Abstract:
A four way valve which is relatively easy to manufacture and which is smaller than conventional four way valves for a given bore size or flow capacity. The valve can be formed utilizing a closure having a pair of intersecting bores, with a separator provided within the closure to form two isolated passageways or flow paths. An improved sealing/seating arrangement is also provided.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to valves, and particularly to four way ball valves, however certain aspects of the invention (e.g., an improved seat/seal assembly) can also be advantageously utilized in other types of valves. 
     2. Discussion of Background 
     FIG. 6 schematically depicts a conventional four way valve. The arrangement can accommodate two inlet flows and provide two outlet flows, and can be used where it is desired to switch or alternate the fluid flows to be fed to different parts of a fluid system. By way of example, a fluid flow system might utilize different fluids and, periodically, it is desired to switch or change the fluids which are to be fed into different flow paths of the system. As shown in FIG. 6, utilizing a four way valve, a single valve can switch a pair of inlets and outlets to change the relationships of the inlets and outlets. The valve of FIG. 6 includes inlets  1 ,  3  and outlets  2 ,  4 , with the position of the ball closure  6  determining the communicating relationships of the inlets and outlets. In the position shown in FIG. 6, the inlet  1  communicates with the outlet  4  and the inlet  3  communicates with the outlet  2 . By rotating the ball closure  6  by 90°, the inlet  3  then communicates with the outlet  4 , and the inlet  1  communicates with the outlet  2 . Thus, the inlet  1  can be selectively placed in communication with the outlet  2  or the outlet  4 , while the inlet  3  is in communication with whichever outlet is not in communication with inlet  1 . 
     FIG. 7 is an enlarged cross-sectional view of the ball closure  6  for the four way valve of FIG.  6 . As shown, the closure  6  includes two bores  6   a,    6   b  to provide two flow paths between the inlets  1 ,  3  and outlets  2 ,  4  as discussed above with reference to FIG.  6 . One of the problems with such a prior art valve is that, in order to accommodate for the bores  6   a,    6   b,  the size of the ball closure is large. In addition, due to the size of the ball closure, the torque required to rotate the ball is also large, and the actuator (the device which turns a valve) must therefore be sized to be able to overcome this torque. 
     The conventional four way valve is undesirable in a number of respects. First, due to the size of the ball closure, the other components of the valve, such as the housing, seats/seals, stems, linkages, must be larger, resulting in higher raw materials costs. In addition, higher manufacturing costs are encountered in forming the various components. The excessive size for a given bore size for the conventional four way valve not only results in excessive costs, but also, the size for which the valve can be practically manufactured is limited. For example, with the conventional arrangement, it is impractical to manufacture valves which are larger than 6″-8″ in bore diameter, since the overall valve size becomes excessively large. 
     As an alternative to the use of a four way valve, a series of valves and additional piping can be utilized. For example, as shown in FIG. 8 (in which inlet and outlet numbers corresponding to FIG. 6 are designated similarly, with the addition of ten), an inlet  11  can alternatingly feed outlets  12 ,  14  utilizing a pair of valves  16   a,    16   b.  In particular, when the valve  16   a  is “on,” and valves  16   b  and  16   c  are “off,” the flow passes from the inlet  11  to the outlet  12 . When valves  16   a  and  16   d  are “off” and the valve  16   b  is “on,” the flow passes from the inlet  11  to the outlet  14 . Similarly, the flow from inlet  13  can be alternatingly fed to the outlets  12 ,  14 , with the flow fed from  13  to  12  when  16   c  is “on” and  16   a  and  16   d  are “off,” and with the flow from  13  to  14  when valves  16   b  and  16   c  are “off” and valve  16   d  is “on.” As should be readily apparent, such is more complex and expensive in that four valves and additional piping are required. Moreover, the system is further complicated in requiring a control system which turns the valves on and off in concert. 
