvertently snagged, damaged or destroyed thereby rendering the features of the inventive subject matter unavailable when needed. 
     In various embodiments, it is to be understood that the device and method disclosed above can be used with conduits  20  of varying sizes and materials. For example, the conduit  20  can be a relatively flexible hose or tube or even a relatively rigid pipe or duct, among other things. Moreover, it is to be understood that the plunger-type valve body  44  may alternately be embodied as a number of sliding members, as is the case in the aforementioned U.S. Pat. Nos. 5,357,998 or as 6,260,569 and 6,546,947 as a flapper, each of which is incorporated herein by reference in its entirety. 
     In one variation of embodiments of the inventive subject matter, and turning now to  FIG. 5 , a plunger-type valve body  44  is provided in the housing  22 / 24  in a manner similar to that shown in  FIG. 2 . Here, though, the valve body  44  is positioned against the retainer  60  during normal, open operation and is relatively farther from the tapered valve seat  42 . Accordingly, and as shown in  FIG. 5 , during such normal, open operation, the valve body  44  and the valve seat  42  define therebetween a compression zone  100  within the valve chamber  38  that is relatively larger as compared with that of  FIG. 2 . 
     With such a relatively larger compression zone  100  as is shown in  FIG. 5 , it should be understood that the housing  22 / 24  does not suffer as much from excessive heat generated by the fluid flowing therethrough, as compared with the housing  22 / 24  of  FIG. 2 . In particular, it is to be appreciated that such heat arises from adiabatic compression that occurs when the fluid enters such compression zone  100 , and such heat can be significant, especially as the pressure and/or the flow rate of the fluid increases. Notably, such heat if extreme can even damage or destroy the housing  22 / 24 . Thus, by increasing the volume of the compression zone  100 , as is shown in  FIG. 5  compared with  FIG. 2 , the effect of adiabatic compression is spread out over the increased volume and thereby reduced. As a result, heat generated in connection with such adiabatic compression is likewise reduced. 
     In various embodiments, the compression zone  100  is constructed to be relatively larger as is shown in  FIG. 5  by reducing the axial length of the plunger-type valve body  44 , increasing the axial length of the valve chamber  38 , or a combination thereof. While such relatively larger compression zone  100  may be quantified in many appropriate forms, it is to be appreciated that in the normal, open position of the valve body  44  in  FIG. 2 , the tapered end  48  of the valve body  44  just contacts the generally transverse plane P ( FIG. 5 ) where the valve chamber  38  begins to taper to the tapered valve seat  42  thereof. 
     In contrast, in the normal, open position of the valve body  44  in  FIG. 5 , the tapered end  48  of the valve body  44  has not as yet approached the plane P that separates the cylindrical portion and the tapered portion of the valve chamber  38 . As should be understood, the valve body  44  resides within such cylindrical portion when in the normal, open position. Thus, with the relatively larger compression zone  100  in  FIG. 5 , the tapered end  48  of the valve body  44  moves into contact with and past the aforementioned plane P when the valve body  44  moves from the normal, open position (as shown in  FIG. 5 ) to the closed position. 
     Thus, the valve body  44  of  FIG. 5  as compared to that of  FIG. 2  must travel a farther distance to the closed position where the tapered end  48  thereof encounters the tapered valve seat  42 . As shown in  FIG. 5 , such distance is about 50 percent greater than the distance from the plane P to the closed position, although other distances may also be provided. 
     In another variation of embodiments of the present inventive subject matter, and turning now to  FIG. 6 , the exterior of the housing  22 / 24  is provided with ribs  102  in the axial region of the compression zone  100 . As should be understood, each rib  102  extends generally circumferentially about the exterior of the housing  22 / 24  adjacent the compression zone  100 , generally radially from the housing  22 / 24  a relatively short distance of perhaps an eighth of an inch, a quarter of an inch, a half of an inch, or so, and also generally axially with respect to the housing  22 / 24  a relatively short distance of perhaps an eighth of an inch, a quarter of an inch, or so. 
     As may be appreciated, such ribs  102  act to dissipate the heat generated by the fluid flowing through the housing  22 / 24 . Again, it is to be appreciated that such heat arises from adiabatic compression that occurs when the fluid enters such compression zone  100 . Here, and as should be understood, the ribs dissipate the heat by increasing the surface area between the housing  22 / 24  and the surrounding environment and thereby increasing the rate of heat transfer. Notably, in various embodiments, only a limited number of ribs  102  are provided, such as for example one or two ribs  102 . Thus, tooling required to impart the housing  22 / 24  with such ribs  102  during manufacturing is minimized. 
     In yet another variation of embodiments of the present inventive subject matter, the cable  58  within the conduit  20  is constructed from a non-ferrous material. As may be appreciated, such a non-ferrous material for the cable  58  is particularly useful when the fluid in the conduit  20  is oxygen or the like which would cause a ferrous cable  58  to rust. Similarly, in yet another variation of embodiments of the present inventive subject matter, the cable  58  within the conduit  20  is constructed from a rod material having increased rigidity. As may be appreciated here, such increased rigidity may be required in situations where the conduit  20  is especially large in cross-sectional diameter, such as for example about four inches or so. 
