A hydraulic control device for liquid-conducting appliances and systems is designed for connection between a source of liquid and an appliance or system using the liquid. The hydraulic control device (1) comprises: —a device body (2′, 3′) having a duct for the liquid (30a, 30b) that extends between an inlet connector (2a) and an outlet connector (3 a); —a flow meter (40, 50) associated to the device body (2\ 3′); and—a valve arrangement (31, 33-37) associated to the device body (2′, 3′), including a valve member (31), which is displaceable between an opening position and a closing position of the duct for the liquid (30a, 30b), and a control mechanism (33-37) for controlling the valve member (31). The control mechanism (33-37) is switchable on the basis of a detection made by the flow meter (40, 50) in order to displace the valve member (31) from the opening position to the closing position of the duct for the liquid (30a, 30b). The flow meter (40, 50) is a non-mechanical flow meter that includes at least two electrical detection elements (42) that are reachable by liquid that flows in the duct for the liquid (30a, 30b).

A hydraulic control device for liquid-conducting appliances and systems is designed for connection between a source of liquid and an appliance or system using the liquid. The hydraulic control device (1) comprises: —a device body (2′, 3′) having a duct for the liquid (30a, 30b) that extends between an inlet connector (2a) and an outlet connector (3 a); —a flow meter (40, 50) associated to the device body (2\ 3′); and—a valve arrangement (31, 33-37) associated to the device body (2′, 3′), including a valve member (31), which is displaceable between an opening position and a closing position of the duct for the liquid (30a, 30b), and a control mechanism (33-37) for controlling the valve member (31). The control mechanism (33-37) is switchable on the basis of a detection made by the flow meter (40, 50) in order to displace the valve member (31) from the opening position to the closing position of the duct for the liquid (30a, 30b). The flow meter (40, 50) is a non-mechanical flow meter that includes at least two electrical detection elements (42) that are reachable by liquid that flows in the duct for the liquid (30a, 30b).

A vacuum-helium-leak-detection method based on a carbon-nanotube-based field-emission sensor that includes a carbon-nanotube-based cathode having a Raman amorphous peak I.sub.D/graphite peak I.sub.G ratio greater than 1.0. The method involves: setting a field-emission current at an initial, small emission current, recording an average of values of the field-emission current in a time period t, forming a sensing characteristic curve of the sensor, and performing fitting on the sensing characteristic curve so as to obtain an index curve; converting pressure values of helium gas into vacuum leak rates; and packaging the cathode into a vacuum chamber in a system to be detected, performing testing when a helium stream in the system to be detected reaches balance, obtaining an average of current variations in the time period t during the testing, and comparing the average with the index curve so as to determine a vacuum leak rate of the system to be detected.

A vacuum-helium-leak-detection method based on a carbon-nanotube-based field-emission sensor that includes a carbon-nanotube-based cathode having a Raman amorphous peak I.sub.D/graphite peak I.sub.G ratio greater than 1.0. The method involves: setting a field-emission current at an initial, small emission current, recording an average of values of the field-emission current in a time period t, forming a sensing characteristic curve of the sensor, and performing fitting on the sensing characteristic curve so as to obtain an index curve; converting pressure values of helium gas into vacuum leak rates; and packaging the cathode into a vacuum chamber in a system to be detected, performing testing when a helium stream in the system to be detected reaches balance, obtaining an average of current variations in the time period t during the testing, and comparing the average with the index curve so as to determine a vacuum leak rate of the system to be detected.

The present invention is a water meter and leak detection system that has a private or public property(ies) facility water supply interruption system. The system is comprised of a water meter collection node system with shut-off/on mechanism that has wireless Bluetooth, Bluetooth low energy, Zigbee, Z-wave LoRa, Wi-Fi, radio frequency and cellular technology with a private or corporate network, or internet connection that transfer water parameter data to a remote computer or server. Or the system can consist of a water meter collection node that communicates by Bluetooth, Bluetooth low energy, Zigbee, Z-wave LoRa, Wi-Fi, radio frequency and cellular technology with a data communication hub whereby the communication hub is in wired or wireless communication with an internet router that communicates with an internet connection, or with a private or commercial network system, to a remote computer/server or a cloud-computing commercial service.

The present invention is a water meter and leak detection system that has a private or public property(ies) facility water supply interruption system. The system is comprised of a water meter collection node system with shut-off/on mechanism that has wireless Bluetooth, Bluetooth low energy, Zigbee, Z-wave LoRa, Wi-Fi, radio frequency and cellular technology with a private or corporate network, or internet connection that transfer water parameter data to a remote computer or server. Or the system can consist of a water meter collection node that communicates by Bluetooth, Bluetooth low energy, Zigbee, Z-wave LoRa, Wi-Fi, radio frequency and cellular technology with a data communication hub whereby the communication hub is in wired or wireless communication with an internet router that communicates with an internet connection, or with a private or commercial network system, to a remote computer/server or a cloud-computing commercial service.

A sensor assembly and a refrigerant sensing system for air conditioning systems can include a sensor controller, a sensor electrically connected to the sensor controller and configured to output sensor data to the sensor controller, and a housing having an interior space enclosing the sensor controller and the sensor. The housing includes a first end and a second end and a barrier disposed between the first end and the second end sealingly separating the interior space. The first end supports the sensor and includes a plurality of openings exposing the sensor to an external environment. The second end supports the sensor controller and substantially prevents the sensor controller from being exposed to the external environment.

A sensor assembly and a refrigerant sensing system for air conditioning systems can include a sensor controller, a sensor electrically connected to the sensor controller and configured to output sensor data to the sensor controller, and a housing having an interior space enclosing the sensor controller and the sensor. The housing includes a first end and a second end and a barrier disposed between the first end and the second end sealingly separating the interior space. The first end supports the sensor and includes a plurality of openings exposing the sensor to an external environment. The second end supports the sensor controller and substantially prevents the sensor controller from being exposed to the external environment.

An HVAC system includes a high-pressure subsystem and a low-pressure subsystem. After determining that refrigerant leak diagnostics should be performed, a controllable valve is closed between a condenser and compressor of the HVAC system. The compressor then operates until a predetermined input refrigerant pressure is reached. After the predetermined input refrigerant pressure is reached, operation of the compressor is stopped. After stopping operation of the compressor and waiting at least a predetermined wait time, the pressure in the low-pressure subsystem of the HVAC system is monitored. A rate of change of the pressure in the low-pressure subsystem is determined. If the rate of change is negative and a magnitude of the rate of change is greater than a threshold value, a leak location is determined to be in the low-pressure subsystem.

A vehicle includes an internal cabin. One or more areas are within the internal cabin. The one or more areas include one or more water-drawing components. A water supply system is within the internal cabin. The water supply system is configured to provide water to the one or more water-drawing components. A water leak detection system includes one or more sensing devices configured to detect water flow from the water supply system to the one or more water-drawing components. One or more shut-off valves are disposed on or within the water supply system. A control unit is in communication with the one or more sensing devices, the one or more shut-off valves, and the one or more water-drawing components. The control unit is configured to operate the one or more shut-off valves to stop the supply of water to the one or more water-drawing components in response to the one or more sensing devices detecting the water flow when the one or more water-drawing components are not in use.