Abstract:
A water treatment system for removing impurities from incoming feed water includes a manifold having a plurality of water treatment filter housings connected thereto. The filter housings are configured to accept a plurality of water treatment filter cartridges, which have, at one end, a filter housing cap fixedly attached thereto. The system manifold is also adaptable to be able to connect to peripheral accessories, filtration devices, and identical water treatment systems.

Description:
FIELD OF THE INVENTION 
       [0001]    This disclosure relates to water treatment systems. Additionally, this disclosure relates to an apparatus for performing water filtration purification, and more specifically, reverse osmosis water filtration purification. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to water filtration purification systems including a plurality of filter cartridges connected together in series for selectively and sequentially removing specific kinds of impurities from an incoming water supply. A typical water filtering system used in purifying water includes a reverse osmosis (hereinafter, “R.O.”) semi-permeable membrane. Typically, the filtration process through an R.O. membrane requires a driving force, most commonly the pressure from a pump or city water lines, to be applied to incoming feed water in order to force the feed water through the membrane. The membrane filters impurities from the feed water leaving the impurities on the feed water side of the membrane, and purified product water on the other side of the membrane. Most R.O. filtration technology also uses a process known as crossflow to allow the membrane to continually clean itself. In this process, only a portion of the feed water passes through the membrane becoming product water. The portion that does not pass through the membrane is flushed downstream for disposal through a drain port, thus sweeping the rejected impurities away from the membrane and reducing the scaling that occurs on the surface of the membrane. Many applications require that more than one filter be employed in series to selectively remove specific impurities. This series of filters is needed due to the fact that some R.O. membrane filters and other specialty filters are sensitive to, or do not work well if the incoming water contains certain chemicals or impurities, like chlorine for example. In these situations, the chlorine is first removed from the feed water by passing through an upstream pre-filter before moving to the chlorine-sensitive filter or R.O. membrane positioned downstream in the R.O. filtration system. 
         [0003]    R.O. filtration purification systems are increasingly being employed to purify municipal and well water supplies to provide improved drinking water by decreasing the total dissolved solids in the municipal or well water, and thereby improving the taste, odor, or chemical makeup of the water. 
         [0004]    Therefore, today there are many versions of R.O. filtration purification units that reduce specific contaminants and/or organics to improve the quality of drinking water. Filter and R.O. membrane cartridges (hereinafter “filter cartridges”) utilized in R.O. water treatment systems generally have a standardized cylindrical configuration including entry and outlet structures for attaching the filters to other system elements. Filter cartridges commonly utilized today also have different standardized diameters and lengths depending on whether the filter cartridge is meant for residential or commercial use. Many of the filter cartridges used in the market today are placed by hand in standardized cup shaped filter housings then attached to the main filter manifold. Once the filter housing is attached to the main filter manifold, the combined filter housing and manifold form a pressure vessel commonly called a filter sump. Incoming feed water then passes into the filter sump under pressure via an inlet port, through the filter cartridge contained therein, and exits the filter sump via an exit port in the filter manifold. 
         [0005]    Current R.O. water treatment systems employ various techniques to attach the filter housings, which house the filter cartridge, to the main filter manifold. Some systems screw the filter housing to the manifold, some pin the filter housing to the manifold, while still others use bayonet style locking to attach the filter housing to the manifold. There are several disadvantages associated with each of these techniques. 
         [0006]    First, a “cup-type” filter housing is essentially a cylindrical cup shaped container in which the filter cartridge is placed before being connected to the main manifold, thus creating a pressure vessel in the form of a filter sump. This type of filter housing has either a threaded lip in order to screw onto a similarly threaded filter manifold, a grooved lip so that it may be clipped or pinned to the filter manifold, or a bayonet style lip to be connected to a manifold that accepts bayonet style sumps. When dealing with “cup-type” filter housings, the user installing the filter cartridge must touch the outsides of the cartridge, including the filter material itself, with his hands in order to install the filter cartridge in the Cup shaped filter sump. This leads to potential contamination of the filter cartridge if proper sanitary methods or protective gear are not used. 
         [0007]    Second, because the filter cartridges used in “cup-type” filter housings must be installed in the filter housing by hand, the tested and certified filter cartridges can be potentially altered from their tested and certified state. Additionally, because filter cartridges generally have a standardized configuration, off-brand replacement cartridges may be used which may not carry the certification of the original cartridges, and if used, may void any and all health claims presented to the end user of the main R.O. water treatment system. 
         [0008]    Third, another popular proprietary filter housing and filter cartridge used in the marketplace is one in which the filter housing fully encapsulates the filter media within a sealed plastic housing and uses a bayonet locking method to attach the filter to the filter manifold as previously mentioned. This method is an effective deterrent against uncertified aftermarket replacements. It also maintains the sanitary handling desired for that brand of filter cartridge because the filter is encapsulated and certified at the factory. The consumer never has the opportunity to inadvertently or purposely contaminate the filter. However, when replacing the filter cartridge, there is an environmental disadvantage in that the user is not only disposing of the old filter, but he is also disposing the large amount of plastic that was used to encapsulate the filter which may end up in a land fill. This is also an undesirable result. 
