Abstract:
A pinch valve for connection between an upstream pipeline and a downstream pipeline, the pinch valve including a body having a fixed upper pinch bar and a moveable lower pinch bar, an elastomeric sleeve, wherein the elastomeric sleeve is situated between the fixed upper pinch bar and the moveable lower pinch bar, and means to raise and lower the moveable lower pinch bar. A method of regulating fluid flow is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of Provisional Application No. 60/403,771, filed Aug. 15, 2002, entitled “Flexible Weir Style Pinch Valve”. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to pinch valves and, in particular, to flow control valves for large diameter storm water or sewage pipelines.  
           [0004]    2. Description of Related Art  
           [0005]    Sewage processing plants can be overloaded or flooded by high flow inputs caused, for example, by a short duration of heavy rainfall. Therefore, it is necessary to limit the amount of flow into the plant to prevent flooding or discharging of untreated (or undertreated) sewage. Currently, thousands of dollars are spent on the failure of valves for use with combined storm and sanitary sewers.  
           [0006]    Conventional methods of controlling storm water include influent flow valves that back up the flow into the upstream piping, which are temporary, limited capacity storage facilities, and frequently diverting the flow to retaining basins, which are longer term, higher capacity storage facilities. These conventional valves are typically pinch valves which close from the top only, the top and bottom on a centerline, or side to side.  
           [0007]    By closing the valve, either partially or fully, this limits the flow into the processing plant and backs up the water in the upstream piping or retaining basin. After the heavy rainfall subsides, this stored water is released under controlled conditions by adjusting the valve to achieve the desired flow.  
           [0008]    There are several disadvantages to using conventional pinch valves to control the influent flow. Since these pipes are usually less than full, the water flows only in the lower portion of the pipe, which is called an open channel flow. If the valve closes from the top only, there is no flow restriction until the upper closing portion of the valve reaches the water level. This results in less than optimum control since much of the valve stroke is ineffective (stroking through air) and not controlling flow.  
           [0009]    With valves that close from both top and bottom simultaneously, the bottom portion of the stroke is effective, but the top portion of the stroke is ineffective until the upper closing portion of the valve reaches the water level. Again, this results in less than optimum control since part of the valve&#39;s top stroke is ineffective (stroking through air) and not controlling flow.  
           [0010]    For valves closing side to side, the flow cannot be shut off completely unless the valve is closed completely. This requires stroking the valve through its entire open/shut range to stop the flow completely, even if there is just three inches of water in a forty-eight inch diameter pipeline.  
           [0011]    It is therefore an object of the present invention to provide improved flow control, by having valves capable of stroking or pinching action only from the bottom of the valve to the top of the valve, which eliminates the problems described above for conventional methods of controlling flow. Currently, there are no known direct air operated pinch valves, electric pinch valves, weir type closure valves, or mechanical pinch bar type pinch valves that close from only the bottom up. Thus, it is further the object of the present invention to provide more accurate control of flow, primarily in large diameter pipes, and to facilitate using the pipe as a temporary storage facility.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention provides, in the preferred embodiment, a pinch valve for connecting an upstream pipeline and a downstream pipeline. The pinch valve includes a body having a fixed upper pinch bar and a moveable lower pinch bar and an elastomeric sleeve having a throughbore, wherein the elastomeric sleeve is situated between the fixed upper pinch bar and the moveable lower pinch bar. The pinch valve also includes a means to raise and lower the moveable lower pinch bar in order to flex a lower portion of the elastomeric sleeve into and out of the throughbore, so as to regulate the flow of liquids therethrough.  
           [0013]    The elastomeric sleeve may be directed inward and outward by utilizing either the moveable lower pinch bar or compressed fluid selectively pumped into and removed from a space adjacent to the lower portion of the elastomeric sleeve. The elastomeric sleeve may be of varying densities and may include reinforcing material built into the elastomeric sleeve. Additionally, stops may be provided on the upper pinch bar to prevent total closure of the elastomeric sleeve.  
