Abstract:
An air-blow valve configured for clean-in-place capability is provided. The valve comprises a valve body defining a valve seat and internal fluid passageways. The valve further comprises valve components disposed within the valve body, including a plug, a piston, and a spring. The valve is separately operatively connected to a pressurized-air source and to a sanitizing-fluid source. In operation, the spring biases the piston, causing the plug to engage the seat, to prevent undesired fluid flow between the passageways and the connecting conduits. Pressurized air is used to space the plug from the seat to achieve flow whenever desired. Periodic selective movement of the piston to space the plug from the seat, enables the cleaning solution to pass through the body and clean the internal passageways, the seat, and the plug, thereby rendering unnecessary disassembly of the valve and/or removal of the valve from the connecting conduits during valve cleaning.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The present invention is directed to an air-blow valve designed for clean-in-place capability and operatively connected to a sanitizing-fluid source, to render the air-blow valve sanitary. The present invention is also directed to a sanitary clean-in-place air-blow valve that is designed to be used in connection with conventional fluid-transport systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    The use of an air-blow valve in conventional fluid-treatment and fluid-processing facilities is well known in the art. Such air-blow valves may sometimes be referred to as “air-blow check-valve assemblies” that serve to allow pressurized air to be injected into a fluid conduit, wherein the pressurized air is used to cause the injected fluid to move from the point of injection to an opening in the conduit spaced from the fluid-injection point. When used thusly, air-blow valves may be operatively connected to a vast assortment of conventional fluid-transport or solids-transport systems to recover, e.g., food products from a supply line, for conveying the recovered products to suitable storage facilities.  
           [0003]    For example, U.S. Pat. No. 2,458,230 to Warcup is directed to the field of a cleaning means for beer dispensers. In particular, Warcup discloses a valve having four internal chambers, wherein the valve is designed to allow water to enter the first chamber and pass to the second chamber, which is connected to a beer line. The Warcup valve is further designed to allow beer to pass to the beer line via the second and third chambers. In the Warcup valve, air is able to pass into the fourth chamber, to enable a rod to engage and move a valve element, thereby to permit fluid communication between the first and second chambers. The Warcup design does not permit water to enter the third chamber.  
           [0004]    In U.S. Pat. No. 3,572,366 to Wiggins, a valve for supplying paint is disclosed. Also disclosed is an embodiment wherein several Wiggins valves are joined to a housing to form a multi-color spray-painting assembly. The assembly is adapted to be operatively connected to a pressurized supply of solvent and, separately, to paint. In that regard, the assembly is adapted to be separately connected to several different-colored paints.  
           [0005]    One feature of each Wiggins valve permits automatically purging certain internal chambers of the assembled valves when the paint supply to an individual valve is cut off.  
           [0006]    U.S. Pat. No. 4,836,420 to Kromrey discloses a clean-in-place valve-actuating device that is used to facilitate the cleaning of a machine for providing soft ice cream and milkshakes. The Kromrey valve-actuating device permits the cleaning-in-place of such a machine, eliminating the need to dismantle the machine for manual cleaning thereof.  
           [0007]    U.S. Pat. No. 5,343,907 to Wagner is directed to a device used for cleaning carbonated beverage-dispensing systems. The essence of the Wagner device is a rather complex valve having a number of interrelated fluid passageways or internal chambers.  
           [0008]    For example, in the Wagner patent, water or a cleaning agent may be introduced either into a first or into a second chamber of the valve. A piston, longitudinally disposed in the first valve chamber, has a third chamber formed therein. The piston, moreover, is especially designed to enable the first and second chambers to be in fluid communication via the third chamber. A fourth chamber of the valve is in fluid communication, via a flow-check valve, with a beverage source. Pressurized carbon dioxide is used to move the beverage from its source, via the flow-check valve, into the fourth chamber. A fifth chamber of the valve is in fluid communication with a line for dispensing the beverage to a consumer. A sixth chamber of the Wagner valve is in fluid communication, directly, with the beverage source. The flow-check valve is designed to permit fluid flow from the sixth chamber into the fourth chamber, but not vice versa. The fifth chamber of the valve is in direct fluid communication with the first four of the above-mentioned chambers.  
