Flow measurement Questions and Answers


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 edge orifice plate.
How many types of orifice plate are there?
Basically there are four types of orifice plate first is concentric orifice plate, second is eccentric orifice plate, third is the segmental orifice plate and fourth is the quadrant edge orifice plate.
Orifice equation is based on?
Flow characteristics.
What is Concentric Orifice Plate?
Basically this orifice plate has a hole in the middle, it is known as concentric orifice plate. And this hole Plate is commonly used in ideal liquid, gas as well as steam services. But this is not an orifice plate Used in slurry or highly corrosive processes.
What is an eccentric orifice plate?
Basically this orifice plate has an eccentric portion or a hole in the middle called an eccentric orifice. plate and this orifice plate is used in viscous and slurry flow.
What is Segmental Orifice Plate?
Basically this orifice plate has a hole in the form of a segment of a circle. And this orifice plate is used Colloidal as well as slow flow.
What is a conical orifice plate?
Basically this orifice plate is installed at the back so that the flow enters from the beveled side, but usually Enter the stream on the non-beveled side.
What is Quadrant Edge Orifice Plate?
Quadrant edge orifice plates are in common use in Europe and are particularly useful for pipe sizes less than 2 inches. Quadrant edge orifices produce a relatively constant coefficient of discharge for services with low Reynolds numbers from 100,000 to 5,000.
What is an integral orifice plate?
Basically this orifice plate is used at low flow rates. What meat is used for the perforated plate? Orifice plate is usually made of stainless steel.
Why use orifice plate pressure tap?
Basically pressure taps are installed on the pipe in conjunction with the orifice plate. and is used to allow A transmitter to tap into a pipe to measure the high and low pressure sides of the flow. Whey hole faucet provided Orifice taps provide an indication of the orifice plate in a line, marked with the orifice diameter, Orifice plate material, orifice plate tag number and inlet symbol in one row.
Orifice How many types of orifice plate pressure taps are there?
There are basically six types of orifice plate pressure taps, first flange tap, second ven contractile tap, third Radius tap, fourth is pipe tap or full flow tap, fifth is corner tap and sixth is elbow tap.
What is Reynolds number?
Dynamic equivalence implies correspondence of fluid forces between two systems. are in general conditions Several classes of forces that influence the behavior of fluids. Some of these inertias are viscous, Gravity, compression, pressure and elastic forces. Some dimensionless ratios are developed Based on fluid properties. Velocity and magnitude, which are essentially force ratios. In flow metering, The nature of the flow can be described by a number - the Reynolds number, which is the average velocity * Density * Internal Diameter of Pipe ÷ Viscosity.
In equation form, it is
R = vDρ/μ,
v = velocity
D = Inside diameter of pipe
Ρ = liquid density
μ = Viscosity.
Why is an orifice tab provided?
Orifice tab is provided for following reasons.
Indications of hole plate in a row.
The hole diameter is marked on it.
Material of orifice plate.
Tag no. of the orifice plate.
Mark the inlet of the hole.
Why is flow measured in square root?
The flow varies directly as the square root of varying pressure F = K AP. From this stream A pen that varies as the square root of the differential pressure does not indicate direct flow. can stream Determine by taking the square root of the pen. Say the pen reads 50% of the charts.
Where do you use a square root extractor?
Square root extractors are used in orifice and other DP transmitters.
What is rota meter?
A rota meter consists of a vertical tapered tube through which the metered liquid flows upwards. direction "Float" is either spherical or conical, denser than the liquid actually measured, Forms an annular passage between its maximum circumference and the weight of the tapered tube. Therefore The flow changes by rising or falling on the float which changes the area of ​​the passage so that the difference across it Only the gravitational force on the "float" balances i.e. the differential pressure is kept constant. The position of float is measured by the rate of flow.
What is a magnetic meter?
An electric potential develops when a conductor is moved across a magnetic field. In most In electrical machines, a conductor is a "wire"; This principle is equally applicable to a moving, electric conductive liquid. The primary device of a commercial magnetometer consists of a straight cylinder An electrically insulated tube with a pair of electrodes is almost flush with the tube wall and is located here Opposite end of tube diameter. A uniform a.c. A magnetic field is provided at right angles to the electrodes diameter and to the axis of the tube. The a.c. is proportional to the voltage developed at the electrodes to the fluid flow rate and magnetic field strength. This device is limited to electricity Conducting fluid. Magnetic meters are particularly useful for measuring slurries and dirty liquids, Because there is no place for solids to collect without the tube wall.
What is a turbine meter?
A turbine meter consists of a straight flow tube in which the turbine or fan is free to rotate. axis which is determined along the center line of the tube. Straightening at the top of the turbine Reduces potential rotational component of fluid flow. Many units have magnetic pick-up system sensors Rotation of the rotor through the tube wall. A turbine meter is a flow rate instrument, from the rotor Speed ​​is directly proportional to flow rate. The output is usually in the form of electrical pulses from Magnetic pick-up with frequency proportional to flow rate. Turbine meters are mainly applied Measurement of clean and corrosive hydrocarbons.
What is a pitot tube?
A pitot tube measures the velocity at the point of conduction. If a rate measurement is desired, it The average velocity at the point of measurement must be calculated from the ratio of the velocity.
What is flow compensation?
In steam or gas flow measurement, the density of the steam or gas varies as pressure and temperature change. This change in density can affect the accuracy of the measured flow rate Uncompensated temperature, pressure compensated flow control is a mathematically adjusted flow Control with one or more additional variables.
What is an Ultrasonic Flowmeter?
Ultrasonic flowmeters transmit high-frequency sound waves into the fluid path to measure fluid velocity. The ultrasonic method uses the change in propagation time of a moving fluid. There are two main ones Types of ultrasonic flowmeters: Doppler and transit time characteristics.
What is volumetric flow?
Volumetric flow is the total volume of fluid passing through the line of operation.
What is the flow rate?
Flow rate is the amount of liquid per time that flows through the process sheet.