         [0009]    Fourth, all of the R.O. water treatment system designs currently used in the market today use filter cartridges of preset lengths and diameters. Those systems are designed for use with one filter cartridge size and do not currently have the ability to utilize filter cartridges of varying sizes. This does not allow the user to utilize filter cartridges of larger or smaller diameters or lengths, depending on his particular needs. This is an additional drawback to existing systems. 
       SUMMARY OF THE INVENTION 
       [0010]    According to the present invention herein disclosed, the main system manifold of the water treatment system includes an upper and lower manifold that are hot plate welded together to form a single unit. The main manifold further includes the cylindrical filter housings which are integrally molded directly into the main manifold, thus forming a solid one-piece manifold with integral filter housings, rather than having the filter housings as separate containers to be attached to the manifold. While other systems also use hot plate welding to create a single manifold design, those systems do not however integrally mold the filter housings into the single manifold. Additionally, the filter cartridges to be inserted into the filter housings include integrated filter housing caps that are permanently connected to the cartridges. 
         [0011]    By molding the cylindrical filter housing, which is the main cylinder portion of a traditional filter sump, into the main filter manifold assembly and permanently attaching the filter housing cap to the filter cartridge itself, all handling of the cartridge can be done via the cap thus eliminating potential contamination of the filter media itself. Additionally, the proprietary filter cartridge, which contains an integrated filter housing cap, helps ensure that no after-market or off-brand filters can be used with the main manifold, thus helping to maintain the originally designed health and environmental parameters of the main system. Furthermore, by minimizing the amount of material used in molding the filter housing cap to or permanently attaching the filter housing cap to the filter cartridge, the amount of plastic that may go to a landfill when the filter cartridge is replaced will be minimized as compared to the prior art filter cartridges that fully encapsulate the filter media with plastic. 
         [0012]    In another aspect of the invention, the filter housing that is designed to be a R.O. membrane housing contains therein at least two staircased and concentric R.O. membrane brine seal housings of differing diameters and heights. These brine seal housings are sized to accept and allow use of both the standard sized residential R.O. membranes and the standard sized commercial R.O. membranes which each have different brine seal diameters. Additionally, more brine seal housings of differing heights and diameters could also be included which would allow use of membranes with custom brine seal diameters. Thus the invention allows users to change the size of membrane that is being used in the system based on the particular demands placed on the system. 
         [0013]    In still another aspect, the invention is a customizable water treatment manifold in that it allows use of filter cylinder extension modules that attach to the integrally molded filter/membrane housings, thus allowing users to utilize filters or membranes of various standard or customizable lengths. Again, the user can choose the length needed based on the particular demands of the system. 
         [0014]    In an additional aspect, the invention is a water treatment system that may be connected in parallel to at least one additional identical system such that they form and operate as one single, larger unit. In this manner, water may flow back and forth between each of the two systems for various levels of processing. Furthermore, in yet another aspect, the invention is also a water treatment system which optionally includes an integrated storage tank as opposed to only utilizing a satellite storage tank. The storage tank is customizable to be used as either an integrated tank or a satellite tank. The water treatment system can thus be customized to use either an integrated tank, a satellite tank, or both an integrated tank and satellite tank at the same time as additional storage capacity is needed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a front view of a conventional prior art reverse osmosis filtration purification system. 
           [0016]      FIG. 2  is an isometric view of a fully assembled water treatment system utilizing a one-piece manifold with integral filter housings made in accordance with the present invention (storage tank not shown). 
           [0017]      FIGS. 3 and 4  are exploded views of the main assembly showing the upper manifold and lower manifold. 
           [0018]      FIG. 5  is a front view of a residential R.O. membrane cartridge and a commercial R.O. membrane cartridge, each having different brine seal diameters. 
           [0019]      FIG. 6A  is a cross sectional view of a filter housing cap hot glued onto the end of a carbon block filter cartridge. 
           [0020]      FIG. 6B  is a cross-sectional view of a filter housing cap spun welded onto a R.O. membrane cartridge. 
           [0021]      FIG. 7  is an exploded view of one embodiment of the water treatment system of  FIG. 2  (storage tank not shown) utilizing cylinder extension modules. 
           [0022]      FIG. 8  is a top view of the R.O. membrane housing of the manifold with integral filter housings of  FIGS. 3 &amp; 4  showing the various sized brine seals therein. 
           [0023]      FIG. 9  is a cross-sectional view of the manifold with integral filter housings showing the various sized brine seals of the R.O. membrane housing and a corresponding filter cartridge. 
           [0024]      FIG. 10A  is an exploded view of a filter housing, a filter cartridge with integral housing cap, and a housing cap retaining pin with retaining pin release clip. 
