Abstract:
An air-driven pump system comprising an efficiency valve. One or multiple efficiency valves integral to the pumping system prevent overfilling of the air chambers, thereby reducing the amount of air used by the system while decreasing the energy wasted by the system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Patent Application No. 61/341,160, filed on Mar. 29, 2010, and entitled “Air-Driven Fluid Pump System,” the content of which is relied upon and incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a pneumatically-driven equipment, and, more specifically, to an efficiency valve in that equipment. 
         [0004]    2. Description of the Related Art 
         [0005]    Pneumatically driven equipment typically relies on mechanically moving parts to operate. The equipment will typically split the inlet motive air into process air and control air, in which the process air is used to perform the work and the control air is used to control the direction or motion of the mechanical components. 
         [0006]    However, there is an inherent inefficiency that occurs in such air-driven equipment. The inefficiency is related to the reaction time or response time of the mechanical components as compared to the flow rate of both the process air and control air. In other words, the flow rate of the motive air far exceeds the velocity of the mechanical components because of friction losses and other dynamic losses acting on the mechanical components, created by the movement of the mechanical components. The inefficiency occurs when motive air is wasted by allowing it to continuously flow un-restricted into the pneumatic equipment when the process air has completed a first segment of work and the control air is mechanically moving components to a position that allows the process air to perform a second segment of work. 
         [0007]    An example of this inefficiency is illustrated in  FIGS. 1-3 , which depict a schematic representation of an air-operated piston pump having a general design. In  FIG. 1 , inlet motive air is split into process air and control air. Control air positions the directional valve piston  11  inside directional valve  10  by filling chambers  12 . Control air is also channeled out of chamber  12  and directional valve  10  and into pilot valve  40 , and is then directed through pilot valve piston  41  to be channeled back to directional valve  10 , thereby pressurizing chamber  13  in directional valve  10 . Although the control pressure is equal for both chambers  12  and  13 , the surface area of piston  11  on which the control pressure is acting is greater in chamber  13 , causing piston  11  to move and remain to the “left” in directional valve  10 . This allows the process air to pass through directional valve  10  and directional valve piston  11  and then be channeled to pump unit  30 , thereby expanding into air chamber  32 , acting on piston  31 , and moving piston  31  to discharge liquid from liquid chamber  33 . At the same time, movement of piston  31  toward the right pulls shaft  54 , thereby moving piston  21  inside pump unit  20 . Movement of piston  21  toward the other pump unit causes liquid to be drawn into liquid chamber  23  as once-used process air is released from air chamber  22  out of pump unit  20  and channeled through directional valve  10  and directional valve piston  11  to atmosphere. 
         [0008]    In  FIG. 2 , piston  21  engages and moves shaft  64 , which is connected to pilot valve piston  41  inside of pilot valve  40 . Movement of piston  21  moves shaft  64  and pilot valve piston  41  to a position that allows channeled control air to be released to atmosphere from chamber  13  inside directional valve  10 . Control air pressure in chamber  12  acts on directional valve piston  11 , moving directional valve piston  11  toward the right inside directional valve  10 . 
         [0009]    In  FIG. 3 , directional valve piston  11  in directional valve  10  is held stationary by the control air pressure in chamber  12  acting on directional valve piston  11 , thereby allowing process air to be channeled through directional valve  10  and directional valve piston  11  to pump unit  20 , where it expands into air chamber  22  as once used process air is released from air chamber  32  in pump unit  30 . The process air is further channeled through directional valve  10  and directional valve piston  11  to atmosphere, making pistons  21  and  31  and shaft  54  reverse their previous directions, thereby causing piston  21  to force liquid from liquid chamber  23  to discharge as piston  31  draws liquid into liquid chamber  33 . 
