Abstract:
A domestic water distribution system that continuously delivers heated water to one or more hot water faucets. The system utilizes a convective return loop from the desired faucets, which is regulated by a flow control device. The control device is specifically designed to allow unhindered flow during circulation without allowing reverse flow when a faucet is opened. The flow control device has an easily accessible handwheel adjustment that is used to select the three modes of operation and the flow rate. These modes are called: HELD-ON, HELD-OFF, and NORMAL-OPERATION. With the first two modes being used to fill and flush the system as is necessary with new installation and recreation vehicles. Also, a lighter-than-water checking element is used, which allows the system to function in single-level plumbing installations without the need for inclined supply and return routing. The circulation is further assured by having the plumbing return and cold water supply connected to the base of the water heater, which creates a flushing action of sediment that accumulates inside and since plumbing insulation is not restricted, heat loss is limited.

Description:
FEDERALLY SPONSORED RESEARCH 
     Not Applicable 
     SEQUENCE LISTING OR PROGRAM 
     Not Applicable 
     BACKGROUND 
     1. Field of Invention 
     This invention relates to thermal convection of heated water for domestic use, specifically to an improved and simplified controlling valve. 
     2. Discussion of Prior Art 
     The inconvenience and wastefulness of waiting for hot water to arrive at the faucet is an expense and bother. Various systems and devices have been developed to address this problem, but have had limited success. 
     Systems that employ pumps such as U.S. Pat. No. 5,277,219 to Lund—Jan. 11, 1994; U.S. Pat. No. 5,323,803 to Blumenauer Jun. 28, 1994; U.S. Pat. No. 5,511,579 to Price Apr. 30, 1996, all require an electrical source, timers, and temperature sensors, that add considerably to the cost and complexity of operation. Similar systems also waste energy by returning some heated water into the cold water plumbing. 
     Aspirator assisted systems such as U.S. Pat. No. 5,331,996 to Ziehm Jul. 26, 1994; U.S. Pat. No. 5,518,022 to Ziehm May 21, 1996; U.S. Pat. No. 5,622,203 to Givler et al. Apr. 22, 1997, all introduce a flow restriction into the cold water system. Also, when hot and cold water faucets are open at the same time, a portion of warmed water is introduced into the cold water system. This type of system does not work well in a one-story dwelling where the plumbing and the water heater are at the same level. Some systems recommend not insulating the return plumbing, creating an energy loss. 
     Basic convective flow systems, such as U.S. Pat. No. 3,929,153 to Hastey Dec. 30, 1975 and U.S. Pat. No. 5,620,021 to Hugo Apr. 15, 1997, have restrictive installation requirements. These and other past art heretofore known suffer from a number of disadvantages: 
     (a) The need to have upwardly sloped supply and downwardly sloped return plumbing with no sections inversely oriented. 
     (b) The need to have venting devices at the highest point in the system. 
     (c) The need to have some kind of connection between the hot and cold water systems, such as, check valves, thermostatic valves, aspirator devices, heat exchangers, and motor driven pumps. 
     (d) The need to have the water heater at the lowest point, preferably 5 feet or more below the faucets being served. 
     (e) The need to have a check valve element that is heavier than the liquid involved so as to favor a closed condition. 
     (f) The need to have the check valve means located at or near the water heater. 
     (g) Some have the need to not insulate the return portion of the convective loop. 
     OBJECTS AND ADVANTAGES 
     Accordingly, several objects and advantages of my invention are: 
     (a) To provide a system that is not sensitive to variations in plumbing orientation, such as downward sloping portions of the supply and upward sloping portions of the return plumbing. 
     (b) To provide a system that does not need air venting devices. 
     (c) To provide a system with no connections needed between the hot and cold water plumbing. 
     (d) To provide a system that can have the water heater on the same level as the faucets being served. 
     (e) To provide a system with a lighter-than-water check valve element, so as to remain open during convective flow periods. This element to be approximately 0.95 specific gravity, so that reverse flow dynamics induces closure during hot water flow at any hot water faucet. 
     (f) To provide a system that can have the controlling check valve located at various places within the return loop from the hot water faucet. 
     (g) To provide a system that can have any amount of insulation used on both the supply and return plumbing loops. 
