Abstract:
Disclosed is a water supply control system for controlling the water supply system in a structure, such as a home or industrial or commercial building. The water supply control system typically includes an electronically controlled on-off valve to shut down the water supply to the structure, and a water pressure relief valve coupled to the on-off valve. Additional means for relieving pressure build up in the water supply system that may be included in the control system are (1) an expansion bladder, or (2) a vent pipe integral to the water supply system and terminating on the exterior of the structure, including an on-off valve electronically controlled so as to open when the water supply system is shut down and to close when the water supply system is turned on, or (3) means for disabling a hot water heater integral to the water supply system, the disabling being accomplished concurrently with the closing of the water supply to the structure.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to apparatus for controlling water supply systems incorporated into structures used, for example, as homes and businesses. More particularly, the present invention relates to apparatus that allows an occupant of a structure to shut down a water supply system to insure against leakage that might cause extensive damage to the structure, especially during times when the structure is unoccupied.  
         BACKGROUND OF THE INVENTION  
         [0002]    Most structures, such as homes and businesses, are supplied with water through a plumbing system. Either plastic or metal pipes carry water, under pressure, from an outside source into the structure and to various apparatus inside the structure that require water for their use. Such apparatus includes, sinks, toilets, washing machines, refrigerator ice makers, hot water heaters, as well as a wide variety of industrial and commercial equipment.  
           [0003]    Leaks occur from time to time inside structures that cause extensive damage to a structure and its contents. For example, leaks might occur in the piping, particularly at the joints. Leaks might also occur when washing machine hoses, washers, seals and other component parts in the water supply system rupture or wear out. Because the typical water supply system is under pressure, a leak will continue to deliver water into the structure indefinitely until someone finds the leak and takes action to stop the water flow. If the structure is unoccupied for a period of time, and the water flows unchecked into the interior of the structure, substantial damage may result. Such damage might include destruction of walls, ceilings, carpet and other flooring, furniture, and the like.  
           [0004]    Lately, such water damage has been resulting in toxic mold buildup inside of structures. Such mold buildup can be very dangerous to human life, and can be fatal in some cases. At a minimum, this mold buildup will exacerbate allergic reactions in humans. Cleaning and eliminating this mold buildup is very expensive and time consuming. Frequently, occupants must vacate the structure for a period of time while the mold is being eliminated by professionals who specialize in this type of work. Once the mold is eliminated, repair of the structure, its aesthetics, and contents must begin. This phenomenon has resulted in many millions of dollars worth of insurance claims. As a result, homeowners&#39; insurance premiums have skyrocketed in various parts of the country where this type of mold damage is found.  
           [0005]    Shutting off the water supply is one way to prevent leaks from occurring at times when structures are unoccupied and leakage can continue unchecked for a significant period of time. Traditionally, shutting off a water supply typically requires knowing where the main shut off valve is and taking action to close it. Some people either do not know where their main valve is, or if they do know where it is they do not know how to shut it. Alternatively, some main valves are located in such inconvenient locations, that people do not bother to take the time and exert the effort to shut the main valve when they leave the structure for any significant length of time. Such inconvenient locations for water main valves include installation in basements and crawl spaces under structures, as well as in below-ground boxes outside of structures, usually near the street.  
           [0006]    Prior art devices have been developed that have attempted to deal with the general problem of water damage in various ways. For example, U.S. Pat. No. 6,237,618 Bi by Kushner, entitled System and Method for Controlling the Unwanted Flow of Water Through a Water Supply Line, hereby incorporated by reference herein, discloses a system that attempts to achieve the stated objective in a relatively complicated and costly way. Kushner&#39;s system includes first and second operations modes, flow meters that detect water flow volume levels within the water supply line, and various actions that take place depending upon the status of the water supply system as detected by Kushner&#39;s control system. An examination of this patent reveals that this is a relatively complex and costly system. This system is not likely to be amenable to quick and easy installation by a plumber or homeowner, and is not likely to be easily installed in existing structures.  
           [0007]    Another example is U.S. Pat. No. 4,845,472 by Gordon et al., entitled Leak Sensing Alarm and Supply Shut-off Apparatus, which discloses a system that shuts down the water supply only after a leak has occurred, and provided that the leakage is detected by the system&#39;s water detection sensor. The water supply may be shut down independently of the water detection sensor, but there is no accommodation for increased pressure in the water system as a result of operation of the water heater.  
