GB2200941A - System for protecting water piping against freeze damage - Google Patents

Abstract

An electrically powered circuit is provided with a manually-resettable, thermostatically-actuated switch (22) to operate solenoids (26, 40) connected to valves (30, 44) controlling the inflow to a water piping system and drainage therefrom. When the ambient temperature surrounding the switch is above the freezing point of water, i.e. 32 DEG F, electrical power (10) to a solenoid (26) connected to the inflow valve (30) holds it open and simultaneously, electrical power (10) to a solenoid (40) connected to the drainage valve (44) holds the latter in its closed position. Upon the ambient temperature dropping to a predetermined value selected by the user, e.g. 33 DEG F, the switch (22) acts automatically to interrupt the supply of power (10) to the solenoids (26, 40) so that the water supply to the protected piping system (P) is shut off and the protected piping system (P) is drained by opening of the drainage valve (44). The protective system maintains itself in this condition until and unless the switch (22) is manually reset. Manual bypassing of the safety system may be obtained to obtain main's flow even when the protective system has acted in response to a low enough ambient temperature. <IMAGE>

Description

TITLE System for protecting water piping against freeze damage.

This invention relates generally to systems for protecting indoor piping systems against damage caused by the freezing of water therein during cold weather and, more particularly, to an electrically powered, adjustable and manually resettable system that automatically shuts off water inflow to the piping system and simultaneously drains the same.

A significant fraction of the world's population, particularly in the northern hemisphere, lives in a temperate zone in which wintertime temperatures frequently fall below 32'F, at which point water contained in indoor piping systems may freeze and crack the pipes unless the environment around the pipes is heated to be above the freezing point of water or a small and inherently flow of water is maintained through- the system. The avoidance of such foreseeable damage at reasonable cost and in a reliable manner has long posed a challenge that has been answered in numerous ways.

Basically, the most practical and economical solution-is to provide for a shut-off of water inflow to the piping system to be protected and, preferably simultaneoulsy, a substantially total drainout of water contained within the piping sys-tem, when the ambient temperature to which the pipes are subjected drops close to the freezing point.

Some of the earliest solutions, typified in U.S.

patent specification no. 346,308 to Newman, and specification nos. 351,093 and 360,139 both to Browne, employ thermostatic elements which deflect sufficiently at or about 329r to init'iate action by a spring and/or weights to operate valves in the piping system to perform the desired functions. U.S. patent specification no 1,246,368 to Wilson discloses apparatus with an adjusting screw to permit manual adjustment of the point at which the device automatically acts to perform its function.

Other systems, utilizing electrical power to perform part or all of the functions of such a protective system are disclosed in U.S. patent specification no.

1,226,696 to Ramseur (utilizing batteries), U.S. patent specification no. 1,875,513 to Smith (utilizing electric current to heat an aldohol container to actuate a valve), U.S. patent specification no. 389,096 to Newman (to magnetically actuate valves), and U.S. patent specification no. 3,812,872 to Block et al (to act after power failure to a heating unit such as a boiler).

Also, U.S. patent specification No. 1,526,718 to Opp, 1,849,491 to Kelley, and 4,360,036 to Shelton, respectively, utilize mechanical or hydrostatic forces to perform the response and valve actuation function in a relatively safe manner, i.e. systems that avoid the use of electrical power at typical household voltages, presumably to avoid the risks of fire.

Despite the numerous solutions listed above, and others of a generally similar nature, each has certain limitations, and it is believed that there still exists a need for a relatively simple, inexpensive, safe, adjustable and reliable system to protect indoor water piping systems against freeze damage.

Accordingly, it is an object of this invention to provide a simple and inexpensive electrically powered protective system that acts automatically, at a user selected low temperature, to protect a water piping system against freeze damage by shutting off water inflow to the piping system and draining the same.

Another object of this invention is to provide a simple, inexpensive, electrically powered, reliable system for protecting a water piping system when the ambient tempçrature drops to a predetermined value by shutting off further water inflow to the piping system and draining the same, whereafter the protective system must be manually reset for any repeated automatic action thereof.

