Patent Publication Number: US-9885599-B2

Title: Nozzle adapter for volumetric test and measurement apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/729,397, filed Nov. 22, 2012, hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to bottom drain liquid proving systems, including provers used to calibrate volume meters on gasoline and diesel pumps at filling stations, and nozzle adapter assemblies for gasoline and diesel nozzles used with liquid dispensing pumps. 
     BACKGROUND OF THE INVENTION 
     Liquid proving systems utilizing a bottom drain liquid prover that drains into a liquid holding tank can be used to prove the accuracy of the reading displayed on a liquid dispensing pump. U.S. Pat. No. 7,874,195 (to Murnane, Jr.; also Canadian Patent No. 2,626,280) and U.S. Patent Application Publication No. 2012/0137750 (to Murnane, Jr. et al.; also Canadian Patent No. 2,727,049) describe the art of proving systems that can be used, in particular, to prove gasoline and diesel pumps at filling (gas) stations (or gas bars) where top-fill and bottom-drain provers are used. Top-fill and bottom-drain provers (test measures) are conveniently used in these small volume applications (typically five gallons (20 liters) or less) since existing standards and convention dictate use of such provers. Combined top-fill or bottom-fill and bottom drain provers are limited in use in known proving systems to large volume meter applications, such as metered filling of gasoline tanker trucks, where a single proving measurement is performed, after which the large volume combined top-fill or bottom-fill and bottom-drain prover is emptied back into the tank from which the liquid was drawn. These combined top-fill or bottom-fill provers typically range in capacity from 500 gallons (1,500 liters) to 1,500 gallons (5,000 liters). Such large volume single proving measurement applications are contrasted with existing small volume top-fill and bottom-drain applications that drain to a directly connected liquid holding tank so that multiple proving measurements can be performed before the liquid holding tank must be emptied back into the tank from which the liquid was drawn. 
     Illustrated in  FIG. 1( a )  is known liquid prover system  101 . Bottom drain prover  100  is installed near a front end of liquid holding tank  200  with the interior of the prover&#39;s drain section  100   c  connected to the interior of liquid holding tank  200  via drain valve  100   d . Bottom drain prover  100  typically has a narrow upper neck  100   a  with fill opening  100   a ′ for filling the prover with liquid from the liquid dispensing pump, a wider diameter body section  100   b  for accumulating and holding the bulk of the liquid pumped into the prover, and a narrow drain section  100   c  with a drain opening. Drain valve  100   d  is provided for controlling release of the accumulated liquid from the prover via drain valve lever mechanism  100   d ′ (shown in  FIG. 1( b ) ). The prover&#39;s volume gauge or indicator can be a gauge glass tube  100   e  that has its interior volume connected to the interior volume of neck  100   a . The gauge glass is marked along its height with a neck scale that reflects the capacity of liquid in the above prover when drain valve  100   d  is closed and the prover is filled with liquid up to the neck region of the prover. The nominal capacity of the prover, and deviations therefrom, are marked on the scale using standards that are established by the applicable standards organizations. Use of the prover is as disclosed in U.S. Pat. No. 7,874,195. Vapor conduit  400  connects the interior volumes of neck  100   a  and tank  200  so as to form a closed path for vapors in prover  100  and tank  200 . The combination of nozzle sealing gasket  900  and nozzle removed self seal assembly  320  minimizes the release of vapors from top-fill opening  100   a ′ regardless of whether or not the dispensing pump&#39;s nozzle is inserted into the fill opening. Ambient air vent  420  allows ambient (atmospheric) pressure equalization in the liquid holding tank as the tank is filled with liquid drained from the prover, and emptied via the tank&#39;s discharge line  200   a  and discharge control valve  200   b.    
       FIG. 1( b )  illustrates three of the liquid prover systems shown in  FIG. 1( a )  connected to common support structure  920 . 
       FIG. 3( a )  illustrates nozzle removed self seal assembly  320  used with the prover system shown in  FIG. 1( a ) . The nozzle removed self seal assembly comprises sealing plate  340  ( FIG. 4 ), which is in the shape of an annular disk with an annulus or through opening  340   a , and through opening self sealing assembly  360  ( FIG. 5  with sealing plate  340  shown in dashed lines), which opens when a dispensing pump&#39;s nozzle is inserted in the through opening and closes when the nozzle is withdrawn from the through opening. The diameter of the through opening is identified as “d” in  FIG. 3( a ) . Generally through opening  340   a  is limited in size to the outer dimension of the nozzle to be inserted into the through opening with additional clearance as required for nozzle insertion into the through opening. 