           [0009]    In U.S. Pat. No. 5,390,694 to Zimmerly, et al., a bottom-fill clean-in-place (CIP) system is disclosed. Illustrated in the patent are a number of Zimmerly, et al. valves, at least as complex as the Wagner valve, wherein the Zimmerly, et al. valves are operatively connected to plural pipelines for separately providing raw materials and/or CIP solution to the bottom portion of a row of tanks and for withdrawing liquid product such as milk therefrom.  
           [0010]    U.S. Pat. No. 5,415,192 to Pera shows a cleaning device for a milk plant. To achieve cleaning of pipelines, disassembly and re-assembly of the pipelines is required.  
           [0011]    U.S. Pat. No. 5,564,457 to Beck is directed to a so-called “vacuum breaker” valve said to have CIP capability. The essence of the Beck valve is yet another rather complex valve defining a number of interrelated fluid passageways or chambers.  
           [0012]    For example, in the Beck valve, milk is introduced into a first chamber of the valve. Air may be drawn into a second chamber of the valve. A sphere, disposed in a third chamber of the valve, is able to engage a first valve seat, thereby forming a plurality of so-called “satellite channels.” The plurality of satellite channels may collectively be thought of as a fourth chamber. The third and fourth chambers, together, enable the first and second chambers to be in fluid communication. The Beck valve uses an air cylinder to cause a piston, disposed in a fifth chamber, to move. The fifth chamber is in fluid communication with the second chamber. In operation, the sphere is able to sealingly engage a second valve seat, thereby to break fluid communication between the second and third chambers; whereupon the piston, caused to move by the air cylinder, is able to re-establish fluid communication between the second and third chambers of the valve.  
           [0013]    In U.S. Pat. No. 5,850,845 to Pereira, et al., a so-called “backflush valve” for a milking machine is disclosed. The backflush valve includes a slide pad that is captively disposed between an inlet plate and an outlet plate. The inlet plate defmes a milk inlet and a cleaning-solution inlet. The slide pad defines a milk-flow path. The outlet plate defines a milk outlet. The milk-flow path provides fluid communication between the milk inlet and the milk outlet when the slide pad is in a so-called “milking” position. The slide pad further defines a cleaning-solution path, which provides fluid communication between the milk inlet and the cleaning-solution inlet, when the slide pad is in a so-called “backflush” position. Compressed air is used to cause a so-called “double acting” piston, which is disposed within the valve, to move between two spaced-apart positions.  
           [0014]    For a number of reasons, principally ever-increasing labor costs and the mandate from management to keep production plants “on stream,” there is a desire to incorporate CIP systems and “retire” procedures that require disassembly and subsequent re-assembly of production-plant component parts, whenever it is possible and economically practical.  
           [0015]    As some of the above-discussed patents suggest, dairies and food-treatment plants use CIP systems, to maintain system cleanliness and achieve sanitary conditions. In such CIP systems, however, air-blow valves, for a number of reasons, have been unable to take advantage of being cleaned in place.  
           [0016]    To keep valve-maintenance as well as labor and replacement-parts costs to a minimum, it would be desirable to have a valve that is relatively simple in design.  
           [0017]    To that end, as my invention illustrates, air-blow valves can be simple in design.  
           [0018]    It thus would be desirable to use air-blow valves, simple in design and configured for clean-in-place capability, in various production plants for an assortment of products.  
           [0019]    It would be even further desirable to have an air-blow valve, simple in design and adapted for clean-in-place capability, where the valve is also relatively simple to operate.  
           [0020]    To that end, my valve is simple to operate. For reasons suggested above, it would therefore be particularly desirable to use, especially in dairies and food-treatment plants, the air-blow valve of this invention, which is adapted to have clean-in-place capability.  
           [0021]    The invention thus relates to a clean-in-place air-blow valve which is both simple in construction as well as in operation, with the result that the air-blow valve is reliable.  
           [0022]    From the analysis of the prior art patents identified above, no single reference or combination of references is able to achieve the desiderata briefly mentioned herein.  
           [0023]    Moreover, in comparison to conventional clean-in-place valves, wherein some of the patents discussed herein are illustrative, the air-blow valve of the present invention employs methods, disclosed in detail below, that have the effect of rendering unnecessary the removal of the present air-blow valve from any associated fluid-transport systems as well as from any fluid-treatment and/or fluid-processing facilities during valve cleaning.  
           [0024]    Further in view of inadequacies of the prior art patents, this invention is generally directed to the field of air-blow valves, connected to conventional fluid-treatment and/or fluid-processing facilities which, in turn, are associated with such conventional material-transport systems as liquid-product transport and/or solid-product transport systems.  