     A further difficulty with the conventional four way valve resides in providing a reliable and durable seating arrangement. The seat or seal is a part which contacts the ball closure so that there is no leakage (or at least minimal leakage) around the ball closure (and the flow passes only through the bores of the closure without bypassing the closure). Since the ball closure moves over the seat as it is being moved to different positions, the seat can wear (causing leakage between the seat and the ball closure), particularly if the valve application calls for the valve to be repeatedly switched (e.g., a million cycles per year). To minimize leakage, a seal can be held tightly against the ball closure, however, particularly with the large conventional four way valve, a large torque is then required to move the valve, making it more difficult to control position and rapidly change the position of the ball closure. 
     Accordingly, an improved four way valve is needed. 
     SUMMARY OF INVENTION 
     It is therefore an object of the invention to provide an improved four way valve which is relatively easy to manufacture and which is smaller than the conventional valve for a given bore size or valve flow capacity. In accordance with the present invention, a standard ball closure is utilized with a pair of intersecting bores extending through the ball closure. An elliptical separator is then provided within the ball closure so that the cross-bores form two isolated passageways (or flow paths) through the closure, and thereby provide a four way valve closure. With this arrangement, the size of the closure for a given bore diameter is greatly reduced. By way of example, with a prior art four way valve as shown in FIG. 7, the ratio of the ball diameter to the bore diameter is approximately 3 to 1. In other words, a valve with a 6 inch diameter bore requires a ball which is approximately 18 inch in diameter. By contrast, with the present invention, the ratio of the ball diameter to the bore diameter can be reduced to 2 to 1 or less. Thus, a valve with a 6 inch diameter bore can be achieved having a ball with a spherical diameter of approximately 12 inches or less. As a result, materials costs are reduced, not only for the ball closure, but also for the other components of the valve, such as the valve housing, seats, stems, etc. Further, the torque required to turn the valve is reduced, and it can therefore also be possible to utilize a smaller actuator or other means for turning the valve. The invention also provides an improved sealing/seating arrangement in which the seal or seat is spring loaded against the closure member. As a result, a reliable seal can be maintained over a large number of cycles as discussed in further detail herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention and many of the attendant advantages will become apparent from the detailed description which follows, particularly when read in conjunction with the accompanying drawings in which: 
     FIG. 1 is a perspective view of the four way closure member of the invention; 
     FIG. 2 is a side cross-sectional view of the ball closure of FIG. 1; 
     FIG. 3 is a perspective view of a present form of the valve housing (or valve body) of the invention with the top removed; 
     FIG. 4 is a side cross-sectional view of the assembled valve of the invention; 
     FIG. 5 is a cut away perspective view of the valve of FIG. 4; 
     FIG. 6 is a schematic representation of a conventional four way valve; 
     FIG. 7 is a cross-sectional view of the closure member of FIG. 6; and 
     FIG. 8 is a schematic representation of a flow system in which on-off valves are utilized in lieu of a four way valve. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 2 respectively depict perspective and cross-sectional views of a preferred form of the closure member for a four way valve in accordance with the invention. As shown, four ports are provided in the ball valve closure. With reference to FIG. 2, the ports include left and right ports  20 ,  22 , and top and bottom ports  24 ,  26 . (Left, right, top and bottom are used herein for ease of reference with respect to the orientations shown in the drawings. It is to be understood that, when installed, the valve can be oriented differently than shown in the drawings.) In the embodiment shown in FIGS. 1 and 2, the ball closure is a trunion-type ball, with trunions  28 ,  30  provided on the top and bottom of the ball. The trunions provide support and bearing surfaces for rotatably mounting the ball closure. It is to be understood that the present invention could also be utilized in non-trunion mounted closures, or with only a single trunion. For example, in lieu of a trunion mounting at the bottom of the ball closure, the bottom port of the closure can directly communicate with the bottom opening of the valve housing, with a seal provided to prevent leakage of the fluid flow between the closure and the housing. The top trunion could also be eliminated, for example, by mounting the valve shaft (or stem) to an apertured plate or a spoke-like assembly which is connected to the ball at the location of the top port of the ball closure (so that the fluid can flow through the top port  24 ). Accordingly, while the presently preferred embodiment includes top and bottom trunions, it is to understood that the invention is also applicable to arrangements which include a single trunion or no trunions. In addition, although a ball closure is presently preferred, it is also to be understood that closure members of other shapes (e.g., cylindrical) could also be utilized. 
