Abstract:
A plurality of manifold valve assemblies each including a generally vertical valve cylinder having an inlet port at its top and at least two outlet ports near its bottom. A single actuator valve is fitted for closing each of the ports, each including a valve actuator, an actuator rod attached to and actuatable by the actuator, one end of the rod projecting outward from the actuator, and at least one valve plug attached to the projecting end of the actuator rod. Two of the three valves have rods that are coaxial with each other, the rods being independently actuatable by their respective actuators, both closing in the same direction so that no valve cage or bonnet is required.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to valves for controlling the flow of fluids, and particularly to block-and-bleed valves assembled together to form manifolds for controlling the flow of fluids, especially liquid foods or beverages, from multiple sources to multiple delivery destinations. The invention represents a further modification and improvement of the manifold systems disclosed in my U.S. patent application Ser. No. 5,232,023 issued Aug. 3, 1993. 
     It is common in the food packaging industry to have a need to connect a number of sources of a fluid, such as different types of milk or different types of soft drinks, to a number of different filler machines to fill containers, such as gallons, half-gallons, quarts and so on. To date these connections have been accomplished in the form of a manifold, including a number of lines from the source tanks crossing a number of lines leading to the filler machines, with valves being provided to control flow of fluid from any selected one or more of the source tanks to any chosen one or more of the filler machines. 
     In the past, it has been conventional to use specially designed valves to control these manifolds, called block-and-bleed valves, sometimes called leak detector valves, with one such valve installed at each manifold intersection. Block-and-bleed valves are particularly applicable to the sanitary industry, because they permit control of flow of different types of fluids through the same valve with double protection against intermixing of those fluids. That is, it may be desirable to have chocolate milk flowing through one part of the valve and white milk through another part, or pasteurized milk through one part and raw milk through another part, or clean-in-place solution through one part and milk or another food fluid through another part. Clearly, it is critical that these fluids not be permitted to mix, and regulations require that even failure of a single seat or valve plug not permit such mixing. 
     While valves used in the past functioned generally satisfactorily, they were extremely complex and expensive, and included multiple, coaxial, independently operable actuators and valve plugs. Under certain circumstances these valves were subject to substantial leakage and product waste, and when they did fail in this manner, while preventing mix of different fluids, their maintenance was difficult and expensive. 
     Even the improved systems heretofore devised have suffered from the problem that, once the input and output valves in a particular valve assembly are closed and the drain or &#34;leak detector&#34; port opened, about one quart of the fluid, for example, milk, would be discharged out of the drain and, thus, wasted. A need has, thus, continued to exist for improved valve assemblies that are economical, readily controlled and which minimize waste of the fluids being conveyed. 
     In my above-noted patent there was shown a manifold valve assembly, that enables the use of three individually controllable valves to control the flow of fluids at each intersection in a manifold and in which each intersection is configured so that substantially all of the fluid can be drained by gravity flow prior to opening of the drain or leak detector port. In that assembly two of valves are combined in a single valve housing and use independently controllable coaxial actuators while a third valve is connected thereto by a short connecting conduit configured so that liquid will drain by gravity from the first two valves through the third to the delivery conduits. Independent control of a drain port that serves as a leak detector was provided for. Concentrically configured or coaxial actuator rods were used to enable independent control by means of simple actuators that are linearly aligned with each other. Both actuators and valve assemblies are readily removable as a single assembly for repair or replacement. 
     These valves, however, required the use of a cage attached to a bonnet which carried a valve seat against which one of the valve bodies worked. The need for such a cage has been found to significantly increase the cost of the manifold valve assemblies. A need has, thus, continued to exist for improved, economical valve systems. 