           [0025]      FIG. 10B  is a side view of a filter housing with a filter cartridge loaded therein and the filter housing cap secured in place by a housing cap retaining pin. 
           [0026]      FIG. 11  is a view of the housing cap retaining pin being used as a filter cartridge removal tool. 
           [0027]      FIG. 12  is a view of one embodiment of a dedicated filter cartridge removal tool. 
           [0028]      FIG. 13  is an exploded view of an integrated water storage tank and the main manifold assembly with an adapter plate mounted there between. 
           [0029]      FIG. 14  is a close-up isometric view of the water pathways, pathway gate notches, and corresponding pathway modification gates that fit into the pathway gate notches of the lower manifold. 
           [0030]      FIG. 15  is a view of the assembled drain barrel inside the drain flow restrictor port. 
           [0031]      FIG. 16  is a close up view of the drain barrel of  FIG. 15 . 
           [0032]      FIG. 17  is an isometric view of an embodiment made in accordance with the present invention wherein two individual main assemblies have been connected by their lower manifold&#39;s to form one larger unit. 
           [0033]      FIG. 18  is an isometric view of an embodiment made in accordance with the present invention, wherein the main assembly has been combined with an auxiliary piece of equipment such as a fourth filtration sump, a pump, an electronic monitoring and control device, or a UV module. 
           [0034]      FIG. 19  is an isometric view of the fully assembled preferred embodiment of the system of  FIG. 2 , wherein the system of  FIG. 2  has been combined with an integrated storage tank as in  FIG. 14 , and an additional decorative cover. 
           [0035]      FIG. 20  is an isometric view of the system made in accordance with the present invention wherein the storage tank utilized is a separate satellite storage tank. 
           [0036]      FIGS. 21 &amp; 22  are isometric views of alternate embodiments of the storage tank made in accordance with the present invention, wherein the tank is used as a satellite storage tank, is physically linked to a second storage tank using the tank&#39;s mounting fasteners and a plurality of universal mounting brackets. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0037]    While the present invention is capable of embodiment in various forms, there is shown in the drawings, and will be hereinafter described, one or more presently preferred embodiments with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated. 
         [0038]    Referring to  FIG. 2 , water filtration system  100  of the present invention is disclosed. System  100  includes a lower manifold  114 , an upper manifold  112 , a plurality of filter housings  116 - 120 , a plurality of filter cartridges  134 - 138  each including an integrated filter housing cap  146  (of which only the filter housing caps  146  are visible in  FIG. 2 ), and a storage tank  194  (shown in FIGS.  14  &amp;  19 - 22 ). 
         [0039]    In the preferred embodiment, the upper manifold  112  and lower manifold  114  are generally rectangular in shape, however, the disclosure of this embodiment should not be read to limit the shape of the upper and lower manifolds. The filter housings  116 - 120  and the filter cartridges  134 - 138  seated primarily inside of the filter housings  116 - 120  (See  FIG. 9 ), are generally cylindrical in shape. The filter housing caps  146  of the filter cartridges  134 - 136  are also generally cylindrical in shape and form a liquid tight seal with the inner walls of filter housings  116 - 120 . However, the disclosure of this embodiment should not be read to limit the shape of either the filter housings  116 - 120 , the filter cartridges  134 - 138 , or the filter housing caps  146 . Rather the filter housings  116 - 120  and filter housing caps  146  are shaped to accommodate and compliment the shape of the filter cartridges  134 - 138 . As such, in alternate embodiments of the matter disclosed herein, the filter cartridges, housings, and filter housing caps may take on additional shapes other than those disclosed herein. Additionally, although the preferred embodiment of  FIG. 2  depicts three filter housings  116 - 120  and three filter cartridges  134 - 138 , this should not be read to limit the number of filter cartridges  134 - 138  or housings  116 - 120  that may be incorporated in the practice of alternate embodiments of the matter disclosed herein. 
         [0040]    Referring to  FIGS. 3 &amp; 4 , the upper manifold  112  includes filter housings  116 - 120 , which are integrally molded thereto, forming a single molded piece. In the preferred embodiment, the integrally molded filter housings  116 - 120  of upper manifold  112  are a sediment pre-filter housing  116 , an R.O. membrane housing  118 , and a carbon post-filter housing  120 . However, the disclosure of this embodiment should not be read to require that a R.O. filter always be utilized in the practice of this invention nor should the disclosure of this embodiment be read to limit the use of the filter housings to only those filters previously discussed. Alternatively, in other embodiments, the filter housings may be used for alternate types of filters and/or membranes such as, but not limited to, sediment filters, sediment/carbon block combination filters, carbon block filters, granulated activated carbon filters, and KDF filters and may be arranged in a different order than that disclosed herein. Additionally, upper manifold  112  also includes all manifold control ports which are the inlet control port  124 , the satellite storage tank control port  126 , the faucet control port  128 , and the drain water control port  122 . The upper manifold  112  further includes a drain flow restrictor port  130 , a shutoff diaphragm valve port  129 , a check valve port  131 , and the upper half of the water pathways  132   a  (see  FIGS. 3 &amp; 4 ). The function of the check valve port  131  is to prevent water contained in the storage tank from draining back to the drain port control  122  when the air gap faucet connected to the faucet control port  128  is shut off and not dispensing product water. 
