Coriolis Mass Flowmeter – A Complete FAQ Guide

Coriolis mass flowmeter has a simple yet effective operating system.  It is a device that measures the flow of fluids within the tube. The Coriolis mass flowmeter was named after the French mathematician Gasper Gustave de Coriolis. They had first introduced 30 years ago. They are globally accepted where precision flow measurement is needed. It is also known as an inertial flow meter or a mass flowmeter because of its dominance in the flowmeter market.

We will discuss the FAQs related to the Coriolis mass flowmeter in detail. These comprehensive answers will help you in understanding the basics associated with Coriolis mass flowmeter. Furthermore, the thorough solutions will help you if you want to operate Coriolis mass flowmeter.

How does a Coriolis mass flowmeter work?

It consists of a tube that is run by a fixed vibration. When the fluid (gas or liquid) passes through the tube, it changes the tube vibration to a phase shift because of the mass flow momentum of the tube. The mass flow rate is the amount of fluid that that travels the tube per unit of time. Therefore, it measures the fluid in mass per unit time rather than mass per volume.

The volumetric flow rate of the Coriolis mass flowmeter is the fluid flow rate divided by fluid density. The signals from the sensor indicated mass flow rate. The mass flow is independent of the tube and can be used for any fluid, water, or gas.

What does the Coriolis mass flowmeter do?

Coriolis mass flowmeter has a different design than thermal or differential mass flow meters. It measures mass through inertia. Liquid or gas flows through the tube. Under the effect of vibration, the acceleration generates the twisting force on the tube. In most Coriolis mass flowmeters, dual-curved tubes are used for more sensitivity and lower pressure drop.

Coriolis mass flowmeter is considered the most accurate but vulnerable to errors when bubbles are present in the liquid. These bubbles can cause noise and create splashing within the tube.

How does the Coriolis mass flowmeter measures density?

You can use the Coriolis flowmeter to measure the density of the liquids as well. The flowmeter vibrates at resonant frequency alongside the sensing tube and the fluid density in the tube. The electrodynamics sensors allow drive frequency to convert into resonant frequency. As the fluid density changes, this causes the change in resonant frequency, so the resonant frequency is dependent on the liquid density.

You can use the RTD (Resistance Temperature Device) to overcome density due to the temperature change and vibrating devices to measure the density of liquids. However, this is not an exact way to measure the density of the fluids because of the sensitivity of these vibrating devices.

What are the typical applications of Coriolis mass flowmeter?

Coriolis mass flowmeters are gaining prominence in flowmeter applications. There has been a steady technical improvement in the structure since they came into the 1970s. As a result, their accuracy and acceptance have increased in the industries. In the process industries, Coriolis mass flowmeter represents a fast-growing percentage of flowmeter applications.

Applications of Coriolis mass flowmeter continue to expand in the petroleum industry. These applications include liquid separators, crude oil, liquid pipelines, refinery applications, viscosity measurements, Lease Automated Custody Transfer (LACT), etc. In addition, other applications unique to Coriolis mass flowmeter are combined with mass flow measurement and online density measurements.

 

What are the features of the Coriolis mass flowmeter?

You can use the Coriolis mass flowmeter for the measurement of liquid and gas. It uses a unique bar vibration that vibrates the detector tube. When fluid flows, it measures the mass of the fluid by detecting phase differences. Here are some of the features of the Coriolis mass flowmeter:

1. The usage of the mass method gives flowmeter high accuracy to measure liquid mass flow rate, resulting in increased productivity.
2. As the Coriolis mass flowmeter measures the flow rate of liquid to 5% of the flow range, it can accurately measure the flow rates at low flow rates.
3. Coriolis mass flowmeter uses a torsion bar for vibration the tube indirectly. This bar allows vibration without vibrating the entire tube. This flowmeter is resistant to piping vibration and changes the density when bubbles are in the fluid.
4. It measures the mass flow of the fluid without changing the parameters. This reduces the chances of measurement error.
5. The high accuracy in the measurement of mass flow makes measurements in a more extensive range.
6. There is no barrier in Coriolis mass flowmeter inside the pipe where fluid flows. This makes the life of the product longer and minor maintenance of the flowmeter.
7. Due to its high accuracy of standard measuring data, you can use the Coriolis mass flowmeter in industrial processes such as petroleum, chemical, pharmaceutical, petrochemical, food, and energy industries.

