Abstract:
A ball valve design with two sets of curved, smooth surfaces on the quarter-turn ball member to provide tight sealing in the fully closed position and protect the seat rings in the fully open position, with wiping action during opening and closing, thus avoiding particulate buildup. Compared to traditional ball valves, substantial, non-essential surface areas of the ball member are eliminated, which minimizes contact with the seat rings, thus reducing wear as well as operating torques as a direct result of reduced friction. The eliminated volume around the ball member creates an envelope for carrying particulate to be freely discharged into the downstream side when the valve is cycled from the closed to the open position. The cavity created around the raised spherical surfaces on the quarter-turn ball member also provides an envelope for modulating flow for control applications.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is based on and claims priority to U.S. Provisional Patent Application Ser. No. 60/857,240, filed on Nov. 7, 2006. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Quarter-turn ball valves have been preferred for many years in various types of valving applications for the simplistic operation, high flow capacity, compactness, relatively light-weight, reliable stem seals and the ease of automation. Quarter-turn ball valves have a big advantage over multi-turn valves, especially when automation is required, since their one-fourth turn (900) operation, compactness, light-weight and low operating torque provides for ease of installation and economy of actuation. As compared to multi-turn valves, such as gate and globe valves, a one-quarter turn ball valve is simpler to operate and maintain and, unlike linear stroking valves, has the advantage of turning within its own axis. Quarter-turn ball valves have been used in many different industries, such as oil and gas, power generation, pulp and paper, chemical, cryogenics, food and beverage, water and waste water, aircraft and aerospace, marine, mining and metals and pipeline applications. 
         [0003]    Although quarter-turn ball valves have proven effective in many of these applications, ordinary quarter-turn ball valves allow fluid media and debris to be trapped between the ball and the inner-body cavity, which can result in the accumulation of debris around the ball, which over time can result in damage to the valve seating surfaces. Therefore, it is an object of the present invention to provide an improved ball valve that allows debris to be flushed from the inner-body cavity to prevent the accumulation of solid matter around the backside of the seating rings and bearings. 
       SUMMARY OF THE INVENTION 
       [0004]    In view of the foregoing factors and condition characteristics of the prior art, it is a primary object of the present invention to provide a new and improved ball valve device. 
         [0005]    Another object of the present invention is to provide a simple, yet effective, ball valve that avoids a tendency to load particles and create buildup on the valve seats and the outer surface of the ball, minimizes contact and friction with the seat rings, reduces wear and operating torques, and thus extends the valve life and provides economic advantage in selection of actuator. 
         [0006]    Still another object of the present invention is to provide a highly configurable spherical surface, including one with built-in cam action, along the path of the quarter-turn moving member coming in contact with the valve seats, allowing flexibility in design of the valve seat/sealing mechanism. 
         [0007]    A further object of the present invention is to provide a relatively low cost manufacturing for the ball member. The ball member includes a spherical outer surface that can be machined to include a pair of flat side surfaces and a recessed, relieved area to reduce the amount of material required to form the ball member while providing the required sealing lips to seal the valve in both the open and closed positions. 
         [0008]    In accordance with an embodiment of the present invention, an improved quarter-turn ball member is provided having two sets of raised spherical surfaces that are in full contact with the valve seats only in the full open or full closed positions. In the full closed position, two opposed, raised spherical surfaces are fully engaged with the valve seats, thus providing tight sealing. In the full open position, the other two opposed, raised spherical surfaces, perpendicular to the open port, fully cover and protect the valve seats. During opening or closing cycles, the two opposed raised spherical surfaces provide a wiping, or scraping action, to clean the valve seats, thus avoiding buildup and allowing debris to be carried around the ball member within the created volume, and discharged freely out from the downstream side of the valve. The eliminated surface area minimizes contact and friction with the seat rings, thus reducing wear as well as operating torques. 