           [0014]    The foregoing and other features of the method and apparatus of the present invention will be further apparent from the description which follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 a  is a sectional side view of a first embodiment of the present invention using an electric motor actuator;  
         [0016]    [0016]FIG. 1 b  is a sectional end view of the first embodiment of the present invention with the sleeve in a fully open position;  
         [0017]    [0017]FIG. 1 c  is a sectional side view of the first embodiment of the present invention about a quarter of the way closed;  
         [0018]    [0018]FIG. 1 d  is a sectional end view of the first embodiment of the present invention about a quarter of the way closed;  
         [0019]    [0019]FIG. 1 e  is a sectional view of a sleeve according to the present invention with an imbedded reinforcing material;  
         [0020]    [0020]FIG. 1 f  is a sectional view of a sleeve according to the present invention with reinforcing material secured to an inner surface of the sleeve;  
         [0021]    [0021]FIG. 1 g  is a perspective view of the first embodiment of the present invention in a partially closed position;  
         [0022]    [0022]FIG. 2 a  is a schematic side view of a second embodiment of the present invention showing water in the valve, with the valve about a quarter of the way closed;  
         [0023]    [0023]FIG. 2 b  is an end view of the device shown in FIG. 2 a;    
         [0024]    [0024]FIG. 3 a  is a partial side view of a third embodiment of the present invention with the valve about a quarter of the way closed;  
         [0025]    [0025]FIG. 3 b  is an end view of the device shown in FIG. 3 a;    
         [0026]    [0026]FIG. 4 a  is a sectional side view of a fourth embodiment of the present invention showing stops on the pinch bar;  
         [0027]    [0027]FIG. 4 b  is a partial end view of the fourth embodiment of the present invention showing stops on the pinch bar; and  
         [0028]    [0028]FIG. 5 is a schematic sectional side view of the valve at two different closure points. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0029]    The flexible weir style pinch valve assembly of the present invention is useful in many specialized applications, but particularly for use in large diameter (typically 24 inches to 84 inches in diameter) storm water or sewage water pipelines.  
         [0030]    A flexible weir style pinch valve  10 , according to the first embodiment of the present invention is shown in FIGS. 1 a  and  1   b.  This embodiment of the flexible weir style pinch valve  10  includes a body  12 , an upper pinch bar  14 , an elastomeric sleeve  16  forming a throughbore, and a lower pinch bar  18 . The upper pinch bar  14  is “fixed” in position relative to elastomeric sleeve  16 , whereas the lower pinch bar  18  is movable from bottom to top. The upper pinch bar  14  should be welded to the body  12  of the flexible weir style pinch valve  10 , which is generally made of a steel body or some similar material. The lower pinch bar  18  may be moved by electric motor actuators  20  as illustrated in FIGS. 1 a  and  1   c,  hand wheels  21  (with and without gear reduction mechanisms) as illustrated in FIG. 1 g,  pneumatic or hydraulic cylinders, or any other suitable mechanism.  
         [0031]    The flexible weir style pinch valve  10 , according to the first embodiment, closes from the bottom of the valve only. A conventional type of pinch bar operated pinch valve closes from the top only, or from the top and bottom simultaneously closing on the centerline. The closure of the first embodiment of the present invention is obtained by moving only the lower pinch bar  18  to close the elastomeric sleeve  16 , as shown in FIG. 1 b.  The lower moving pinch bar  18  is on the bottom of the elastomeric sleeve  16  and strokes upward pushing the elastomeric sleeve  16  against the fixed upper pinch bar  14 . As illustrated in FIG. 1 c,  this operation raises the bottom of the elastomeric sleeve  16 , providing, in effect, a weir or high spot  22  that the water must flow over to pass the flexible weir style pinch valve  10 .  
         [0032]    When the flexible weir style pinch valve  10  is open, the elastomeric sleeve  16  is fully round, providing no restriction to the water flow as shown in FIG. 1 b.  As the lower pinch bar  18  moves upward, it generates a weir or high spot  22 , that the water must flow over as shown in FIG. 1 c.  This action begins immediately as the flexible weir style pinch valve  10  begins to stroke and works even if there is little water in the pipe. There is no wasted motion stroking the lower pinch bar  18  through the air space above the water, as in the case of conventional top closing, or top and bottom closing valves, as mentioned above.  
         [0033]    The elastomeric sleeve  16  in some applications may be fastened to the upper pinch bar  14  and the length of the elastomeric sleeve  16  is of a longer length, for example, a three to one ratio since closure is from only one side. Additionally, as illustrated in FIG. 1 e,  a stiffener or reinforcing material  24 , such as a band of steel, may be inserted in the top of the pinch valve sleeve  16  to hold it rigidly against the top of the upper pinch bar  14 . This reinforcing material  24 , such as a band of steel, may be curved and may be approximately 10 to 15 percent of the circumference of the sleeve. Preferably, as illustrated in FIG. 1 f,  the reinforcing material  24  may also be mounted on the inner portion of the elastomeric sleeve  16 . This may require the use of a plate  26 , to protect the reinforcing material  24  and hold it in place. The plate  26  may be approximately 90 percent the length of the flexible weir style pinch valve  10 , and may be held in place with fasteners  28  to the body  12  of the flexible weir style pinch valve  10 .  
         [0034]    The flexible weir style pinch valve  10 , according to a second embodiment of the present invention is shown in FIGS. 2 a  and  2   b,  and is operated by fluid (such as air). A conventional type of fluid operated pinch valve closes simultaneously from two or more sides inward, or in a triangular form. The flexible weir style pinch valve  10 , described by the second embodiment of the present invention, closes from only one side, the valve bottom  36 . The valve top  34  is relatively fixed against collapsing inward.  