     In  FIG. 3( a ) , nozzle sealing gasket  900  is seated adjacently above nozzle removed self seal assembly  320  to form a combination prover fill opening self sealing assembly wherein the nozzle sealing gasket  900  primarily prevents release of vapors through the fill opening when a nozzle is inserted in opening  900   a  in gasket  900 , and closed flapper door  360   a  in the nozzle removed self seal assembly  320  prevents release of vapors through the fill opening when a nozzle is not inserted through opening  340   a  in sealing plate  340 . Nozzle sealing gasket  900  has opening  900   a , which is sufficiently large in cross section (shown as diameter “d 1 ” in  FIG. 3( a ) ) to push a nozzle through while substantially maintaining a vapor seal between the perimeter of opening  900   a  and the exterior section of the nozzle pushed through opening  900   a . As shown in  FIG. 3( b ) , alternative nozzle sealing gasket  900 ′ may be of an annular ring shape and positioned within through opening  340   a  as shown in  FIG. 3( a ) . 
       FIG. 5  illustrates through opening self sealing assembly  360  that can be used with the prover system shown in  FIG. 1( a ) . The through opening self assembly comprises flapper door  360   a , self-closing spring loaded hinge  360   b , and shim  360   c  as shown in  FIG. 6( a ) ,  FIG. 6( b )  and  FIG. 6( c ) , respectively. Flapper door  360   a  is located on the side of sealing plate  340  that faces the interior of the prover&#39;s neck volume, and positioned so that the flapper door is seated over the entire through opening  340   a  when a nozzle is not positioned in the through opening, thus providing a seal to prevent release of vapors through the fill opening to atmosphere. Flapper door  360   a  is attached to first wing  360   b ′ of self-closing spring loaded hinge  360   b  while the second wing  360   b ″ is suitably attached to shim  360   c , which, in turn, is suitably attached to sealing plate  340  as seen in  FIG. 3( a ) . The first and second wings are suitably connected to spring  370  of the self-closing spring loaded hinge. Therefore the flapper door ensures that vapors are not released from the neck of prover  100  to atmosphere unless a dispensing pump&#39;s nozzle is inserted into the sealing plate&#39;s through opening  340   a . Inserting the nozzle into the through opening will force the spring loaded flapper door to open against the inserted nozzle. Preferably the diameter of through opening  340   a  is sufficiently large enough to allow easy passage of the nozzle, or a range of nozzles, intended to be used with the prover, without excess release of vapors though any clearance space between the through opening and the outer diameter of the nozzle. 
     The combination of nozzle sealing gasket  900  and nozzle removed self seal assembly  320  minimizes the release of vapors from fill opening  100   a ′ regardless of whether the dispensing pump&#39;s nozzle is inserted into the fill opening. 
     Ambient air vent  420  ( FIG. 1( a )  and  FIG. 1( b ) ) is generally located near the (rear) end of liquid holding tank  200  that is opposite the (front) end near where prover  100  is located. 
     As illustrated in  FIG. 1( a ) ,  FIG. 2( a )  and  FIG. 2( b )  breather cap assembly  300  can be disposed over nozzle sealing gasket  900  and nozzle removed self seal assembly  320  when prover  100  is not being used for extended periods, for example, when the prover is being transported between gas stations. As seen in  FIG. 2( c ) through 2( e ) , through opening  900   a  in nozzle sealing gasket  900  is smaller than the through openings  300   a ′ and  100   f  in bayonet flange  300   a  and prover&#39;s neck flange  100   f . Further opening  900   a  is sized to form a tight fit around the exterior of a pump&#39;s nozzle that is inserted through the opening. Typical nozzle sealing gasket  900  comprises a flexible material, such as a rubber composition, at least around through opening  900   a  so that the gasket seals around the nozzle inserted through opening  900   a.    
     Liquid prover system  101  as described above and in U.S. Pat. No. 7,874,195 results in an improved accuracy particularly when the liquid is highly volatile. It is an object of the present invention to provide a liquid prover with an improved vapor elimination system that results in greater accuracy than that of the liquid proving system described above when the bottom-drain prover is connected to a liquid holding tank. 
     It is another object of the present invention to provide a liquid proving system with a selectable top-fill or bottom-fill and bottom-drain prover that can be used in small volume proving applications. 
     It is another object of the present invention to provide a liquid proving system with a bottom-fill and bottom-drain prover that can be used in small volume proving applications. 
     It is another object of the present invention to provide a nozzle adapter assembly that can be used with nozzles, including automatic shut-off nozzles, that are used with liquid dispensing pumps. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect the present invention is apparatus for, and process of, measuring a volume of liquid with a small volume bottom drain liquid proving system. The small volume bottom drain prover is a combined top-fill and bottom-fill prover, or a bottom-fill prover without top-fill. The small volume bottom drain prover has an upper section for receiving the liquid when the top-fill option is used, an intermediate section for accumulating liquid pumped into the prover, and a small volume bottom drain section for draining accumulated liquid from the prover into a liquid holding tank and receiving the liquid when the bottom-fill is used. A prover gauge or indicator is in communication with the interior volume of the prover to measure a volume of liquid pumped into the prover. A vapor conduit is provided between the upper section of the prover and the interior volume of the liquid holding tank to establish a saturated vapor environment in the interior volume of the prover with a vapor tank baffle assembly. 