     In the arrangement shown in FIGS. 1 and 2, a shaft  34  (which is also called a “stem”) is connected to the trunion  28  for rotating the ball closure. As also shown in the drawings, the top trunion  28  includes a plurality of apertures  29 . The apertures  29  allow the flow to pass from the port  24 , through the trunion  28 , with the fluid exiting the trunion via apertures  29 . The lower trunion  30  is generally cylindrical and includes an aperture  31  so that the flow passing into or out of the port  26  flows through the aperture  31 . A separator or divider  36  separates the ports  22 ,  26  from the ports  20 ,  24 , so that two flow paths are provided. In particular, flow which enters port  22  will exit port  26  (and vice versa depending upon the direction of the flow, i.e., flow which enters port  26  will exit port  22 ), while flow which enters port  20  will exit port  24  (and vice versa). 
     As should be apparent, the valve closure is advantageous as compared with the prior arrangement in a number of respects. First, the bore size for a given ball diameter are significantly larger than that of the prior art arrangement. As discussed earlier, the ratio of the ball diameter to the bore diameter can be on the order of 2 to 1 or less, while with the prior four way valve, a ball diameter of approximately 3 times the size of the bore was needed. This not only made the conventional valve costly, but restricted the size which could be practically manufactured. Accordingly, where a very large flow or flow rate is required, the conventional four way valve could not be utilized and alternate solutions would be necessary, for example, utilizing plural valves as discussed earlier with reference to FIG.  8 . However, utilizing a series of valves is undesirable in that the cost of the valves and associated piping is less than optimal, and the control system required to operate the valves in concert becomes more complex. Moreover, as noted earlier, with a large conventional four way valve, additional complications are encountered in terms of the torque required to turn the valve (and thus the actuator required to turn the valve) and such problems can be particularly troublesome where the valve is required to rapidly and repeatedly switch flow relationships. 
     An additional advantage of the valve in accordance with the invention is that it is relatively simple to manufacture. In particular, the ball closure  18  can be formed simply by machining two cross bores (or, if desired, casting a valve with two cross bores), with one bore extending from port  20  to port  22  and the other extending from port  24  to  26 . The separator  36  can then be inserted into the closure so that it extends across the intersection of the bores to separate the ports of each bore and form the two flow paths. In a present form, the separator  36  is a plate which is affixed inside of the ball closure  18 , for example, by welding. In the embodiment shown in FIGS. 1 and 2, the separator  36  is an elliptical plate. 
     Referring now to FIG. 3, a housing for the closure of FIGS. 1 and 2 is shown, with the top of the housing removed. The housing includes four openings,  40 ,  42 ,  44  and  46  to allow the passage of fluid for the four ports of the ball closure. (As discussed hereinafter, the housing top includes a fifth opening which is not a flow passageway, but which receives the top trunion of the closure member.) The housing can be formed, for example, of carbon steel. In the arrangement of FIG. 3, the housing is formed of welded steel plates, however it is to be understood that the housing can have various forms, for example, with the housing being cast and having a different shape than that shown in FIG.  3 . 
     The lower trunion  30  sits into the bottom aperture  46  so that the flow passing through the port  26  and aperture of the trunion  30  also passes through the aperture  46 . The flow which passes through the upper port  24  of the ball closure  18  passes through the apertures  29  and then into the valve housing itself (in the space between the closure member and the housing). Since the other apertures are sealed (as discussed in further detail hereinafter), the flow exiting the apertures  29  and into the housing exits through the aperture  44 . 