According to the present invention there is provided a system for selectively protecting water piping adapted to be disposed substantially within a building structure, against freeze damage in cold weather, comprising: an electrical circuit, including a manually resettable and thermostatically-actuated electrical switch for controlling a current flow in the circuit and solenoid means operable in response to the current flow for providing driving motion, and valve means, connected to the piping and driven by the solenoid means, for shutting-off water inflow to the piping and opening the piping to drain water contained therein, the switch being thermostatically-actuated in response to a drop in ambient temperature to a predetermined value to operate the solenoid means to effect the shut-off of water inflow to and drainage from the piping, the switch requiring manual resetting thereafter for a repeat of said actuation thereof.

Such a protective system, therefore, does not go through its protective actions repeatedly in the event that the ambient temperature repeatedly exceeds and falls below 32PF during cold weather.

In one aspect of this invention, to secure against the danger of electrical fires during adverse weather conditions, the protective system includes transformer and rectifier means for converting standard household current to a low voltage DC supply, for example an electric circuit so that all operative elements thereof operate in a relatively safe, low voltage DC circuit.

By way of example.a preferred embodiment of the invention will now be described with reference to the accompanying drawings, wherein: Figure 1 is a schematic illustration of a protective system coupled to a portion of a piping system to be protected, and Figure 2 is an enlarged illustration of a portion of the protected piping system to illustrate more clearly the operation of the valves shown.

Most buildings in developed areas are normally connected to a mains water supply, e.g. the town or county water mains. Under certain circumstances, buildings and other facilities located remotely from developed areas may have their own artesian well or other supply of water for use within the building. In either case, in the present context it is understood that there is a source from which water may be supplied to the piping system that is to be protected. In both Figures 1 and 2 the arrow marked M is intended to represent the direction flow of water from such a main supply to the piping system.

With reference to Figure 1, it is understood that there is also a mains power supply, typically an AC supply, most commonly available at 110 volts or 220 volts and that, except during emergencies, such a power supply is constantly available. Even for more remotely located facilities, for present purposes it will be assumed that there is a continuous supply of AC power for use with the illustrated protective system.

Referring still to Figure 1, a mains AC supply 10 supplies AC electric power to a power conversion unit 12 that typically includes a voltage step-down transformer 14 (for example, type no. ATHOlCTKR9ll, manufactured by Honeywell Co.) and rectifier means 16 of known kind to provide, preferably, a 24 volt DC output between terminals 18 and 20. The principal elements of the illustrated protective system are electrically connected to DC output terminals 18 and 20 of power conversion unit 12.

A manually resettable thermostatically actuated switch 22 (for example, a White Rogers-Freeze protection Temperature Control Type 16A60-9) is connected across terminals 48 and 50 and is thermostatically actuated by an adjustable thermostat element 24 of known kind.

Persons skilled in the art will be familiar with resettable-switches used in a variety of contexts, e.g.

in burglar alarm systems, on rubbish disposal system drives, and the like. Likewise, such persons are expected to be familiar with adjustable thermostaticallyactuated switches, e.g. in air-conditioning and heating controls in cars and homes and the like. The requisite elements are commonly available at electrical parts and supply stores or hardware stores, and a detailed description of their structures is believed unncessary for purposes of explaining the operation of the invention.

Very briefly, thermostatic switch 22 serves as a normally closed switch that permits the flow of current in the circuit between terminals 48 and 50. The thermostat element 24 in switch 22 is, in effect, adjusted by a user to select a temperature just a little above freezing temperature e.g. 33elf. The switch 22 maintains its closed position so long as the temperature remains above this selected temperature. When the ambient temperature surrounding the relay drops to 33?,F, by thermostatic action switch 22 is actuated to open the circuit between terminals 48 and 50. When this happens, the flow of current through the operative elements of the protective circuit between terminals 18 and 20 is interrupted.

Solenoid 26 is connected between terminals'52 and 54 which are, respectively, connected to DC output terminals 18 and 20 so long as switch 22 is in its normally closed position between terminals 48 and 50.

Solenoid 26 consists, typically, of an electrical coil to generate a magnetic field and a movable core element, driven by the magnetic field, that is mechanically connected by link 28 to main water inlet valve 30 which controls the flow of all water from the mains water supply to the piping system.

Under normal everyday conditions while the temperature is above the predetermined temperature, e.g.

330.F, switch 22 remains closed between terminals 48 and 50 and electric current passes through solenoid 26 to maintain its core (and hence mechanical link 28) in such a position that main inflow valve 30 (for example, valve type no. 102-1-FC, manufactured by the Hydro Rain Company) is open and the mains water supply continually provides water to the piping system as and when needed.