           [0008]    In view of the foregoing, there is a clear need for a system that allows the occupant of a structure to shut down a water supply system in a quick, easy, uncomplicated way. There is also a need for a system that is relatively inexpensive and easy to install, in both new structures as well as existing structures. Such a system must also provide for relief of pressure that may build up to hazardous levels as a result of operation of a hot water heater. These and other objectives are met by the present invention.  
         SUMMARY OF THE INVENTION  
         [0009]    Disclosed is a water supply control system integral to a water supply system in a structure and capable of shutting down the supply of water to the structure. The structure typically has an interior and an exterior.  
           [0010]    The water supply control system comprises electronically controlled means for shutting down the water supply to the structure, integrally coupled to the water supply system. The water supply control system also comprises means for relieving pressure build up in the water supply system while the water supply is shut down, the means for relieving pressure build up being integrally coupled to the water supply system and located on the downstream side of the electronically controlled means for shutting down the water supply. The water supply control system further comprises at least one additional means for relieving pressure build up in the water supply system, integrally coupled to the water supply system.  
           [0011]    The electronically controlled means for shutting down the water supply to the structure may comprise an electronically controlled solenoid valve assembly, or any electronically controlled on-off valve. The means for relieving pressure build up in the water supply system may comprise a water pressure safety relief valve. Additional means for relieving pressure build up in the water supply system may comprise (1) an expansion bladder integral to the water supply system, or (2) a vent pipe integral to the water supply system and terminating on the exterior of the structure, the vent pipe comprising a second solenoid valve electronically controlled so as to open when the water supply system is shut down and to close when the water supply system is turned on, or (3) means for disabling a hot water heater integral to the water supply system, the disabling being accomplished concurrently with the closing of the water supply to the structure, and enabling of the hot water heater being accomplished concurrently with opening of the water supply to the structure.  
           [0012]    Also disclosed is a method for controlling the water supply system of a structure. This method comprises the steps of (1) installing electronically controlled means for shutting down the water supply system of the structure; (2) installing means for relieving pressure build up in the water supply system while the supply is shut down, the installation occurring on the downstream side of the electronically controlled means for shutting down the water supply system, and (3) installing at least one additional means for relieving pressure build up in the water supply system, integral to the water supply system.  
           [0013]    The electronically controlled means for shutting down the water supply system may be a solenoid valve assembly. The means for relieving pressure build up in the water supply system may be a water pressure safety relief valve.  
           [0014]    The present invention will become clear to those skilled in the art from a review of the drawings and the following description of the preferred embodiments.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    For a better understanding of the present invention, reference is made in the text of the specification to the drawings which are described as follows:  
         [0016]    [0016]FIG. 1 is a schematic view of a water supply system to a structure built on a slab foundation, in accordance with the present invention.  
         [0017]    [0017]FIG. 2 is a schematic view of a water supply system to a structure built on a full basement foundation, in accordance with the present invention.  
         [0018]    [0018]FIG. 3 is an exploded detail view of the mechanism of the present invention shown in FIGS. 1 and 2.  
         [0019]    [0019]FIG. 4 is a schematic diagram of the electronics encompassed within the control box of FIGS. 1 and 2.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]    Referring now to FIG. 1, there is shown a structure  10  equipped with the present invention. Structure  10  in FIG. 1 is built on a slab foundation  11 . Pressurized water supply  12  to structure  10  may be a municipal water supply from water pipes run through the street adjacent to structure  10 , or may be an artesian well drilled on the property. Typically, with regard to a structure built on a slab  11 , the main valve and water meter  14  are contained within an access box built into the ground on the property. Such setups are often used in parts of the country where the ground does not freeze in the winter, or buried at a depth that is dependent upon the depth of winter soil freezing.  
         [0021]    Downstream from main valve and water meter  14  would be any exterior water use application  16 , such as an automatic lawn sprinkler system or the like. This exterior water use application  16  is located between main valve and meter  14  and mechanism  18  so that the exterior water use application  16  will remain active even when the water supply to structure  10  is shut down via the present invention.  
         [0022]    Mechanism  18  houses components, further described below, that are controlled by control box  20 . Control box  20  contains electronics that operate the system, further described below. Control box  20  has an on/off switch  22 , a light emitting diode  24  that may be red in color, and a light emitting diode  26  that may be green in color. Electrical leads  28  electronically couple control box  20  to mechanism  18 . In FIGS. 1 and 2, control box  20  and  20   a  are shown in an exaggerated size with respect to structure  10  and  10   a  simply for sake of clarity and explanation. It is contemplated that control box  20  may be equipped with means to provide a sound, such as an audible “beep”, when the present invention is activated or deactivated as further described below.  