           [0025]    These and other features of the present invention, which will now be summarized, shall become apparent to those skilled in the art after reviewing this patent specification.  
         SUMMARY OF THE INVENTION  
         [0026]    An air-blow valve, configured for clean-in-place capability, comprises a hollow valve body, select valve components, and at least two conduits. The hollow valve body defines an internal chamber presenting an inner surface, an internal shoulder, an internal valve seat, and an internal fluid passageway. The select valve components, disposed in the valve body, include a piston disposed within the chamber, a spring, and a valve plug.  
           [0027]    The piston is so adapted and dimensioned relative to the inner surface of the chamber of the valve body as to be slidably engageable in a fluid-tight manner between first and second positions along the chamber inner surface. The spring, captively retained within the valve body, abuttingly engages the piston and the shoulder, for urging the piston into the first position. The valve plug, operatively connected to the piston, is configured (i) to engage the valve seat in a fluid-tight relationship when the piston is in the first position and (ii) to permit fluid flow between the valve plug and the valve seat when the piston is in the second position.  
           [0028]    One of the two conduits, which is in fluid communication with a pressurized-air source and operatively connected to the valve body, provides pressurized air to the chamber for urging the piston into the second position. The other of the two conduits, which is in fluid communication with a sanitizing-fluid source and separately connected to the valve body, provides a sanitizing fluid into a portion of the valve body, for sanitizing the valve seat, the valve plug, and the internal fluid passageway.  
           [0029]    Preferably, the hollow valve body (summarized above), includes at least two body portions, which define an interfit connection, wherein the interfitting body portions are detachably joined in an air-tight manner.  
           [0030]    Also in reference to the air-blow valve (summarized above), the internal chamber is preferably elongated and cylindrical, and the internal shoulder is preferably annular.  
           [0031]    Further in reference to the air-blow valve of the invention, the fluid passageway is preferably cylindrical, and the valve seat is preferably “quasi frusto-conical” in shape. This means that the valve seat resembles a frustum in that the valve seat, in sectional view, is seen to include the basal part of a cone-like shape formed by cutting-off the top (of the cone-like shape) via a plane parallel to the base. The valve seat is thus “quasi” frusto-conical in shape, for the reason that the valve seat, in the illustrated preferred embodiments, is configured to engage the valve plug in a fluid-tight relationship, when the piston is in the first position and the valve plug is operatively connected to the piston.  
           [0032]    Still further in reference to the air-blow valve of the present invention, the several valve components enumerated above are preferably characterized as further including an elongated valve stem which is disposed within the valve body. The elongated valve stem has opposite end portions. The piston is releasably affixed adjacent to one end portion of the stem, and the valve plug is mounted on the opposite end portion of the stem. Also, the spring, preferably helical, is captively retained in the valve body by the valve stem. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0033]    A clear understanding of the various advantages and features of the present invention, as well as the construction and operation of conventional components and mechanisms associated with the present invention, will become more readily apparent by referring to the exemplary, and therefore non-limiting, embodiments illustrated in the following drawings which accompany and form a part of this patent specification.  
         [0034]    [0034]FIG. 1 is a schematic illustration of the clean-in-place air-blow valve of the present invention, shown in its preferred environment for two possible applications.  
         [0035]    [0035]FIG. 2 is an isometric detailed view, on an enlarged scale relative to FIG. 1, of the clean-in-place air-blow valve of the present invention, shown operatively connected to a conventional shuttle valve.  
         [0036]    FIGS.  3 - 8  are a series of sequential cross-sectional views, all of which are presented on an enlarged scale relative to FIG. 1, of the clean-in-place air-blow valve of the present invention, shown operatively connected to the shuttle valve.  
         [0037]    [0037]FIG. 9 is a cross-sectional view, on an enlarged scale relative to FIG. 3, and with structure behind the planes  9 - 9  removed.  
         [0038]    [0038]FIG. 10 is a cross-sectional view, on an enlarged scale relative to FIG. 6, and with structure behind the planes  10 - 10  removed.  
         [0039]    Throughout the drawings, like reference numerals refer to like parts.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0040]    While the present invention is susceptible to embodiment in various forms, there is shown in the drawing FIGURES and hereinafter described in detail a number of presently preferred embodiments, with the understanding that this disclosure is to be considered as providing an example of the invention without limitation to the embodiments illustrated.  