     In still another variation of embodiments of the present inventive subject matter, the cable  58  within the conduit  20  is replaced by a generally helical spring. As may be appreciated, the spring  104  ( FIG. 7 ) is appropriately sized and configured to urge each valve body  44  into the normal, open position against the respective retainer  60  during normal operation of the conduit  20 , and also to move each valve body  44  into the closed position against the tapered valve seat  42  in the event that the conduit  20  fails. Thus, the spring  104  functions in a similar manner as the cable  58 . 
     Notably, and as seen in  FIG. 7 , the spring  104  resides within the interior of the conduit  20  and is sized to be in substantially complete contact with the interior wall of the conduit  20 . Thus, the spring  104  additionally functions to provide the conduit  20  with structural strength. As such, the conduit  20  may be constructed from a relatively lighter grade of material, thus reducing material costs in connection with such conduit  20 . 
     As may be appreciated, the use of a spring  104  in the conduit  20  prompts a consideration of whether the conduit  20  with the spring  104  therein can be coiled, such as may be performed to store the conduit  20  and/or package the conduit for shipping and the like. In particular, if the spring  104  is too large in diameter relative to the length of the conduit  20 , coiling the conduit  20  with the spring  104  therein may be difficult if not impossible, especially if the coiling itself has a relatively small diameter. Essentially, the spring  104  may bunch if the coiling is too tight, or may prevent such coiling from being performed. 
     Generally, a conduit  20  with a spring  104  of relatively modest diameter, perhaps on the order of ¼ to ½ inch or so, can be coiled with relative ease, presuming the length of the conduit  20  is beyond of a minimum, perhaps on the order of 7 feet or so. In contrast, a conduit  20  with a spring  104  of relatively large diameter, perhaps on the order of 4 to 8 inches or so, cannot be coiled in any significant manner regardless of the length of the conduit  20 . Thus, in various embodiments of the present innovation, the length of the conduit  20  is taken into consideration when determining whether a spring  104  of a set diameter is employed therein, and also the need to coil the conduit  20  is taken into consideration when determining whether a spring  104  of a set diameter is employed therein. 
     In yet another variation of embodiments of the present inventive subject matter, and turning now to  FIG. 8 , a valve housing  106  similar to if not identical with the valve housings  22 / 24  is placed in-line/in series with the hose or conduit  20 . As shown in  FIG. 8  (and  FIGS. 5 and 6  as well), the valve arrangement in each of the housings  22 / 24 / 106  is a poppet-type valve arrangement, although other types of valve arrangements may also be employed in each of the housings  22 / 24 / 106 , such as for example a flapper-type valve arrangement or a multi-wedge valve arrangement. 
     Notably, the valve body  44  within the valve housing  106  is not tethered to any cable such as the cable  58  set forth above, any spring such as the spring  104  set forth above, or any other type of tether. Accordingly, the valve body  44  effectively floats within the housing  106  and is free to slide generally axially from one side where the valve body  44  is generally in contact with the valve retainer  60  to the opposite side where the valve body  44  is generally in contact with the valve seat  42 . As may be appreciated, the position of the valve body  44  is thus determined by the general flow of fluid within the housing  106  and also the housings  22 / 24  and conduit  20 . 
     In particular, and as shown in  FIG. 8 , when fluid is flowing in what has been designated as a normal direction from left to right, the valve body  44  is urged by such normal flow to the right and into stopping contact with the retainer  60 . As such, the valve body  44  is in an open position where the normal flow of the fluid is not generally impeded by the valve body  44  and retainer  60 . In contrast, when fluid is flowing in a backward direction opposite the normal direction and from right to left, the valve body  44  is urged by such backward flow to the left and into stopping contact with the valve seat  42 . As such, the valve body  44  is in a closed position where the backward flow of the fluid is generally impeded by the valve body  44  and valve seat  42 . Thus, the housing  106  as installed in-line/in series with the conduit  20  acts as a one-way check valve that generally allows the normal flow and generally prevents the backward flow of the fluid through the conduit  20 . 
     As may be appreciated, the housing  106  that implements the one-way check valve for the conduit  20  is placed in-line or in series with such conduit by being appropriately coupled at an appropriate end thereof to one of the housings  22 / 24  by way of a coupling device  108 . Such coupling device  108  may be rigid or flexible and may be any appropriate coupling device, such as for example a length of coupling hose, a copper or brass pipe, a length of conduit such as the conduit  20 , or the like. The housing  106  may be coupled at the other end thereof to an external element by way of threads akin to the threads  36  (not shown), another coupling hose or conduit attached to a ferrule (not shown) on the housing  106  akin to the ferrule  26 , or the like. 
     As shown in  FIG. 8 , and again, the normal flow is from the left to the right. However, such normal flow may be reversed in any of several manners. For example, the housing  106  may alternately be manufactured with the valve body  42  and retainer  60  switched and with the valve body appropriately repositioned within the housing  106 . Alternately, the housing  106  as shown may be detached from the one housing  22 / 24  and attached to the other housing  22 / 24 . Also alternately, the entire system including the housings  22 / 24 / 106  and the conduit  20  may be detached from the external elements, reversed in an end-to-end manner, and then re-attached to the external elements. 
     While the inventive subject matter has been described with respect to particular embodiments, it is apparent that other embodiments can be employed to achieve the intended results. Thus, the scope of the inventive subject matter should not be limited by the foregoing description, but rather only by the scope of the claims appended hereto.