System and valve for water use monitoring and control
A valve assembly capable of converting a small leak of a device into a measurable, relatively larger or “burst” flow event is described. In certain embodiments, the valve assembly includes a compliant chamber and, following pressurization of the device, permits flow when the pressure in the compliant chamber drops to a configured fill pressure and restricts (or prevents) flow when the pressure in the compliant chamber increases to a shut-off pressure. The disclosed valve assemblies may be incorporated into a leak detection assembly capable of transmitting usage and/or alarm data to a central service.
1. A valve assembly for use between a fluid source, having an inlet pressure, and a valved device, the valve assembly comprising:
an inlet, wherein the inlet is in fluid communication with the fluid source when the valve assembly is in use;
an outlet, wherein the outlet is downstream of the inlet and is in fluid communication with the valved device when the valve assembly is in use;
a main valve between the inlet and outlet, the main valve operating in either an open state or closed state;
a pressure compliant chamber in fluid communication with the outlet, downstream of the main valve, the compliant chamber having a pressure when the valve assembly is in use;
a pressure sensor in fluid communication with the compliant chamber, the pressure sensor gradually responsive to changes in pressure of the compliant chamber;
a pilot valve in fluid communication with the main valve and responsive to the pressure sensor, the pilot valve operating in either an open state or closed state, wherein when the pilot valve is open, the main valve is open, thereby permitting flow of fluid from the inlet to the outlet, and when the pilot valve is closed, the main valve is closed, thereby preventing flow of fluid from the inlet to the outlet;
the pilot valve being in the closed state when the compliant chamber is pressurized at or about the inlet pressure and remaining in the closed state until the pressure in the compliant chamber decreases to a fill pressure, less than the inlet pressure; and
the pilot valve toggling from the closed state to the open state, thus opening the main valve, when the pressure in the compliant chamber decreases to at or about the fill pressure and remaining in the open state and transitioning from the open state to the closed state when the pressure in the compliant chamber increases to at or about a shut-off pressure;
wherein the fill pressure is lower than the shut-off pressure.
2. The valve assembly of claim 1 wherein the shut-off pressure is at or about the inlet pressure.
3. The valve assembly of claim 1 wherein the fill pressure is at or about atmospheric pressure.
4. The valve assembly of claim 1 wherein the pressure sensor includes a piston, the valve assembly further comprising:
a main flow channel between the inlet and outlet;
a pilot actuation pin, a pilot slide, a middle slide, and a diaphragm slide, each in axial alignment with the pilot valve and moveable in the axial direction;
a valve close latch; and
a valve open latch;
wherein:
the pilot actuation pin extends through the main flow channel downstream of the main valve and is coupled to the pilot slide;
the middle slide is moveable relative to the pilot slide;
the diaphragm slide is coupled to the piston and moveable relative to the middle slide;
the valve close latch is either (i) engaged with the pilot slide, in which the pilot slide and pilot actuation pin are in a first position and the main valve is open, or (ii) not engaged with the pilot slide, in which the pilot slide and pilot actuation pin are moveable to a second position and the main valve is closed;
the valve close latch toggling from being engaged to being disengaged when the compliant chamber increases to at or about the shut-off pressure; and
the valve open latch is either engaged with the middle slide, in which movement of the middle slide is restricted, or not engaged with the middle slide, in which movement of the middle slide is not restricted and the pilot slide and pilot actuation pin are free to toggle to the first position, thereby opening the main valve;
the valve open latch toggling from being engaged to disengaged when the pressure in the compliant chamber decreases to at or about the fill pressure.
5. The valve assembly of claim 1 wherein the pressure sensor includes a piston, the valve assembly further comprising:
a main flow channel between the inlet and outlet;
a housing in fluid communication with the compliant chamber and the piston;
a frame within the housing, the frame being gradually moveable in relation to pressure in the compliant chamber between a valve open position and a valve closed position;
a pilot actuation pin coupled to the pilot valve and passing through the main flow channel and into the housing;
a switch plate coupled to and responsive to movement of the frame, the switch plate toggling between a valve open position and a valve closed position, wherein in the valve open position, the switch plate is in contact with the pilot actuation pin and the pilot valve and main valve are open, and in the valve closed position, the switch plate is spaced away from the pilot actuation pin and the pilot valve and main valve are closed; and
wherein the switch plate toggles from the open position to the valve closed position when the pressure in the compliant chamber decreases to at or about the shut-off pressure, and the switch plate toggles from the valve closed position to the valve open position when the pressure in the compliant chamber increases to or about the fill pressure.
6. The valve assembly of claim 5 , wherein the frame includes a linear section in axial alignment with the piston, a first arm and a second arm, wherein when in the first position, the first arm is adjacent the housing, the second arm is spaced away from the housing and the switch plate is in the valve open position, and wherein when in the second position, the second arm is adjacent the housing, the first arm is spaced away from the housing and the switch plate is in the valve closed position.
7. The valve assembly of claim 1 , wherein the main valve and the pilot valve in fluid communication with each other.
8. The valve assembly of claim 1 , wherein the pressure sensor and the pilot valve are in electronic communication with each other.
9. The valve assembly of claim 1 further comprising one or more detents restricting opening of the pilot valve until the fill pressure is reached and restricting closing of the pilot valve until the shut-off pressure is reached.
10. The valve assembly of claim 9 wherein the detent includes a magnetic, mechanical, or electromechanical detent.