9 Key Venturi Meter Advantages and Disadvantages | Uses of Ventura Meter | Parts of Venturi Meter

What is a Venturi Meter? | Venturi Meter Advantages and Disadvantages | Venturi Effects | Types of Venturi Meters?

What is a Venturi Meter?

A venturi meter is a device that measures the flow of fluid through pipes. The idea of Bernoulli’s equation underpins this flow measurement device.

Pressure differential is established inside the pipe by lowering the cross-sectional area of the flow route.

This pressure differential is monitored using a manometer and aids in estimating the rate of fluid flow or other discharge from the pipe line.

Because the primary inlet size is larger than the neck area, the velocity of fluid at the throat increases and the pressure lowers.

 A pressure difference is formed between the venturi meter’s inlet and throat as a result of this.

As a result of reducing the cross-sectional area of the flow tube, a pressure differential is formed, which we measure using the Bernoulli equation and discharge formula.

Venturi meters are highly required for industrial and commercial operations that require precise flow measurement, particularly in high-pressure applications.

They are employed in industries like oil & gas, pharmaceutical, agriculture, and mining industry to measure flow rate accurately without much trouble.

J.B. Venturi initially published the principle of this flow metering apparatus in 1797 in Italy. The operating concept of these devices is that as the cross-sectional area of the flow diminishes, some pressure head is converted to velocity head (Bernoulli equation).

Venturi meter was later improved by Clemens Herschel in 1846 for measuring the flow rates of gases like air and steam. It was a simple device with a reduced diameter at the throat section and two ports for placing the manometer.

The first all-steel venturimeter was developed by Louis Tung in 1914 that was capable of measuring air, water, oil, and gas flow rates.

Venturi Effects

The Venturi effect is the decrease in fluid pressure that occurs when a fluid passes past a pipe’s confined section (or choke).

The Venturi effect is named after its discoverer, Giovanni Battista Venturi, an 18th century Italian physicist.

A venturimeter is a type of flowmeter that operates on the Bernoulli’s Equation concept. This equipment is commonly used to monitor the flow rates of fluids inside a pipe in the water, chemical, pharmaceutical, and oil and gas industries.

Venturi Meter Working Principle

A venturi is a pipe constriction that modifies the flow characteristics of a fluid (either liquid or gas) passing through the tube.

The pressure in the throat decreases as the fluid velocity in the throat increases. Giovanni B Venturi (1746-1822), an Italian physicist, was the first to discover this behavior.

The idea that a pressure decrease occurs with increased flow velocity is important to fluid dynamics laws.

In 1738, Swiss mathematician Daniel Bernoulli discovered the association between pressure, velocity, and other physical properties of fluids.

His theorem is traditionally used in the engineering of aircraft wings to produce thrust from the passage of air across the wing profile.

A venturi can be used for one of two things. The pressure drop and flow rate down the throat can be estimated by mounting manometers to three portions of the tube. This is known as a Venturi Meter.

A venturi, on the other hand, can employ this negative pressure to draw a second fluid into the primary flow. This phenomenon has many uses in a variety of industries. However, the fundamental mechanism has remained unchanged for nearly 200 years.

Types of Venturi Meters?

Following are the types of Venturi meters:

a)  Horizontal venturi meter

Horizontal means the mounting of this type is horizontal and is a widely used flow meter. A horizontal pipe is used where the Kinetic energy is high, as it flows horizontally.

Potential energy is low as its weight in the particular control volume is less.

b)  Vertical venturi meter

This is a pressure measurement device that is mounted vertically in the pipe and measures the flow of liquids or gases. Potential energy is high as the weight of the liquid in a particular volume is more.

The effect of Bernoulli’s equation may be seen when a fluid passes through a confined area, which reduces its pressure. The pressure drop across the Venturi meter increases with the cross-sectional area reduction.\

c)  Inclined venturi meter

This type of flow meter can be used to measure the flow rate of a fluid in an inclined direction.

The inclination angle should be between 30 and 60 degrees, while the pipe diameter should be equal to or greater than 80% of that of the throat size.

 The inclined venturi meter has a moderate velocity that incurs moderate kinetic and potential energy.

Parts of Venturi Meter

1. Converging part or converging cone

Converging cone is usually made of stainless steel or aluminum. It is fixed to the converging-type meter’s stem.