         [0041]    The lower manifold  114  includes the lower half of the water pathways  132   b  (see  FIG. 3 ) and a plurality of fluid flow configuration ports  140  (see  FIG. 4 ). Both the upper manifold  112  and the lower manifold  114  are made from a high strength material such as, but not limited to, GFN3 which is 30% glass filled Noryl (a polymer manufactured by GE Plastics), GTX (a polymer manufactured by GE Plastics), or Xyron (a polymer manufactured by Asahi Thermofill, Inc.). The upper manifold  112  and the lower manifold  114  are hot plate welded together to form the main filter assembly  110 , (see  FIGS. 3 &amp; 4 ) which thereafter is one solid piece. When the upper and lower manifolds  112  &amp;  114  are hot plate welded together, the upper half of the water pathways  132   a  aligns and seals with the lower half of the water pathways  132   b  to become one hermetically sealed set of water pathways  132 . Although in the preferred embodiment the upper and lower manifolds are hot plate welded together, in alternate embodiments, they may be fusion bonded together, sonic welded together, or joined together in any other manner that provides a hermetic seal therebetween. 
         [0042]    Having the filter housings  116 - 120  molded into the upper manifold  112 , and thus the main assembly  110  following the hot plate welding procedure, is unique to the R.O. system  100  disclosed herein. The advantages of integrally molding the filter housings  116 - 120  into the system&#39;s main assembly  110  will be discussed below. 
         [0043]    Referring to  FIG. 5  specifically depicting a residential  160  and a commercial  166  R.O. membrane cartridge, but generally applicable to all filter cartridges, the filter cartridges  134 - 138  include a filter media portion  168 , a filter housing cap  146 , and a fluid seal connector  169 . If the filter cartridge is an R.O. membrane cartridge as in  FIG. 5 , then the filter media portion  168  is essentially a molded, hollow, and perforated plastic tube, having multiple layers of various filter materials wrapped thereon. If, however, the filter cartridge is a pre or post-filter such as a carbon block filter, then the filter media portion  168  is generally either a porous, extruded cylindrical filter media solid having a hollow cylindrical center, or it is a perforated cylindrical plastic housing filled with a particular granulated filter media (not shown). The creation of various types of filter media is well known in the art and will be understood by those skilled in the art and will not be repeated herein. The filter media  168  is the portion of a filter cartridge through which feed water is forced in order to remove the water&#39;s impurities. Generally, feed water surrounds the outer cylindrical surface of the filter media portion, passes through the outer surface of the filtration media and into the hollow center, and travels down the hollow center and out of the filter housing in order to move downstream to the next filtration stage. 
         [0044]    The filter housing cap  146  is generally a cylindrical, tubular sidewall that is closed off at one end by a concentric, circular shaped top wall joined thereto. The cap  146  includes a mating and sealing portion defined by the outer surface of the cap&#39;s  146  cylindrical sidewall and further includes a decorative domed grill on the outer surface of the circular shaped top wall. The inner surface of the cap&#39;s  146  top wall is generally flat. The cap  146  is generally made from high strength plastic but can be alternatively made from other high strength materials. The filter housing cap  146  includes at least one liquid sealing o-ring  147  seated around the outer circumference of the mating portion of the filter housing cap  146 , a retaining pin retention groove  176  recessed in the full outer circumference of the cap and positioned between the o-rings  147  and the cap&#39;s  146  top wall, and a plurality of housing cap removal tool holes  180  situated in the outer decorative grill of the housing cap  146 . The o-rings  147  are what form the liquid tight seal between a filter housing  116 - 120  and the filter housing cap  147  when the two are mated together. The retention groove  176  is the feature on the cap  146  that, when engaged by a retention pin  170 , keeps the housing cap secured in place when the filter sumps  148 - 152 , which are the pressure vessels formed by mating the cartridges into the filter housings, become pressurized due to water flowing through the system  100 . The cap removal tool holes  180  are essentially thru holes into which a cap removal tool  182  is hooked to help pull the mated housing cap  146  off of the filter housings  116 - 120  when the filter cartridges need to be removed. 
         [0045]    The fluid seal connector  169  is the portion the filter cartridge  134 - 138  that connects the filter media portion  168  to the manifold&#39;s housing outlet port  186 . It also provides the path through which water, which has just passed through a particular filter inside of a filter sump, is reintroduced back into the manifold&#39;s water pathways  132  for further processing downstream or for dispensing, depending on where the particular filter is located in the process. The fluid seal connector  169  includes a filter connection nipple  163  containing at least one o-ring  147  thereon, such that, when the nipple  163  is mated with the housing outlet port  186 , a fluid tight seal is created there between, thus reducing the possibility that unfiltered water can reenter the system prior to being filtered. Also, when the filter in question is a R.O. membrane filter, the fluid seal connector  169  further contains a brine seal  158  or  164  which forms a liquid tight seal with an appropriately sized brine seal housing  156  or  162 . The liquid tight seal formed between the brine seal  158  or  164  and brine seal housing  156  or  162  separates the pre-filtered inlet water coming into the membrane sump  150  from the crossflow drain water which leaves the system as waste for disposal. 