     FIG. 4 is a cross-section of the assembled valve, while FIG. 5 is a cut-away view of the assembled valve. As discussed earlier, the housing in FIG. 3 has its top removed. The top is depicted at  50  in FIG. 4, and includes an opening which receives the trunion  28 . The trunion (and thus the ball closure) is thereby rotatably mounted with respect to the housing, with the bearing surfaces  28   a  (see FIGS. 1 and 2) in sliding contact with the housing top  50 . Within the space  52  between the housing top and the bearing surfaces  28   a  a suitable seal, such as an O-ring, can be disposed to prevent leakage through the top  50  of the housing. As shown in the drawing, fluid which enters from the right side of the housing will pass into port  22  of the closure  18 , and then will exit through the port  26  of the closure and through the aperture  31  of the trunion  30  so that the flow exits the bottom of the valve (or the flow can be in the opposite direction). Flow which enters from the left side of the housing enters port  20  and then flows upwardly until it exits port  24  and apertures  29  of the upper trunion  28 . The flow passing out of the apertures  29  then flows into the housing in the space between the ball closure and the housing, and the flow then exits the opening  44  (see FIG. 3) of the housing. Of course, suitable piping is connected to each of the openings of the valve housing. As noted earlier, the opening  44  is not sealed with respect to the closure member of the valve, but instead, the opening  44  communicates with a space between the housing and the closure member so that the fluid exiting trunion apertures  29  will pass through the space between the closure and the housing and will exit through opening  44  (or vice versa depending upon the flow direction). The closure member  18  is sealed with respect to the remaining apertures to prevent leakage of the fluid into the valve body or around the closure member. 
     As noted earlier, the upper trunion is sealed with respect to the housing top  50  by, for example, an O-ring seal  52 . Similarly, the bottom opening  46  (FIG. 3) of the housing is sealed with respect to the trunion  30  by suitable means, such as an O-ring seal in the space shown at  54 . Similar to the mounting of the top trunion, the bottom trunion  30  is rotatably received in the bottom opening of the housing, with bearing surfaces  30   a  (FIGS. 1 and 2) in sliding contact with the bottom surface of the housing at the housing opening  46 . The top and bottom trunions  28 ,  30  can be connected to the closure member at the respective ports  24 ,  26 , for example, by welding. 
     Although the seals about the upper and lower trunions are relatively easy to achieve, e.g., with O-ring seals, providing a durable seal at the ball closure and about the ports  20 ,  22  can be more complicated. In particular, the seal at the closure member is provided upon a spherical surface (i.e., where the closure is a ball closure) which moves across the seal repeatedly, and which can be subjected to forces associated with the fluid flow. In certain applications, the valve could cycle (i.e., change positions) one million times or more per year. Thus, it is desirable to provide a seal arrangement which is durable so that leakage is minimized despite repeated cycling of the valve. 
     In the arrangement shown in FIG. 4, a spring loaded seal assembly is provided at the left and right sides of the ball closure. Since the seal assemblies are the same on the left and right sides, the same reference numerals are utilized for simplicity. The seals are shown at  60 , and are disposed within a flanged cylinder or sleeve  62 . By way of example, the seals can be formed of a high density polyethylene, and the flanged cylinder  62  can be stainless steel. The flanged cylinder  62  provides for a proper positioning of the seal  60 , and also provides a good sliding surface for a spring holder  64 . The spring holder  64  is an annular disk-like member having a plurality of apertures or recesses  66  therein for receiving springs, such as helical springs. For example, eight recesses  66  can be distributed about the periphery of the spring holder  64  for accommodating eight springs. The spring holder  64  is slidable along the flanged cylinder  62 , and therefore should also have an outer surface which provides for good sliding contact with the inner surface of the flanged cylinder  62 . For example, the spring holder  64  can be formed of stainless, with a polyethylene sleeve or ring disposed about the spring holder for sliding contact with the flanged cylinder  62 . Optionally, an O-ring can additionally be provided between the spring holder  64  and the seal  60  (at the outer periphery of the spring holder) for further prevention of leakage. 