     Further objects and advantages are to provide a system that can be easily used and serviced by an average homeowner. Specifically suitable for use in a recreational vehicle (RV) where periodic servicing such as winterizing, flushing, cleaning, and filling is a necessary operation. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
     SUMMARY 
     This invention is a simplified hot water circulation system with a multifunctional flow control device that specifically addresses single level systems such as those found in recreation vehicles. The flow control device employs a movable element that is lighter-than-water which allows unimpeded flow; the flow is induced by the differential density within the water heater. This system is also readily adaptable to single level dwellings without a basement as well as multilevel dwellings. 
    
    
     DRAWINGS 
     Drawing Figure 
     FIG. 1 shows a partial sectional view of the valve in a normal operating position and an end view indicating the section location. 
     FIG. 2 shows a section fragment of the valve in the closed position. 
     FIG. 3 shows a section fragment of the valve in the defeated or held-open position. 
     FIG. 4 shows a diagrammatic illustration of a hot water system in a recreation vehicle (RV). 
     FIG. 5 shows a diagrammatic illustration of a hot water system in a single story dwelling with overhead plumbing. 
     FIG. 6 shows a diagrammatic illustration of a hot water system in a single story dwelling with below floor plumbing. 
     FIG. 7 shows a diagrammatic illustration of a hot water system in a two story dwelling, showing options for control valve locations. 
    
    
     REFERENCE NUMERALS IN DRAWINGS 
       10  valve assembly 
       12  checking element 
       14  restrainer pin 
       16  valve stem 
       18  handwheel 
       20  packing nut 
       22  packing 
       24  bonnet 
       26  valve body 
       28  gasket 
       30  flow arrow 
       32  slot 
       34  inlet 
       36  outlet 
       38  RV-type water heater 
       40  hot water pipe 
       42  shutoff valve 
       44  sink faucet 
       46  shower faucet 
       48  tee 
       50  return water pipe 
       52  cold water supply pipe 
       54  insulation 
       56  home-type water heater 
       58  drain valve 
     DETAILED DESCRIPTION 
     Description—FIGS.  1 ,  2 , 3 , and  4  Preferred Embodiment 
     A preferred embodiment of the present invention is illustrated in FIG. 1 (sectional view) and an end view indicating the section location. Valve assembly  10  is a familiar globe-type valve with modified and additional parts that serve a multipurpose function. Said valve showing inlet  34 , outlet  36 , and flow arrow  30  to have a normal fluid flow direction (right to left). Typical valves of this type have a handwheel  18 , valve stem  16 , packing nut  20 , and packing  22  which do a sealing function between the external moving parts. The threaded engagement of bonnet  24  into valve body  26  completes the assembly of nonmoving parts. 
     FIG. 1 (sectional view) is illustrated in a normal operating position, with valve stem  16  and restrainer pin  14  assembly such that pin  14  is in the center of slot  32 . Checking element  12 , which is in an off position, is shown resting on the seat portion of valve body  26 . Checking element  12  is free to move vertically until restrainer pin  14  contacts the bottom of slot  32 . Since checking element  12  is made from a lighter-than-water material, element  12  will float to an ON position when valve assembly  10  is filled with water. 
     FIG. 2 Illustrates stem  16  and pin  14  assembly in the lowest position, which is the HELD-OFF condition. 
     FIG. 3 Illustrates stem  16  and pin  14  assembly in the highest position, which is the HELD-ON condition. These conditions are explained in more detail in the operation section. 
     FIG. 4 Illustrates a diagramatic plumbing system typically found in a recreation vehicle. RV-type water heater  38  is a small under-counter design that has a capacity of 6 to 10 gallons. Hot water flow, as indicated by flow arrows  30 , goes first through shutoff valve  42  and then on through tees in hot water pipe  40  to tee  48 . Thereby supplying sink faucet  44  and shower faucet  46  with heated water. This convective flow continues on through tees  48  into return water pipes  50 , arriving at inlet  34  of valve assembly  10 . The outlet  36  of valve  10  is connected to a tee along with the cold water supply pipe  52  which is in turn connected to the inlet of water heater  38 . Also note that both hot water pipe  40  and return water pipe  50  are continuously covered by insulation  54 . 