     SUMMARY OF THE INVENTION 
     Briefly summarized, the invention provides a plurality of manifold valve assemblies each including a generally vertical valve cylinder having an inlet port at its top and at least two outlet ports near its bottom. A single actuator valve is fitted for closing each of the ports, each including a valve actuator, an actuator rod attached to and actuatable by the actuator, one end of the rod projecting outward from the actuator, and at least one valve plug attached to the projecting end of the actuator rod. Two of the three valves have rods that are coaxial with each other, the rods being independently actuatable by their respective actuators, a hollow cylindrical valve stem attached to the projecting end of the hollow actuator rod, having a valve plug for opening and closing an inlet port, the valve plug having a central opening through which the first actuator is fitted and being positioned above said inlet port and being downwardly facing so that said inlet port is closed by extension of said second actuator rod, the other two valves having valve plugs for opening and closing outlet ports, and being independently controllable by a valve actuator, one of the outlet ports. The two valves which have rods that are coaxial with each other both close in the same direction, downwardly, so that no valve cage or bonnet is required. 
     The outlet ports are configured so that liquids will drain by gravity from the lower end of the cylinder into either one of the outlet ports when the other of the outlet ports is closed. 
     An important advantage of the present invention results from the fact that independent control of the three independently controllable valves enables closing of the inflow valve while the leak detector port remains closed to permit gravity draining of liquids out of the outflow valve, which remains open. After such draining is complete, the outflow valve can be closed and the drain port opened. Thus, no significant loss of fluid occurs when the valves are in motion. The valves of this invention are particularly effective in preventing the inadvertent mixing of different types of fluids, even on failure of one valve seat or valve plug. 
     A further important advantage of the invention relates to the provision of an economical valve assembly that provides a leak detector, or opening to the atmosphere, that complies with applicable regulations governing equipment used in the dairy industry and yet avoids spillage of milk each time the leak detector is opened. Provision is made for controllable separation of food processing circuits from cleaning circuits. In accordance with an important related aspect of the invention, cleaning of the valve assembly is facilitated by the fact that, unlike prior art valve assemblies, each valve in the assembly can be fully and adequately cleaned by virtue of the fact that each valve stem in the system can be fully extended and retracted for purposes of cleaning. This assures adequate cleaning of the valve parts and associated O-rings or similar seals. 
     Other objects and advantages of the invention will become apparent hereinafter. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top, partially cut away, view of a manifold valve assembly constructed according to one embodiment of the invention. 
     FIG. 2 is an elevational cross sectional view taken along line 2--2 of FIG. 1. 
     FIG. 3 is an elevational cross sectional view taken along line 2--2 of FIG. 1 with components shown in different positions than those of FIG. 2. 
     FIG. 4 is an enlarged fragmentary cross sectional view of the concentric valve stems and one of the valve seats. 
     FIG. 5 is a fragmentary view with parts is cross section illustrating removal of the coaxial valve subassembly. 
     FIG. 6 is a fragmentary vertical cross sectional view illustrating a further embodiment of the invention. 
     FIG. 7 is an elevational view with parts in cross section showing yet another embodiment of the invention. 
     FIG. 8 is a cross sectional view taken along Line 8--8 of FIG. 7. 
     FIG. 9 is a cross sectional view taken along Line 9--9 of FIG. 7. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, there is shown a manifold assembly 10, employing a number of manifold valve assemblies 12 constructed according to one embodiment of the invention. As there shown, the manifold assembly 10 is connected to and receives supply from a number of sources 14, such as tanks of fluid. The manifold assembly 10 is also connected to and supplies the fluid to a number of destinations 16, such as filler machines for filling containers with one or more of the fluids from the fluid supply tanks. The purpose of the manifold assembly 10 is to control and selectively permit the flow of fluid from one or more predetermined sources 14 to a predetermined destination 16. The manifold assembly includes one supply tube 18 for each fluid supply source 14, and one delivery tube 20 for destination 16. While the manifold assembly 10 shown in FIG. 1 is fragmentary, it will be understood that the invention may be applied to any number of fluid supplies and destinations. 
     As can be seen from FIG. 1, this manifold assembly results in a crossed pattern of supply tubes 18 and delivery tubes 20. The supply tubes 18 and delivery tubes 20 do not actually intersect, but rather are positioned parallel in sets, in parallel planes, with the supply set being in the upper plane and the delivery set being in the lower plane. According to the embodiment of the invention shown in the drawings, the delivery tubes 20 are positioned in a plane beneath the plane of the supply tubes 18 so that fluids will tend to drain toward the delivery tubes by gravity flow. One manifold valve assembly 12 is provided at each crossing point of a supply tube 18 with a delivery tube 20. 