     If the optional top-fill is provided, a prover fill opening self sealing assembly is disposed over the top opening in the upper section of the prover through which liquid is pumped into the prover. The prover fill opening self sealing assembly has a self sealing opening that opens when a liquid dispensing nozzle is pushed against the self sealing opening and forms a substantially vapor tight seal around the nozzle. 
     A vent connects the interior volume of the liquid holding tank to atmosphere and a liquid holding tank controlled fill volume is provided in the liquid holding tank to ensure saturated vapor remains in the fluid loop defined by the liquid holding tank controlled fill volume, the vapor conduit and the bottom-drain prover. 
     A nozzle adapter assembly can be provided so that a nozzle, including an automatic shut-off nozzle, used with the liquid dispensing pump can be used directly with a bottom-fill prover of the present invention or other test and measurement equipment. 
     The above and other aspects of the invention are set forth in this specification and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing brief summary, as well as the following detailed description of the invention, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary forms of the invention that are presently preferred; however, the invention is not limited to the specific arrangements and instrumentalities disclosed in the following appended drawings. 
         FIG. 1( a )  is a simplified cross sectional elevation view of an existing top-fill and bottom-drain liquid prover with the prover&#39;s drain connected to a liquid holding tank. 
         FIG. 1( b )  is an isometric view of three bottom-drain liquid provers shown in  FIG. 1( a ) , with their dedicated separate liquid holding tanks connected to a common support structure. 
         FIG. 2( a )  is a side elevation view of a breather cap assembly used with the prover system shown in  FIG. 1( a ) . 
         FIG. 2( b )  is a side elevation exploded view of the prover fill opening self sealing assembly and breather cap assembly used with the prover system shown in  FIG. 1( a ) . 
         FIG. 2( c ) ,  FIG. 2( d )  and  FIG. 2( e )  are top views of a bayonet flange used with the breather cap assembly; nozzle sealing gasket; and prover&#39;s neck flange, respectively. 
         FIG. 3( a )  is a prover top-fill opening self sealing assembly used with the prover system shown in  FIG. 1( a ) . 
         FIG. 3( b )  is one alternative prover top-fill opening self sealing assembly that can be used with the prover system shown in  FIG. 1( a ) . 
         FIG. 4  is one example of a sealing plate used in a nozzle removed self seal assembly that forms a part of the prover top-fill opening self sealing assembly shown in  FIG. 3( a ) . 
         FIG. 5  is one example of a through opening self sealing assembly that forms a part of the nozzle removed self seal assembly shown in  FIG. 4 . 
         FIG. 6( a ) ,  FIG. 6( b )  and  FIG. 6( c )  illustrate components of the through opening self sealing assembly shown in  FIG. 5   
         FIG. 7( a )  is an isometric view of one example of a combined top-fill or bottom-fill and small volume bottom drain liquid prover of the present invention used in one example of a proving system of the present invention. 
         FIG. 7( b )  is a simplified cross sectional elevation view of one example of the small volume bottom drain liquid proving system shown in  FIG. 7( a ) . 
         FIG. 8( a )  is a detail isometric view of one example of a bottom-fill assembly used with the liquid proving system shown in  FIG. 7( a )  and  FIG. 7( b ) . 
         FIG. 8( b )  is an exploded view of the bottom-fill assembly shown in  FIG. 8( a ) . 
         FIG. 8( c )  is a detail isometric view of another example of a bottom-fill assembly used with the liquid proving system shown in  FIG. 7( a )  and  FIG. 7( b ) . 
         FIG. 9( a )  is an isometric view of one example of an automatic shut-off nozzle adapter assembly used in the present invention. 
         FIG. 9( b )  is an isometric exploded view of the automatic shut-off nozzle adapter assembly shown in  FIG. 9( a ) . 
         FIG. 9( c )  is a cross section elevation view of the automatic shut-off nozzle vacuum tube sensing port interface component used in the automatic shut-off nozzle adapter assembly shown in  FIG. 9( a )  and  FIG. 9( b ) . 
         FIG. 9( d )  is a cross sectional elevation view of the automatic shut-off nozzle adapter assembly shown in  FIG. 9( a )  and  FIG. 9( b )  with a nozzle&#39;s spout inserted therein. 
         FIG. 9( e )  is a cross sectional view of a cam lock fluid fitting. 
         FIG. 10( a )  and  FIG. 10( b )  are isometric views of an automatic shut-off nozzle shown relative to an exploded view and assembled view, respectively, of the automatic shut-off nozzle adapter shown in  FIG. 9( a )  and  FIG. 9( b ) . 
         FIG. 11( a )  is the detail isometric view of the bottom-fill assembly shown in  FIG. 8( a )  when used with a liquid dispensing pump&#39;s hose. 