         [0009]    The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may be best understood by making reference to the following description taken in conjunction with the accompanying drawings in which like reference characters refer to like elements in several views. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The drawings illustrate the best mode presently contemplated of carrying out the invention. In the drawings: 
           [0011]      FIG. 1  is a top, section view of a prior art ball valve shown in a partially open position; 
           [0012]      FIG. 2  is a perspective view of a prior art ball valve that includes a generally spherical outer surface and a pair of opposed openings to a flow passageway; 
           [0013]      FIG. 3  is a perspective view of the ball member of the present invention illustrating the pair of oppositely located inlets to a flow passageway through the ball valve and a pair of planar side surfaces; 
           [0014]      FIG. 4  is a section view taken through the ball member of  FIG. 3 ; 
           [0015]      FIG. 5  is a top, section view of the ball valve of the present invention illustrating the flow of fluid along the outer surface of the ball member to flush debris and solids; and 
           [0016]      FIG. 6  is a side, section view illustrating the flow of fluid through a ball valve assembly including the ball valve of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring first to  FIG. 1 , thereshown is a valve assembly  10  that represents a prior art, quarter-turn ball valve that has been available for many years. The valve assembly  10  includes a valve body  12  that defines an inner-body cavity  14  that extends between an inlet  16  and an outlet  18  to selectively allow fluid to flow through the valve assembly  10 . As illustrated in  FIG. 1 , the inner cavity  14  contains a ball member  20  that can rotate a quarter-turn (900) within the inner cavity  14 . The ball member  20  includes a flow passageway  22  that extends between an inlet  24  and an outlet  26  of the ball member  20 . The ball member  20  includes a generally spherical outer surface  28 , as can be seen in  FIGS. 1 and 2 . As illustrated in  FIG. 2 , the top of the spherical ball member  20  includes a recessed area  30  including a valve stem receiving area  32 . The receiving area  32  receives the valve stem of the valve assembly and allows the ball member  20  to be rotated 90° within the inner cavity of the valve assembly. 
         [0018]    Referring back to  FIG. 1 , when the ball member  20  is in the partially open position as shown, debris  34  has a tendency to accumulate in the low pressure areas within the inner cavity  14 , as shown. In applications in which the ball valve is used with fluid including entrained particles, such as sand or other abrasive elements, the accumulation of debris  34  along the outer surface  28  of the ball member can have a detrimental effect on the durability of the valve assembly  10 . 
         [0019]    Specifically, when the ball member  20  includes an accumulation of debris  34  and rotates from the position shown in  FIG. 1  to a fully closed position, the debris  34  contained on the outer surface  28  contacts the seating assembly  36  positioned at both the inlet and the outlet of the valve body  12 . Typically, the seating assembly  36  includes a resilient seat  38  that forms a fluid-tight seal around the outer surface of the ball member. However, if the outer surface of the ball member includes the accumulation of debris, the debris, over a number of cycles, wears down the seat  38 , thereby decreasing the performance of the ball valve assembly and necessitating maintenance. 
         [0020]    Referring now to  FIG. 5 , thereshown is a valve assembly  40  constructed in accordance with the present invention. In the valve assembly  40  shown in  FIG. 5 , the valve assembly includes an improved ball member  42 . Like the ball member  20  shown in  FIG. 1 , the ball member  42  includes an inlet  24  and an outlet  26  that define a flow passageway  22  through the ball member  42 . However, unlike the ball valve shown in  FIG. 1 , the ball member  42  includes a pair of generally flat side surfaces  44  formed in the otherwise generally spherical outer surface of the ball member  42 . As illustrated in  FIG. 5 , when the ball member  42  is in the partially open position, fluid can flow between the outer surface of the ball member  42  and the inner surface  46  that defines the inner cavity  14 . Thus, when the ball member  42  is in the partially open position, a small amount of fluid flows along the outer surface of the ball member  42  to prevent the accumulation of debris  34 . 
         [0021]    Referring now to  FIG. 3-4 , thereshown are detailed views of the ball member  42  constructed in accordance with the present invention. The ball valve  42  includes a generally spherical outer surface  48  and a flow passageway  22  that extends through the center of the ball member. As illustrated in  FIG. 4 , the ball member  42  includes a pair of opposed, flat side surfaces  44  that are each defined by a curved, side sealing lip  52 . As can be seen in  FIG. 4 , the curved, side sealing lip  52  is formed having a radius of curvature R that is the same as the radius of curvature of the outer surface of the generally spherical ball valve  42 . Each of the side surfaces  44  is a planar surface machined from the otherwise spherical outer surface of the ball member. 
         [0022]    In addition to the side surfaces  44 , the ball member includes a trunnion  54  defined by a sloping outer rim  56 , which in turn defines the recessed area  58  that includes the valve stem receiving area  60 . As can be understood by a comparison of  FIGS. 2 and 4 , the recessed areas  30 ,  58  and receiving areas  32 ,  60  generally correspond to each other such that the ball member  20  shown in  FIG. 2  can be replaced by the ball member  42  shown in  FIG. 4 . 
