Abstract:
Disclosed is a water pressure booster apparatus which can be employed for the dispensing of beverages. The booster can be combined as a carbonator and water pressure booster apparatus for holding both carbonated and non-carbonated water at elevated pressures, for the dispensing of carbonated and non-carbonated beverages. The apparatus has a tank including a tank chamber with a booster chamber therein. The two chambers are separated by a flexible membrane such that the elevated pressure is essentially the same in the two chambers. The booster chamber is removable through an access port in the tank. A valve provides inlet water to the tank chamber and the booster chamber. The location of the membrane controls the valve between charging of the two chambers. The valve is a spool valve with one end coupled to the membrane. The quantities of water in the two chambers controls activation of a pump which provides charging water to the chambers.

Description:
BACKGROUND OF THE INVENTION 
     The field of the present invention relates to apparatus for boosting water pressure and/or for use in carbonated and/or non-carbonated beverage dispensers and beverage vending machines. 
     Carbonation devices, generally referred to as carbonators, used in conjunction with carbonated beverage dispensers and/or vending machines, for example, are well-known. FIG. 1 shows a typical prior art carbonator  10 . It includes means for supplying both fresh non-carbonated water  16  and carbonating gas, such as CO 2 , at a regulated pressure to a carbonator tank  12  where the two are mixed to form carbonated water  30 . It also includes a conduit for transporting carbonated water  30  from the carbonator tank  12  to a post-mix dispensing nozzle  42  of a post-mix tower and dispenser assembly  40 , where the carbonated water  30  is mixed in suitable proportions with a quantity of flavor concentrate or syrup  34  from a supply source  32  to produce the composite carbonated drink. 
     The carbonator  10  also normally includes some type of water pump  18  to supply and replenish non-carbonated water  16  from a water supply  14  at an elevated pressure to the carbonator tank  12  which also receives CO 2  at elevated pressures from a source  24 . Both mechanical and electrical pump configurations have been utilized. The pump  18  (and a motor  20 , in case of electrical configurations) is generally controlled by means of a level control  28  which senses the amount of carbonated water in the carbonator tank  12 . Thus, when a volume of carbonated water  30  is dispensed from the carbonator tank  12 , it is replaced by a fresh volume of pressurized non-carbonated water  22 . 
     With the increased popularity of non-carbonated beverages such as tea, orange drink or lemon-lime, there is a greater need for post-mix tower and beverage dispenser assemblies that are equipped to provide both carbonated and non-carbonated beverages. Consequently, the prior art apparatus of FIG. 1 includes a conduit for transporting non-carbonated water  16  (which is generally at a lower pressure) from a water supply  14  to a post-mix non-carbonated beverage dispensing nozzle  49 , where non-carbonated water  16  is mixed with a suitable quantity of flavor concentrate or syrup  46  from a source  44  to make the desired non-carbonated beverage. The water supply  14  for making the non-carbonated beverage may be the same supply as that utilized in the carbonator tank  12  for making carbonated water  30 . 
     The mixing of the beverage syrup or concentrate ( 34  or  46 ) and carbonated water  30  or non-carbonated water  16  needs to be properly proportioned or “ratioed.” Depending on the desired end beverage, a precise ratio of water and syrup is mixed in order that the ultimate taste of the end beverage not be compromised. For example, if too little water or too much syrup are mixed, the end beverage would be too sweet for consumption. 
     In the case of making a carbonated beverage, because the carbonator tank  12  holds the carbonated water at an elevated and uniform pressure that is nearly independent of any fluctuations in pressure of the water supply  14 , the proper ratios in mixing of the carbonated water  30  and the syrup  34  are not significantly compromised by any pressure fluctuations in the water supply  14 . However, if the non-carbonated water  16  is drawn from a typical water source  14  (e.g., tap water), the ratio of non-carbonated water  16  to syrup  46  will be affected by the variations or fluctuations that typically occur in the pressure of such a water supply  14 . These pressure fluctuations may have numerous causes, including the use of water in other parts of the premises from which water is drawn, such as water fountains, sinks, showers, and toilets. 