         [0010]    The inefficiency with the above-described design occurs during the transition from  FIG. 2  to  FIG. 3 . During the total time period that it takes moving pilot valve piston  41  in pilot valve  40  to move to a position that re-directs control air to or from directional valve  10  and directional valve piston  11  moves completely to its new position to allow process air to perform a new segment of work (from “left” in  FIG. 2  to “right” in  FIG. 3 ), process air is allowed to continue entering the air chamber (air chamber  32  in  FIG. 2 ) unrestricted, which overfills or over pressurizes the air chamber without additional liquid being discharged from it corresponding liquid chamber (liquid chamber  33  in  FIG. 2 ). This overfilling or over pressurizing of the air chamber is a waste of energy. 
         [0011]    There is, therefore, a continued need for pneumatically driven equipment such as air-driven liquid pumps that are more efficient and utilize less energy than previous designs. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    It is therefore a principal object and advantage of the present invention to provide a more efficient pneumatically driven pump. 
         [0013]    It is another object and advantage of the present invention to provide a pneumatically driven pump that utilizes less air for pumping. 
         [0014]    It is yet another object and advantage of the present invention to provide a pneumatically driven pump that utilizes less energy. 
         [0015]    Other objects and advantages of the present invention will in part be obvious, and in part appear hereinafter. 
         [0016]    In accordance with the foregoing objects and advantages, the present invention provides an air-driven piston pump comprising: (i) a directional unit that defines a directional air chamber and comprises a directional piston, a first process air intake, and a second process air intake; (ii) a first pump unit comprising a first liquid chamber, a first air chamber, and a first piston, where the first piston is located inside the first pump unit between the first liquid chamber and the first air chamber, and the first piston moves between a first position and a second position; (iii) a second pump unit comprising a second liquid chamber, a second air chamber, and a second piston, where the second piston is located inside the second pump unit between the second liquid chamber and the second air chamber, and the second piston is moveable between a first position and a second position; (iv) a first shaft affixed at one first end to the first piston and affixed at the other end to the second piston; (v) an efficiency unit comprising an efficiency piston, wherein the efficiency unit is configured to divide inlet air entering the air-driven piston pump into control air, first process air, and second process air, and wherein the efficiency piston is in communication with the control air, first process air, and second process air before the air is distributed to the directional unit; (vi) a second shaft which is in communication with the efficiency piston. In a preferred embodiment, the efficiency piston is moveable between a first position and a second position, where the first position allows control air to communicate with the directional unit air chamber, allows first process air to distribute to the first process air intake of the directional unit, and restricts second process air, thereby allowing restricted second process air to distribute to the second process air intake of the directional unit. In the second position, the efficiency piston allows control air to communicate with the directional valve air chamber, allows second process air to distribute to the second process air intake of the directional unit, and restricts first process air, thereby allowing restricted first process air to distribute to the first process air intake. The efficiency piston is preferably affixed to the second shaft at some location along the length of the second shaft. 
         [0017]    According to a second aspect of the present invention, the second shaft comprises a first end and a second end. The first end is located at least partially within the first pump unit and is positioned to communicate with the first piston when the first piston is in the second position. The second end is located at least partially within the second pump unit and is positioned to communicate with the second piston when the second piston is in the second position. In a preferred embodiment, when the first end of the second shaft is in communication with the first piston, the efficiency piston moves to the second position, and when the second end of the second shaft is in communication with the second piston, the efficiency piston moves to the first position. 
         [0018]    According to a third aspect of the present invention is provided an air-driven piston pump comprising: (i) a directional unit which defines a directional air chamber and comprises a directional piston, a first process air intake, and a second process air intake; (ii) a first pump unit comprising a first liquid chamber, a first air chamber, and a first piston, the first piston located inside the first pump unit between the first liquid chamber and the first air chamber and moveable between a first position and a second position; (iii) a second pump unit, the second pump unit comprising a second liquid chamber, a second air chamber, and a second piston, the second piston located inside the second pump unit between the second liquid chamber and the second air chamber and moveable between a first position and a second position; (iv) a first shaft affixed at a first end to the first piston and affixed at a second end to the second piston; (v) a first efficiency unit comprising a first process air inlet, a first process air outlet, and a first efficiency piston comprising a first efficiency piston shaft, where the first efficiency piston is moveable between a first position and a second position; (vi) a second efficiency unit comprising a second process air inlet, a second process air outlet, and a second efficiency piston comprising a second efficiency piston shaft, where the second efficiency piston is moveable between a first position and a second position; (vii) a pilot unit comprising a pilot piston, where the pilot piston is moveable to at least a first position and a second position; and (viii) a second shaft which is in communication with the pilot piston. 
