Patent Publication Number: US-2007102041-A1

Title: Valve

Description:
The invention relates to valves, and particularly, though not exclusively, to valves for use in controlling the flow of fluid out of containers, for example tanker vehicles.  
      Various types of valve for use in controlling the flow of liquid out of containers are well known, and generally comprise some type of valve member movable into an out of engagement with a valve seat. However such valves can leak, particularly over a period of time, for example if a container full of liquid is going to be transported over a long distance, for example by sea. Such leakage is not only undesirable in terms of lost product, but can also be harmful, for example in the case of aggressive liquids, which may, for example be corrosive.  
      The invention provides a valve for use in controlling the flow of liquid out of a container, the valve comprising a valve body having an inlet and an outlet for liquid, a valve seat, and a valve member movable onto the valve seat to close the valve, the valve also comprising a secondary seal in the form of a barrier member positioned to prevent any leakage of liquid from the valve outlet.  
      The valve may have means to breach the barrier when it is desired to use the valve to dispense liquid.  
      The means to breach the barrier may be activated by movement of the valve member off the valve seat.  
      The barrier may comprise a membrane.  
      The membrane may have at least one line of weakness to facilitate breaching of the membrane.  
      The valve may have a breaching member, the valve being such that movement of the valve member off the valve seat forces the membrane into engagement with the breaching member.  
      The breaching member may comprise a sharp edge.  
      The breaching member may be arranged at an angle such that when the valve member moves off the valve seat, the membrane is initially brought into engagement with a first part of the breaching member, thus applying concentrated breaching pressure to the membrane.  
      Alternatively, the breaching member may be provided with one or more teeth.  
      The valve member may be mounted in the valve body such that the valve member performs translational movement between open and closed positions.  
      The invention includes a container for liquid, when fitted with a valve as defined above.  
      The container for liquid may comprise an ISO container. 
    
    
      By way of example, a specific embodiment of the invention will now be described, with reference to the accompanying drawings, in which:  
       FIG. 1  is a cross-sectional view through one embodiment of valve according to the invention; and  
       FIG. 2  is a view illustrating the embodiment of valve in situ on a container for liquid.  
    
    
      The embodiment of valve  10  shown in  FIG. 1  is, in use, mounted on the inner face of the base  11  of a container  12  for liquid. The base  11  has an outlet aperture  13  therein.  
      The valve  10  comprises a valve body  14  having inlet  15  and an outlet  16 . The outlet  16  is in registration with the aperture  13 .  
      A tapered surface  17  of the valve body  14  comprises a valve seat. A valve member  18  is movable onto and off the valve seat to open and close the valve. The valve member  18  is guided for translational movement by means of a stem  19  sliding in a sleeve  20 . The sleeve  20  is secured to the valve body  14 .  
      Movement of the valve member  18  is carried out by a first pivotal lever  21  mounted on a shaft  22  extending through valve body  14 . On the outside of the valve the shaft  22  is connected to another lever  23  which can be moved in any desired manner to operate the valve.  
      Although the valve member  18  is fitted with a ring seal  24 , the valve member may leak over a significant period of time, for example if the container has to be transported over a long distance.  
      Accordingly, a secondary seal is provided in the form of a membrane  25  which is trapped between the valve body  14  and the base  11  of the container, in such a way that the membrane provides a total barrier across the outlet of the valve.  
      As seen in the enlarged portion of  FIG. 1 , the membrane  25  has a circular line of weakness provided by regions  26  of reduced thickness.  
      Also trapped between the valve body  14  and the base  11  is a breaching member  27  having an annular cutting edge  28 .  
      When the valve member  18  is in position on the valve seat  17 , the membrane  25  is spaced from the cutting edge  28  and provides a total seal preventing leakage of liquid from the container, even if some liquid seeps past the ring seal  24 .  
      When a container reaches its destination and it is desired to dispense liquid, movement of the valve member  18  off the valve seat  17 , by actuation of the external lever  23 , forces the weakened portion of the membrane  25  against the knife edge  28 , fracturing the membrane and permitting liquid to pass out of the container.  
      Other embodiments are possible. A valve may for example be arranged to move a breaching member into contact with a membrane, instead of moving a membrane into contact with a breaching member.  
      The breaching member may have a different configuration to the knife-edge shown in  FIG. 1 . For example, the breaching member may be provided with one or more cutting teeth.  
      The valve is particularly appropriate for use with an ISO container which might be transported over a long distance, for example by sea.  FIG. 2  is a perspective view of an ISO container  12 , the valve  10  being positioned at the point shown in the figure.  
      A particularly suitable material for the membrane is PTFE.  
      The reader&#39;s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.  
      All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.  
      Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.  
      The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.