What are the different types of flow meters? Differential pressure (DP) flow meter Velocity flowmeter Positive displacement flowmeter Mass flowmeter Differential pressure (DP) flow meter Examples of DP flow meters are orifice plate, venturi meter, flow nozzle, rotameter. Velocity flowmeter Examples of velocity flow meters are electromagnetic flowmeter, ultrasonic flowmeter, turbine flowmeter, paddlewheel flow meter. Positive displacement flowmeter Examples of PD flow meters are nutting disc, rotary vane, gear, diaphragm flowmeter. Mass flowmeter Examples of mass flow meters are Coriolis flow meters, thermal dispersion meters

What is Differential Pressure Flow Meter? Differential pressure meters work on the principle of partially obstructing the flow in a pipe. This creates a difference in static pressure between the upstream and downstream sides of the machine. This difference in static pressure is measured and used to determine the flow rate. DP flow meters are widely used in industry to measure flow and are popular due to their simple design and low cost. Differential Pressure (Δp) Flow Meter Manometer tubes measure the difference between the static pressure upstream and downstream of the restriction. When a fluid flows through a restriction, it accelerates to a higher velocity (ie V2 > V1 ) to conserve mass flux and as a result its static pressure decreases. This differential pressure (Δp) is then a measure of the flow rate through the device. Simply put, for a given size of restriction, the higher the Δp, the higher the flow rate. The relationship between differential pressure and flow rate is deriv

Flow What is the primary component of flow measurement?  The primary components of flow measurement are orifice plate, flow nozzle, annubar, pilot tube, DP cell, Weirs/flumes and venturi tubes. What are the different flow meters? Based on the working principle of flow meter is DP flow meter, velocity flow meter, positive displacement flow meter and mass flowmeter Differential pressure (DP) flow meter: orifice plate, venturi meter, flow nozzle, rotameter. Velocity Flowmeter: Electromagnetic Flowmeter, Ultrasonic Flowmeter, Turbine Flowmeter, Paddle wheel flow meter. Positive Displacement Flowmeter: Nutating Disc, Rotary Vane, Gear, Diaphragm Flowmeter. Mass Flowmeter: Coriolis Flowmeter, Thermal Dispersion Meter What is Orifice Plate? Basically an orifice plate is a metallic plate with a hole in it. And the orifice plate is commonly used in flow Measurements are also of four types namely Concentric Orifice Plate, Eccentric Orifice Plate, Segmental Orifice plate and quadrant e

Coriolis Flow Meter A Coriolis flow meter measures mass by the inertia of a liquid or gas flowing through a vibrating tube that is equipped with a set of sensors at the inlets and outlets of the meter. The increased movement of the flow produces measurable oscillation that is proportional to the mass. The design and function of Coriolis flow meters has made them the most reliable form of fluid and gas measuring instruments. Types for Coriolis Flow Meters Single Tube Flow Meter Dual Tube Flow Meter Continuous Loop Flow Meter Straight Tube Flow Meter U Shaped Flow Meter Micro-Bend Flow Meter Triangle Shaped Flow Meter Single Tube Flow Meter The single tube design measures high fluid velocity that is created by reducing the cross sectional area in relation to the pipe. Tube distortion is measured in relation to a fixed point or plane. The tube is excited at a high amplitude bending force that is created at an anchored point. Dual Tube Flow Meter In the dual tube design of a Coriolis flo

Differential Pressure Flow Meters Differential pressure flow meters use laminar plates, an orifice, nozzle, or Venturi tube to create an artificial constriction then measure the pressure loss of fluids as they pass that constriction. According to Bernoulli's principle, the pressure drop across the constriction is proportional to the square of the flow rate. The higher the pressure drop, the higher the flow rate. These rugged, accurate meters are ideal for a wide range of clean liquids and gases. What is a differential Pressure (Δp) meter? Differential pressure meters work on the principle of partially obstructing the flow in a pipe. This creates a difference in the static pressure between the upstream and downstream side of the device. This difference in the static pressure (referred to as the differential pressure) is measured and used to determine the flow rate. Differential-pressure meters are hugely popular and it is estimated that at least 40% of industrial flow meters in use