         [0023]    Mechanism  18  is located in a below ground access box exterior to structure  10 . From mechanism  18 , the water supply line enters structure  10  and supplies water to toilets, sinks, hot water heaters, refrigerator ice makers, washing machines, and any other equipment that requires water for operation.  
         [0024]    [0024]FIG. 2 represents structure  10   a  which is built on a full basement foundation  11   a . FIG. 2 could also represent a structure built on a crawl space foundation. In parts of the country where winters are harsh and the ground freezes, water supply  12   a  is typically supplied through piping which is buried below the frost line. This may be too deep to accommodate a below ground access box on the property. Therefore, the typical setup encompasses water supply  12   a  running via piping into basement  11   a  where the piping is then coupled to water main valve and meter  14   a . Exterior water use application  16   a  would then be coupled into the piping so as to be operative even when the present invention is activated to shut down the water supply to the rest of the structure. Mechanism  18   a  would then be coupled into the water supply piping, and would be controlled by control box  20   a  as described above.  
         [0025]    A water heater is almost always included in a water supply system to a structure. If the water supply to a structure is shut down, and the water heater is still operative, the water in the closed system will expand and increase in volume when the water heater turns on. This will cause pressure build up within the closed system. If the pressure builds up beyond a certain threshold level, there is a danger that damage will occur to the system. For example, joints in the piping could burst open, and seals and washers in fixtures could give out. If this were to happen while occupants of the structure were away for an extended period of time, water would then flow into the structure and cause the types of damage discussed previously.  
         [0026]    In order to prevent such pressure build up, certain precautionary devices are contemplated as part of the present invention which operate along with the portion of mechanism  18  that shuts down the water supply. Let us now turn to a detailed discussion of the components of mechanism  18 , as shown in FIG. 3.  
         [0027]    [0027]FIG. 3 shows water supply  12  entering, via piping, electronically controlled solenoid valve assembly  30 . Valve assembly  30  may be any electronically controlled on-off valve, and function within the scope of the present invention. Electrical leads  28  from control box  20  are coupled into valve assembly  30  for electronic activation and deactivation of valve assembly  30 . A typical valve assembly  30  would be, for example, Irritrol 2004T, {fraction (3/4)} inch valve, 24 VAC solenoid coil, normally open, manufactured by Industrial Plastic Valves in Carson City, Nev. This valve assembly  30  is normally open, meaning that it must be activated to close and thereby shut off the water supply. Valve assembly  30  has an inflow port  32  into which water flows, and an outflow port  34  out of which water flows when the valve is open.  
         [0028]    Valve assembly  30  is then coupled to water pressure safety relief valve  36  via piping. Relief valve  36  must be supplied with a T-connector  38 . T-connector  38  has inflow port  40  into which water flows and outflow port  42  out of which water flows into structure  10  and to the equipment within structure  10  that require water for their operation.  
         [0029]    T-connector  38  also has relief valve port  44  to which is coupled relief valve  36 . A typical relief valve  36  would be, for example, the ¾ inch, Series 530C, adjustable pressure relief valve, manufactured by Watts Regulator of North Andover, Mass. Valve  36  includes a calibrated screw knob used to set a predetermined pressure level that causes the valve to trip open. This predetermined pressure level is typically set just above the normal operating pressure of the pressurized water supply to the structure. When the pressure in the system reaches the preset threshold value, the valve trips open and water is released from relief valve exit port  46  in order to avoid damage to the water supply system from over pressurization. In the case of the structure shown in FIG. 1, water from exit port  46  would run into the ground. In the case of the structure shown in FIG. 2, exit port  46  would need to be coupled to piping that runs outside of structure  10   a  so that water released from exit port  46  would run into the ground and not onto the floor of basement  11   a.    
         [0030]    [0030]FIG. 4 is a schematic of the electronics of control box  20  which activate and deactivate valve assembly  30 . 120 volt AC power  48  is supplied to control box  20 . 1.5 amp transformer  50  then converts 120 volt AC to 24 volt AC. A 1.5 amp fuse  52  is coupled between transformer  50  and DPST switch  54 . When switch  54  is in the off position (shown), green light emitting diode  56  ( 26  in FIG. 1) glows to indicate that water is flowing through the system. When switch  54  is in the on position, red light emitting diode  58  ( 24  in FIG. 1) glows to indicate that the water supply is shut off. Connections  60  are the equivalent of leads  28  in FIG. 1, and couple the electronics within control box  20  to valve assembly  30 . 24 volt AC solenoid coil  62  represents the electronics within valve assembly  30  that open and close the valve. 48 volt 0.2 watt metal oxide varistor  64  is placed across the leads to solenoid coil  62  inside control box  20 . Varistor  64  acts as a surge protector and prevents inductive voltage spikes, which occur each time solenoid coil  62  is activated, from damaging light emitting diodes  56  and  58  and switch  54 .  