     As non-carbonated beverages have garnered a greater share of the beverage market, there have been efforts to find a solution to the detrimental effects of water pressure fluctuations on the proper ratio of non-carbonated water  16  and syrup or concentrate  46 . One such effort to minimize the effect of pressure fluctuations in the water supply  14  is depicted in FIG.  2 . There, the carbonation and post-mix beverage dispensing system of FIG. 1 is modified to include a separate means for pressurizing non-carbonated water  16  drawn from the source  14  and storing it in a separate water booster tank  50  for making the non-carbonated drink. The tank  50  is usually made of cold-rolled steel and includes an internal plastic liner or special coating to prevent rusting and/or the emission of metallic or other undesirable tastes. The tank  50  incorporates a flexible membrane  51  such as a thick rubber diaphragm or bladder that is locked in place, dividing tank  50  into two sides. The membrane  51  is installed before the tank  50  is closed, after which the tank  50  is fully welded and sealed. Therefore, if the membrane  51  should fail, the tank  50  is usually completely discarded since there is no way to effect replacement of the membrane  51 , other than by cutting the tank  50  open and attempting to reweld and reseal it. 
     One side of the tank  50  is generally pre-charged with air to 30 psi at the tank manufacturer&#39;s location, however, additional pressure can be added by the customer up to as high as 100 psi. There is generally a tire valve stem  55  on one end of the tank  50  to introduce the air pressure, with the opposite end having an inlet for plain water  56  to be admitted and stored. To overcome the pressure on the opposite (air) side of the membrane  51 , a pump and motor must be utilized. Water  16  from the supply  14  may, for example, be pumped to the desired elevated pressure by a pump  52  and a motor  54 , and then supplied to the tank  50 . As water  56  enters the water side of the tank  50 , the membrane  51  expands into the air side of the tank  50 , raising the pressure therein. When the air pressure is increased to the desired amount, a pressure switch  60  will stop the motor  54  and the pump  52 . Non-carbonated water  58  at the desired elevated pressure can then be drawn from the tank  50  on demand for mixing with syrup  46  from the syrup supply  44 . A properly mixed non-carbonated beverage is then available at a designated post-mix dispensing nozzle or faucet  49 . 
     The apparatus of FIG. 2, however, suffers certain deficiencies. Even with the separate water booster tank  50 , dispensing non-carbonated drinks can be problematic because water boosters generally do not exceed 100 psi and normally operate between 60 and 80 psi, while soda water carbonators pressures normally run from 100 to 150 psi. Accordingly, the proportions or rates of syrup flow for carbonated versus non-carbonated drinks need to be set differently. Further, the float controls may need to be sized differently in the non-carbonated faucets than in the carbonated faucets, resulting in increased equipment costs and installation costs because of the extra parts, special spouts, diffusers and faucets. Moreover, the pressures of the carbonated versus non-carbonated water supplies are independent of each other, introducing further difficulties in trying to maintain the proper mixing ratios of water to syrup. 
     Further complicating matters, because the majority of drinks sold through most beverage dispensers are carbonated, dispenser faucets are usually equipped with diffusers that create a pressure drop to slow the soda water down as it pours into the cup, thereby preventing foaming. But, because the non-carbonated water pressure is generally already lower than that of the carbonated water, the further reduction in pressure created by these diffusers can cause the non-carbonated water to flow too slowly and/or in insufficient quantity. 
     A further problem posed by the independent water booster is that some customers like beverages dispensed with reduced carbonation. To achieve this, they may try to blend plain water in a 1:1 ratio with soda water in the faucet. The pressure differential between the carbonated and non-carbonated water supplies, however, may determine the actual ratio of carbonated to non-carbonated water, preventing the desired blending. 
     Moreover, from the standpoint of cost and space requirements, providing separate means of pressurizing and storing non-carbonated water for preparation of non-carbonated beverages is unsatisfactory. As seen in FIG. 2, the modified post-mix tower and dispenser assembly requires two pressure vessels (or tanks)  12  and  50 , possibly two pumps  18  and  52 , two motors  20  and  54 , a liquid level control  28  set for making carbonated beverages, and a pressure switch  60  set for making non-carbonated beverages. Aside from space requirements (which in the beverage dispenser and vending machine industry is an important concern), this solution entails nearly double the costs of manufacturing, installing and servicing. 
     In short, the pressurization and pumping equipment required for the non-carbonated water for making non-carbonated beverages in conventional post-mix beverage dispensers and/or vending machines can result in a relatively large, bulky, heavy and costly system which is ill-suited for utilization in low-volume, cost-driven, limited space environments, and still may not produce reliable results. Additionally, the need for cleaning, repairing and replacing such devices can prove to be a burden as well. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a booster for water pressure. One application for such a booster is as a non-carbonated water source. It may be combined with a carbonated water source as well. A tank is divided by a flexible membrane. One chamber is for a compressible fluid while the other may contain a body of water at substantially the same pressure. 