         FIG. 11( b )  is the detail isometric view of the bottom-fill assembly shown in  FIG. 8( a )  when used with an automatic shut-off nozzle and nozzle adapter assembly shown in  FIG. 9( a ) . 
         FIG. 11( c )  is a detail isometric view of another example of a bottom-fill assembly when used with the automatic shut-off nozzle and nozzle adapter assembly shown in  FIG. 9( a ) . 
         FIG. 12( a )  is a partial isometric view of a liquid proving system of the present invention illustrating one example of a liquid holding tank baffle assembly shown in a tank cut-out view as used in a liquid proving system of the present invention. 
         FIG. 12( b )  is the liquid holding tank baffle assembly shown in  FIG. 12( a )  when it is removed from the liquid holding tank. 
         FIG. 12( c )  is a top view of the liquid holding tank baffle assembly shown in  12 ( b ). 
         FIG. 13( a )  through  FIG. 13( d )  illustrate fluid and vapor flow within and around the liquid holding tank baffle assembly as the liquid holding tank fills. 
         FIG. 14  is an isometric view of another example of the small volume bottom drain liquid proving system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, wherein like numerals indicate like elements there is shown in  FIG. 7( a )  and  FIG. 7( b )  one example of liquid prover system  10  of the present invention. The liquid prover system in this example comprises (test measure) prover  12  and liquid holding tank  14 . 
     In some examples of the present invention prover  12  is similar to prover  100  described above with the addition of bottom-fill assembly  20  in modified drain section  100   c ′. Bottom-fill assembly  20  used in this example is best seen in  FIG. 8( a )  and  FIG. 8( b ) . In general bottom-fill assembly  20  is a tubular assembly with its interior opening (through passage) having a first (prover) end into drain section  100   c ′ of prover  12 , which is located above drain valve  100   d . The interior of the second (supply) end of the bottom-fill assembly that opposes the first end is connected to a supply of liquid (such as gasoline) that is being volumetrically measured by the prover system as further described below. In this example of the invention, the first end of the bottom-fill assembly is at a horizontal height H 1  that is higher than the horizontal height H 2  of the second end of the bottom-fill assembly. In other examples of the invention, the horizontal height H 1  may be lower than the horizontal height H 2  of the second end of the bottom-fill assembly as illustrated in  FIG. 8( c )  with elbow fitting  22   d , for example, when the nozzle adapter assembly  70 , as further described below and illustrated in  FIG. 11( c )  with elbow fitting  22   d , is used. In all examples of the invention, it is preferable that at least the check valve  24  is disposed at a lower height than the first (prover) end of the bottom-fill assembly to prevent the trapping of air in the bottom-fill assembly (between the first (prover end) and the check valve) when an optional top-fill is utilized. 
     In this particular example in  FIG. 8( a )  and  FIG. 8( b )  elbow assembly  22  comprises fittings  22   a ,  22   b  and  22   c  and is provided as a matter of convenience to provide a satisfactory position of the bottom-fill assembly relative to other components of the prover system. In this example of the invention, fittings  22   a  and  22   c  are pipe sections suitably connected to elbow fitting  22   b . Fitting  22   c  is connected to the outlet of check valve  24  that prevents back flow of the liquid in the prover that was supplied from the second (supply) end (H 2 ) of assembly  20  to the first end (H 1 ) of the assembly when a bottom-fill prover measurement is performed. Interconnect fitting  26  is connected at a first end to the inlet of check valve  24  and at a second opposing end to the first end of liquid flow control device  28 . The second end of liquid flow control device  28  is connected to liquid supply locking device  90  at the second (supply) end of the bottom-fill assembly. During bottom-fill proving measurements, the second (prover) end of liquid supply adapter  91  (as shown in  FIG. 11( a ) ) or nozzle adapter assembly  70  (as shown in  FIG. 11( b )  or  FIG. 11( c ) ) is locked into liquid supply locking device  90 . Normally the end fitting of the gas pump&#39;s hose  92  would interface with a nozzle when the gas pump is used to supply gasoline to the filler neck of an automobile&#39;s fuel tank. In use with the bottom-fill assembly, the nozzle is removed from the end fitting of the gas pump&#39;s hose (typically a male/female screw thread interface) and the first end of the liquid supply adapter  91  is connected to the end fitting of the gas pump&#39;s hose  92 . Flow control device  28  can be any device that suitably controls flow of the liquid through the bottom-fill assembly, for example, a ball valve. In this example, flow control device  28  has a flow control lever mechanism  28   a  for opening or closing the valve. Fittings  22   a ,  22   b  and  22   c  are not necessarily used in other examples of the invention, and the check valve and flow control device (if used) may be directly or otherwise connected to each other. A device for preventing back flow, such as check valve  24  is the required component in the bottom-fill assembly. Liquid supply locking device  90  at the second end of the assembly, can be any type of locking device, for example, an external clamping lock that clamps either to a liquid supply adapter  91 , as further described below or a nozzle adapter assembly  70 , as further described below. As mentioned above in some examples of the invention, at least the liquid supply locking device  90  (and optional flow control device  28 ) can be oriented at an angle above horizontal so that the liquid supply can enter the liquid supply locking device  90  in a downwards direction, for example, when a pump&#39;s nozzle is used and it is desired to point the spout of the nozzle in a downward direction before dispensing liquid from the liquid dispensing pump. As mentioned above it is always preferable that the check valve is disposed at angle below horizontal to avoid trapping air in the bottom-fill assembly between the check valve and its first (prover) end. 
