A flow rate control method for raising a flow rate performed in a flow control device having a first control valve, a second control valve downstream of the first control valve, and a pressure sensor for measuring a pressure between the first and the second control valves, comprises a step (a) of determining a pressure remaining downstream of the first control valve in a state of closing the second control valve, and a step (b) of controlling the pressure remaining downstream of the first control valve by adjusting the opening degree of the second control valve based on the output of the pressure sensor to flow the fluid downstream the second control valve at the first flow rate.

A measured quantity of gas is introduced into a gas reservoir via a filling station including a flow meter. The quantity of gas transferred by the filling station to the reservoir is measured by the flow meter. The measured quantity of gas is reduced or increased by a predetermined corrective amount to yield a corrected gas quantity.

An intelligent self-balancing downstream device (e.g., air fixture or diffuser) that can obtain accurate flow measurements that can be used to perform the self-balancing in situ and during operation to satisfy a set point. The downstream device may be controllable by a single software system or network accessible locally on site or remotely off site. The downstream device can operate in a single zone or be coupled with multiple like apparatuses for multi-zone operation. It is a high turndown ratio and self-balances, which can allow for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The downstream device can include multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

The LFFC technology allows for accurate measurement and metering of fluids in a HVAC system-based on parameters such as pressure, velocity, volume, particles, and temperature. A procedure in a processor allows for the calibration of the aperture devices thru various methods in real time based on the actual system performance. The fluid aperture device calibration curves can be developed in a lab environment, on calibrated flow stands and/or field calibration methods using adaptive learning software based on sensor data. The procedure can rely on calibration curves, characterizations, equations, predictive analysis, machine learning, artificial intelligence, simulation software, calibrated flow stands, duplicating environmental conditions, various sensor data and programming software executed by a processor or system software. Upstream and downstream reference points for temperature, flow, particles, and pressure can be used as additional data to auto calibrate/commission the system thru the software.

An intelligent self-balancing downstream device that can obtain accurate flow measurements (e.g., flow of a liquid or gas through a tube) that can perform the self-balancing in situ and during operation to satisfy a set point and without k factors or the use of TAB balancers. The downstream device may be controllable by a single software system or network. The downstream device can operate in a single zone or be coupled with multiple like apparatuses. It has a high turndown ratio and self-balances, which can allow for continuous commissioning with built-in fault diagnostic systems. A fluid metering device can include control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.

An electromagnetic flowmeter for measuring flow of fluid flowing in a conduit of the electromagnetic flowmeter, wherein the electromagnetic flowmeter includes: a coil attached to an inner surface of the conduit; a movable magnetic ring having segments of magnetic materials that is magnetically coupled with the coil to generate an electromagnetic field to interact with the fluid flowing through the conduit wherein the conduit is provided with an insulating liner. A pair of electrodes mounted on the conduit for measuring potential difference generated by the interaction of the electromagnetic field in the fluid. Wherein the segments of magnetic materials are having varying magnetic properties arranged to have an orderly varying electromagnetic field in the conduit adjustable by rotating the movable magnetic ring. The movable magnetic ring is positioned between the at least one coil and the insulating liner.

A water heater including an inflow terminal for connecting a tankless water heater to a cold water supply and an outflow terminal for connecting the tankless water heater to a tap. A fluid channel proves a fluid connection from the inflow terminal to the outflow terminal. A heat element arrangement is arranged at or within at least a section of the fluid channel for transferring heat to fluid present within the fluid channel. An electronic controller is configured to control a heating power provided to the heat element arrangement. A flow sensor is arranged at or within the fluid channel downstream the heat element arrangement. The electronic controller is further configured to detect the presence of air bubbles within the fluid channel based on a change of a flow signal provided by the flow sensor and to adapt the heating power provided to the heat element arrangement in reaction to the determination of air bubbles.

Devices, methods, and systems for operating gas meters are described herein. The systems may include a gas measuring system connectable to a gas line, where the gas measuring system may include a flow rate sensor, a pressure sensor, and a controller in communication with the flow rate sensor and the pressure sensor. The flow rate sensor and the pressure sensor may be configured to sense measures of a gas passing through the gas line. The controller may repeatedly obtain pressure measurements at set pressure measurement times. Measures from the flow sensor may be monitored and when a measure from the flow sensor measure meets a flow rate criteria, the controller may trigger an extra pressure measurement without waiting for a next pressure measurement time. The controller may initiate closing of a gas valve when a measure from the pressure sensor exceeds a threshold value.

A method/structure for calibrating a product fluid flow device having one or more apertures with aggregate area A.sub.o, where fluid flows along a fluid flow path therethrough in response to pressure differentials ΔP across the apertures. Calibration is effected relative to a calibration fluid flow device having a geometry and operational parameters corresponding to those of the product fluid flow device. A piecewise curved calibration controller establishes calibration conditions and generates a discrete point calibration flow rate (dpCFR) Function by measuring at a sparse set of points in a range of interest and determining a piecewise curved mathematical representation of fluid flow through the calibration fluid flow device. Data representative of the CFR function is transferred to a product blade controller, which processes the mathematical representation, and controls fluid flow through product fluid flow device based on values extracted from the received dpCFR Function.

A system for measuring the flow rate of a fluid medium includes an input line of a fluid medium, elements for measuring the flow rate of the fluid medium in transit which are interposed between the input line and the output line, and an electronic unit functionally associated with the elements for measuring.

The elements for measuring include at least two connecting lines arranged in parallel between the input line and the output line, and a flowmeter in fluid communication with each one of the connecting lines. A corresponding interval of measurable flow rate values stored in the electronic unit is associated with each flowmeter.