Venturimeter: Definition, Parts, Working Principle, Applications

A venturi meter is an instrument which is to calculates the liquid flow in tubes. This meter works on the principle of Bernoulli’s equation. The venturi meter is a flow-measuring instrument that comes with a narrow throat for the conversion of the potential energy of the fluid passing in pipe where devices connected kinetic energy and flow rate are measured.

Table of Contents

Introduction to venturi flow meter

A venturimeter is a flow-measuring device that measures liquid flow in a tube. That works based on Bernoulli’s equation.
Venturin tubes come with 72-inch dimensional and can allow 25 to 50 percent more flow than orifice plates of the same pressure droplet.

It transforms pressure energy into Kinetic energy and measures the flow rate of liquid in the pipe
It comes with a tube of larger diameter and small constriction in the middle
Venturi meter operated on the Bernoulli equation such as the velocity of fluid increases when pressure decreases.
This theorem defines that the cross-sectional area of flow reduces and pressure difference is produced between different part of flow
It helps to measure the difference for the pressure that helps to get discharge inflow.

Parts of a Venturi Meter

Converging Part:

The cone area reduces when water flows. so there is an increase in the speed of water flowing and reduces pressure.

Throat Diameter:

Area is constant in throat diameter when water passes so speed and pressure are also constant values.

Diverging Part:

Area increases when water passes through the cone and speed reduces and pressure decreases

Venturi Principle

This principle explains that as the speed of fluids increases pressure decreases.
If liquid flows in venturi at a position where cross-sectional area A1 pressure P₁, and speed V₁.
This configuration is based on the potential and kinetic energy of liquid at a single point. Energy is conserved for sealed configuration, which says the addition of KE and PE for the same point is equal to the sum of both at another point.
if potential energy affects at one point KE will increase at that point. The liquid second point of the venturi has area A₂, which is lesser than first area A₁.
According to the law of conservation, mass is not produced not created and the flow rate of fluid is A1 and equal to area A₂.
If A2 is less than A1 liquid flow fast for a saving flow rate at the same value. That increase in speed resulted in a reduction of pressure that operated on Bernoulli’s Theorem. The pressure and cross-sectional area are for two different points and one can measure the speed of the liquid. With the speed of liquid, we can measure the flow rate.
There is a need of two pressures of venturi and one temperature measure for accurate liquid flow. The pressure is measured at Venturi’s inlet position, P₁.

Benifits Venturi Meter

It decreases propelling prices.
It has a low price compare to other venturi meters.
It has no moving part and it can easily repair if a fault occurs at it.
There is a need of insignificant square tube space necessities.
Its brushoff ratio is10:1

It has a repeatability of ± 0.1%
It can be based in any location
Its design is so simple which draws minimum pressure.

Types of Venturimeter

Horizontal Venturimeter

This meter comes with horizontal axis flow. The horizontal meter comes with a high kinetic energy value and low potential energy.

Vertical Venturimeter

In this meter, flow is axis vertical and comes with low kinetic energy and high potential energy

Inclined Venturimeter

In this meter flow axis is at an angle and the kinetic and P.E of these fluids is between horizontal and vertical types of meter

Features

Now we discuss the features of the venturi flow meter.
This meter delivers stability, and fidelity, and works for a long time.
It offers an un-adjusted precision of ±0.75 percent with repeatability of ±0.1 percent.
Is intended in harmony with the same and iso criteria and it proposes the uppermost “as constructed” correctness.
It decreases the propelling prices.
It also offers the deepest level of enduring pressure damage of any venturi smartness, meaningfully fewer than orifice plates.
It is a customary and exclusive amalgam,
It provides a long-lasting elucidation for fluids, vapor, mist, and varied mediums.
With slight alterations, the SSL can be distorted into a bi-steering movement meter.
It can connect in any location with a negligible square tube.
It is also recognized as Herschel.
It working is like an RTD.

Venturi Meter Specification

The Line size of the venturi meter range is about 100 mm to 800 mm.
Accuracy can be from +/-0.25 % to +/-3.0%.
The flow coefficient value is 0.98 for different values of diameter
The beta ratio value is 0.3 and 0.75.

Applications of a Venturi Meter

It is used for measuring chemical flow in pipelines.
it is also used for measuring the flow rate of fluid discharged in the pipe
it is a common part of the waste treatment process for larger-diameter pipes.
It is also used in industries for measuring pressure and gas quantity and liquids in flow.
The rate of flow of blood is measured with this device.
it has features to recover high-pressure