     In a first separate aspect of the present invention, a combined carbonated and non-carbonated water source for a beverage dispenser includes a tank with a chamber and an access port. A booster chamber extending into the tank is formed from a flexible membrane and a closure element. The closure element is positionable in sealing engagement with the access port. The booster chamber has a first configuration allowing insertion and withdrawal from the tank chamber. 
     In a second separate aspect of the present invention, a combined carbonated and non-carbonated water source for a beverage dispenser includes a tank with a chamber and an access port. The tank includes an inlet and a source of pressurized carbonating gas. A booster chamber extending into the tank also includes an inlet and is formed from a flexible membrane and a closure element. The closure element is positionable in sealing engagement with the access port. A source of pressurized water extends to a valve assembly which is in communication with the inlet to the tank and the inlet to the booster chamber to provide communication between the source of pressurized water and alternatively the tank inlet and the booster chamber inlet. 
     In a third separate aspect of the present invention, a combined carbonated and non-carbonated water source for a beverage dispenser includes a tank with a chamber and an access port. A booster chamber extends into the tank and has a flexible membrane. A source of pressurized water extends to a valve assembly which is in communication with an inlet to the tank and an inlet to the booster chamber. The valve assembly provides communication between the source of pressurized water and alternatively the tank inlet and the booster chamber inlet. The valve assembly is operatively coupled with the membrane to control communication through the valve assembly. 
     In a fourth separate aspect of the present invention, a combined carbonated and non-carbonated water source for a beverage dispenser includes a tank with a chamber and a source of pressurized carbonating gas. A booster chamber extends into the tank and has a flexible membrane. A source of pressurized water extends to a valve assembly in communication with an inlet to the tank and an inlet to the booster chamber. The valve assembly provides communication between the source of pressurized water and alternatively the tank inlet and the booster chamber inlet. The valve assembly is operatively coupled with the membrane to control communication through the valve assembly. A liquid level sensor switch is in the tank chamber and a membrane position switch is coupled to the membrane. These switches control the state of the source of pressurized water to elevate the water pressure to above the gas pressure for recharging of the tank with water. 
     In a fifth separate aspect of the present invention, a non-carbonated water source for a beverage dispenser includes a tank with an access port, a source of pressurized carbonating gas in communication with the tank and a booster chamber extending into the tank. The booster chamber includes an inlet, a flexible membrane and a closure element and is capable of insertion and withdrawal from the tank through the access port. 
     In a sixth separate aspect of the present invention, a non-carbonated water source for a beverage dispenser includes a tank, a source of pressurized carbonating gas in communication with the tank, a valve assembly controlling supply to the tank and a booster chamber in the tank, defined by a membrane. The valve assembly is operatively coupled with the membrane to control communication through the valve assembly. 
     In a seventh separate aspect of the present invention, a water booster includes a tank with an access port, pressurized gas in the tank and a booster chamber including an inlet, a flexible membrane and a closure element. The flexible membrane is in the tank with one side of the flexible membrane being sealed from the pressurized gas and being in communication with the closure element. The booster chamber has a first configuration allowing insertion and withdrawal from the tank through the access port. 
     In an eighth separate aspect of the present invention, a water booster includes a tank, pressurized gas in the tank and a booster chamber including an inlet and a flexible membrane. The flexible membrane is in the tank with one side of the flexible membrane being sealed from the pressurized gas and being in communication with the inlet. A valve assembly controls flow to the inlet and is operatively coupled with the membrane so that membrane position controls communication through the valve assembly. A membrane location switch may also be employed to activate a source of pressurized water to elevate the water pressure to above that of the gas in the tank. 
     In a ninth separate aspect of the present invention, any of the foregoing aspects are contemplated to be combined. 
     Thus, an object of the present invention is to provide an improved water pressure booster. Other objects and advantages will appear hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly diagrammatic, partly schematic view of a carbonation and post-mix beverage dispensing system of the prior art. 
     FIG. 2 is a partly diagrammatic, partly schematic view of a carbonation and post-mix beverage dispensing system of the prior art in which non-carbonated water for preparation of non-carbonated beverages is maintained at an elevated pressure in a separate holding tank. 
     FIG. 3 schematically depicts a side elevational view of a single-tank combined carbonater and non-carbonated water booster tank. 
     FIG. 4 schematically depicts an end elevational view of the embodiment of FIG.  3 . 