         [0019]    According to a fourth aspect of the present invention, the second shaft of the above-described pump comprises a first end and a second end. The first end is located at least partially within the first pump unit and is positioned to communicate with the first piston when the first piston is in the second position. The second end of the second shaft is located at least partially within the second pump unit and is positioned to communicate with the second piston when the second piston is in the second position. In a preferred embodiment, when the first end of the second shaft is in communication with the first piston, the pilot piston moves to the second position, and when the second end of the second shaft is in communication with the second piston, the pilot piston moves to the first position. 
         [0020]    According to a fifth aspect of the present invention, at least a portion of the first efficiency piston shaft is located within the first pump unit and is positioned to communicate with the first piston when the first piston is in the second position. At least a portion of the second efficiency piston shaft is located within the second pump unit and is positioned to communicate with the second piston when the second piston is in the second position. Further, when the first efficiency piston shaft communicates with the first piston, the first efficiency piston moves to the second position and restricts the distribution of air through the first efficiency unit to the first process air intake of the directional unit. When the second efficiency piston shaft communicates with the second piston, the second efficiency piston moves to the second position and restricts the distribution of air through the second efficiency unit to the second process air intake of the directional unit. When the first efficiency piston shaft is no longer in communication with the first piston, the first efficiency piston moves to the first position and allows, or un-restricts, the full distribution of first process air through the first efficiency unit to the first process air intake of the directional unit. When the second efficiency piston shaft is no longer in communication with the second piston, the second efficiency piston moves to the first position and allows, or un-restricts, the full distribution of second process air through the second efficiency unit to the second process air intake of the directional unit. 
         [0021]    According to a sixth aspect of the present invention is provided an air-driven piston pump comprising: (i) a directional unit defining a directional air chamber and comprising a directional piston, a first process air intake, and a second process air intake, the directional piston moveable between a first position and a second position; (ii) a first stage pump unit, the first stage pump unit defining a first stage air chamber; (iii) a first pump unit, the first pump unit comprising a first liquid chamber, a first second stage air chamber, and a first piston, where the first piston is located inside the first pump unit between the first liquid chamber and the first second stage air chamber and is moveable between a first position and a second position; (iv) a second pump unit, the second pump unit comprising a second liquid chamber, a second second stage air chamber, and a second piston, where the second piston is located inside the second pump unit between the second liquid chamber and the second second stage air chamber and is moveable between a first position and a second position; (v) a first shaft affixed at a first end to the first piston and affixed at a second end to the second piston; (vi) a first stage piston located inside the first stage air chamber and affixed to the first shaft, wherein the first stage piston and the first shaft are moveable from a first position to a second position; (vii) a first efficiency unit comprising a first control air port, a first air inlet, a first process air outlet, and a first efficiency piston comprising a control air channel and a first efficiency piston shaft, where the first efficiency piston is moveable between a first position and a second position; and (viii) a second efficiency unit comprising a control air port, a second air inlet, a second process air outlet, and a second efficiency piston comprising a control air channel and a second efficiency piston shaft, where the second piston is moveable between a first position and a second position. 