         [0046]    Referring to  FIG. 6B , for the R.O. membrane cartridges  136 , the cap  146  is preferably spun welded onto the molded tube portion of the filter media  168 , thus becoming permanently attached or incorporated into the cartridge and creating a new proprietary disposable filter cartridge. Alternatively, the filter housing cap  146  can be integrally molded into a filter cartridge, snapped or press-fit onto the filter media portion  168 , or glued onto the end of the filter media portion as is done with many carbon block filters and seen in  FIG. 6A , thus creating one solid cartridge and cap unit. Referring to  FIG. 6A , when the cap  146  is hot melt glued to the open end of an extruded carbon block filter, the glue forms the seal on the open end of the hollow cylinder preventing water from entering into the center of the cylinder without first passing through the filtration material. With such a filter cartridge design, if the filter media portion  168  of a filter cartridge  134 - 138  is removed or separated from the filter housing cap  146 , it renders the filter cartridge unusable. In a preferred embodiment, filter cartridges  134 - 138  are a sediment pre-filter cartridge  134  to be loaded into the pre-filter housing  116 , a R.O. membrane cartridge  136  to be loaded into the R.O. membrane housing  118 , and a carbon post-filter  138  to be loaded into a post-filter housing  120 . 
         [0047]    When each filter housing  116 - 120  is capped off with a filter housing cap  146  containing at least one o-ring seal  147 , the combined parts form a series of sealed filter sumps  148 - 152 , as previously mentioned. A filter sump is simply a pressure vessel, inside of which water will pass, under pressure, through the filter media  168  of the filter  134  and  138  or membrane  136  contained therein. Referring to  FIG. 7 , because of the system&#39;s integrated filter housings  116 - 120 , an alternate embodiment of the invention disclosed herein allows for use of cylinder extension modules  154  to be coupled to the open, uncapped ends of the filter housings  116 - 120 . The caps  146  may then be secured to the open ends of the cylinder extension modules  154  creating a liquid tight seal. In this manner, the main assembly  110  is altered to allow the system  100  to use longer filter cartridges  167  which in turn will increase the product water output potential. 
         [0048]    Referring to FIGS.  5  &amp;  8 - 9 , the aforementioned filter housings  116 - 120 , at either their standard lengths or extended lengths, via cylinder extension modules  154 , are capable of receiving multiple filters and membranes of various diameters. The membrane housing  118  specifically has, but is not limited to, two staircased brine seal housings  156  and  162  attached to the flat, bottom, inner surface of the membrane housing  118  and extending upwards in the same direction as the housing itself (See  FIGS. 8 &amp; 9 ). The first brine seal housing  156  has been sized to accept the brine seal  158  of the standardized residential diameter R.O. membrane cartridge  160  while the second brine seal housing  162  has been sized to accept the larger diameter brine seal  164  of standardized commercial diameter R.O. membrane cartridges  166  (See  FIG. 5 ). Alternatively, additional brine seal housings may be utilized and sized to accept unique membrane brine seals of nearly any diameter in the practice of an embodiment of the invention disclosed herein. 
         [0049]    The preferred embodiment which incorporates the cap  146  and filter cartridge  134 - 138  into one unit has several advantages over prior standard cartridge configurations. First, when installing most standard filter cartridges, the filter media must be touched by the user&#39;s hand creating the potential to contaminate the filter media  168  and the entire system if proper sanitary methods or protective gear is not used. However, when using the one-piece manifold with integral filter housings, all handling and installation is done by the outside edges and surface of the cap  146  which never comes in contact with the water in the system  100 , thus eliminating the potential contamination of the filter media  168 . Second, unlike current filter cartridges, tested and certified filtration media cartridges made in accordance with the invention cannot be altered from their tested and certified state. Many off brand replacement filters do not carry the certification that the original cartridges do and if used may void any/all health claims presented to the end user of the main RO unit. By controlling the supply of certified filter cartridges, the manufacturer can ensure the product works as claimed. Third, unlike a popular proprietary filter cartridge used in the market today that fully encapsulates the filter media within a sealed plastic housing, the one-piece manifold with integral filter housings minimizes the amount of plastic that may end up in landfills upon disposal of the filter cartridge. When the aforementioned fully encapsulated filter media is disposed of, the user is disposing of not only the filter media inside, but the fairly large plastic housing that fully encapsulates the filter media as well. With most other filtration systems, this plastic filter encapsulation housing is usually meant to be a detachable, yet permanent part of the main system and is normally reused after replacing the filter media contained therein. By comparison, upon disposal of the filter cartridges  134 - 138  of the present invention, the filter media  168 , the filter housing cap  146 , and the filter connection nipple  163  are the only parts disposed of, while the main filter housings  116 - 120  which make up the largest portion of the filter sumps are reused with the new replacement filter cartridges. The obvious environmental advantage is that significantly less plastic may be disposed of in landfills upon cartridge replacement. 