     FIG. 5 is a partial side sectional view of the embodiment of FIGS. 3 &amp; 4, taken along the lines A—A (shown in FIG.  4 ), showing the pressurized non-carbonated water chamber fully compressed, and showing the corresponding conditions in the directional chamber selector valve that is mounted onto the tank. 
     FIG. 6 is a partial side sectional view similar to FIG. 5, but taken along the lines B—B, and showing the non-carbonated water chamber fully expanded, and showing the corresponding conditions of the chamber selector valve. 
     FIG. 7 schematically depicts a side elevational view of a water pressure booster. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This disclosure is a companion of the disclosure in U.S. Pat. No. 5,855,296, the disclosure of which is incorporated herein by reference. 
     As shown in FIGS. 3 and 4, a carbonated and non-carbonated water source includes a combined carbonator and pressurized non-carbonated water tank  110  defining a tank chamber that is internally divided into a carbonated water chamber  114  and a non-carbonated water chamber  112  by a flexible membrane  116 . The tank  110  may be made of any material that is not reactive with carbonated water, such as stainless steel, and the membrane  116  may be a bladder made of latex or other suitable polymer. 
     In use, the chamber  114  contains a body of carbonated water  118  and a “head” of CO 2  gas  120 , while the chamber  112  contains a body of non-carbonated water at a pressure equal to the pressure of the CO 2  gas head  120 . The carbonated and non-carbonated dispensing nozzles of an associated post-mix beverage dispensing assembly (not shown) are thus supplied by a carbonated water outlet line  168  which attaches to an open outlet in the carbonated water side of the tank  110 , and by a non-carbonated water outlet line  138  which attaches to an open outlet on a valve assembly  126  communicating with the water chamber  112 . The membrane  116  may be designed and placed such that, for example, a minimum of 75% of the tank  110  is always available for the carbonated water chamber  114 , and the remaining 25% is available for the non-carbonated water chamber  112 . 
     The flexible membrane  116  is part of a subassembly booster chamber defining the non-carbonated water chamber  112 . The booster chamber includes the flexible membrane  116 , a closure element  127 , an inlet which is an outlet  180  from the valve assembly  126  and an outlet to a passageway  184 . The flexible membrane  116  may find closure at the opening of the tank  110  in a number of ways. An access port may include a collar  125  welded or otherwise affixed in a sealing manner to the end of the tank  110 . An annular socket on the collar  125  receives a bead  124  on the membrane  116 . The closure element  127  mates with the collar  125  where it is secured by bolts  131  and compresses the bead  124 . Thus, the closure element  127  circumferentially engages and tightly seals the open end  125  of the tank  110 , and, as in the embodiment shown in FIG. 3, also simultaneously engages and seals the bead  124  of the membrane  116 . 
     The closure element includes a bore  192  therethrough which forms part of the valve assembly  126 . The valve assembly  126  may be a bidirectional valve and directs water to one or the other of the carbonated water chamber  114  and the non-carbonated water chamber  112 . A source of pressurized water, for example, a pump  154  driven by a motor  156 , pumps water under pressure through a double ball valve  157  and a water line  158  and into the valve assembly  126  where it is directed to either the carbonated water chamber  114  (through water line  134 ) or the non-carbonated water chamber  112  (through passageway  184 , shown in FIG.  5 ). The pump  154  and motor  156  do not continuously operate in this embodiment. The source of pressurized water may be in a first state with the motor powered. In this state, the water  156  pressure is above the pressure of the carbonating gas so that water may flow into the chambers  112  and  114  faster than it is being depleted. In the inactive state with the motor  156  off, check valves prevent back-flow. 
     A high pressure carbonating gas source  130  forces gas such as CO 2  into chamber  114  through a gas inlet line  132  and a check valve  183 . A level sensor switch  170  (such as the liquid level sensing apparatus disclosed in McCann, U.S. Pat. No. 4,631,375, particularly adapted for use in vessels or tanks containing a fluid of the type utilized in liquid vending machines) activates the motor  156  when the level of carbonated water  118  drops to a predetermined lower limit, and turns it off when the level reaches a predetermined upper limit. 