Flow Switch A flow switch is one detecting the flow of some fluid through a pipe. Flow switches often use “paddles” as the flow-sensing element, the motion of which actuates one or more switch contacts. A flow switch, like all switches, is a device designed to make and break an electric current in a circuit. In an industrial system, a flow switch is essential in monitoring and controlling the flow rate of process media – such as steam, liquids, and gases. Flow switches help maintain safe and manageable rates of flow by triggering actions in various machines within a system to provide on/off flow control of process media. Principle of Flow Switch The “normal” status of a switch is the resting condition of no stimulation. A flow switch will be in its “normal” status when it senses minimum flow (i.e. no fluid moving through the pipe). For a flow switch, “normal” status is any fluid flow rate below the trip threshold of the switch. Working of the flow switch  Firstly th

  Annubar flow meter An annubar is very similar to a pitot tube. The difference is that there is more than one hole into the pressure measuring chambers. The pressure in the high-pressure chamber represents an average of the velocity across the pipe. Annubars are more accurate than pitots as they are not as position sensitive or as sensitive to the velocity profile of the fluid. There may be a single port or multiple tapping ports on the opposite side of the bar to measure the low static pressure in the downstream region. The difference between the total and static pressures is effectively a measure of the fluid velocity head, which together with the pipe area enables the volumetric flowrate to be determined. Annubar flow meter Principle The  Annubar primary flow element is a device used to measure the flow of a liquid, gas or steam fluid that flows through a pipe. It enables flow measurement by creating a differential pressure (DP) that is proportional to the square of the velocity of

Ultrasonic Flow Meter Working Animation

  Flow Meter Questions and Answers 1. What are the major three methods of flow meters? Area flow meter Mass flow meter Quantity meters 2. List some examples of the inferential flow meter. In the inferential type of flow metering techniques, the out quantity flow rate is inferred from a characteristic effect of a related phenomenon. Turbine flow meters Target flow meters Ultrasonic flow meters 3. What are the different types of positive displacement meters? Reciprocating piston type Rotating vane type Nutating disk type Lobed impellar type Oscillating piston type 4. What are the different types of thermal flow meters? Heat transfer flow meters Hot wire flow meters 5. Name the different types of weighing methods  Semiconductor feed belt weighing ( Batch weighing) Continuous conveyor scale radio active transmission gauge volumetric solid methods 6. Write any two points of calibration of flow meter Wet meter – manometer which is calibrated with mercury Dry meter – manometer which is cali

  Flow Nozzle What is Flow Nozzle ? Flow Nozzle has a smooth elliptical inlet leading to a throat section with a sharp outlet. Restriction in the fluid flow causes a pressure drop, which relates to the flow rate by applying Bernoulli’s equation. The smooth inlet of the Flow Nozzle results in a higher coefficient of discharge than most other differential meters. This higher efficiency means greater flow capacity when compared to most other differential meters of the same size. How it works Flow nozzles are often used as measuring elements for air and gas flow in industrial applications. When a gas/liquid accelerate through a nozzle, the velocity increase and the pressure and density decrease. The maximum velocity is achieved at the throat. After the pressure difference has been generated in the differential pressure flow meter. Flow rate can be calculated. Flow Nozzle Principle When a flow nozzle is placed in a pipe carrying whose rate of flow is to be measured, the flow nozzle causes a

Positive displacement flow meter Introduction A positive displacement meter is a type of flow meter that requires fluid to mechanically displace components in the meter in order for flow measurement. Positive displacement flow meters measure the volumetric flow rate of a moving fluid or gas by dividing the media into fixed, metered volumes.  Positive displacement flow meters are very accurate and have high turndown. They can be used in very viscous, dirty and corrosive fluids and essentially require no straight runs of pipe for fluid flow stream conditioning though pressure drop can be an issue. They are widely used in the custody transfer of oils and liquid fluids (gasoline) and are applied on residential home natural gas and water metering. A diaphragm meter, with which most homes are equipped, is an example of a positive displacement meter. This type of meter is appealing in certain custody transfer flow applications where it is critical that the metering be functional in order for

 Magnetic flow meter ( Electromagnetic flow meter) A magnetic flow meter (electromagnetic flow meter) is a transducer that measures fluid flow by the voltage induced across the liquid by its flow through a magnetic field. A magnetic field is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines. The physical principle at work is electromagnetic induction. The magnetic flow meter requires a conducting fluid, for example, water that contains ions, and an electrical insulating pipe surface, for example, a rubber-lined steel tube. Electromagnetic Flow Meters Working Principle Electromagnetic Flow Meters, simply known as mag flow meter is a volumetric flow meter which is ideally used for waste water applications and other applications that experience low pressure drop and with appropriate liquid conductivity required. The device doesn’t have any moving parts and cannot work with hydrocarbons and distilled wate