         [0022]    According to a seventh aspect of the present invention, at least a portion of the first efficiency piston shaft is located within the first pump unit and is positioned to communicate with the first piston when the first piston is in the second position. Similarly, at least a portion of the second efficiency piston shaft is located within the second pump unit and is positioned to communicate with the second piston when the second piston is in the second position. In a preferred embodiment, when the first efficiency piston shaft communicates with the first piston, the first efficiency piston moves to the second position and restricts the distribution of first process air through the first efficiency unit to the first process air intake of the directional unit, and allows control air to communicate between the directional air chamber and first air chamber. Similarly, when the second efficiency piston shaft communicates with the second piston, the second efficiency piston moves to the second position and restricts the flow of second process air through the second efficiency unit to the second process air intake of the directional unit, and allows control air to communicate between the directional air chamber and the second air chamber. When the first efficiency piston shaft is no longer in communication with the first piston, the first efficiency piston moves to the first position and allows, or un-restricts, the full distribution of first process air through the first efficiency unit to the first process air intake of the directional unit and allows control air to communicate with the directional air chamber. When the second efficiency piston shaft is no longer in communication with the second piston, the second efficiency piston moves to the first position and allows, or un-restricts, the full distribution of second process air through the second efficiency unit to the second process air intake of the directional unit and allows control air to communicate with the directional air chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0023]    The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
           [0024]      FIGS. 1-3  represent an air-driven expansible chamber pump system of the prior art. 
           [0025]      FIGS. 4-6  represent an air-driven expansible chamber pump system of this invention. 
           [0026]      FIGS. 7-9  represent an alternative air-driven expansible chamber pump system of this invention. 
           [0027]      FIGS. 10-13  represent a 2 stage air-driven expansible chamber pump system of this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in  FIGS. 4-13  several air-driven pump systems according to embodiments of the present invention. Each air-driven pump system comprises an efficiency valve that allows pneumatic equipment to significantly reduce the energy waste associated with overfilling or over pressurizing during operation, as compared to prior art designs. 
         [0029]    The pump systems described herein have a multitude of different uses and utilities. For example, the pump systems described herein and claimed below can be used to pump a wide variety of liquids. In addition to liquids, the pump systems can pump any gas capable of being pumped, including air. Any reference to a “liquid” pump system should be construed to mean a pump system capable of pumping a liquid and/or a gas. 
         [0030]    It should be noted that while the Examples described herein refer to several different elements as a “piston,” these elements could also be a diaphragm component in other embodiments of the present invention. A diaphragm component would typically comprise a central diaphragm with a piston element located on either or both sides which perform(s) the functions of the pistons described in the Examples below. Further, it should be noted that in a preferred embodiment, each of the pistons described herein comprise a perimeter seal such as an o-ring or a sleeve to prevent leakage, although any mechanism of preventing leaking known in the art could be used. 
       Example 1 
       [0031]    The air-driven pump system described in Example 1 is shown in  FIGS. 4-6 . Starting with  FIG. 4 , inlet motive air enters the pneumatic pump. A small portion of the motive air is used as control air and is channeled to directional valve  210 , thereby pressurizing chamber  212  to act on the small surface area of directional valve piston  211  inside directional valve  210 . The balance of the inlet motive air enters efficiency valve  240  and is segmented into control air, left process air and right process. Control air passes through efficiency valve piston  241  and exits efficiency valve  240  and is channeled to pressurize chamber  213  in directional valve  210  acting on the large surface area of directional valve piston  211  inside directional valve  210 , moving and holding directional valve piston  211  to the left inside directional valve  210 . Left process air passes through efficiency valve piston  241  inside efficiency valve  240 , unrestricted in its flow rate. Right process air passes around efficiency valve piston  241  inside efficiency valve  240 , maximally restricted in its flow rate. Both left and right process air are channeled to directional valve  210 . Directional valve piston  211  inside directional valve  210  blocks maximally restricted right process air and allows unrestricted left process air to pass through and exit directional valve  210  and be channeled to pump unit  230  where it expands and pressurizes air chamber  232  causing piston  231  to displace liquid from liquid chamber  233 . At the same time, shaft  254  being connected to pistons  231  and  221  moves piston  221 , inside pump unit  220 , drawing liquid into liquid chamber  223  as once used process air is released from air chamber  222  out of pump unit  220  and channeled through directional valve  210  and directional valve piston  211  to atmosphere. 
         [0032]    In  FIG. 5 , toward the end of its stroke, piston  221  in pump unit  220  engages and moves shaft  264  which is connected to efficiency valve piston  241  inside of efficiency valve  240 . The movement of efficiency valve piston  241  un-restricts the exiting right process air out of efficiency valve  240  and maximally restricts the left process air flow rate out of efficiency valve  240 . 