     Use of liquid supply adapter  91  requires removal of the nozzle that is used with the liquid dispensing pump being proved with the prover system of the present invention. If the nozzle is, for example, an automatic shut-off nozzle (with or without stage II vapor recovery), the nozzle may not interface directly with bottom fill assembly  20 . An automatic shut-off nozzle utilizes a vacuum tube sensing port near the tip of the dispensing end of the nozzle&#39;s spout. For a stage II vapor recovery nozzle, vapor recovery holes will also be present on the spout. The vacuum tube sensing port comprises one or more openings  82  in the outer perimeter of spout  84  of the automatic shut-off nozzle  80  as shown in  FIG. 10( a ) . In order to dispense a liquid (such as gasoline) from the nozzle, the opening(s) of the sensing port (and, if used, the stage II vapor recovery holes) need to be in communication with a supply of air (ambient) since the automatic shut-off components inside the nozzle depend upon vacuum suction intake of air to enable normal gasoline dispensing. In normal operation, for example, when the spout is inserted into the filler neck of an automobile&#39;s fuel tank the automatic shut-off activates when gasoline supplied from the spout begins to rise in the filler neck to block air to the sensing port and enables the automatic shut-off of gasoline from the spout. If, for example, the spout of an automatic shut-off nozzle is inserted directly into the first (supply) end of the liquid supply locking device  90  in the above example of the invention, supply air would be blocked from the sensing port on the spout of the nozzle and it would not be possible to disable the automatic shut-off of the nozzle so that gasoline could be supplied to prover  12 . 
     It is another object of the present invention to provide apparatus and method for defeating the automatic shut-off of a nozzle when the nozzle is being used with a test or measurement apparatus, such as a liquid prover of the present invention.  FIG. 9( a )  illustrates one example of a nozzle adapter assembly  70  of the present invention. As further illustrated in  FIG. 9( b )  assembly  70  in this example comprises: a spout lock fitting  70   a ; a spout sensing port interface fitting  70   b ; and a prover (or other test or measurement) dock fitting  70   c . Supplemental sealing elements between these fittings, such as O-rings  76 ′ and  76 ″ can be provided as required. Optional spout lock fitting  70   a  provides a means for locking (sealing) spout  84  of a nozzle into the interior through opening of assembly  70 . Any suitable locking mechanism, such as a camlock fluid fitting  72  as illustrated in  FIG. 9( e )  can be used. Prover dock fitting  70   c  is configured to lock (seal) in the second (supply) end of supply liquid locking device  90  in the bottom-fill assembly (or other test and measurement apparatus). Spout sensing port interface fitting  70   b  enables a supply of ambient air to the spout sensing port (opening(s)  82 ) on the spout when an automatic shut-off nozzle is inserted into spout lock fitting  70   a  (with or without stage II vapor recovery holes) in order to dispense a liquid from the automatic shut-off nozzle as disclosed in the previous paragraph. One example of spout sensing port interface fitting  70   b  is illustrated in cross section in  FIG. 9( c )  and  FIG. 9( d ) . An annular air intake plenum  70   d  is provided in fitting  70   b . The annular ambient air intake plenum has one or more air passages  70   e  in communication with internal annular air plenum  70   f  provided within axial distance d 9  of spout sensing port interface fitting  70   b . As shown in  FIG. 9( d )  when spout  84  is properly inserted into nozzle adapter assembly  70  the spout sensing port  82  is in communication with internal annular air plenum  70   f  so that a supply of ambient air is maintained to the spout sensing port and dispensing of gasoline through the nozzle&#39;s spout is possible and enabled without enabling automatic shut-off of liquid flow through the nozzle. A spout insert stop ledge  70   c ′ can be provided in prover dock fitting  70   c  so that the tip of an inserted spout butts up against ledge  70   c ′ to ensure that the spout sensing port  82  (and, if used, stage II vapor recovery holes) is in communication with internal annular plenum  70   f . Therefore nozzle adapter assembly  70  allows proving the meter on the dispensing pump with the pump&#39;s nozzle installed as in normal operation with the liquid proving system of the present invention as shown in  FIGS. 10( b ) and 11( b ) . As mentioned above, when any nozzle is used, it may be preferably to have the nozzle spout point downwards for entry into the nozzle adapter assembly as shown in  FIG. 11( c ) . In these examples of the invention the bottom-fill assembly can be arranged with at least the liquid supply locking device  90  disposed at an angle above horizontal. Alternatively nozzle adapter assembly  70  can incorporate an elbow section that allows the spout entry to the nozzle adapter assembly be positioned at an angle above horizontal as shown in  FIG. 11( c )  with elbow fitting  22   d.    