         [0041]    Referring initially to FIG. 1, there is shown an air-blow valve  100  configured for clean-in-place capability. The air-blow valve  100  of the present invention is shown in a preferred environment for two possible applications. In particular, the clean-in-place (CIP) air-blow valve  100  is shown operatively connected to first and second tanks  102  and  104  to provide the tanks  102  and  104  with the ability to sample the tank contents as well as to provide each tank  102  and  104  with clean-in-place capability.  
         [0042]    The first tank  102  includes an inlet line  103  to allow a liquid material to be introduced into the first tank  102 . Tank contents are passed from the first tank  102  to the second tank  104  via a conduit  106  and a first pump  108 . The tanks  102  and  104  are provided with internal nozzles  109  configured and directed to provide a conventional clean-in-place solution from a source (not shown) to the inner surfaces of the tanks  102  and  104  via conduits  111 A and  111  B. From the second tank  104 , the tank contents are passed by a conduit  110  and second pump  112  to another location (not shown) for storage or further processing of the tank contents, as desired.  
         [0043]    To provide the illustrated tanks  102  and  104  with clean-in-place (CIP) capability, as was mentioned above, the air-blow valve  100  is preferably operatively coupled to a shuttle valve  114 , as is shown in FIG. 2. The shuttle valve  114  is preferably connected to a source (not shown) of pressurized air via a conduit  116 .  
         [0044]    After completing a transfer of liquid material from the first tank  102  to the next tank  104 , an outlet valve  118  of the first tank  102  is closed and the pump  108  is shut off. At this point, any liquid remaining in the line  106  is transferred into the next tank  104 . This is accomplished by injecting pressurized air via conduit  116  (FIG. 2) into the shuttle valve  114 , operatively coupled to the air-blow valve  100 . The pressurized air then passes through the air-blow valve  100  and into the conduit  106  (FIG. 1). As a result, the pressurized air pushes the liquid through the conduit  106  and into the next tank  104 .  
         [0045]    For product-sample mode, the tanks  102  and  104  are provided with side-mounted bottom valves  120  (FIG. 1). The side-mounted bottom valve  120  of the first tank  102 , for example, is operatively connected to one of the air-blow valves  100 . The air-blow valve  100  preferably includes a push knob  122  (FIG. 2), adapted for manual operation by plant personnel. When the knob  122  is pushed, a portion of the liquid contents of the tank  102  will flow freely through the side-mounted bottom valve  120  of tank  102  and into a sample container  124  until the push knob  122  is released. To achieve such a result, the side-mounted air-blow valve  100  is preferably connected to the clean-in-place (CIP) solution source (not shown) via a coupling  126  and an auxiliary CIP solution conduit  128 , both shown disconnected in FIG. 1. The second tank  104  is similarly equipped.  
         [0046]    Thus, whether in “sample” or CIP mode, the illustrated air-blow valve  100  is itself cleaned-in-place along with associated tanks and connecting conduits.  
         [0047]    Reference is next invited to FIGS.  3 - 10 , so that the clean-in-place air-blow valve  100  of the present invention may be discussed in detail. The illustrated clean-in-place air-blow valve  100  is preferably used in combination with a conventional shuttle valve  114  having a movable shuttle valve element  130 .  
         [0048]    The clean-in-place (CIP) air-blow valve  100  of the present invention comprises a hollow valve body  132  (FIGS.  3 - 8 ), valve components, and first and second conduits  131  and  133 . The hollow valve body  132  defines an internal chamber  134  (FIGS. 9 and 10) presenting an inner surface  136 , an internal shoulder  138  (FIG. 9), an internal valve seat  140  (FIG. 10), and an internal fluid passageway  142 . The internal chamber  134  is preferably cylindrical, and the internal shoulder  138  is preferably annular.  
         [0049]    The above-mentioned valve components, which are disposed within the valve body  132 , include a piston  144  (FIGS. 9 and 10), a biasing element such as a spring  146 , and a valve plug  148 . The piston  144  is disposed within the chamber  134 .  