     As seen in FIGS. 3-6, the valve assembly  126  has a water inlet  164  which can receive non-carbonated water at elevated pressures through a check valve  160  and the water line  158 , which is fed by the pump  154 . The chamber selector valve assembly  126  has an annular water outlet  180  that can selectively communicate water at elevated pressures from the inlet  164  (from the line  158 , if the pump  154  is pumping) into the non-carbonated water chamber  112 . The valve assembly  126  also has a water outlet  162  that can selectively communicate water at elevated pressure from the inlet  164  (from the line  158 , if the pump  154  is pumping) into the carbonated water chamber  114  through the line  134  and the check valve  136 . Finally, the valve assembly  126  has a non-carbonated water outlet  166  which is always open, allowing non-carbonated water in the chamber  112  to flow through the passageway  184  and into the water line  138 , as it is drawn off at the non-carbonated beverage faucets of the dispenser assembly (not shown). 
     The valve assembly  126  is configured such that it provides pressurized non-carbonated water from the pump  154  to one or the other of the chambers  114  and  112  of the tank  110 . As in the preferred embodiment shown in FIGS. 5 &amp; 6, this may be accomplished by means of a spool valve  190  axially disposed within the bore  192  of valve assembly  126 . It would also be possible to employ a solenoid valve in certain applications. An attachment bushing  122  at the distant end of the spool valve  190  firmly engages and anchors the center of the membrane  116  at the far end thereof (in the embodiment shown, a firm and sealing attachment is made through an orifice provided in the membrane  116 ). 
     FIGS. 5 &amp; 6 illustrate how, at any given point the spool valve  190  may block one or the other of the water inlets  162  or  180  with the land  191  in either a first or second position. Thus, when the membrane  116  is fully extended, as in FIG. 6, the spool valve  190  preferably blocks the water outlet  180 , preventing communication of water into the non-carbonated water chamber  112 . On the other hand, as in FIG. 5, when the membrane  116  is sufficiently compressed and contracted within the tank  110 , the water outlet  162  is prevented from communicating with the carbonated water chamber  114 . 
     The spool valve  190  is shown to be a multi-part configuration extending from the operative valve configuration to the attachment bushing  122 . A tie bar  133  extends from the interior of the valve element  190  and includes springs to either side of a spring retainer  135  to cushion movement of the tie bar  133  relative to the valve element  190 . The tie bar  133  includes an inner shaft  137  and an outer shaft  139  telescoped together. A lip  141  interferes with a restraint  142  to prevent full extraction of the inner shaft  137 . The combination of the inner shaft  137  sliding within the outer shaft  139  and the tie bar  133  itself sliding within the valve element  190  creates a loss motion device to allow substantial motion of the flexible membrane  116  to control a much smaller travel associated with the valve element  190 . 
     To begin operation, the tank chamber (which is initially empty) is connected via the line  132  and the check valve  183  to the carbonating gas source  130 , and also to the line  134  via the check valve  136 . The pump  154  and the motor  156  may then be connected to the water supply  150  via the line  152  and to a power source  176 . CO 2  is then allowed into the carbonated water chamber  114  and attains a desired pressure, typically 100-150 psi. This high pressure causes the membrane  116  to become fully compressed in a contracted position within the tank  110 . The motor  156  is activated causing the pump  154  to direct water through the line  158 , the check valve  160 , and into the inlet  164  of the valve assembly  126 . 
     Because the membrane  116  is fully compressed, the land  191  of the spool valve  190  of the chamber selector valve assembly  126  obstructs the outlet  162 , preventing the flow of pressurized water from the line  158  into the carbonation chamber  114 . Instead, the spool valve  190  directs water from the line  158  through the annular outlet  180  and into the non-carbonated chamber  112 . Then, as seen in FIG. 6, as the chamber  112  expands, the spool valve  190  blocks the outlet  180 , preventing further introduction of water into the chamber  112 . At the same time, the spool valve  190  no longer obstructs the outlet  162 , allowing pressurized water from the line  158  to enter the carbonation chamber  114  where it absorbs CO 2  from the existing pressurized carbonating gas head  120 , creating carbonated water  118 . Water may flow into the carbonation chamber  114  until the level of carbonated water  118  reaches a predetermined maximum point at which the level sensor  170  shuts off the motor  156  (and thus the pump  154 ) via the electrical line  172 . 
     If only carbonated drinks are drawn from the associated beverage dispenser (not shown), the non-carbonated chamber  112  is not utilized, and the lip  141  remains extended close to or pressed against the restraint  142 . If non-carbonated drinks are drawn off, water is forced out of the non-carbonated water chamber  112  at substantially the same pressure as in the carbonated water chamber  114 , because the pressure is transmitted by the membrane  116 . The water level in the carbonated water chamber  114  then lowers as the membrane  116  contracts and the chamber  112  reduces in size. 