     Each manifold valve assembly 12 includes in effect three separate valve bodies, a supply valve body 22 a delivery valve body 24 and a drain port or &#34;leak detector&#34; valve body 29. In the arrangement of FIGS. 1-5 and 7-9 the valve bodies 22 and 24 are formed at opposite ends of a valve cylinder or housing 25. Each of these valve bodies 22, 24 and 29 is supplied with its own actuator assembly 26, 28 and 30, respectively. As shown in FIGS. 2 and 3, valve bodies 22 and 29 are interconnected and linearly aligned with each other. Valve body 29 is connected to the side of valve cylinder 25 at its lower end. 
     As can best be seen in FIGS. 2 and 3 the delivery tubes 20 are connected to the bottoms of valve bodies 24. Thus, liquids will flow by gravity through the valve assemblies toward the delivery tubes 20. 
     The interior detail of each valve body can be best seen by reference to FIGS. 2 and 3. Supply valve body 22 includes its own actuator 26, having a hollow annular actuator rod 32, actuatable between two positions, as shown. Valve body 22 has, at its top, a pass-through section including an inlet 36 substantially aligned with an outlet 38. Relating FIG. 2 with FIG. 1, the inlet 36 and outlet 38 of the supply valve body 22 connect to and in effect form part of one of the supply tubes 18, permitting flow of fluid from upstream destination valves at all times regardless of whether valve 22 is open or closed. 
     A valve plug 40 is attached to the end of valve stem 33 which is in turn attached to actuator rod 32. Plug 40 is provided to close a port 42 at the top of valve body 25. The perimeter of port 42 is defined by a valve seat 45. Valve seat 45 is positioned below valve plug 40 so that it is closed by extension of actuator rod 32. The actuator 26, thus, has two positions, one where port 42 is open and the other where port 42 is closed. 
     As seen in FIGS. 2 and 3, valve 29 is also a simple actuator type valve. Actuator 30 operates in actuator rod 35 which is connected to a valve stem 37. A valve plug 39 is affixed to or integrally formed with valve stem 37. Valve stem 37 is located concentrically within stem 33. Valve plug 39 is adapted to fit into and close a valve seat 47 which defines a port 48 at the bottom of the housing of valve 29 so as to close a drain port 49. Openings 44 in hollow valve stem 32 provide a visual indication in the event of leakage of liquid between the interior of stem 32 and the exterior of stem 37. 
     Also, delivery valve body 24 has its own actuator 28 connected to an actuator rod 52, actuatable between two positions. Delivery valve body 24 has a pass-through section including an inlet 54 substantially aligned with an outlet 56. Relating FIG. 3 with FIG. 1, the inlet 54 and outlet 56 of the delivery valve body 24 connect to and in effect form part of one of the delivery tubes 20, permitting free flow of fluid to downstream delivery valves at all times regardless of the position of the valve 24. 
     As with supply valve body 25, actuator rod 52 has affixed thereto a valve stem 53, by any suitable removable means, such as by threading. A valve plug 58 is affixed to or integrally formed with the valve stem 53. Once the valve stem 53 is assembled to the actuator rod, plug 58 is positioned within delivery valve body 24 to close port 64. As was the case with supply actuator 26, delivery actuator 28 has two positions, one where port 64 is open and the other where port 64 is closed. 
     Each of the three valves of the assembly can, thus, be individually controlled. In will be apparent that when supply valve 22 is open, delivery valve body 24 is also open, and valve 29 is closed, that fluid can flow from supply tube 18 into delivery tube 20. Then, to discontinue the flow, valve 22 is closed while valve 29 remains closed for a time sufficient to allow gravity drainage of liquids remaining in the valve bodies through valve 24 into delivery tube 20. Subsequently, valve 24 is closed. Drain port valve 29 is then opened without consequential waste of liquid. 