Advantages of Coriolis mass flowmeter?

1. It is a direct and accurate mass flow measurement method for liquid and gas.
2. The accuracy level for liquid is 0.1% and 0.5% for gases.
3. The Coriolis mass flowmeter measurement ranges from less than 5 grams to 350 tons/hour.
4. Density, mass flow, and temperature are accessible through one sensor.
5. It can easily measure high viscosity fluids like crude oil, heavy oil, or other high viscosity liquids.
6. Coriolis mass flowmeter is a multifunctional, reliable, and accurate flow measuring instrument.
7. It directly measures the mass flow rates of gas and fluid without any temperature or pressure compensation.

Disadvantages of Coriolis mass flowmeter

1. Coriolis mass flowmeter is expensive compared to other flowmeters. It has a high initial cost for large pipe sizes.
2. It is not a good instrument for measuring fluids with a lower density like low-density gas.
3. The bent tubes may trap fluid inside and make it unclean for various applications.
4. You can not use Coriolis mass flowmeter for larger diameters. Its maximum size is 8 inches flow meter.

How to install Coriolis mass flowmeter?

The installation and design of the Coriolis mass flowmeter are similar to the standard liquid metering installation. You should follow the manufacturer’s installation guidelines and recommendations. During the Coriolis mass flowmeter operation, the meter must remain complete with liquid so that the air cannot be trapped inside the tubes.

Coriolis mass flowmeter can endure pipeline solids without damaging the meter as strainer upstream protects the meter prover and other flowmeter components. There is a back pressure valve located on the meter that prevents flashing and cavitation. Flow conditioning is not necessary for Coriolis mass flowmeter. The flow velocity is higher because the main role is to operate in the upper end of the performance range.

How does Coriolis mass flowmeter measure the flow?

Coriolis mass flowmeter measures the flow from the acceleration caused by moving the fluid to the area of rotation. The fluid flows in a flexible hose that is oscillated back and forth. The movement of water flows toward and away from the hands; as a result, opposite forces are generated, which cause the hose to twist.

You must be careful while using Coriolis mass flowmeter for gas and vapor flows as flow rates are lower in the flow range where accuracy cannot be achieved. However, you can apply the flowmeter in gas and vapor applications smaller than 6-12 inches. Coriolis mass flowmeter is operated on the upper flow range if the pressure drop is acceptable.

How does pressure affect Coriolis mass flowmeter?

A mass flowmeter is a system used to measure fluid flows in mass units; tons, pounds. Coriolis mass flowmeter with large diameter tubes is affected by increasing pressure. The rising pressure results in stiffing of tubes and resists the Coriolis force. Therefore, every design and size of this flowmeter has different pressure effect specifications.

A flow pressure effect correction must be applied to adjust the mass flow rate of the flowmeter measuring the pressure. As the Coriolis mass flowmeter measures the flow of liquid or gas, you can also calculate the gross liquid volumetric flow rate. Its flow rate output is similar to other meters, such as turbine flow meters. In some Coriolis mass flowmeter applications for the measurement of gas or liquid, the pressure effect can alter the accuracy of the measurements. In Coriolis technology, pressure can cause span error in the flowmeter. Span error means the relationship between the input and output over an operating range.

How many tubes can use in Coriolis mass flowmeter?

The primary purpose of the Coriolis flowmeters is to measure the flow rate of liquids. The Coriolis mass flowmeter consists of parallel vibrating tubes or a single vibrating tube with two parallel sections. The two parallel tubes deflect based on fluid flow.

The vibratory motion of each tube causes a force on the particles, resulting in fluid-particle motion in the direction of fluid flow. This leads to Coriolis force that caused the deflection of the tubes.

How is viscosity measured using Coriolis mass flowmeter?