         [0050]    The valve components further preferably include an elongated valve stem  145  disposed within the valve body  132  and having opposite end portions, wherein the push knob  122  is removably affixed to one end portion of the stem  145 , wherein the piston  144  is releasably affixed via a threaded connector  147  (FIGS. 9 and 10) adjacent to the one end portion of the stem  145 , and wherein the plug  148  is mounted on the opposite end of the stem  145 . The plug  148  is preferably removably mounted on stem  145  along end portion  184 , shown as dashed line in FIGS. 9 and 10. The spring  146 , disposed between the end portions of the valve stem  145 , is preferably helical and captively retained in the valve body  132  by the valve stem  145 .  
         [0051]    In the valve body  132 , the piston  144  is adapted and dimensioned relative to the inner surface  136  of the chamber  134  as to be slidably engageable in a fluid-tight manner between first and second positions therewithin. In the first position (FIG. 9), the piston  144  is spaced from an internal stop  150  and the valve plug  148  abuttingly engages the valve seat  140 . The preferred embodiment of the valve plug  148 , itself, has a vulcanized-rubber coating  148 A on the exterior of the valve plug  148  up to the dashed line  184  (FIGS. 9 and 10) between the valve stem  145  and the valve plug  148 , to provide a vulcanized rubber fluid-tight seal along the valve seat  140 .  
         [0052]    In the second position (FIG. 10), the valve plug  148  is spaced from the valve seat  140  and the piston  144  abuttingly engages the internal stop  150 . The first conduit  131 , in fluid communication with a pressurized-air source (not shown) is operatively connected to the valve body  132  via a conventional threaded nipple  135  (FIGS.  3 - 8 ), for providing pressurized air to the chamber  134  (FIGS. 9 and 10) for urging the piston  144  into the second position.  
         [0053]    In the valve body  132 , the spring  146  abuttingly engages the piston  144  and the shoulder  138 , for urging the piston  144  into the first position. The valve plug  148  is operatively connected to the piston  144 , as is described above. The valve plug  148  is configured to engage the valve seat  140  (FIG. 10) in a fluid-tight relationship (FIG. 9) when the piston  144  is in the first position and to permit fluid to flow between the valve plug  148  and the valve seat  140  (FIG. 10) when the piston  144  is in the second position.  
         [0054]    The fluid passageway  142  is preferably cylindrical, and the valve seat  140  is preferably “quasi frusto-conical” in shape. This means that the valve seat  140  resembles a frustum in that the valve seat  140 , in sectional view, is seen to include the basal part of a cone-like shape formed by cutting-off the top (of the cone-like shape) via a plane parallel to the base. The preferred valve seat  140  is thus “quasi” frusto-conical in shape, for the reason that the valve seat  140 , in the illustrated preferred embodiments, is configured to engage the valve plug  148  in a fluid-tight relationship, when the piston  144  is in the first position and the valve plug  148  is operatively connected to the piston  144 .  
         [0055]    The second conduit  133 , in fluid communication with a sanitizing-fluid source (not shown) is operatively connected to the valve body  132 , for providing a sanitizing fluid into a portion of the valve body  132 , for sanitizing the valve seat  140 , the plug  148 , a portion of the elongated valve stem  145 , and the internal fluid passageway  142 .  
         [0056]    The second conduit  133  and the valve body  132  each preferably include flanged ends  137  and  139 , enabling a conventional fluid-tight and leak-proof gasket  141  to be disposed therebetween. A conventional annular clamp  143  is circumferentially mounted on the flanged ends  137  and  139  of the valve body  132  and conduit  133 , for holding the valve body  132  and conduit  133  together in a fluid-tight manner.  
         [0057]    The second conduit  133  is in fluid communication with a sanitizing-fluid source (not shown) via a transfer line  149 . (The second conduit  133  and the transfer line  149  are shown in phantom line in FIGS.  3 - 8 .) The second conduit  133  is operatively connected to the valve body  132 , to provide a sanitizing clean-in-place (CIP) fluid into a portion of the valve body  132 , for sanitizing the valve seat  140 , the plug  148 , a portion of the valve stem  145  connected to the plug  148 , and the internal fluid passageway  142 .  