Preferably in parallel across solenoid 26 is a second solenoid 40 connected across electrical terminals 56 and 58 which are, respectively, connected to terminals 52 and 54. Solenoid 40, like solenoid 26, includes an electrical coil and a movable core connected by link 42 to a second valve 44 (for example, valve type no. 2500604 manufactured by Tory): Valve 44 is connected to the piping system 32,34,36 by means of a length of piping 38 and is, preferably, located at the lowest point thereof. Under normal conditions, while the ambient temperature is above the preselected temperature, e.g.

33q5, solenoid 40 holds drain valve 44 in the latter's closed position so that it remains closed and prevents egress therethrough of water contained within the piping - system.

Refer-ring now to the enlarged view of Figure 2, water flow along the direction of arrow M enters from the mains water supply through main intake valve 30 held in its open position by link 28, and passes through pipe 36 as indicated schematically by arrow P into the piping system that is to be protected. At this time, under normal circumstances, the movable core of solenoid 40, through link 42, holds drainage valve 44 in its closed position to prevent any drainage from the piping system.

When tile ambient temperature around switch 22 drops to the preselected temperature, e.g. 33be', the thermostatic element therein acts to open switch 22, thus creating an electrical break between terminals 48 and 50.

As a direct consequence of this break in the current, power supply ceases between terminals 52 and 54 for solenoid 26 and between terminals 56 and 58 for solenoid 40. Note that direct physical connection between valves 30 and 44, operated respectively by solenoids 26 and 40, is not necessary. It is conceivable, however, that persons skilled in the art may under appropriate circumstances wish to mechanically connect valves 30 and 44 to operate in tandem to perform the functions as discussed herein, in which case, only a single solenoid coil may be appropriate.

The cessation of electric current through solenoids 26 and 40 causes the movable cores thereof to move so as to close valve 30 to shut off water inflow from the main's water supply and to simultaneously open drain valve 44. This permits the flow, under gravity, of water from the piping system, connected to pipe 36 through the drainage extension pipe 46, into a bed of gravel and/or sand 60 provided in a-hollow in the ground 62. Gravel bed 60 need not necessarily be outside the building but may, where convenient, be provided underneath the same. The arrow marked by the letter D illustrates the direction of flow of water drained from the piping system through drain valve 44 into gravel bed 60.

A principle advantage of the preferred embodiment described above over the numerous systems taught in the prior art is that the switch 22, once it has acted to shut off the mains power supply and open the drain, does not automatically reset itself to repeat the performance.

In other words, if on a mild winter s day the temperature in any 24 hour period falls below 33 '7 and then rises a number of times past it, the protective system will not permit repeated charging and discharging of the piping system that is to be protected. Thus a family that utilizes such a system may leave for an entire winter weekend after setting the system to operate, and at the first occasion where the ambient temperature falls below the predetermined value, e.g.

335F, the system will shut off the mains water supply, drain the entire house piping system, and will maintain this situation regardless of how much the temperature fluctuates without wasting any more water or operating the valves back and forth unnecessarily. This not only saves water but, over a long duration, prolongs the life of the valves. Upon the family's return, knowing that they intend to heat the house and thus maintain the piping system inside the house at a temperature above freezing, and knowing that they will intermittently cause water to flow through the internal piping system, the owner of such a system will very simply manually reset the relay so that it is in the protective mode once again. This will allow water to flow into the piping system for normal use and the protective system will be "triggered" to act again when needed.

Consider a -scenario in which the user of such a system has reset the relay manually, so that the system is operating to protect the piping. system within the house. In the event that there is a severe winter storm and the mains electrical power supply to the house is interrupted, a foreseeable consequence is that heating in the house will cease so that eventually the piping within the house may experience a temperature drop to the predetermined value, e.g. 33o.: The instant that the mains power supply fails, the protective system will shut off the mains water supply at valve 30 and will drain the piping system within the house by opening drainage valve 44. Thus, even when the user of such a system is present, under circumstances where it is most appropriate for the protective system to act, it will.

It is contemplated that through the use of any of numerous commercially available adjustable thermostatic switches, the user will select a temperature that is appropriate to his geography and climate. A suitable value may be somewhat above the freezing point temperature of water, e.g. 3.32 , but the user has an option in the preferred embodiment to adjust the same.

Operating on the principle that it is better to be safe than sorry, it is very likely that responsible owners of such a system will set the activation temperature somewhat higher than the freezing point, i.e. higher than 32"'F. If this is done, the protective system will act well before a problem arises, i.e. the protective system will take prophylactic action.