     Liquid holding tank  14  is similar to liquid holding tank  200  described above in that it contains an interior mid-tank vertically oriented anti-slosh baffle  210  and liquid level float switch  212 . Anti-slosh baffle  210 , which is visible in the liquid holding tank cross section in  FIG. 7( b )  and the liquid holding tank cutout detail in  FIG. 12( a ) , is not related to proving measurements of the present invention; it is provided to dampen lateral liquid sloshing oscillations when prover system  10  is mounted on a movable structure, such as the bed of a pickup truck. Liquid float switch  212  is visible in the liquid holding tank cross section in  FIG. 7( b )  and is shown in alternate tank empty (solid lines) and tank full (dashed lines) positions. The switch in the tank&#39;s interior gives an operator an indication of when the tank is full and requires emptying via discharge line  200   a  and discharge valve  200   b.    
     Unlike prior liquid holding tank  200 , liquid holding tank  14  contains tank baffle assembly  40 , which is shown in  FIG. 12( b )  and installed in liquid holding tank  14  in  FIG. 12( a ) . In this example of the invention, tank baffle assembly comprises forward plate  40   a , rear plate  40   b , interior lower plate  40   c  and exterior lower plate  40   d . Side tabs  40   a ′,  40   b ′ and  40   d ′ provide one method of attaching the forward, rear and exterior lower plates to the interior sides of liquid holding tank  14 , and the rear plate&#39;s top to the interior top of the liquid holding tank. In this example, when installed in tank  14 , rear plate  40   b  is oriented vertically in the tank and is positioned behind the end of vapor conduit  400  opening  400   a  into liquid holding tank  14 . Interior lower plate  40   c  is in contact with the surface of the rear plate facing the vapor conduit opening at interior lower plate end tabs  40   c ′ at an interior lower plate distance above the lower edge of the rear plate. The surface of the interior lower plate  40   c  facing the vapor conduit opening forms an obtuse angle with the upper surface S, of rear plate  40   b , and the open space between end tabs  40   c ′ establishes liquid spillway opening  42 . The lower edge of interior lower plate  40   c  is connected at an angle to the lower edge of forward plate  40   a , which may be, for example, at a 90 degree angle, with the forward plate being oriented (tilted) off of vertical in a direction away from the vertical rear plate, and located under the interior opening of the prover&#39;s drain section  100   c ′ so that when liquid is in the prover and drain valve  100   d  is open, liquid from the prover splashes on to the angled surface, S″, of forward plate  40   a  to cause a turbulent flow that disperses the liquid and enhance saturated vapor formation from the liquid in the bounding volume of the tank baffle assembly that can be referred to as the baffle volume. The upper edge of exterior lower plate  40   d  is connected at an obtuse angle to the lower edge of rear plate  40   b , which obtuse angle may be equal to the obtuse angle formed between the interior lower plate and the rear plate as described above. One or more openings  44  in the connected edges of the forward and interior lower plates allow a restrained low flow of liquid into the bottom of liquid holding tank  14 . Optionally, as shown in  FIG. 12( b )  and  FIG. 12( c )  inward tapering of the lower side edges  40   c ″ of the interior lower plate  40   c  and inward tapering of the lower edges  40   a ″ of the forward plate  40   a  establish spillways that allow liquid to escape to the bottom of the tank in a restrained low flow in the space between the lower side edges and the interior side walls of tank  14  as liquid is poured into the tank controlled volume bounded by the surfaces, S′, S″ and S, of the forward, interior lower and rear plates, respectively, of tank baffle assembly  40 . As the liquid further rises in this tank controlled volume, liquid spills out of the tank controlled volume through spillway opening  42 , which liquid splashes onto the upper surface of exterior lower plate  40   d , which disperses and enhances the formation of vapor between the opposing surfaces of the lower interior and exterior surfaces and impedes vapor dissipation into the liquid holding tank volume outside of the bounding volume of the tank baffle assembly. As shown in  FIG. 12( a )  the lower surface of the exterior lower plate is located above the interior bottom of the liquid holding tank to allow a restrained flow of the liquid outside of the bounding volume of the tank baffle assembly and into the remaining volume of the liquid holding tank. Most broadly the tank baffle assembly  40  is arranged to reduce the liquid holding tank volume in which vapor is dispersed particularly during early filling of the tank from prover measurements. As disclosed above tank baffle assembly  40  enhances vapor formation in the tank controlled volume formed by the tank baffle assembly by creating splashing and turbulence within the tank controlled volume and directs the flow of the liquid and vapor from the tank controlled volume. In this example of the invention the tank controlled volume is formed primarily from forward plate  40   a , rear plate  40   b , interior lower plate  40   c , the opposing interior side walls of the liquid holding tank and the top of the liquid holding tank between the rear plate and forward plate that encompasses the vapor conduit opening  400   a  into the liquid holding tank and the prover&#39;s drain section opening into the liquid holding tank. Variations from the above tank baffle assembly that can accomplish these functions and are within the capabilities of one skilled in the art are contemplated as being within the scope of the invention. 
