Self-maintaining automatic flushing valve with internal freeze protection

1. A device attached to a subterranean water supply, the device comprising a valve operable to flush water from the subterranean supply through the device, a turbine operable to generate electricity when water is flushed through the device, an enclosure containing the valve, a temperature sensor operable to sense temperature within the enclosure, a heater operably connected to the turbine and being operable to heat the enclosure, and a control system operable to open the valve to cause the turbine to operate the heater when the temperature sensor indicates the approach of a dangerously low temperature.

2. The device of claim 1 wherein the device comprises a timer which periodically flushes water through the system.

3. The device of claim 1 wherein the device both flushes water and samples at least one condition of the water flowing through it.

4. The device of claim 1 wherein the enclosure is insulated to a thermal resistance of at least about R-9 (U.S.) (R-1.6 SI).

5. The device of claim 1 wherein the device comprises a condition sensor which senses at least one condition of the subterranean water and opens the valve to flush the water through the device in response to a condition sensed by the condition sensor.

6. The device of claim 5 wherein the condition sensor is configured to sense a condition of a sample of water drawn by the device from the subterranean water supply.

7. The device of claim 1 wherein the turbine is located downstream of an outlet of the flushing device.

8. The device of claim 7 further including a nozzle in the outlet, the nozzle guiding an exit stream into vanes of the turbine.

9. The device of claim 1 further comprising at least one rechargeable battery within the enclosure, and wherein an electrical resistive dissipater is electrically connected to the turbine generator to prevent overcharging the battery and to act as a heater.

10. The device of claim 9 further comprising a fan-heater energized by at least one of the turbine and the battery.

11. The device of claim 9 wherein the temperature modification device comprises at least one of a fan and a heater, the fan or heater being energized by at least one of the turbine and the battery.

12. A device attached to a subterranean water supply, the device comprising a valve operable to flush water from the subterranean supply through the device, a turbine operable to generate electricity when water is flushed through the device, an enclosure containing the valve, a temperature sensor operable to sense temperature within the enclosure, a temperature modification device operably connected to the turbine and being operable to heat or cool the enclosure, and a control system operable to open the valve to cause the turbine to operate the temperature modification device when the temperature sensor indicates the approach of a dangerously low or high temperature.

13. The device of claim 12 wherein the device comprises a condition sensor which senses at least one condition of the subterranean water and opens the valve to flush the water through the device in response to a condition sensed by the condition sensor.

14. The device of claim 12 further comprising at least one rechargeable battery within the enclosure, and wherein an electrical resistive dissipater is electrically connected to the turbine generator to prevent overcharging the battery.

15. A method of operating a device connected to a subterranean pressurized water supply and unconnected to an external source of electricity, the device comprising an insulated housing and an electronics package in the insulated housing, the method comprising sensing a temperature within the insulated housing and, when the temperature drops below a predetermined value, running water from the pressurized water supply through the device to generate electricity to heat the enclosure.

16. The method of claim 15 wherein running water through the device operates a turbine connected to an electrical generator.

17. A method of operating a flushing and monitoring device connected to a subterranean pressurized water supply and unconnected to an external source of electricity, the device comprising an insulated housing, a rechargeable battery in the housing, a turbine generator in the housing, and a water condition sensor in the housing, the method comprising sensing a temperature within the insulated housing, sensing a water condition, and sensing a battery charge level, and running water from the pressurized water supply through the device to run the turbine generator whenever any one of the temperature, water condition, or battery charge level reaches a value indicating the need for electrical energy.

18. The method of claim 17 wherein flow of flushing water through the device is controlled by a latching solenoid, and wherein an electronic control senses whether the latching solenoid is open or closed before trying to open or close the solenoid.

19. The method of claim 17 wherein the water condition sensed is a concentration of disinfectant in the water.

20. The method of claim 19 wherein the disinfectant is chlorine.