         [0050]    Referring to  FIGS. 7 ,  10 A, and  10 B, each cap  146  is secured to its filter housing  116 - 120  or cylinder extension module  154  by pinning the cap  146  to the open end of the filter housing  116 - 120  or cylinder extension module  154  using a horseshoe shaped retaining pin  170 . The filter cartridge  134 - 138  is first inserted into the filter housing  116 - 120  and the integral filter housing cap  146  containing o-rings  147  is fully seated in the open end of the filter housing  116 - 120 . Next the legs  172  of the retaining pin  170  are inserted through corresponding retaining pin engagement holes  174  located in the walls of the filter housing  116 - 120 . The legs  172  of the pin  170  slide through the engagement holes  174  in the filter housing  116 - 120 , engaging the corresponding retention groove  176  above the o-rings  147  in the outer circumference of the filter cap  146 , and emerging from pin engagement holes  174  on the opposite side of the filter housing  116 - 120 . When the legs  172  of the retaining pin  170  are engaged in the cap&#39;s retention groove  176 , they create an interference fit, thus securing the cap  146  in place and preventing it from being removed. 
         [0051]    The retaining pins  170  that secure both the housing caps  146  in place and the filter cartridges  134 - 138  inside the filter housings  116 - 120  may become difficult to remove after the filter sumps  148 - 152  have been pressurized for a long time. To aid in the removal of the retaining pin  170 , a release clip  178  is attached to the retaining pin  170 . The release clip  178  is manually pulled downward and the resultant lever action against the filter housing  116 - 120  ejects the pin  170  or moves the pin free from its resting place making it easier to remove. While the preferred embodiment uses pinning as the preferred method to connect the filter housing caps  146  or cylinder extension modules  154  to the filter housings  116 - 120 , alternatively the caps  146  and cylinder extension modules  154  can be connected by screwing, bayonet style locking, or any other method that would provide a secure connection between the caps  146  and housings  116 - 120 , the caps  146  and extension modules  154 , or the extension modules  154  and housings  116 - 120 . 
         [0052]    Referring to  FIGS. 11 and 12 , the retaining pin  170 , after it is removed, can also function as a filter cartridge removal tool. One leg  172  of the retaining pin  170  is inserted into one of a plurality of cap removal tool holes  180  located in the outer surface of the filter housing cap  146  and is used to twist and pull up on the filter cartridge&#39;s integral cap  146  in order to remove the filter cartridge  134 - 138  from its filter housing  116 - 120  (See  FIG. 11 ). Preferentially however, a specially designed removal tool  182  that aids in the removal of filter cartridges  134 - 138  is employed to remove the filter cartridges  134 - 138 . The tool  182  is essentially a T-shaped handle with hooks  184  located on the vertical portion of the T that are used to engage the cap removal holes  180  in the filter cap  146 . The tool  182  is then used to twist and pull upwards on the filter cartridge  134 - 138  to remove it from the filter housing  116 - 120  (See  FIG. 12 ). Alternatively, the tool can take the form of many other shapes as well, such as a simple U-shape. 
         [0053]    Referring to  FIG. 13 , due to the naturally long time it takes to process water through a R.O. membrane, a pressurized storage tank  194  is usually employed in the system  100 . Water which has already passed through the R.O. membrane collects and is temporarily stored in the storage tank  194  when the air gap faucet, through which the water will ultimately be dispensed, is shut off. Once the air gap faucet is opened, the pressure in the storage tank  194  is sufficient to force the treated water out of the tank, either for dispensing and use if it is fully processed product water, or for further processing downstream if it has been only partially-treated. In the preferred embodiment, the storage tank  194  is generally cylindrical in shape with hemispherical ends, however, the disclosure of this embodiment should not be read to limit the shape of the storage tank. 