     One feature of the present invention is that the tank baffle assembly  40  is formed to trap vapor within the tank controlled volume rather than allowing the vapor to disperse freely within the total interior volume of the liquid holding tank as the liquid holding tank fills from multiple prover measurements.  FIG. 13( a )  through  FIG. 13( d )  illustrate this feature for the particular example tank baffle assembly  40  described above. In  FIG. 13( a )  liquid state (designated by dotted regions and reference number  66 ) in prover  12  (which may be a 5 gallon prover) from a top or bottom fill prover measurement drains into the liquid holding tank controlled volume within tank baffle assembly  40  (the baffle volume) when drain valve  100   d  is opened. Liquid splashing on forward plate  40   a  enhances formation of saturated vapor within the tank controlled volume and the saturated vapor (designated by dense stippled regions and reference number  60 ) exits up into vapor conduit  400  (indicated by upwards pointing arrow) in  FIG. 13( a )  as the liquid  66  accumulating in the tank controlled volume slowly drains directly to the bottom of the tank at the restrained flow rate through openings  44  in the connected edges of the forward and interior lower plates and in the regions formed between the side walls and optional lower inward tapered edges ( 44   a ″ and  44   c ″) of the forward and interior lower plates ( 44   a  and  44   c ) if provided. The tank controlled volume is generally sized to allow unhampered gravity drain of a prover&#39;s volume of liquid. Generally this means that the tank controlled volume is slightly larger than the volume of the prover, that is, for example, from 1.0 to approximately 1.2 times larger than the volume of the prover. For example a liquid prover system with a 5 gallon capacity prover with an 80 gallon total capacity liquid holding tank and a tank controlled volume of 6 gallons (approximately 1.2 times larger than 5 gallons) can be described as a liquid prover system with a 6 gallon primary liquid holding tank (the tank controlled volume) that drains into an 80 gallon secondary liquid holding tank (the total liquid holding tank volume). A smaller volume may be acceptable since the liquid in the tank controlled volume is continuing to drain into the remaining liquid holding tank volume. Minimizing the controlled tank volume according to the above requirements decreases the time required to reach vapor saturation in the substantially closed volume formed by the combination of the vapor tank baffle assembly, the vapor conduit and the bottom drain prover, and results in more accurate volumetric test results. As shown in  FIG. 13( b )  saturated vapor  60  is trapped within the tank controlled volume while a level of non-saturated vapor in the remainder of the tank (designated by less dense stippled regions and reference number  62 ) is significantly lower than saturated. In  FIG. 13( c )  as liquid continues to rise in the tank controlled volume, it spills over through spillway opening  42  between the interior lower plate and the rear plate, and over the surface of the exterior lower plate to continue to trap saturated vapor  60  from the liquid and direct the vapor up into vapor conduit  400  as indicated by the arrow in  FIG. 13( c ) . Since the top-fill opening is sealed during a top-fill or bottom-fill of prover  12  as described above, the saturated vapor is contained within the interior volume of the prover (as shown by the arrows) and repeated prover measurement accuracy previously degraded by vapor dispersing throughout the entire interior volume of the liquid holding tank is improved. For a top-fill, the top-fill opening is further sealed by placement of the nozzle in the top-fill opening self sealing assembly, and for a bottom-fill the top-fill opening is sealed by placement of the breather cap over the top opening as described above. In  FIG. 13( d )  the entire holding tank  14  and closed prover environment is a combination of saturated vapor  60  and liquid  66  as the holding tank continues to fill from repeated prover measurements. 
       FIG. 14  illustrates another example of the liquid prover system of the present wherein a plurality of liquid prover systems  10 ′, namely three in this example, as shown in  FIG. 7( a )  and  FIG. 7( b )  are connected to common support structure, which can be outfitted with wheels to form a wheeled trailer that can be transported between sites for calibration measurement of dispensing pumps&#39; meters at each site. Alternatively the plurality of provers and structure support may be installed on a vehicle, such as the flat bed of a pickup truck. Multiple prover systems installed on a common vehicle are convenient, for example, for proving pumps dispensing multiple grades of gasoline. Meter calibration for each grade of gasoline can be accomplished in a separate prover and liquid holding tank installed on the common vehicle. 