In most Venturi meters, this cone is the sole piece of the meter’s mechanism which requires adjustment as it becomes clogged.

2. Diverging part or diverging cone.

Diverging cone measures the sample flow as it leaves the meter. It is usually made of stainless steel or aluminum as well and connected to the Venturi meter’s stem.

3. Throat part

The throat part is usually made of glass and pressed on the Venturi tube. Its conical-shaped helps to concentrate all the flow into a very small area. It is connected to the nozzle.

The Venturi meter also has a nozzle that restricts any air from going into the Venturi tube until it reaches this point.

 Benefits of Ventura Meter

Venturi meter is used in almost all types of flow measurement, which include chemical, agricultural, water, and oil. They are mainly used in industries where large pressure changes are required.

 It offers simplicity in flow measurement and improvement on accuracy as well.

Elliptical meters show very good results in measuring liquids flows at small pressure drops. These flows are very difficult to measure using any other means of flow measurement.

Application & Uses of Ventura Meter

1. Plumbing

Venturi meters are often used in pipelines at wastewater treatment plants and collection systems.

They are utilized in wastewater pipes because the general design structure allows sediments to move through them rather than gathering in front of them.

 Less accumulation in the pipes allows for more accurate readings of the pressure and thus velocity of the effluent.

2.  Engine Carburetors

The flow rate of air into the engine carburetor is important for engine performance. That means it is important to know how fast the fuel enters the carburetor.

One of the ways to know this is with a Venturi meter. The Venturi meter can measure the air and fluid flow into one side of a float chamber and an indicator readout on that side shows how much fluid entered that side.

3.  Oil Drilling

In an oil drilling industry, it is assumed that the flow rate of the fluid needs to be maintained at a constant level.

The Venturi meter can be used in many ways, such as measuring the flow of oil coming from an oil well when pressure is applied to it.

4. Chemical Industry

Because the temperatures and pressures of chemicals in a pipeline have no effect on the accuracy of a Venturi flowmeter, they are employed in crude oil pipelines.

During the lengthy arctic winter months, crude oil pipelines, such as those in Alaska, are subjected to high temperatures.

Another benefit of employing the Venturi meter in such volatile and chilly conditions is that it has no moving parts that could freeze and shatter owing to thermal expansion.

5. Pharmaceutical & Medical Industry

The medical industry often needs to monitor the flow rate of blood flow in the arteries is measured by centimeters.

6. Water Supply Industry

The water supply industry requires each and every property to have a utility bill that is issued by the city. It is important for the utility company to know if there is a leak in the main supply line since this can lead to water damage.

The use of a Venturi meter in a pipe in order to accurately measure flow rate is essential since variables such as temperature, pressure, location, and humidity can cause errors.

Venturi Meter Advantages and Disadvantages

Advantages of Venturi meters

1.       Venturi meters Are Simple to use: The measurement of flow is very simple and easy using these devices.

2.       They provide accurate results: The readings are very accurate and precise, which are quite difficult to measure using other flow measuring methods.

3.       Predictable behavior: It helps predict the behavior of liquid liquids and gases.

4.       Venturimeter can be installed in any position:  can be installed vertically, horizontally, or inclined:

5.       It is compact: They are small in size so they can be easily transported to other locations for measuring flow rate and pressure drop of the liquid flow.

6.       Simple installation: The addition of a Venturimeter to the existing pipeline is easy as there are no changes required to the system or process.

7.       They provide immediate results: The measurement shows immediate results and avoids errors related to time lag issues in some methods used for flow measurement.

8.       It cannot clog: They are not prone to clogging and provide continuous flow of liquid or gas.

9.       They require less maintenance: They do not require any maintenance.

10.   Easily adjustable: By adjusting a Venturi meter, it is possible to easily convert it for different flow rates

Disadvantages of Venturi meters

1.       Expensive: It is not a cheap instrument and may be expensive to purchase.

2.       Requires specific adjustment: The flow rates and pressures may change when the Venturi meter is adjusted. To get a clear reading, it requires proper setting of the instrument and an adequate initial setting.

3.       Not suitable for very small diameter pipes: The flow rates and pressures may increase with a reduction of the diameter size of the pipe.