         [0035]    The operation of the second embodiment of the present invention is similar to that described for the first embodiment of the flexible weir style pinch valve  10  described above. The only significant difference is that in the case of this embodiment, the valve bottom  36  moves in a curved line profile as shown in FIG. 2 b,  rather than a more straight line profile when using lower pinch bar  18 . Valve bottom  36  is moved with compressed fluid (such as air), which may be electrically controlled and pumped into and withdrawn from the lower portion of the valve body  12  by means well known to those skilled in the art. Water may be seen gathering in the upstream pipeline above raised valve bottom  36 .  
         [0036]    As illustrated in FIG. 2 a,  the top portion of the sleeve  34  is manufactured to be stiffer or more rigid than the lower portion of the sleeve  36 . This may be accomplished by using high durometer elastomer, for example, Shore A 90 durometer, additional layers of reinforcing fabric, or embedding reinforcing material  24  in the top portion (for example, top ⅜ th ) of the sleeve  34 . (NOTE: The typical range for elastomeric sleeve material is Shore A 35 to 60.) The bottom portion (for example, bottom ⅝ th ) would be more flexible rubber, such as Shore A 30. Additionally, the length of the elastomeric sleeve  16  is longer, for example, a three to one ratio since closure is from only one side. Thus, when fluid (such as air) is pumped into the valve body  12 , only the more flexible lower portion  36  of the sleeve collapses inward.  
         [0037]    Some suitable reinforcing materials  24  include solid steel plate, perforated steel plate, heavy steel mesh, steel wire, and other suitable materials. The comers and edges of the reinforcing materials  24  are rounded so they do not cut into the elastomer (and fabric reinforcing material, when used). Preferably, perforated plates and mesh are used since the elastomer flows into the openings and provides a superior bond to the reinforcing material  24 .  
         [0038]    The flexible weir style pinch valve  10  according to a third embodiment of the present invention is shown in FIGS. 3 a  and  3   b.  In this embodiment, the flexible weir style pinch valve  10  is similar to the second embodiment flexible weir style pinch valve  10 , with like reference numerals indicating similar parts. The third embodiment flexible weir style pinch valve  10 , as an alternative, includes a standard non-stiffened elastomeric sleeve  16 , which must be fastened to the inside top of the body  12 . This may be done in many ways, for example, by using adhesives or, mechanically by using bolts  38  penetrating through the elastomeric sleeve  16 , and through the body  12  and then holding the bolts  38  in place using nuts  40 . Although not shown in FIG. 3 b,  a rounded plate (for example 130 degrees by approximately ⅓ rd  length of the valve) may be used to secure elastomeric sleeve  16  to the valve body  12  with bolts  38 . Since this method penetrates two or three pressure boundaries (through the elastomeric sleeve  16  and through the valve body  12 ), great care must be taken to adequately seal these penetrations.  
         [0039]    The flexible weir style pinch valve  10 , according to a fourth embodiment of the present invention, is shown in FIGS. 4 a  and  4   b.  In this embodiment, the flexible weir style pinch valve  10  is similar to the first embodiment flexible weir style pinch valve  10 , with like reference numerals indicating similar parts. The fourth embodiment flexible weir style pinch valve  10 , as an alternative, includes stops  42  to prevent a 100% closure of the flexible weir style pinch valve  10 . Specifically, the stops  42  prevent the lower pinch bar  18  from contacting the upper pinch bar  14 .  
         [0040]    With reference to FIG. 5 and with continuing reference to FIG. 1 g,  a typical environmental setting in which the flexible weir style pinch valve  10  may be utilized is that of an urban area, in which it would be advantageous to control the flow of storm water, especially the flow of storm water during any initial storm water surge, which may normally result in flooding. To this end, multiple flexible weir style pinch valves  10  of various sizes are installed in appropriate areas of a storm water network to form a valve system. Each flexible weir style pinch valve  10  includes various closure points, as determined by the movement of the lower pinch bar  18  in relation to the elastomeric sleeve  16 . Thus, an operator of the flexible weir style pinch valve  10  may select different closure points of the flexible weir style pinch valve  10  in response to various storm water conditions. For example, a reduced flow closure  44  may be selected for normal storm water conditions, whereas a highly reduced flow closure  46  may be selected to control the flow of storm water at the peak of a major storm. Each closure  44 ,  46  forms a dam of a certain height, which either partially or fully reduces the flow of the storm water at certain areas within the valve system. Each flexible weir style pinch valve  10  may include a flow meter that measures the volume of storm water that is contained by the flexible weir style pinch valve  10 . Thus, the operator overseeing the operation of the valve system will be aware of the total volume of storm water that is stored within the valve system.  
         [0041]    This invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. There are, of course, other methods for operating a pinch valve from the bottom up, any of which may be used to achieve the improved operation described in this invention disclosure. It is intended that the invention be construed to include all such modifications and alterations.