A flow measuring device for measuring flow of a fluid. A housing has a passage which extends between an inlet and an outlet. A shaft is disposed within the housing and is rotatable about a central axis. A flow detector is mounted on the shaft and disposed at least partially within the passage. The flow detector includes a rotatable, generally cylindrical body that rotates about a central axis as the fluid flows. A magnet is disposed within the housing such that the central axis extends through it, and is configured to rotate simultaneously with the body about the central axis. A magnetic encoder is disposed within the housing and configured to sense rotation of the magnet as the flow detector angularly displaces about the central axis so as to detect angular displacement of the flow detector.

Methods, apparatus, and systems for flow measurements by alternating magnetic fields are provided. An example alternating magnetic field flowmeter includes a magnetic token movable within a conduit for guiding a fluid flow (conductive or non-conductive) along a flow path, a magnetic field generator configured to generate alternating magnetic fields within the conduit to move the magnetic token along the flow path with a first flow velocity and opposite to the flow path with a second flow velocity, a detector configured to measure respective first and second electrical signals responsive to the alternating magnetic fields, the first and second electrical signals associated with the first and second flow velocities, and a processor configured to determine a flow rate of the fluid based on the first and second electrical signals. The alternating magnetic field flowmeter can include a calibrator configured to manually or automatically calibrate the flow rate with a correction factor.

A taper pipe-shaped area flow meter uses a magnetostrictive distance measurement method through which a flow rate may be accurately measured by measuring a height of a float through a magnetostrictive method. A taper pipe-shaped area flow meter using a magnetostrictive distance measurement method includes a taper pipe including an inlet at a lower portion thereof and an outlet at an upper portion thereof and formed in a taper shape having a diameter decreasing downward, a float in which a magnet is embedded and a height of the float is changed according to a flow rate in the taper pipe, a probe shaft in which a magnetrostrictive line is embedded and which is installed in the taper pipe and detects a position of the float through the magnetostrictive method, and a magnetostrictive distance measuring part, which is configured to apply a pulse to the probe shaft, receive a signal reflected by the magnet of the float, measure a position of the float, and calculate a flow rate from the position of the float. The taper pipe-shaped area flow meter using the magnetostrictive distance measurement method has a high accuracy because the magnetostrictive method is applied thereto and may inexpensively measure a flow rate by using a simple mechanical structure, and there is an advantage in that a measured value is provided as an electric signal and used in various fields such as a process control.

A taper pipe-shaped area flow meter uses a magnetostrictive distance measurement method through which a flow rate may be accurately measured by measuring a height of a float through a magnetostrictive method. A taper pipe-shaped area flow meter using a magnetostrictive distance measurement method includes a taper pipe including an inlet at a lower portion thereof and an outlet at an upper portion thereof and formed in a taper shape having a diameter decreasing downward, a float in which a magnet is embedded and a height of the float is changed according to a flow rate in the taper pipe, a probe shaft in which a magnetrostrictive line is embedded and which is installed in the taper pipe and detects a position of the float through the magnetostrictive method, and a magnetostrictive distance measuring part, which is configured to apply a pulse to the probe shaft, receive a signal reflected by the magnet of the float, measure a position of the float, and calculate a flow rate from the position of the float. The taper pipe-shaped area flow meter using the magnetostrictive distance measurement method has a high accuracy because the magnetostrictive method is applied thereto and may inexpensively measure a flow rate by using a simple mechanical structure, and there is an advantage in that a measured value is provided as an electric signal and used in various fields such as a process control.

A variable area flowmeter having a float and having a display unit, the display unit includes a pointer element, the pointer element is connected directly or indirectly to the float such that the pointer element is mechanically deflected by the float during the measuring process. The variable area flowmeter that operates particularly reliably and is flexibly applicable at the same time is achieved in that the display unit comprises at least one bi-stable display which only requires an energy supply in order to modify the displayed representation and/or to restore the representation.

The present disclosure relates to a crude oil flow metering device, which includes a measuring part and a metering part; the measuring part includes a measuring tube and a float assembly; the float assembly is in-built in the measuring tube, and includes a float and a float connection rod integrally connected with the float; an end of the float connection rod is connected to a detection part; the detection part protrudes out of the measuring tube when the float rises from a bottom end; the metering part includes a position detection module and a processing module; the position detection module is arranged in a detection cavity located above the measuring tube and formed by a first housing; when the detection part at the end of the float connection rod extends into the detection cavity, the position detection module detects a position of the detection part at the end of the float connection rod to obtain a float height detection signal; and the processing module calculates a flow rate of measured crude oil according to the float height detection signal. The present disclosure can safely meter the crude oil flow of a crude oil transport pipeline and meet the accuracy of metering crude oil.

A flowmeter (5) is provided having a housing (28) configured to accept a flow of a process material. A diaphragm (18) is disposed in the housing (28), and is deformable by the flow of the process material. A sensor (48) is configured to detect a deformation in the diaphragm (18), and the flowmeter (5) is configured to measure the flow of the process material.

A flow rate assembly can include a fluid flow interface portion having a front facing wall and a back facing wall. The flow interface portion can include an inlet passage within the fluid flow interface portion, an outlet passage within the fluid flow interface portion, at least one inlet aperture extending through the front facing wall of the fluid flow interface portion into the inlet passage, and at least one outlet aperture extending through the back facing wall of the fluid flow interface portion into the outlet passage. In some cases, the fluid flow interface portion includes a plug forming at least a portion of the inlet passage.

A flow rate assembly can include a fluid flow interface portion having a front facing wall and a back facing wall. The flow interface portion can include an inlet passage within the fluid flow interface portion, an outlet passage within the fluid flow interface portion, at least one inlet aperture extending through the front facing wall of the fluid flow interface portion into the inlet passage, and at least one outlet aperture extending through the back facing wall of the fluid flow interface portion into the outlet passage. In some cases, the fluid flow interface portion includes a plug forming at least a portion of the inlet passage.

Flow sensors are provided that can provide both leak detection and flow monitoring. The flow monitoring enables a determination whether there are blockages or leaks in a fluid system during normal operation of the system. The leak detection enables detection of leaks when the system is shut off. The flow sensors can use a frusto-conical flow guide to provide a more compact flow sensor.