Viscosity is the measure of a fluid’s internal resistance to shear stress. The differential pressure (DP) method is a traditional method to measure viscosity in a mass flowmeter is through the differential pressure (DP) method. Certain types of fluids offer different viscosity. For instance, syrup can be poured easily and has a high viscosity, while gasoline is thinner and has a lower viscosity.

You can measure the viscosity in Coriolis mass flowmeter by identifying the pressure drop in the flowmeter. The fluid is forced to move due to the rotational motion of the tube, and velocity induces shear forces in the fluid. This reduces the oscillation of the measuring tube and can be measured through excitation current. The excitation current measures viscosity.

How is density measured using Coriolis mass flowmeter?

The vibration frequency of the tubes is affected by the stiffness of the tube and mass. Since the amount of fluid is constant, a change in density of the fluid causes the difference in the mass. The frequency of the tubes changes with the change in the mass inside the tube. This natural frequency is related to the density of the liquid inside the tube.

You can measure the density by the rate at which mass flow affects the oscillation of the tubes. A higher density will reduce the resonance frequency of the tube, and lower density increases it.

How to choose the best Coriolis mass flowmeters in the market?

It is essential to select the suitable Coriolis mass flowmeter as they are crucial for data collection. Choosing the wrong one can disturb your budget. Therefore, you have to take some aspects in mind while purchasing the flowmeter. The first criteria to select the flowmeter are price and popularity. If you choose the flowmeter just based on price, the chances are that you may end up with the wrong one.

If the initial investment of the Coriolis mass flowmeter is higher, it may cost you less to maintain and operate. Mostly Coriolis mass flowmeters are expensive to purchase than the other flowmeters, but they can save money in the long run because of their easy maintenance and less downtime. The new Promass 300/500 Coriolis flowmeter brings a lot of Endress+Hauser experience with its flow measurement. The new ROTAMASS Coriolis mass flowmeter brings remarkable improvement to the flow meters. Some other features to consider are digital protocols or meter verification.

What are the specifications of the Coriolis mass flowmeter?

Coriolis mass flowmeter can measure the mass flow of the liquid without changing the intermediate parameters, thus avoiding the measurement error. When using the Coriolis mass flowmeter to measure gas, the measurement accuracy is as high as 0.1%. In addition, it can obtain maximum barging pressure of 20 bar with a maximum operating temperature of 100 degrees in the flow range of 0.5 to 10 LPM.

The maintenance-free operation and self-monitoring of the entire flowmeter make Coriolis mass flowmeter more reliable. They are rather sensitive instruments that you need to install in well-aligned piping. They are consist of unique and patented box-in-box features that make them less susceptible to stress.

How accurate is Coriolis mass flowmeter?

Mass flow measurement is one of the essential operations throughout industries to measure the flow. You can the mass flow from the outputs of the volumetric flow meter and densitometer in the past. However, these measurements did not provide accurate results because the relationship between pressure, temperature, and density are unknown.

Coriolis mass flowmeters provide 0.1-2% inaccuracy over the mass flow range of up to 100:1. Thus, you can directly and accurately measure density and mass flow using the Coriolis principle. The Coriolis principle will affect measuring tubes from meager flow rates, so its measuring span is more significant than other measuring flowmeters. This ensures high accuracy on the entire range.

How does Coriolis mass flowmeter cost?

The first and perhaps the only barrier that comes up in Coriolis mass flowmeter is its cost. For example, if you purchase a one-inch magnetic flow meter and transmitter, it will cost you almost 3000$ or more minor. While if you are buying a Coriolis mass flowmeter of the same size, that may cost you a good fortune of 9000$ or more.

However, some competitive Coriolis mass flowmeters have come into the market with prices closer to the traditional flowmeters in the last few years. But these low prices Coriolis flowmeters offer less accuracy and fewer features than those with higher-priced counterparts.

How to maintain Coriolis mass flowmeter?

If you are working on Coriolis mass flowmeter, it must be well tested and maintained. During the usage of the flowmeter, the Coriolis flowmeter may experience zero drift. Zero drift can make the measurement inaccurate. Zero point drift is the problem often encountered in Coriolis mass flowmeter. Many factors caused it, like installation stress of the sensor, change in the fluid characteristics, etc.