         [0033]    In  FIG. 6 , efficiency valve piston  241  is moved to a position that allows channeled control air to be released to atmosphere from chamber  213  inside of directional valve  210 . Control air pressure in chamber  212  of directional valve  210 , acts on and moves directional valve piston  211  to the “right” inside of directional valve  210 . During the movement of directional valve piston  211 , maximally restricted left process air continues to flow at its maximally restricted flow rate through directional valve  210  and directional valve piston  211  channeled to air chamber  232  of pump unit  230 , reducing over filling or over pressurizing of air chamber  232 . Directional valve piston  211  is held stationary to the right inside directional valve  210  by the control air pressure in chamber  212 . Maximally restricted left process air exiting efficiency valve  240  is channeled to directional valve  210  and blocked by directional valve piston  211 . Unrestricted right process air exiting efficiency valve  240  is channeled through directional valve  210  and directional valve piston  211  to pump unit  220 , expanding into air chamber  222  as once used process air is channeled to atmosphere from air chamber  232  out of pump unit  230  and through directional valve  210  and directional valve piston  211 . Pistons  221 ,  231  and shaft  254  reverse their directions. Unrestricted right process air acts on piston  221  in pump unit  220  to discharge liquid from liquid chamber  223  as piston  231  in pump unit  230  draws liquid into liquid chamber  233 . 
       Example 2 
       [0034]    The air-driven pump system described in Example 2 is shown in  FIGS. 7-9 . Starting with  FIG. 7 , inlet motive air enters the pneumatic pump. A small portion of the motive air is used as control air and is channeled to directional valve  510 , pressurizing chamber  512  acting on the small surface area of directional valve piston  511  inside directional valve  510 . Also, control air is channeled out of chamber  512  and directional valve  510  and enters pilot valve  540  passes through pilot valve piston  541  and is channeled back to directional valve  510  where it pressurizes chamber  513  acting on the large surface area of directional valve piston  511 , moving and holding directional valve piston  511  to the left inside directional valve  510 . The balance of the inlet motive is segmented into left and right process air. Left process air enters efficiency valves  570 , passes around efficiency valve piston  571  and exits efficiency valve  570  unrestricted in its flow. Right process air enters efficiency valves  580 , passes around efficiency valve piston  581  and exits efficiency valve  580  maximally restricted in its flow. Both unrestricted left process air and maximally restricted right process air are channeled to directional valve  510 . Directional valve piston  511  inside directional valve  510  blocks maximally restricted right process air and passes through unrestricted left process air. Unrestricted left process air exits directional valve  510  and is channeled to pump unit  530  where it expands and pressurize air chamber  532  causing piston  531  to displace liquid from liquid chamber  533 . At the same time, shaft  554  being connected to pistons  531  and  521  moves piston  521  inside pump unit  520 , drawing liquid into liquid chamber  523  as once used process air is released from air chamber  522  out of pump unit  520  and channeled through directional valve  510  and directional valve piston  511  to atmosphere. 
         [0035]    In  FIG. 8 , toward the end of its stroke, piston  521  in pump unit  520  engages and moves efficiency valve piston  571  in efficiency valve  570 . Efficiency valve piston  571  moves to a position that maximally restricts left process air flow rate out of efficiency valve  570 . The maximally restricted left process air continues to be channeled to directional valve  510 . Right process air moves efficiency valve piston  581  inside efficiency valve  580 , allowing right process air to exit efficiency valve  580  unrestricted and continues to be channeled to directional valve  510 . Piston  521  in pump unit  520  also engages and move shaft  564  which is connected to pilot valve piston  541  inside of pilot valve  540 . 