         [0023]    As shown in  FIG. 3 , the trunnion  54  is set off from the side sealing lip  52  surrounding the side surfaces  44  and the lip  62  surrounding the outlet  26  and the inlet (not shown) by a relieved area  64 . The relieved area  64  is machined from the generally spherical outer surface  48  of the ball member  42  and defines a set off wall  66  that forms the outer rim  56  and the set off wall  67  that forms both the sealing lip  52  and the sealing lip  62 . The relieved areas  64  are each defined by an inner wall  65  that is recessed radially inward from the side sealing lip  52  and the outer rim  56 . The relieved areas  64  provide another flow path for debris to pass along the outer surface of the ball member  42  when the ball valve is in a partially open position, such as shown in  FIG. 5 . 
         [0024]    Referring now to  FIG. 4 , the radius of the side sealing lip  52  surrounding the side surface  44  matches the radius of the sloped outer rim  56  that defines the trunnion  54 . During manufacture of the ball member  42 , the outer surface of the ball member  42  is formed with a smooth, spherical configuration and a portion of the ball member  42  is machined away to define the generally planar side surfaces  44  and the relieved areas  64 . 
         [0025]    In addition to the sealing lip  52  and the outer rim  56 , the sealing lips  62  surrounding both the inlet and the outlet  26  to the flow passageway have the same radius of curvature as the outer surface  48 . As shown in  FIG. 3 , the sealing lip  52  and the sealing lip  62  merge together at a junction point  70 . Since the relieved areas  64  are machined from the otherwise spherical outer surface  48  of the ball member, the relieved areas  64  define the top and bottom edges of both the sealing lip  52  and the sealing lip  62 . 
         [0026]    In the preferred embodiment of the invention, the ball member is formed from a hard chromed stainless steel. 
         [0027]    As can be understood in  FIG. 5 , when the ball member  42  is in its fully closed position, the side sealing lip  52  contacts the seating assembly  36  to provide a fluid-tight seal around the ball member. As the ball member  42  rotates to an open position, an edge surface  68  ( FIG. 5 ) that defines the junction between the planar side surface  44  and the side sealing lip  52  contacts the seating assembly  36  to clean the seating assembly of any debris. Thus, in accordance with the present invention, the improved quarter-turn ball valve includes two sets of parallel side surfaces  44  that are in contact with the valve seats in the fully closed position. In the fully closed position, the two parallel side surfaces  44  are fully engaged with the valve seats, thus providing tight sealing. In the full open position, the side sealing lips  52  fully cover and protect the valve seats. In this manner, the two sets of sealing lips  52  provide a wiping, or scraping action during opening and closing of the ball valve which cleans the valve seats and avoids buildup. Further, as was shown in  FIG. 5 , the configuration of the ball member  42  allows debris to be carried around the ball member within the inner cavity  14 , thus allowing debris to be discharged freely from the downstream side of the valve. 
         [0028]    In addition to providing the features described above, the pair of planar side surfaces  44  reduce the surface area of the ball member to minimize contact and friction with the seat rings, thus reducing wear as well as reducing operating torque. Both these features extend the valve life and provide economic advantages in the selection of the valve actuator. The two sets of parallel sealing lips  52  provide flexibility in the design for configuring an optimizing cam action loading against the seating rings, thus facilitating innovation of more effective sealing mechanisms. 
         [0029]      FIG. 6  illustrates the positioning of the ball member  42  within a piping arrangement between an inlet pipe  72  and an outlet pipe  74 . The ball member  42  receives the valve stem  76  from a valve actuator  78  including a handle  80  that is operable to rotate the ball member  42  between its fully open and fully closed positions. When the ball member  42  is in the partially open position shown in  FIG. 6 , fluid and debris is able to pass over the flat side surfaces  44  to prevent the accumulation of debris. Likewise, when the ball member  42  is in the fully closed position, fluid and debris can pass through the flow passageway  22  in a conventional manner. 
         [0030]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different configurations, systems, and method steps described herein may be used alone or in combination with other configurations, systems and method steps. It is to be expected that various equivalents, alternatives and modifications are possible within the scope of the appended claims.