An ultrasonic flowmeter includes: a flow path body having a flow path through which a fluid to be measured flows; a pair of ultrasonic transducers disposed in the flow path body; a substrate fixed to the flow path body; a sensor plate on which a temperature sensor for detecting a temperature of the fluid to be measured is disposed, the sensor plate being flat; and an arithmetic unit that calculates a flow rate of the fluid to be measured from a propagation time of ultrasonic waves between the pair of ultrasonic transducers and the temperature detected by the temperature sensor. The sensor plate is configured to project from the substrate and to project into a flow path cross-section of the flow path from a sensor hole provided in the flow path body at a time of fixing the substrate to the flow path body.

Methods of determining if it is safe to restore service to a gas meter remotely are provided. The method includes determining if any pre-existing conditions are present in the gas meter responsive to issuance of a restore command to restore service from a remote location. The pre-existing conditions indicates that safety test results are unreliable. If it is determined that no pre-existing conditions are present, a valve on the gas meter is opened to fill the gas meter with gas until the gas meter reaches a predefined fill state. It is determined if pressure in the gas meter is stable at the predefined fill state and the valve on the gas meter is closed if the pressure is stabilized. A pressure decay test is performed after the valve on the gas meter is closed. The valve to restore gas flow is opened if the pressure decay test passes.

Heat resistant sensors equipped with any of a variety of transducers for measuring any of a variety of properties of fluids are constructed with components comprising materials that can withstand very high temperatures. Some embodiments of the sensors include a first pressure sensitive element and a second pressure sensitive element with respective first and second membranes positioned in juxtaposed relation to each other to form a capacitor. Some embodiments include a pusher that extends from the membrane toward a first electrode. Some embodiments have a housing comprising a ceramic substrate with a sensor element mounted on an inside surface of the substrate. Other embodiments have direction sensing capabilities including a heater positioned in a core material and at least three temperature sensors located at or near the peripheral surface of the core material and spaced apart angularly in relation to each other.

A method of using a fluid monitoring assembly for measuring the flow rate of a fluid through a flexible conduit comprising a wall that defines a lumen through which the fluid passes. The assembly includes a housing having first and second portions each defining respective recessed interior portions that define a cavity that is configured to encapsulate and retain the flow sensor and the flexible tubing contained therein. The flow sensor may be removably secured around the outside of the flexible conduit and include one or more transducer/receiver pairs.

A flow sensor of a domestic appliance has an axle that is substantially perpendicular in the installed state to the flow direction of a fluid channel of the domestic appliance. The bearing component is designed as a single part and has at least two interconnected limbs, each limb having an axle mount for one end of the axle of the flow sensor, wherein the two axle mounts are mutually spaced apart in such a way that they correspond in a relaxed condition of the bearing component to an extension of the axle of the flow sensor. The two limbs are designed to be elastic such that the spacing between the axle mounts can be increased in order to insert the flow sensor between the axle mounts.

A flow sensor sub-assembly for sensing flow of a fluidic medicament includes a flow tube having a flow tube inlet and a flow tube outlet, and an acoustical transmission rate. The medicament flows through the flow tube. A first piezo element is arranged at an upstream position of the flow tube and a second piezo element is arranged at a downstream position of the flow tube, such that the first piezo element and the second piezo element are mounted apart a pre-selected distance from each other. An absorber sheath encircles the flow tube. The absorber sheath has an upstream end and a downstream end. The absorber sheath is comprised of a material with an acoustical transmission rate different than the flow tube.

A flow rate control apparatus can obtain a flow rate of a fluid passing through a downstream-side valve in a form in which noise is significantly reduced with little time delay, and has improved responsiveness. The flow rate control apparatus includes: a downstream-side valve flow rate meter that measures a downstream-side valve flow rate that is a flow rate of a fluid passing through a downstream-side valve; and an observer including a downstream-side valve flow rate estimation model that estimates the downstream-side valve flow rate on the basis of an input parameter that changes an opening degree of the downstream-side valve. The observer is configured so as to be fed back a deviation between the measured value of the downstream-side valve flow rate and the estimated value of the downstream-side valve flow rate.

A method for fluid flow measurement for a discrete area of a fluid supply network, where the fluid supply network includes a network of pipes that includes a main pipe for transporting fluid from a source into the fluid supply network for delivery to consumers, wherein the main pipe crosses a boundary between the discrete area and a further area of the fluid supply network, which is outside of the discrete area, and a plurality of distribution pipes each transport fluid from the main pipe to a consumer, where fluid pressure and the fluid consumption on at least two selected key metering points located inside and outside of the discrete area are measured, and where the fluid pressure and the fluid consumption measured on these selected key metering points the fluid flow in the main pipe that crosses the boundary of the discrete area is calculated.

In order to provide a flow rate control apparatus capable of reducing pressure loss due to a downstream valve while enhancing responsiveness in flow rate control, a controller is designed to control the downstream valve on the basis of a flow rate deviation when a valve opening of the downstream valve is smaller than a predetermined valve opening. The controller is designed to control an upstream valve on the basis of the flow rate deviation when the valve opening of the downstream valve is the predetermined valve opening or more.

Introduced herein are a dimensionless relationship between a volumetric flow rate, a head and a kinematic viscosity in a pump operation and a method that uses the dimensionless relationship to predict a viscous performance of a pump from water performance characteristics. Using the introduced dimensionless relationship, which is called Ketan's viscous head number, the introduced method determines a viscous head correlation that allows the prediction of the pump performance to be made accurately at any given speed, flow rate and viscosity. The introduced Ketan's viscous head number and method thus allow a prediction of a pump performance in a viscous application to be made from water performance characteristics without physically testing the pump in the viscous application.