     If the volume of the chamber  112  is reduced sufficiently, the consequent reduction in the level of carbonated water  118  in the chamber  114  will cause the liquid level control  170  to signal the motor  156  to operate the pump  154  and direct water to the valve assembly  126 . The valve assembly  126 , in turn, directs water flow into the chamber  112  until the expansion of the chamber  112  raises the level of the carbonated water  118  in the chamber  114  sufficiently, or until the lip  141  reaches the restraint  142  (after which any further incoming water is directed by the valve assembly  126  into the carbonated chamber  114  as needed). In either case, the liquid level probe  170  turns off the motor  156  when the level of the carbonated water  118  reaches its maximum design limit. The lip  141  and the restraint  142  comprise a supplementary feature that can prevent over-expansion of the non-carbonated chamber  112 . 
     Conversely, as a separate back-up feature to prevent the chamber  112  from contracting too far, the chamber selector valve assembly  126  may also incorporate a membrane position switch  128  that becomes mechanically actuated when the non-carbonated water chamber  112  is almost empty and the membrane  116  is in a contracted rather than an extended position, activating the motor  156  (irrespective of the state of the liquid level probe  170 ) via the line  174 , causing the pump  154  to direct water to the valve assembly  126 , through the annular outlet  180  and into the chamber  112 . It should be noted that, depending on the configuration, the auxiliary switch  128  may not come into use frequently, because drawing off from the non-carbonated chamber  112  will also cause the level in the carbonated chamber  114  to drop, and depending on the settings, this may ordinarily be enough to activate the pump  154 . 
     Easy replacement of the membrane  116  can be allowed for by making the tank access port  125  sufficiently large to extract and insert the desired bladder therethrough. The membrane  116 , being flexible, may assume a configuration in the relaxed state to fit through the access port  125 . 
     It is thus seen that a combined carbonator and water pressure booster can eliminate the need for much of the apparatus that is required by prior art devices providing both carbonated water and non-carbonated water to conventional post-mix beverage dispensers. Accordingly, the manufacturing, installation and servicing costs, and the space requirements may be reduced substantially. At the same time, a better controlled non-carbonated water pressure which is balanced with the pressure of the carbonated water can be achieved. In addition to improving the reliability of mixing proportions under all conditions, this is a particularly desirable feature in making lower carbonated drinks which require mixing both plain water and carbonated water with syrup. Further, the device disclosed herein can also be constructed so as to allow easy replacement of the parts most likely to fail, and it can be made as a unitary apparatus, or as one that attaches to existing equipment with little modification thereto. 
     FIG. 7 illustrates a water pressure booster which is not integrally formed with a carbonator tank. In this configuration, the tank  110  would not need a dedicated liquid inlet or a dedicated liquid outlet for water subject to carbonation. Pressure may be provided by either a static charge or a continuous supply. FIG. 7 illustrates both methods. A tire valve stem  194  might be employed to initially charge the interior of the tank  110  with pressurized gas. Under such a static charge, a two or four gallon tank is advantageous as the larger volume of compressed air will vary less in pressure with variation in the size of the water chamber  112  where the water chamber  112  is a smaller percentage of the total tank volume. 
     Alternatively, a source of pressurized gas  130  may extend to the tank  110  as also shown in FIG. 7 to provide pressurized gas in the tank  110 . A separate source of pressurized gas  130  may provide uniform pressure between multiple tanks. The source of pressurized gas  130  may feed a carbonator tank or draw from a carbonator tank. In this instance, the booster tank would match the pressure in a carbonator tank to provide a similar rate of supply to a beverage dispensing machine or the like. A source of pressurized gas  130  provides a more constant level of pressure gas in the tank  110  unaffected by the position of the membrane  116 . The inlet to the tank  110  of the source of pressurized gas  130  may be located at the bottom of the tank  110  in a recess  195 . This placement allows for the displacement of any water, including condensate, back through the line to the source of pressurized gas  130  if that source is a carbonator and the flow path is not too long and/or downwardly from the tank  110 . The check valve  183  would not be employed in such an application. The valve assembly  126  can also be simplified through the elimination of the outlet  162 . The outlet  162  may otherwise simply be closed off. 
     Thus, an improved carbonator and non-carbonated water pressure booster are disclosed. It is clear from the foregoing disclosure that while particular forms of the invention have been illustrated and described, various modifications may be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited to the foregoing disclosure except as by the appended claims.