     It will also be apparent that, as needed, the supply tubes can be cleaned and drained without affecting the delivery tubes, and vice versa. For example, valves 22 and 29 could be open and valve 24 closed so that the supply side is cleaned without affecting the delivery side, or vice versa. 
     The invention provides structure permitting easy removal of the actuator and valve stem from any one of the valves at any time. Using a supply valve body 22 and drain port valve 29 as an example, the valve plugs are both carried by a valve bonnet 70. Valve stems 33 and 37 are inserted through an opening 78 in the bonnet 70. The actuators 26 and 30 together with their associated valve stems, rods and plugs can be installed or removed as a unit as seen in FIG. 5. The bonnet 70 has a flange 80 which flares outward from the central opening, to fit onto a mating flange surface 82. Upon assembly the two flanges are clamped together by a suitable clamp 84. Sealing means, such as an O-rings 85 can be provided where needed in the assembly to ensure against leakage. 
     If one of the actuators 26 or 30 requires service, or if one of the valve plugs 40 or 39 needs replacing or other service, the clamp 84 is opened and the actuators and bonnet 70 removed as best seen in FIG. 5. Valve 24 is constructed with a bonnet 70 similar to that described for valves 22 and 29. 
     It is not unusual for the delivery tubes 16 to be smaller in size than the supply tubes 14, such as 2 inch delivery tubes being used with 3 inch supply tubes. In order to satisfy sanitary requirements, it is necessary that the total drain opening area of the manifold valve assembly 12 is at least as large as the smaller of the supply tubes 14 or the delivery tubes 16. 
     In addition to the specific configurations of valves shown in FIGS. 1-5, other combinations can be used as desired. Specifically, as shown in FIG. 6, drain port 49 can be located so as to be controlled by valve 24 instead of valve 29. In this arrangement the flow to distribution line 20 is located beneath cylinder 25 and is controlled by valve 29. 
     Referring now to the embodiment of FIGS. 7-9, which show a another embodiment of the invention, there is seen a configuration wherein two outlet ports 90 and 92 are provided in the side of cylinder 25. Each of these outlet ports is connected to an elbow conduit 93 and 94, respectively. Valve bodies 24a and 24b are connected to conduits 94 and 93, respectively, and each include valve plugs 58 operated by actuators 28a and 28b, respectively. The other valve components are identical to those described above with respect to the embodiment of FIGS. 1-5. It will be noted that each of the conduits 93 and 94 is so located and configured as to allow gravity drainage from cylinder 25 toward distribution conduits 20 when valves 22 and 29 are both closed and valve 24 is open. 
     The embodiments shown in all of FIGS. 1-9 utilize the same arrangement for attachment of the valve bonnet and other operational details. These are therefore not repeated herein. It will be noted that by use of a single valve housing with each outlet therefrom capable of gravity drainage of liquids therefrom, a great reduction of waste is achieved. Cleaning of either the supply side or distribution side of the assembly while maintaining separation of the opposite side is also facilitated. It will also be noted that both of the valves 22 and 29 can travel a sufficient distance to facilitate cleaning of the valve components. 
     Note that, in operation, port 49 can be closed by means of valve seat 39 prior to opening of ports 42 and 64. Thus, no waste of fluid occurs when the valves are in motion. 
     A further variation of the present invention involves the addition of a side port for the purpose of installing an air blow check valve. Such valves are known in the art and are used to provide a means for blowing out of the lines and valves by means of air pressure. Such blowing may be desired in order to insure that all liquid is expelled prior to further use of the system. Such port would be provided in addition to the other ports already described herein. 
     It will be noted that each embodiment of the invention enables use of three simple single actuator valves to perform fluid flow control operations that previously required costly and complex valves. Use of these valves in accordance with the invention still prevents the mixing of different types of fluids running through the same valve assembly, even on failure of one valve seat or valve plug. 
     While the apparatus hereinbefore described is effectively adapted to fulfill the aforesaid objects, it is to be understood that the invention is not intended to be limited to the specific preferred embodiment of manifold valve assembly set forth above. Rather, it is to be taken as including all reasonable equivalents within the scope of the following claims.