         [0036]    In  FIG. 9 , pilot valve piston  541  in pilot valve  540  is moved to a position that allows channeled control air to be released to atmosphere from chamber  513  inside of directional valve  510 . Control air pressure in chamber  512 , moves directional valve piston  511  to the “right” inside of directional valve  510 . During the movement of directional valve piston  511 , maximally restricted left process air continues to flow at its maximally restricted flow rate channeled into air chamber  532  of pump unit  530 , reducing over filling or over pressurizing of air chamber  532 . Directional valve piston  511  is held stationary to the right inside directional valve  510  by the control air pressure in chamber  512  of directional valve  510 . Maximally restricted left process air exiting efficiency valve  570  is channeled to directional valve  510  and blocked by directional valve piston  511 . Unrestricted right process air exiting efficiency valve  580  is channeled through directional valve  510  and directional valve piston  511  to pump unit  520 , expanding into air chamber  522  as once used process air is channeled to atmosphere from air chamber  532  out of pump unit  530  and through directional valve  510  and directional valve piston  511 . Pistons  521 ,  531  and shaft  554  reverse their directions. Unrestricted right process air acts on piston  521  in pump unit  520  to discharge liquid from liquid chamber  523  as piston  531  in pump unit  530  draws liquid into liquid chamber  533 . 
         [0037]    While this example refers to an embodiment with two efficiency units, one for left process air and the other for right process air, an alternative single efficiency unit embodiment could process both left and right process air inclusive. Such an embodiment would, therefore, combine certain elements of, for example,  FIGS. 4 and 7 . 
       Example 3 
       [0038]    The air-driven pump system described in Example 3 is shown in  FIGS. 10-13 . Starting with  FIG. 10 , inlet motive air enters the pneumatic pump. The inlet motive air enters both efficiency valves  440 ,  460  and is segmented into control air, left process air and right process air by efficiency valve piston  441 ,  461  respectively. Control air passes through restrictive orifice inside efficiency valve piston  461  and exits efficiency valve  460  and is channeled to directional valve  410  where it enters and pressurizes chamber  412  acting on the directional valve piston  411 . Simultaneously, lower pressure once used left control air from second stage air chamber  422  in pump unit  420  enters efficiency valve  440  and passes around efficiency valve piston  441  exiting efficiency valve  440  and is channeled to directional valve  410  where it enters and pressurizes chamber  413  acting on directional valve piston  411 , allowing directional valve piston to move and be held to the left in directional valve  410 . Left process air passes around efficiency valve piston  441 , maximally restricted in its flow rate. Right process air passes through efficiency valve  460 , unrestricted in its flow rate by efficiency valve piston  461 . Both left and right process air are channeled to directional valve  410  from their respective efficiency valves  440 ,  460 . Directional valve piston  411  positioned to the left in directional valve  410 , blocks maximally restricted left process air and allows unrestricted right process air to pass through and exit directional valve  410 . Unrestricted right process air is then channeled to first stage pump unit  470  where it expands and pressurize first stage air chamber  473  acting on piston  471 . Pistons  471 ,  421  and  431  are conjoined by shaft  454 . Once used fixed volume left process air in first stage air chamber  472  of first stage pump unit  470  exits first stage pump unit  470  and is channeled through directional valve  410  and directional valve piston  411  to pump unit  420  where it expands into and pressurizes larger volume second stage air chamber  422  to a lower pressure acting on piston  421 . Both second stage air chamber  422  and first stage air chamber  472  are at equal lower pressures. Simultaneously, twice used right process air is released from second stage air chamber  432  out of pump unit  430  and channeled through directional valve  410  to atmosphere. The combined air pressure forces acting on pistons  471 ,  421  and  431 , all conjoined by shaft  454 , moves piston  471 ,  421  and  431  in a direction that displaces liquid from liquid chamber  423  in pump unit  420  and draws liquid into liquid chamber  433  in pump unit  430 . 
         [0039]    In  FIG. 11 , inlet motive air moves efficiency valve piston  441  in efficiency valve  440  allowing left process air to exit efficiency valve  440  unrestricted in its flow as it is channeled to directional valve  410  where it continues to be blocked by directional valve piston  411  in directional valve  410 . Control air passes through restrictive orifice inside efficiency valve piston  441  and exits efficiency valve  440  and is channeled to directional valve  410  where it continues to pressurize chamber  413  inside directional valve  410 . Control air passes through restrictive orifice inside efficiency valve piston  461  and exits efficiency valve  460  and is channeled to directional valve  410  where it continues to pressurize chamber  412  inside directional valve  410 . Both chambers  412 ,  413  in directional valve  410  are at equal pressures acting on directional valve piston  411  continuing to hold directional valve piston  411  to the left inside of directional valve  410 . Towards the end of its stroke, piston  431  in pump unit  430  engages and moves efficiency valve piston  461  inside efficiency valve  460 . Efficiency valve piston  461  in efficiency valve  460  is moved to a position that maximally restricts right process air flow rate out of efficiency valve  460  as it is channeled to directional valve  410 . 