         [0054]    The tank  194  includes at least one tank fluid flow port  196  through which water enters and leaves the storage tank. The tank fluid flow port  196  is connected to either, the satellite storage tank control port  126  of the upper manifold  112  in the main assembly  110  if the tank is a satellite tank, or it is connected to one of the pathway configuration ports  140  (not visible in  FIG. 13 ) of the lower manifold  114  in the main assembly  110  if the tank is an integrated tank. The tank  194  also includes an internal sealed, gas-pressurized bladder  198  (not visible). This bladder  198  is what provides the pressure to the water stored in the tank  194  in order to force it out of the tank  194  once the air gap faucet is opened. The internal workings of the tank  194  are well known in the art and therefore will not be addressed in any great detail. The tank  194  further includes a plurality of threaded fasteners  200 , integrally disposed in the outer surface of the storage tank  194 . Standard system designs use a satellite storage tank that is separated from the main filtration system assembly  110 . In the preferred embodiment however, the fasteners  200  allow the tank to mount to the main assembly  110  (See  FIGS. 13 &amp; 19 ) using threaded posts such as screws  202  or bolts and an integrated tank adapter plate  203  attached to the lower manifold  114 , thus creating an integrated single-unit R.O. system. Alternatively, the fasteners  200  may be snap-type cantilevered beams, holes to accept rivets or pins, bayonet type mounting holes to accept bayonet type screws, or any fastening means that will provide a robust field-removable linkage between the tank and the main manifold assembly  110 . 
         [0055]    Referring to  FIG. 13 , in the preferred embodiment, the tank also includes removable legs  204  which fasten to the tank  194  in the same manner as the tank fastens to the main assembly  110 . When the tank is used as a satellite tank, the legs  204  can be removed and reattached to the tank  194  via the fasteners  200  and screws  202  at another location on the tank&#39;s surface, in order to change the resting orientation of the tank  194  (See  FIG. 20 ). Additionally, in alternate embodiments, more than one tank may be utilized to increase the storage capacity by using both an integrated tank and a satellite tank as described above, or, referring to  FIGS. 21 &amp; 22 , by using multiple satellite tanks that are physically linked together via a plurality of removable universal mounting brackets  206  and the fasteners  200  and screws  202  previously discussed. Furthermore, using the removable brackets  206 , the satellite tanks may be mounted to various structures in multiple orientations as needed, such as hanging vertically from a ceiling rafter or mounting horizontally to a wall. 
         [0056]    In operation, the preferred embodiment of the invention disclosed herein works as follows: the filter cartridges  134 - 138  are loaded into the filter housings  116 - 120  and the integral filter housing caps  146  are secured in place with retaining pins  170 . Impute feed water enters the system via an inlet control connection port  124  and travels through the pre-filter  134 , the R.O. membrane  136 , and the post-filter  138  via the hermetically sealed water pathways  132 . Referring to  FIG. 4 , the design of the lower manifold  114  is unique in that it has multiple pathway configuration ports  140  molded into it in a closed state to optionally be opened and used for alternate water pathway configurations. Additionally, referring to  FIG. 14 , incorporated into the lower manifold&#39;s  114  design are multiple pathway gate notches  142  within the water pathways  132  that accept separate pathway modification gates  144 . The purpose of the configuration ports  140 , gates  144 , and notches  142  is to force the water to travel alternate paths and to flow into or out of various attachments when alternate embodiments are employed. Depending on the desired water flow path in and out of the main assembly  100 , prior to hot plate welding the upper  112  and lower  114  manifold together, select configuration ports  140  are drilled open and gates  144  are press fit or sonic welded into specific notches  142  in order to shut off specific internal ports or close off specific pathways  132 . This effectively changes the path the water will take through the water pathways  132  and the main assembly  110 , or changes the order in which the feed water enters the various filter sumps  148 - 152 . The opened configuration ports  140  are then connected to other opened ports  140  by tubes. In this manner, the system can be configured in a variety of ways to perform a variety of desired tasks. This procedure is also how the ports  140  are opened up to allow water to flow into and out of an integrated storage tank  194  as previously discussed as opposed to only utilizing a separate satellite storage tank. Referring to  FIG. 17 , this design thus allows, in an alternate embodiment, two fully assembled main assemblies  110  to be joined to form a single unit by blocking their proper water pathways  132  with gates  144 , opening their proper configuration ports  140 , connecting their corresponding opened pathway configuration ports  140  with tubing, and mounting the lower manifolds of the two assemblies  110  together using an adapter plate (not shown). By doing so, water can flow between the two sets of water pathways of the two main assemblies  110 . 
         [0057]    In the preferred embodiment, after entering the system via the inlet control port  124 , the impure feed water is first channeled down the water pathways  132  and into a pre-filter sump  148  containing a sediment pre-filter  134  used to remove dirt, sand, and other suspended solids. The feed water passes, under pressure, through the pre-filter  134  and exits the pre-filter sump  148  via a filter housing outlet port  186  where it re-enters the water pathways  132 . 