         [0058]    A third conduit  152  (FIGS.  3 - 8 ) may operatively be connected to the valve body  132  for the purpose of joining the shuttle valve  114  to the air-blow valve  100 , preferably by integrally joining the third conduit  152  to the valve body  132 . The third conduit  152  is also operatively coupled to the shuttle valve  114  via a fourth conduit  154  which is preferably integrally joined to the shuttle valve  114 . The third and fourth conduits  152  and  154  preferably include flanged end connections, enabling a conventional fluid-tight and leak-proof gasket  156  to be disposed therebetween. A conventional annular clamp  158  is circumferentially mounted on the flanged ends of the conduits  152  and  154 , for holding the conduits  152  and  154  together in a fluid-tight manner. The third conduit  152  is in fluid communication with a pressurized-air source (not shown) via the shuttle valve  114 . The shuttle valve element  130  is movable between first (FIGS. 3, 7 and  8 ) and second (FIGS. 5 and 6) positions for providing pressurized air to the internal fluid passageway  142  (FIG. 10) for urging the valve plug  148  away from the valve seat  140 .  
         [0059]    For the air-blow valve  100 , optional components or elements include O-rings  160  (FIGS. 9 and 10) circumferentially mounted in external grooves of the elongated valve stem  145 . For the air-blow valve  100 , the hollow valve body  132  may include two body portions  162  and  164  defining an interfit connection along the interfitting surface portions (FIGS. 9 and 10) thereof, wherein the interfitted body portions are detachably joined in an air-tight and fluid-tight manner. An annular retaining ring  166 , commercially available and made of metal, is preferably used in a conventional manner to hold the body portions  162  and  164  together. Another O-ring  186  is preferably included between the body portions  162  and  164  of the valve body  132  adjacent the retaining ring  166 . A conventional T-shaped air-exhaust port  168  (shown in cross section in FIGS. 9 and 10) is threaded into the side of body portion  164  to provide a path for air to exhaust from the chamber  134  when the piston  144  moves within the chamber  134 , enabling the piston  144  to engage the stop  150 .  
         [0060]    Additional optional elements or components shall now be discussed. The shuttle valve  114  includes an elongated hollow valve body  170  in which the moveable shuttle valve element  130  is longitudinally slideably engageable. A portion of the moveable shuttle valve element  130  is disposed through a helical spring  172 . An end portion of the shuttle valve element  130  carries a plate  174 . Opposed ends of the helical spring  172  engage an inner shoulder  176  and the plate  174  (FIG. 3). Movement of the shuttle valve element  130  ceases when plate  174  engages an internal stop  178 . Internal openings  180  permit pressurized air entering the shuttle valve  114  via the conduit  116  to enter the fluid passageway  142  via the conduits  152  and  154  when the shuffle valve element  130  is fully extended (FIGS. 5 and 6) by pressurized air. The shuttle valve  114  includes an air outlet  182  (shown in phantom line) for exhaust purposes.  
         [0061]    The air-blow function of the present invention shall now be summarized. To begin the air-blow function, pressurized air is introduced via the conduit  116  into the body  170  of the shuttle valve  114 , causing the valve element  130  to move to the right. (FIGS.  3 - 5 .) Prior to movement of the valve element  130 , note that the valve plug  148  of the air-blow valve  100  is seated, and that product is flowing in the process line  149 . As the valve element  130  moves, the spring  172  of the shuttle valve  114  is compressed. (Compare FIGS. 3 and 5.) The valve element  130  moves to the right until the plate  174  engages the internal stop  178 , at which time the outlet  182  of the shuttle valve  114  is sealed off (FIG. 5), and pressurized air enters the internal fluid passageway  142  of the air-blow valve  100  (FIG. 9) via the internal openings  180  of the shuttle valve  114  and the conduits  152  and  156  (FIG. 5) connecting the shuttle valve  114  to the air-blow valve  100 .  
         [0062]    Pressurized air in the internal fluid passageway  142  of the air-blow valve  100  causes the valve plug  148  to become spaced from the valve seat  140  (FIGS. 6 and 10), exhausting the pressurized air into the transfer line  149  (FIG. 6). Unseating the valve plug  148  (within the air-blow valve body  132 ) in this manner (FIG. 10) thus causes the piston  144  to compress the spring  146  within the air-blow valve  100  (FIGS. 6 and 10).  
         [0063]    When pressurized air to the shuttle valve  114  ceases (FIGS. 3, 6 and  7 ), the valve element  130  is moved to the left (FIGS. 7 and 8) by the force of the compressed helical spring  172  (FIGS. 5 and 6). Just prior to cessation of the pressurized air to conduit  116 , note that the valve plug  148  is seated (FIG. 6), and that immediately after cessation of the pressurized air into the internal chamber  142  of the air-blow valve  100  that the compressed spring  146  causes the valve plug  148  to seat (FIGS. 5 and 9) in the air-blow valve  100 . At such time, within the air-blow valve  100 , the valve plug  148 , the valve stem  145 , and the piston  144  return to their “normal” positions (FIG. 8), which is caused by the spring  146  urging the piston  144  and the shoulder  138  apart (FIG. 9).  