         [0040]    In  FIG. 12 , efficiency valve piston  461  in efficiency valve  460  is moved to a position that redirects and releases channeled control air from chamber  412  in directional valve  410  through second stage air chamber  432  in pump unit  430  coupling with residual twice used right process air and then channeled through directional valve  410  to atmosphere. 
         [0041]    In  FIG. 13 , the combined control air pressure forces in chambers  412  and  413  of directional valve  410  act on and move directional valve piston  411  to the right inside of directional vale  410 . During the movement of directional valve piston  411 , maximally restricted right process air continues to flow at its maximally restricted flow rate channeled into first stage air chamber  473  of first stage pump unit  470 , reducing over filling or over pressurizing of first stage air chamber  473 . Directional valve piston  411  is held stationary by the control air pressure in chambers  412  and  413  inside directional valve  410 . Maximally restricted right process air exiting efficiency valve  460  and channeled to directional valve  410  is blocked by directional valve piston  411 . Unrestricted left process air exiting efficiency valve  440  and channeled to directional valve  410 , passes through directional valve piston  411  and directional valve  410  channeled to first stage pump unit  470  where it expands and pressurize first stage air chamber  472  acting on piston  471  in first stage pump unit  470 . Pistons  471 ,  421  and  431  are conjoined by shaft  454 . Once used fixed volume left process air in first stage air chamber  473  of first stage pump unit  470  exits first stage pump unit  470  and is channeled through directional valve  410  and directional valve piston  411  to pump unit  430  where it expands into and pressurizes larger volume second stage air chamber  432  to a lower pressure acting on piston  431 . Both second stage air chamber  432  and first stage air chamber  473  are at equal lower pressures. Simultaneously, twice used right process air is released from second stage air chamber  422  out of pump unit  420  and channeled through directional valve  410  to atmosphere. The combined air pressure forces acting on pistons  471 ,  421  and  431 , all conjoined by shaft  454 , moves piston  471 ,  421  and  431  in a direction that displaces liquid from liquid chamber  433  in pump unit  430  and draws liquid into liquid chamber  423  in pump unit  420 . Simultaneously, lower pressure once used right control air from second stage air chamber  432  in pump unit  430  enters efficiency valve  460  and passes around efficiency valve piston  461  exiting efficiency valve  460  and is channeled to directional valve  410  where it enters and pressurizes chamber  412  acting on directional valve piston  411 , allowing directional valve piston  411  to remain held to the right in directional valve  410 . 
       DEFINITIONS 
       [0042]    The following definitions are provided for claim construction purposes: 
         [0043]    The word “restrict” does not mean to shut off completely. Accordingly, if a flow is “restricted,” the flow is not completely shut off. 
         [0044]    Present invention: means “at least some embodiments of the present invention,” and the use of the term “present invention” in connection with some feature described herein shall not mean that all claimed embodiments include the referenced feature(s). 
         [0045]    Embodiment: a machine, manufacture, system, method, process and/or composition that may (not must) be within the scope of a present or future patent claim of this patent document; often, an “embodiment” will be within the scope of at least some of the originally filed claims and will also end up being within the scope of at least some of the claims as issued (after the claims have been developed through the process of patent prosecution), but this is not necessarily always the case; for example, an “embodiment” might be covered by neither the originally filed claims, nor the claims as issued, despite the description of the “embodiment” as an “embodiment.” 
         [0046]    Although the present invention has been described in connection with a preferred embodiment, it should be understood that modifications, alterations, and additions can be made to the invention without departing from the scope of the invention as defined by the claims.