Venturi Meter FAQs

1. What is a Venturi meter?

A Venturi meter is a type of flowmeter that operates on the Bernoulli’s Equation concept. This device is frequently used to monitor the flow rates of fluids inside a pipe in the water, chemical, pharmaceutical, and oil and gas industries.

 The cross-sectional area of the pipe is reduced, resulting in a pressure difference that is measured with a manometer to calculate the rate of fluid flow.

As a result, the venturi meter is a differential head flowmeter that converts pressure energy into kinetic energy.

 The theory of the Venturi meter was proven by Giovanni Batista Venturi but Clemens Herschel was the first to employ it in practical metering applications.

2. What is the principle of Venturi meter?

Venturi meter works on the principle of fluid dynamics. The flows can be laminar or turbulent but should not be vicious.

3.  How does a venturi meter work?

A venturi operates by gauging the difference in pressure between two points. The pressure differential is established by narrowing the pipe, causing the fluid to flow quicker. In the wider segment of the venturi, the fast moving fluid has a lower pressure than the slower fluid.

4. What are the types of Venturi meters?

Venturi meters comes in three main types:

a. Vertical Venturi meter:

This is the most widely used venturi meter. Also, this is a differential head meter that measures flow rates (Q). A vertical pipe is used where kinetic energy is low as it flows vertically while the potential is high.

The pipe’s cross-sectional area is reduced, which results in a pressure drop at the throat section and sustained by a manometer to calculate flow rate (Q).

b. Horizontal Venturi meter:

The kinetic energy and potential energy of the fluid flow through this type of venturi meter are both high. Hence, these are differential head meters.

c. Inclined Venturi meter:

This type of venturi meter could be used to measure the flow of a fluid in an inclined direction. The inclination angle should be between 30 and 60 degrees while the pipe size should be equal to or greater than 80% of that of the throat diameter. This has a moderate velocity with low kinetic and potential energy.

5.  What are the applications of Venturi meter?

It is used in wide and diverse applications such as industrial water supply, chemical and industrial plants, power plants, etc.

They are also used in the medical and pharmaceutical industries because they provide accurate readings on a continuous basis.

6. Where is the venturi meter used?

A Venturi Meter is primarily used to assess the rate of flow of liquid through a pipe by lowering the cross-sectional area and creating a pressure gradient.

with this, a Venturi meter is used to measure the rate of flow of fluid passing through a pipe.

The Venturi is used in many industries such as water supply, oil refineries, chemical plants, pharmaceutical industries, etc.

7. What is the purpose of a venturi?

Venturi are used to assess the speed of a fluid by measuring the pressure changes from one point to the next along the journey. A venturi meter can also be used to pump one liquid or gas into another.

Venturi meter is most commonly used in chemical and oil and gas industries to measure liquid flow rates, gas flow rates, and gas-liquid mixtures at low-pressure drops.

8. Venturi meter is used to measure?

The Venturi Meter is used to measure the change in volume or flow rate of a fluid caused by a change in pressure

. Venturis are used in a variety of applications, but are most commonly found in applications involving water flow.

Water meters measure the flow of water by using a Venturi tube in the pipe. There are many different uses for venturi meter because there are many different applications they can be used for.

Venturis are used to measure the change in volume of a fluid caused by a change in pressure in the venturi.

This is done by measuring the pressure of the incoming fluid and the pressure of the fluid at the opening of the venturi.

What is the difference between venturi meter and orifice?

Both orifice and venturi meters work on the same principle: they establish a constriction in the flow channel and measure the pressure difference across the restriction, which is proportional to the rate of discharge of flowing fluid via the pipeline.

Venturi meter, a type of flow measuring device, is a differential pressure type flow meter that is based on the Venturi principle. It usually consists of a tube, through which water or other fluid flows. The flow rate is measured by a pressure differential that is created in the area of the flow tube.

The Venturi meter reading is the difference in pressures (pressure drop) across the tube, minus the atmospheric pressure. The pressure differential is due to the Venturi principle

An orifice meter is a device that uses an orifice plate to measure the flow rate in a pipe. It can estimate cubic flow rates, and it works on the same basis as a venturi meter, which is Bernoulli’s principle, which claims that the pressure and velocity of a fluid are related. If the velocity increases, the pressure decreases and vice versa. The flow is measured using an orifice plate, which can reduce or restrict the flow.