         [0058]    Next, depending on the configuration of the water pathways  132 , the water enters an R.O. membrane sump  150  containing the R.O. membrane  118  used to remove bacteria, salts, and other dissolved solids. Most of the water in the membrane sump  150  passes through the membrane  118  contained therein, thus filtering out most of the total dissolved solids in the water. The water exits the R.O. membrane sump  150  in one of two paths. The first path is for water that passes through the R.O. membrane  118 , which is not the path taken by the majority of the water in the sump  150 . The first path carries the membrane filtered water from the R.O. membrane sump  150  down the water pathways  132  to a tank control port  126  which is connected to a satellite storage tank  194 . The storage tank  194 , pressurized to less than the feed water line pressure, holds the R.O. filtered water until an air gap faucet connected to the main assembly  110  is opened by a user. Once the faucet is opened, the water stored in the storage tank  194  is forced out of the storage tank  194  by the gas-pressurized bladder  198  contained therein. The water flows back through the tank control port  126  of the main assembly  110  and back into water pathways  132  of the main assembly  110 , where it then enters a post-filter sump  152  containing a carbon filter to remove impurities that affect the water&#39;s taste and odor. Once the water passes through the carbon post-filter, it leaves the post filter sump  152 , enters the water pathways  132  one last time, and travels through a faucet control port  128 , which is connected to the air gap faucet, in order to dispense the water from the faucet when called for by the user. 
         [0059]    The second path through which water may exit the R.O. membrane sump  150  is for drain water which is routed to a drain water flow restrictor  130 . This is the path through which the majority of the water in the sump  150  flows. The large portion of the pre-filtered feed water that does not pass through the R.O. membrane  136  leaves the R.O. membrane sump  150  sump via a filter housing drain port located on the same side of the membrane as the housing&#39;s inlet port. This water is essentially concentrated waste water containing all of the impurities filtered out during the R.O. filtration process, which then leaves the system  100  through the main assembly&#39;s  110  drain control port  122  as drain water for disposal. By splitting off part of the incoming water as drain water rather than forcing all of the incoming feed water through the R.O. membrane  136 , the R.O. membrane  136  is constantly being cleaned and having the impurities discarded rather than allowing them to build up on and clog the pores of the membrane surface, thus significantly extending the life of the R.O. membrane  136  and the time until the membrane  136  needs to be replaced. 
         [0060]    Referring next to  FIGS. 15-16 , all R.O. units need to control the rate at which drain water leaves the membrane sump  150  while processing water through the R.O. membrane  136 . The cleaner the feed water, the less drain water needs to be split off and discarded. Controlling the drain rate is accomplished via the drain flow restrictor port  130  which contains a drain control barrel valve  188 . The drain barrel  188  has several orifices  190  located within it, through which drain water flows, which may be selectively opened or closed to increase or decrease the flow of the drain water. The drain barrel  188  is rotated in order to select various predetermined drain rates or ratios of drain water to product water. Two additional settings outside of the necessary incorporated drain ratios are “off”, which is a setting that completely closes the orifices  190  of the drain barrel and does not allow any water to flow through the drain flow restrictor  130 , and “fast flush,” which fully opens the drain barrel orifices  190 , flushing the majority of the water in the sump  150  to the drain for disposal. As membrane production rate technology improves, the need to send water to drain may be eliminated. The “off” position can be used for any reason no flow through the drain barrel  188  is desired, while the “fast flush” position allows for manually flushing the existing membranes currently being used in the industry. Alternatively, similar drain functions can be achieved in the practice of an embodiment of the matter disclosed herein by use of needle valves, ball valves, or any other valve technology which allows a user to selectively adjust flow rates through said valve. 
         [0061]    Referring to  FIGS. 17-19  showing alternate embodiments of the matter disclosed herein and as previously discussed, the lower manifold  114  is designed such that the main assembly  110  can accept accessory filtration devices or peripherals to it, or can be mounted directly to other drinking water devices. The design allows for two or more R.O. unit main assemblies  110  to be connected to each other and work as one larger unit (See  FIG. 17 ). Additional alternate embodiments of the matter disclosed herein include the incorporation of, but are not limited to: auxiliary filter housings that can be implemented at any filtration stage desired; pumps, electronic monitoring and control devices, and UV modules connected to or mounted to the main assembly  10  (See  FIG. 18 ); office water coolers and drinking fountains connected to or mounted to the main assembly  110 . The ability to incorporate electronic monitoring and control devices and other peripherals discussed above into various embodiments of the matter disclosed herein allows for an “auto flush” system to perform the drain rate monitoring functions, “fast flush” functions, and “no flow” functions discussed above, on time-based or volume-based flushing or cleaning schedules. Additionally, when an electronic monitoring and control module is incorporated by itself into an embodiment of the matter disclosed herein or with other incorporated modules, alarms can be used to indicate important information such as, but not limited to, filter replacement timelines, cleaning schedules, or unit maintenance. 
         [0062]    Furthermore, in yet another embodiment, the system can utilize secondary membrane housings and be configured to allow parallel flow through two or more membranes  136 . Additionally, in yet another embodiment, a decorative cover  192  fits over the main assembly  110  to create the attractive appliance feel that the main assembly  110  is lacking (See  FIG. 19 ). The cover  192  uses a variety of shapes and contours that accentuate the existing main assembly. 
         [0063]    While the present invention has been described in terms of the embodiments depicted in the drawings and discussed above, it will be understood by one skilled in the art that the present invention is not limited to these particular embodiments, but includes any and all such modifications that are within the spirit and the scope of the present invention as defined in the appended claims.