     Fastened to the exterior of the housing are flanges  68 , which provide mounting sites for connecting pipe flanges to the valve. Mounting of the flanges  68  to the housing causes loading of the springs (which extend between the spring holders  64  and the flanges  68 ). Once the flanges  68  are mounted and the springs are loaded, the spring holder  64  (which is in sliding contact with the flanged cylinder  62 ) in turn is urged against the seals  60  so that a tight seal is ensured against the ball closure  18 . This arrangement is advantageous in a number of respects. The spring loading ensures that a tight seal is maintained against the ball closure. Since the spring holder  64  is slidably mounted, even upon the occurrence of wear, a tight seal is maintained, since the spring holder  64  can move toward the ball closure and continue to urge the seal  60  against the ball closure. It is to be understood that alternate seal assemblies can be utilized with the four way valve of the invention, however the use of a spring loaded seal assembly is presently preferred to ensure a tight seal over a large number of valve cycles. It is also to be understood that, although the seal assembly described above is advantageously utilized with the four way valve of the invention, it could also be utilized with other types of valves. 
     As to the other elements of FIGS. 4 and 5, a mounting bracket is shown at  70 , and can be used for mounting whatever means are utilized for turning the valve via shaft  34  (e.g., an actuator, motor, etc.). Bolts  72  are provided for fastening the top  50  to the remainder of the housing, however, other fastening expedients could also be utilized. As also shown in FIG. 5, the flanges  68  include two sets of apertures  74 ,  76 . One set of apertures  74  is utilized for fastening the flanges  68  to the valve housing (and thus loading the springs of the seal assemblies), while the other set of apertures  76  is utilized for mounting of a pipe flange to the valve housing flange  68  and mount of the necessary piping to the valve. In the present arrangement, the apertures  74  are not threaded. Fasteners are inserted into the apertures  74  and screw into threaded apertures provided in the housing walls. 
     In operation, the valve as discussed herein can provide for rapid switching or alternating of the fluid flow in a given system. For example, in the FIG. 4 position, the port  20  of the ball closure is in communication with the opening in the left side of the housing (the opening  40  of FIG. 3) and fluid entering the left side of the housing will then pass through the port  20 , to the port  24 , and then through the apertures  29  of the trunion  28  so that the flow exits through the opening  44  (FIG.  3 ). When the ball closure is rotated 180° from the FIG. 4 position, the port  22  is then in communication with the opening on the left side of the housing, so that the fluid entering the left side of the housing exits through port  26  and then through the bottom opening of the housing (opening  46  in FIG.  3 ). Similarly, in the position shown in FIG. 4, the port  22  is in communication with the right side opening of the housing so that the flow which enters from the right passes through port  26  and exits through the bottom of the housing. However, when the valve is rotated 180° from the position shown in FIG. 4, the port  20  is in communication with the right side opening of the housing so that the flow entering the right side of the housing passes from port  20 , through port  24  and apertures  29 , and then passes through the space between the ball closure and the valve housing to exit opening  44  of the housing. 
     As should be apparent, a four way valve in accordance with the invention can be utilized for a wide number of applications. Depending upon the system design or the fluid pressures encountered, a particular port might be an inlet for one valve position and an outlet for another valve position. Alternately, the fluid could be fed to only one inlet, so that the valve is essentially utilized to change the flow path for that fluid. As a further alternative, the four way valve can be utilized for reversing a flow. For example, a fluid can be fed into port  22 , so that it flows to port  26  in the position shown in FIG. 4. A pump can be connected to the left side of the valve such that when the valve is rotated 180° from the position shown in FIG. 4, the fluid which flowed from port  22  to outlet  26  is then pumped from port  26  to port  22 . The foregoing are merely exemplary, and the four way valve of the invention can be utilized in a variety of applications. 
     As noted earlier, although a particular form of the present invention has been described herein, for example, with the closure member a ball closure member having a pair of trunion mountings the invention is not limited to the arrangement specifically depicted. For example, the closure could be provided in different forms, for example, with a cylindrical closure member. In addition, in lieu of the use of a pair of trunion mountings, a single trunion mounting could be provided at either the top or the bottom of the closure member, or the ball closure could be mounted without the use of trunions. 
     Obviously, numerous modifications and variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the present invention can be practiced otherwise than as specifically disclosed herein.