As is well known in the art of adjustable thermostatic controls, e.g. home climate controls, the user can turn a knob or move a control lever against a precalibrated scale to select the temperature at which the desired thermostatic input to actuate the relay is obtained. The actual location of the thermostatic switch, reset button and valves are best decided by a user of the system according to his or her needs and conveniences.

Although the preferred embodiment is described above as being one in which a mains electrical power supply at the conventional voltage, e.g. 110 volts or 220 volts AC, is converted to a low voltage DC power supply to the protective circuit, this is not necessary and may under certain circumstances not even be the most 1 desirable arrangement. Thus, omission of rectifier 16 would provide a comfortable and safe 24 volt, AC power supply for the circuit controlling water flow valves.

Such an entirely AC circuit may be preferable for certain applications, e. g. residential units, and is within the scope of the present disclosure.

It is expected that persons skilled in the art will exercise reasonablejudgement in selecting various elements, e.g. switch 22 and solenoids 26 and 40, to suit the electrical power supply that is most appropriate under given circumstances. Such matters of-judgement are best left to the user who will undoubtedly be in a position to select components and system operating parameters to suit his or her needs.

Persons skilled in the art can reasonably be expected to consider replacing the two separate water flow controlling valves 30 (mains supply) and 44 (drain) by a single three way valve of known type to perform the equivalent solenoid actuated function. Likewise, such persons can be expected to consider providing an electrical override or an even simpler manually controlled bypass, e.g. piping 64 controlled by a valve 66, to deliberately obtain emergency water flow from the mains supply even when ambient temperatures fall low enough to activate the system.

Claims (12)

1. A system for selectively protecting water piping adapted to be disposed substantially within building structure, against freeze damage in cold weather, comprising: an electrical circuit, including a manually resettable and thermostatically-actuated electrical switch for controlling a current flow in the circuit and solenoid means operable in response to the current flow for providing driving motion, and valve means, connected to the piping and driven by the solenoid means, for shutting-off water inflow to the piping and opening the piping to drain water contained therein, the switch being thermostatically-actuated in response to a drop in ambient temperature to a predetermined value to operate the solenoid means to effect the shut-off of water inflow to and drainage from the piping, the switch requiring manual resetting thereafter for a repeat of said actuation thereof.

2. A protective system according to Claim 1, wherein the thermostatically-actuated switch comprises a thermostat element including manually settable means for enabling a user to manually reset the thermostat element for subsequent actuation of the switch in response to the drop in the ambient temperature.

3. A protective system according to Claim 1 or claim 2, wherein the thermostatically-actuated switch comprises temperature selection means for enabling a user to select the predetermined temperature at which the switch responds to operate the solenoid means.

4. A protective system according to any preceding claim1 wherein the valve means comprises an inflow valve that allows the water inflow when in an open position and totally shuts off the water inflow when in a closed position, and a drain valve that shuts off the drainage when in a non-drain position and allows substantially complete drainage of the piping when in a drain-open position.

5. A protective system according to Claim 4, wherein the solenoid means, upon manual resetting, maintains the inflow valve in the open position and the drain valve in the non-drain position until actuation of the switch, whereupon the solenoid means drives the inflow valve to the closed position and the drain valve to the drain-open position.

6. A protective system according to any preceding claim, further comprising power supply means for providing a low voltage direct current to operate the circuit.

7. A protective system according to Claim 6, wherein the power supply means comprises voltage transformer means for transforming a standard alternating current (AC) power supply voltage to a selected low voltage AC.

8. A-protective system according to Claim 7, further comprising rectifier means for rectifying the low voltage AC to a corresponding low voltage direct current (DC), such that the transformer means and the rectifier means coact and the circuit is supplied thereby with low voltage DC.

9. A protective system according to Claim 2 or any claim appendant thereto, wherein the thermostat element is located substantially within a portion of the water piping whereby the temperature of the thermostat element is substantially the same as that of water in the said portion of the piping.

10. A protective system according to Claim 3 or any claim appendant thereto, wherein the temperature selection means comprises a movable element moved by a user with respect to a scale indicating a value of the predetermined temperature.

11. A protective system according to any preceding claim further comprising manually operable bypass means to permit emergency water inflow to the piping even while the electrical current is in operation.

12. A system for selectively protecting water piping substantially as herein described with reference to the accompanying drawings.