         [0064]    At this time, there will be product residue and air, from the air-blow valve  100 , within the conduit  133  and the process line  149 . (FIG. 3.) Preferably, the product transfer line  149  has been isolated from its associated process (not shown) prior to this air-blow operation, and the process line  149  has been drained or at least partially emptied.  
         [0065]    Just prior to CIP operations, note that the valve plug  148  is seated (FIG. 3), and that a conventional CIP sanitizing liquid is pumped through the product transfer line  149 . During clean-in-place of the transfer line  149 , there are certain times when it is desirable, within the air-blow valve  100 , to unseat the valve plug  148  so that the pressurized CIP solution within the process line  149  forcefully floods the internal fluid passageway  142 , a portion of the valve stem  145 , and the valve plug  148 , so as to clean and sanitize all of these wetted parts. (Compare FIGS. 3 and 7.) With valve plug  148  unseated (FIG. 7), the sanitizing fluid sanitizes the above-identified wetted parts, exits the air-blow valve  110 , and passes through the shuttle valve  114  via the drain port  182  to atmosphere.  
         [0066]    The clean-in-place (CIP) capability of the air-blow valve  100  of the present invention shall now be summarized. To begin, pressurized air is introduced via conduit  131  into the internal chamber  134  body, causing the spring  146  to become compressed and spacing the valve plug  148  from the valve seat  140 . (Compare FIGS. 9 and 10.) As the piston  144  moves within the internal chamber  134 , pressurized air is vented to atmosphere via the air exhaust port  168 . When the helical spring  146  is fully compressed (FIG. 10), the valve plug  148  is spaced from the valve seat  140 . Then pressurized CIP liquid is forced from process line  149  into the internal chamber  142 , cleaning the seat  140 , internal chamber  142 , plug  148  and stem  145 , and is discharged via outlet  182 , as described above. To stop CIP procedures, the pressurized air supplied via conduit  131  ceases, pressurized air is vented from the chamber  134  via the air exhaust port  168 , and the compressed spring  146  (FIG. 10) moves the piston  144  to the left (FIG. 9) until the plug  148  is seated, which ends the flow of CIP liquid into air-blow valve  100 .  
         [0067]    Note that the shuttle valve  114 , since it is operatively connected to the air-blow valve  100 , is able to permit the discharge of materials that may have originated with either the process line  149  or the compressed air that was introduced into the air-blow valve  100  via the conduit  131 . For example, during clean-in-place (CIP) sanitizing of the process line  149 , the valve plug  148  of the air-blow valve  100  will be unseated for a period of time that may range between about one second up to several minutes, as desired, during which time the liquid CIP sanitizing fluid will have passed through the air-blow valve  100  as well as through the outlet  182  of shuttle valve  114 .  
         [0068]    In this way, the clean-in-place procedures set forth in this patent specification, which result from preferred operation of the air-blow valve of the present invention, are able to take place without the need to disconnect process equipment.  
         [0069]    The “sample valve” feature of the invention, which enables sampling of fluid or product from a tank or process pipe into a sampling vessel, will now be summarized. If air-blow capability is required, the use of the air-blow valve  100  in conjunction with the shuttle valve  144  is suggested. Otherwise, only the air-blow valve  100  is suggested.  
         [0070]    To begin sampling, the air-blow valve  100  includes the knob  122 , permitting manual operation to compress the spring  146  and unseat (FIG. 10) the valve plug  148 . Pressurized air within the chamber  134  is vented via the outlet  168 . Releasing manual pressure on the knob  122  allows the compressed spring  146  to extend (FIG. 9) to seat the valve plug  148 .  
         [0071]    What has been illustrated and described herein is an air-blow valve, designed and configured to have clean-in-place capabilities. However, as the air-blow valve has been illustrated and described with reference to preferred embodiments, it is to be understood that the invention is not to be limited to these embodiments. In particular, and as those skilled in the relevant art can appreciate, functional alternatives will become apparent after reviewing this patent specification. Accordingly, all such functional equivalents, alternatives, and/or modifications are to be considered as forming a part of the present invention insofar as they fall within the spirit and scope of the appended claims.