         [0031]    Control Box  20  should be located in any convenient location, preferably in a utility room or near an exit door. When an occupant is leaving structure  10  for any significant length of time, the person can activate switch  22  to shut down the water supply to the structure. Green light emitting diode  26  will then shut off, and red light emitting diode  24  will then illuminate to indicate that the water supply is shut off. During this time, if the water heater activates thereby increasing pressure in the closed system, relief valve  36  will open when the pressure in the closed system reaches the preset threshold pressure of relief valve  36 . As water flows out of exit port  46 , pressure in the system is reduced to a safe level, and relief valve  36  returns to the closed position.  
         [0032]    Alternative means for pressure relief within the closed water supply system are contemplated for use with the present invention. The first such alternative would be a second water pressure safety relief valve located on a drain outlet on the hot water heater. Such relief valves on hot water heaters are common, but because hot water heaters are usually located within the structure, it is undesirable for drainage to take place at the site of the hot water heater unless the drain is coupled to piping that runs outside the structure. The present invention contemplates that the threshold relief pressure on relief valve  36  would be set lower than the threshold pressure on a similar relief valve at the hot water heater. This would result in relief valve  36  activating as the primary safety mechanism, and the valve at the hot water heater operating only as a back up device in the case of extreme overload on the system or malfunction of relief valve  36 .  
         [0033]    The second alternative means for pressure relief would be an expansion bladder, coupled into the water supply system proximate to the hot water heater. Such devices are known in the plumbing art, and allow for expansion of the water in a closed system when the pressure, and thereby the volume of water, in the system increases without damage to the system. An example of such an expansion bladder is contained in U.S. Pat. No. 5,584,316 by Lund, entitled Hydrothermal Stabilizer and Expansion Tank System. Other types of expansion bladders are known in the plumbing art.  
         [0034]    Another alternative means for pressure relief would be a vent pipe coupled into the water supply system. This vent pipe would terminate outside the structure and would include a second solenoid valve assembly, or any other type of electronically controlled on-off valve. The electronics in the control box would be configured so that when the water supply is turned on, this second solenoid valve in the vent pipe would be closed to prevent water from running out the vent pipe terminus. When the water supply is turned off, this second solenoid valve in the vent pipe would open to prevent any pressure build up from water volume expansion. In such case, water would run out the vent pipe terminus onto the ground outside the structure. The vent pipe must be run up to an elevation above any equipment in the structure that uses water so that the force of gravity will not cause the water in the system to drain out the vent pipe terminus when the second solenoid valve is open.  
         [0035]    Yet another alternative means for pressure relief in the system would be to automatically disable the hot water heater when valve assembly  30  is closed and the water supply is shut off. Such means could include a switch built into control box  20  that simply shuts off the supply of electricity to an electric hot water heater, thereby preventing any heating of the water in the system, and the accompanying water expansion, when the water supply is shut down.  
         [0036]    In the case of a gas hot water heater, the gas control valve of the hot water heater does not have electricity supplied to it. The voltage for opening the gas supply to the burner is supplied to an internal solenoid valve within the gas control valve. When the pilot light is lit, millivolts are produced by a pilot generator. This generator produces from 250 to 750 millivolts which is available to open the internal solenoid valve. The valve opens when the water temperature inside the tank drops below the desired temperature setting. At this point, two dissimilar metals inside the probe come in contact with each other causing a circuit to close and sending the millivolts of power to the main gas valve to open. This allows gas to flow to the burner which is ignited by the pilot light. When the water in the tank reaches the desired temperature setting, the dissimilar metals break contact, thus opening the circuit and shutting off the gas supply. To shut down this system all together, a switch would need to be installed which kept the millivolts of power from reaching the main gas valve, thereby preventing gas flow to the burner.  
         [0037]    Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the above disclosures are exemplary only and that various other alternatives, adaptations, and modifications may be made within the scope of the invention. Accordingly, it is to be understood that the present invention is not limited to the precise construction as shown in the drawings and described hereinabove.