     FIGS.  5 ,  6 ,  7  Additional Embodiments 
     Additional embodiments illustrated in FIG.  5  and FIG. 6 are similar in many ways to FIG.  4 . With FIGS. 5 and 6 illustrating the use of a home-type water heater  56 . Cold water supply pipe  52 , which can be routed into said water heater either into the top, as indicated by solid-line plumbing, or into the bottom, as indicated by a dashed-line. 
     FIG. 5 Illustrates hot water pipe  40  above the supplied sink faucets  44 , which employs the same circulation principals shown in FIG.  4 . 
     FIG. 6 In contrast, shows hot water pipe  40  routed down to the same level as the return pipe  50 . This arrangement can be found in pre-manufactured homes and homes without a basement. Similarly, the cold water pipe  52  can be routed to either the top or the bottom of water heater  56  (as shown in FIG.  5 ). 
     FIG. 7 Illustrates a diagramatic plumbing system typically found in a single level home where the home-type water heater  56  is in a basement area. The convective flow, as indicated by arrows  30 , employs the same principal as previous figures. Similarly, the cold water supply pipe  52  can be routed to either the top or the bottom of water heater  56  (as seen in both FIGS.  5  and  6 ). The advantage of connecting to the bottom of heater  56  will be explained in the ensuing operation section. An important feature difference in FIG. 7 is the optional location of valve assembly  10  and valve  42 . The conventional location of valve  10  is at the base of heater  56  as illustrated with solid lines. The preferred optional location is next to tee  48 , as indicated by dashed outline of valve  10 . An additional preferred location of valve  42 , is also next to tee  48 , as indicated by dashed outline of valve  42 . The drain valve  58  is moved so as to conform to the arrangement shown in FIGS.  5 , 6 , and  7 . 
     Advantages 
     From the description above, a number of advantages become evident: 
     (a) Saving of time waiting for hot water to arrive at a faucet. 
     (b) Saving of energy used to reheat cooled water in a conventional water system. 
     (c) Saving potable water resource as well as less water lost into the sewer system. 
     (d) All of the above savings become much more crucial when such a system is used in a recreational vehicle, while operating in a self-contained condition. Not only is the tank for heat energy of limited size, the fresh water and the waste water also have a limited capacity. Water used from the fresh water tank must be collected and held onboard the RV. 
     (e) Valve  10 , tee  48 , and valve  42  (as shown in FIG. 7) could be a single unit device for ease of installation and operation. 
     Operation—FIGS.  1 ,  2 ,  3 , and  4  Preferred Embodiment 
     To begin describing the main mode of operation, first consider having an installation such as shown in FIG.  4 . The water heater  38  is at floor level with the plumbing  40  routed vertically, supplying the first faucet  44 , then proceeding overhead before dropping down to tees  48  that supply faucets  44  and  46 . The above said plumbing would constitute a normal distribution system. Additional plumbing leaving tees  48 , proceeds back down to floor level through plumbing  50  and then to inlet  34  of valve  10 . The outlet  36  of valve  10  and cold water supply pipe  52  are then jointly routed to the input of water heater  38 . Said arrangement forms a convective loop that circulates due to the pressure produced by density differences within the water heater and the plumbing arrangement. These pressures developed within a single floor, as in FIG. 4, are very small, thus a convective loop that is unhindered by any mechanical device is essential. 
     FIG. 1 Shows valve  10 , previously described as a globe type valve, with the internal parts in a normal operating mode. The three basic modes of operation are as follows: 
     (a) HELD-ON Handwheel  18  fully counterclockwise as shown in FIG.  3 . 
     (b) HELD-OFF Handwheel  18  fully clockwise as shown in FIG.  2 . 
     (c) NORMAL OPERATION Handwheel  18  approx. one turn counterclockwise from the HELD-OFF position. 
     These three modes are utilized as follows during filling, flushing, and normal operation. 
     In filling the system (as shown in FIG.  4 ), the following steps should be taken: 
     1. Turn valve  10  to the HELD-OFF position. 
     2. Turn other valves off and apply water pressure to pipe  52 . 
     3. As water heater  38  fills, open valve  42 , and valves  44  and valve  46  so as to allow trapped air to be released. (Supply loop  40  should now be filled to all faucets.) 
