Flow meter

A flow meter is basically a device used to measure or indicate the flow of a liquid, gas or any fluid moving through a pipe. A flow meter basically measures the amount of steam, liquid and gas flowing through a pipe, and there are several types of flow meters or flow sensors that measure the flow rate of a liquid or gas.  A flow meter measures the flow of a gas or liquid through a closed or open pipe.

Basically flow is the amount of liquid or gas passing through a pipe or system and the formula for measuring flow is Q=V*A where Q is the flow rate, V is the flow velocity and A is the pipe area. And the unit of flow measurement is liter/minute, m3/hour, cut/second, kg/second, ton/hour, gallon/minute.

flow

Flow is the flow of a gas or liquid through a closed or open pipe. And basically flow is the amount of liquid/gas passing through the system. The unit of flow is liter/minute, kg/second, gallon/minute, tans/hour, m3/hour.

flow rate

Flow rate is equal to the velocity of flow in the area of the pipe and rate of flow is basically defined as flow rate is the fluid flowing through the process pipe at any given time.

flow measurement

Flow measurement is mainly of two types primary component or secondary component. Primary component devices consist of orifice plate, venturi, flow nozzle and secondary component devices are manometer and differential pressure.

The primary components used for flow measurement are orifice plate, venturi tube, pitot tube, anubar, flow nozzle.

Different flow meters are used to measure flow

A flow meter mainly used for flow measurement is DP flow meter and also known as differential pressure flow meter, velocity flow meter, positive displacement flow meter and mass flow meter.

Orifice plate, flow nozzle, venturi meter and rotameter are examples of DP or differential pressure flow meters. Examples of velocity flow meters are turbine flow meters, electromagnetic flow meters, paddlewheel flow meters, and ultrasonic flow meters. Examples of positive displacement flow meters are diaphragm flow meters, nutating disk flow meters, gear flow meters, and rotary vane flow meters. Thermal dispersion and Coriolis flow meters are examples of mass flow meters.

Types of flow meters

• Positive displacement flow meter
• Differential pressure flow meter
• Electromagnetic flow meter
• Ultrasonic flow meter
• Coriolis mass flow meter
• Thermal mass flow meter

Differential pressure flow meter

Differential pressure flow meters are the most common types of flowmeters known as DP flow meters that measure fluid flow rates. Basically a differential pressure or DP flow meter measures the volume flow between liquids, vapors and gases. They are generally used in situations where high pressure, high temperature or large diameter play a role. They are mainly found in the chemical, oil, gas, power industry, water treatment, pharmaceutical, food and beverage, mining, chemical manufacturing and HVAC industries.

Example of a differential flowmeter

Orifice plate, flow nozzle, venturi meter and rotameter are examples of DP or differential pressure flow meters

Advantages of differential pressure flowmeter

• The DP flowmeter is of simple construction
• DP flowmeters are also used in larger pipes up to a few meters in diameter
• DP flowmeters are made in a variety of materials so they can be used with many types of gases and liquids.
• DP flowmeter is easy to maintain
• The DP flowmeter is suitable for low and high temperature applications in the temperature range of -270°C to 500°C.
• DP flowmeter is less expensive

Velocity flowmeter

The principle of operation of the flowmeter is that the flow rate of the liquid is equal to the cross-section of the pipe multiplied by the velocity of the liquid. By measuring the velocity of the fluid flowing through the pipe, a velocity flowmeter can determine the flow rate of the fluid.

Example of a velocity flowmeter

 Examples of velocity flow meters are turbine flow meters, electromagnetic flow meters, paddlewheel flow meters, and ultrasonic flow meters.

Positive displacement flowmeter

Positive Displacement Flowmeters One of the most common types of flowmeters known as PD flowmeters. A PD flowmeter determines the flow rate of a liquid by measuring the volume of the liquid. A positive displacement flow meter is a direct measurement of the volume of liquid passing through the flow meter. It achieves this by trapping fluid in pockets between moving elements in a high precision chamber. Counting the number of times a beaker is filled can be compared to repeatedly filling a beaker with liquid and pouring the contents down.

Example of a positive displacement flowmeter

Examples of positive displacement flow meters are diaphragm flow meters, nutating disk flow meters, gear flow meters, and rotary vane flow meters.

Mass flowmeter

A mass flowmeter measures the flow of a fluid as it moves through a pipe. Mass flowmeters are commonly used in the mining, wastewater, power, chemical and gas industries.

Open the channel flowmeter

Open channel flow meters measure the total volume and height of water flowing through channels, flumes, weirs, and partially filled pipes.