To overcome these sorts of issues, it is necessary to check the flowmeter and make adjustments regularly. You should also check the operating parameters, flow, density, and temperature.

What is the authenticity of Coriolis mass flowmeters?

Coriolis mass flowmeter is the multivariable device that measures the mass of flowing liquid and gasses.  It also measures the tube’s temperature and liquid density, which helps calculate the gross volume of liquids. Coriolis mass flowmeters have been approved under the type evaluation programs and comply with national and international standards.  It is extensively used globally in various fluid flow applications successfully.

What is the working principle of the Coriolis mass flowmeter?

The operating principle of the Coriolis mass flowmeter is very effective. It works by following the principle of motion detection, and when it enters the tube, the fluid is divide. As the tube oscillates, the voltage creates a wave. The time delay between two waves is directly proportional to the mass flow rate.

Coriolis mass flowmeter has a U-shaped sensor, and inside this sensor, there is a U-shaped flow tube. It is vibrated at the natural frequency, and the vibration completes the entire cycle about 80 times/second. The liquid flows in the tube in the vertical direction. When the tube is moving upward, the liquid is pushed down on the tube. When the tube is moving downward, the liquid flows in the opposite direction.

What are the types of mass flowmeters?

The Coriolis mass flowmeter with curved tubes has higher flow sensitivity. Flow sensitivity is the microseconds of phase shift per unit of mass flow rate. Therefore, the device is more sensitive if the per-unit flow of the tube is greater.

Tubes are consist of different materials, but the most common material is stainless steel. These tubes have various shapes, including U-shaped, triangle-shaped, helix-shaped, and straight. The vibrations in the two tubes are 180 degrees. Therefore, flowmeters with high flow sensitivity have lower pressure drops.

What are volume and mass flow in Coriolis mass flowmeter?

Coriolis mass flowmeter measures the actual mass flow of the fluids, while thermal mass flow depends on the physical properties of the fluid. As a result, mass flow is an important measurement tool across the industry as it overcomes any inaccuracies caused by the fluid’s physical properties. In addition, mass flow is not affected by changing temperature and pressure.

Volume flow is also accurate in measuring the flow of fluids. Variable area meters and turbine flow meters are the devices of volumetric flow. However, they cannot differentiate pressure or temperature changes.

What is the role of Pipe in Coriolis mass flowmeter?

You can use the Coriolis meters to measure the weights of gas and liquids. The Coriolis flowmeter consists of a C-shaped pipe which is the central part of the flowmeter through which the fluid flows. The pipe and the fluid are accelerated by the vibration, which sets the C tube into oscillation. This oscillation results in velocity, which changes in direction.

The Coriolis forces on the fluid act in the opposite directions and cause C to become displaced. When the direction of angular velocity is reversed, then the Coriolis forces are also changed. You can monitor the displacements by the sensors and are proportional to the mass flow rate.

Is Coriolis mass flowmeter expensive than other flowmeters?

The installed cost of the Coriolis mass flowmeter is high compared to the other flowmeters in the market. Their installation costs are higher, but the maintenance cost is lower. The increased flow velocity keeps the meter swept clean. The Coriolis mass flowmeter has high accuracy and performance, reducing ownership cost despite the high initial price.

What are implementation and control systems in Coriolis mass flowmeter?

A Coriolis mass flowmeter is designed with high technology that can control and measure the direct flow of fluids and gases. The force creates the counterclockwise rotation to the Northern hemisphere and clockwise rotation to the Southern hemisphere.

Coriolis principle is accurate for volumetric correction. However, they are more popular for transfer and control measurements. They are more accurate in the height of sizes from 1/16 through 6 inches.

Conclusion

Coriolis mass flowmeter is used widely in hydrocarbon and natural gas service with high accuracy and reliability. You can use it simultaneously to measure the mass flow rate, density, and temperature. Thus, it can be of long-term use despite its high purchase price. If you have any questions regarding Coriolis mass flowmeter, you can contact us to get guidance. Our teams of professionals are here to assist you in every possible way. You can contact us at sales@instruthink.com. Customers are our top priority.