     4. Now turn valve  42  off and valve  10  to the HELD-ON position, allowing pipe  50  to fill as valves  44  and  46  are opened to release trapped air. 
     5. Return valve  10  to the NORMAL-OPERATION position, (approx. one turn open) and open valve  42 . 
     The plumbing system is now filled with water without the use of venting devices. Water heater  38  can now be activated electrically or by gas flame. When the water heater reaches its set temperature, convective flow will supply instant hot water at faucets  44  and  46 . Well known with this and other prior art, a check valve must be in the system to prevent simultaneous flow from the top and bottom of water heater  38  when any faucet is opened. If not addressed, a mixture of hot and cold water would arrive at the faucet due to reverse flow in water pipe  50 . 
     Referring to FIG. 1, valve  10  is shown in a normal operating position, with checking element  12  resting in a seated position as would be the case without water being present. Since element  12  is free to rise vertically until contacting pin  14 , which would in turn allow unhindered flow as indicated by arrow  30 . When any faucet is opened, reverse flow between element  12  and the seat portion of valve body  26  will be initiated. This flow, due to the Bernoullie-effect, forms a reduced pressure at this opening which in turn draws element  12  onto a seated position. This action causes the flow in pipe  50  to stop. As long as a faucet remains open, the pressure at outlet  36  (back side of element  12 ) will be greater than inlet  34  (under side of said element) which causes valve  10  to stay off until said faucet is turned off. At this time, under no-flow conditions, the pressure will become equalized on either side of valve  10 , which will allow checking element  12  to float free and return to normal convective flow. 
     A further understanding of fluid dynamics involved with the above explanation would require an understanding that is beyond the scope of this operation section. 
     It should be added that valve  10  can also adjust the effective circulation rate from nearly off, to a maximum which is just before pin  14  contacts the top of slot  32 . Any additional counterclockwise rotation would cause said valve to be in the HELD-ON position. 
     Operation—FIGS.  5  and  6  Additional Embodiment 
     FIGS. 5 and 6 Illustrate very similar hot water systems compared to FIG. 4, except water heater  56 , which is a home-type water heater. The circulation principals are the same as the above operation section but, with the following additions or differences: 
     (a) Cold water supply pipe  52  (dashed line) shows the preferred location into a cross connector at the base of heater  56 . 
     (b) Water heaters  56  are on the same floor as the faucets being supplied. 
     (c) FIG. 6 shows the plumbing  40  and  50  routed at or below floor level. 
     Note: This configuration has the least level of circulation pressures, which led to the specific design of checking element  12 , which addressed this problem. 
     FIG. 7 Illustrates an additional similar system but water heater  56  is located in the basement below the living area. Circulation principals are the same but, with the following additions or differences: 
     (a) Cold water supply pipe  52  (dashed line) shows the preferred location into a cross-type connector at the base of heater  56 . Note: The main advantage of this location is to clear sediment away from inside the heater. This assures unhindered circulation loop as previously discussed above. 
     (b) Valve  10  has a preferred location next to tee  48  (as shown by dashed outline). This location should always be next to the most remote faucet in the system. This location would likely be in an easily accessible cabinet that would make changing the mode of operation very convenient. Such as turning valve  10  off while away for extended periods which would conserve energy-loss through the insulation  54 . 
     Conclusion, Ramifications, and Scope 
     Accordingly, the reader can easily understand that having a system as previously described, would save time, money, and natural resources. The costs of adding the necessary items to a new home or to an existing home can be recovered within a few years. Additionally, having such a system in a recreation vehicle would enable the user to conserve water that is limited by tank capacities. 
     While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Several other variations are possible, for example: 
     The circulation loops can simultaneously supply faucets on two separate floors as found in two story buildings; 
     Solar heating could be added to the supply plumbing  40  which would offset heat losses; 
     A ball-type version of valve  10  with a side push rod to tilt the ball away from its seat, thus creating a HELD-ON mode of operation; 
     A solenoid valve in conjunction with a timer could be used to stop the circulation during periods of nonuse; 
     The system could easily be adapted for use in a house-boat or a floating home;