     The above examples of the invention describe prover system  10 , which has combined top-fill and bottom-fill features. In other examples of the invention, the top opening of prover  12  may be permanently sealed to form a bottom-fill only and bottom drain prover system with liquid holding tank  14 . 
     When the combined top-fill feature is provided on prover  100 , the method of using the liquid proving system of the present invention can be the same as that disclosed in U.S. Pat. No. 7,874,195, which is incorporated herein in its entirety, since the check valve in the bottom-fill assembly prevents flow of liquid out of the second end of the bottom fill assembly as described above. 
     In operation one example method of using the bottom-fill feature of the liquid proving system of the present invention is as follows. If the proving system also provides optional top fill operation, the breather cap assembly  300  remains installed on the prover through the bottom fill operation. Prover  12  is at least once initially filled with liquid from a metering device or pump, for example, by attaching liquid supply adapter  91 , as shown in  FIG. 11( a ) , or nozzle adapter assembly  70 , as shown in  FIG. 11( b )  or  FIG. 11( c )  to the liquid supply locking device  90  at the second end of bottom-fill assembly  20  or  20 ′, and pumping liquid into the prover either through the top or bottom fill assembly from a liquid dispensing nozzle or liquid dispensing device prior to performing a calibration fill. In the example shown in  FIG. 11( a )  liquid supply adapter  91  is connected to a liquid supply hose  92 ; in other examples of the invention, liquid supply adapter  91  may be connected to piping or other liquid supply elements. In a calibration fill, a nominal volume (for example 5.0 gallons or 20.0 liters) of the liquid, as measured by the meter reading on the metering device is pumped into the prover from the dispensing pump. The meter reading is compared with the volume of liquid in the prover as measured by the volume gauge (neck scale reading) on the prover to determine the degree of error in the meter reading. If the error exceeds an allowable value, the meter can be recalibrated and another calibration fill of the prover can be made to confirm that the recalibration brings the meter within an acceptable tolerance range. 
     As mentioned above another method for a calibration fill is to pump liquid into the prover until the neck scale on the prover reads the nominal capacity, at which time, the meter on the pump can be recalibrated to the nominal capacity. 
     The pre-calibration filling of the prover is performed to wet down the internal surfaces of the prover so that the quantity of fluid adhering to these internal surfaces is consistent during repetitive fillings of the prover. Since the calibration measurement fill is performed after one or more pre-calibration fills, vapor saturation of the air in the prover, vapor conduit and liquid holding tank is assured, in particular by use of the tank baffle assembly as described above, particularly if the liquid (such as gasoline) has a strong tendency to evaporate. Maintaining a vapor saturated environment inside the prover effectively restricts the vaporization of the volatile liquid. Minimizing evaporation from the volume of liquid pumped into the prover, and release of vapor from the prover, during a calibration fill is important since for a highly volatile liquid such as gasoline, the volume of liquid lost in the release of vapor, for example, by allowing the vapor to dissipate into the entire holding tank volume without the tank baffle assembly of the present invention, can be significant. Consequently without controlling vapor release as with the liquid prover system of the present invention, the prover&#39;s gauge reading may incorrectly attribute a volumetric error to the calibration of the meter in the liquid dispensing device that actually results from vapor loss during filling of the prover. 
     After each filling of the prover with liquid, the liquid can be drained from the prover by opening drain valve  100   d  with the distribution of liquid and saturated vapor in the prover system of the present invention being as typically described above, and illustrated in  FIG. 13( a )  through  FIG. 13( d )  after the prover is drained. Since the interior of the prover, the vapor conduit and the vapor tank baffle assembly in the liquid holding tank are a substantially closed path system, vapor saturated air is drawn (suctioned) into the interior prover volume via vapor conduit to replace the drained liquid from the prover. By maintaining the vapor saturated environment, evaporation is effectively restricted. 
     The prover can be repeatedly used by draining each measured volume of liquid from the prover into the liquid holding tank after being filled until a decision is made to empty the liquid holding tank before full capacity of the liquid holding tank is reached. At that time, liquid holding tank drain valve  200   b  ( FIG. 7( a )  or  FIG. 14 ) can be opened to drain the accumulated fluid from the liquid holding tank (with air flowing into the liquid holding tank via air vent  420  typically back into a storage tank supplying liquid to the dispensing pump. 
     In some examples of the invention separate top-fill and bottom-fill volume gauges or indicators may be provided on a prover used in a liquid prover system of the present invention. 
     While the above applications of the invention describe liquid dispensing pumps at gas stations and the like, the liquid proving system of the present invention is also of benefit in other applications, particularly where the liquid is highly volatile. 
     The nozzle adapter assembly disclosed herein may be utilized in other test or measurement applications that required provisions for overriding an automatic shut-off nozzle. 
     The present invention has been described in terms of preferred examples and embodiments. Equivalents, alternatives and modifications, aside from those expressly stated, are possible and within the scope of the invention.