Liquid Turbine Flow Meter is one of the most ideal flow meters for measuring liquids. Liquid Turbine Flow Meter is suitable for measuring low-viscosity media, such as water, diesel, gasoline, etc.

Liquid Turbine Flow Meters

The Liquid Turbine flow sensor can measure the instantaneous flow rate and the total cumulative volume of the liquid, and can also quantitatively control the liquid. Turbine flow meters are velocity flow meters. The principle is to use the relationship between the rotational angular velocity of the impeller placed in the liquid and the liquid flow rate. Calculate the size of the liquid flow by measuring the speed of the impeller. The flow can be displayed on-site and can also be matched with the corresponding flow totalizer.

Sino-Inst offers a variety of Liquid Turbine flow meters for Liquid flow measurement. If you have any questions, please contact our sales engineers.

Featured Liquid Turbine Flow Meters

Types of Turbine Flow Meter

Different measuring medium

According to different measuring media, turbine flow meters can be divided into gas turbine flow meters and liquid turbine flow meters.

Gas turbine flowmeters are significantly different from liquid turbine flowmeters in structure.

You can learn more about gas turbine flow meters.

Different output signal

According to the different output signals, we divide the liquid turbine flowmeter into the following 4 categories.

A. On-site display type

The intelligent flowmeter is a new type of flowmeter display instrument designed with advanced single-chip microcomputer technology, and it is matched with the flow sensor (such as turbine, vortex) with pulse signal output.

  • Can display instantaneous flow and cumulative total.
  • Cumulative flow: 8 digits, 3 significant digits after the decimal point.
  • Instantaneous flow: six digits, can show the change per liter.
  • Display accuracy: ±1 display unit.
  • Signal output: pulse output: 1~3000Hz
  • External power supply +12~+24VDC
  • Current output: 4~20mA
  • External +24VDC power supply (two-wire system) built-in 2 3V lithium batteries in parallel for power supply.
  • When the voltage is lower than 2.7V, there will be an undervoltage indication, explosion-proof type.
  • Small signal removal function.

B. Pulse output type

  • Working voltage: +12VDC or +24VDC (the customer must select a power supply before ordering).
  • Signal transmission distance: less than 250 meters.
  • Output signal: square wave signal
  • Amplitude: +12VDC power supply amplitude is about 10V +24VDC power supply amplitude is about 20V
  • Installation: The connection between amplifier and turbine flow sensor is M16×1.5 thread. After the turbine flow sensor is installed, screw the amplifier to the turbine flow sensor. Tighten the lock nut until you feel the amplifier to the end.
  • Wiring: The pulse output type amplifier has three external leads, red wire, white wire and shield. The red wire is connected to the positive power supply, the white wire is the pulse output and other display instruments or equipment, and the shield is grounded.

C. 4~20mA output type

  • Working voltage: external power supply +24VDC (two-wire system)
  • Output signal: 4~20mA or 1-5V. 4mA corresponds to the zero flow of the turbine flow sensor, and 20mA corresponds to the maximum flow of the turbine flow sensor. See the nameplate of the turbine flow sensor for the flow range.
  • Signal transmission distance: less than 250 meters.
  • Installation: After the turbine flow sensor is installed, screw the amplifier to the turbine flow sensor connector (m16×1.5 thread). Tighten the lock nut by hand until you feel the amplifier is at the bottom.
  • Wiring: The external leads of the 4-20mA output amplifier are red and white wires. The red wire is the power wire and the white wire is the signal wire.

D. Split remote display type

  • Working voltage: 220VAC from external power supply
  • Signal transmission distance: less than 250 meters
  • Instantaneous four digits of the indicator: nine digits for the cumulative total
  • Display size: horizontal type: 160mm×80mm vertical type: 80mm×160mm
  • Display instrument with 4~20mA output and can be connected with computer

Know more about: Turbine type Flow Meter for Liquid & Gas technology

What liquids can be measured by Liquid Turbine Flow Meters?

In terms of measuring liquid flow, turbine flowmeters should be used in the following areas:

  1. Partially corrosive liquid measurement. Such as sulfuric acid, hydrochloric acid, nitric acid, acetic acid and other acids and various chemical solutions.
  2. Flow measurement of various industrial water. Including recycled water, waste water and waste liquid in various production processes in chemical, light industry, electric power, metallurgy, building materials, petroleum and other industries.
  3. Partial low viscosity oil flow measurement. Such as gasoline, kerosene, diesel, and heavy oil and residual oil whose viscosity is reduced by heating.
  4. Water flow measurement in large-diameter pipes, of which the full-pipe turbine flowmeter is mainly used for small and medium pipe diameters. The plug-in turbine flowmeter can be used for large pipe diameter (DN≥300mm) pipeline flow measurement. It is widely used in urban water pipelines and industrial water main lines of enterprises such as chemical industry, electric power, metallurgy, papermaking, and chemical fiber.
  5. Measurement of non-conductive liquids. If it is said that electromagnetic flowmeters dominate the flow measurement of conductive liquids. In the field of non-conductive liquid flow measurement, electromagnetic flowmeters are powerless. The turbine flowmeter is very useful. Turbine flowmeters with small diameters introduced in recent years are more suitable for applications in this field.
  6. Some turbine flowmeter products use a compression molding process to make the turbine flowmeter sensor into an all-plastic product. Then configure a non-contact ultrasonic detection element to measure the liquid without contact. It can be used for flow measurement of corrosive liquids and high purity liquids.
  7. According to relevant information, in the petrochemical, pharmaceutical, food and semiconductor industries, turbine flowmeters have obtained fruitful applications. For example: methanol, formaldehyde, acetone, toluene, trichloroethylene, ethylene, butane liquid ammonia, etc. There are also pure water for the semiconductor industry, ultra-clean pure water and so on.

Turbine Flow Meter Application Case: Demineralized Water.

In fact, if your measuring medium is conductive liquid, or corrosive conductive liquid, or wastewater. It’s better consider using an electromagnetic flowmeter. Let’s take a quick look.

Extended reading: Turbine Flow meter Vs Gear Flow meter

Turbine flow meter Advantages and Disadvantages

Turbine Meter Advantages

  • The cost is moderate.
  • Very good at clean, low viscosity fluids of moderate velocity and a steady rate.
  • Turndown is very good as it can read very low compared to the greatest flow.
  • They are reliable if put in a clean fluid especially if it has some lubricity.
  • AGA and API approved for custody transfers.
  • They do cause some pressure drop where that may be a factor such as gravity flows.
  • High accuracy. Among all flowmeters, it is the most accurate flowmeter.
  • No zero drift, good anti-interference ability.
  • High accuracy. Among all flowmeters, it is the most accurate flowmeter.
  • No zero drift, good anti-interference ability.

Turbine Meter Disadvantages

  • Not reliable for steam.
  • Bearings wear out.
  • Requires constant backpressure to prevent cavitation.
  • Accuracy adversely affected by bubbles in liquids.
  • Turbine meters can be used with clean liquids and gases only (may need to install a strainer upstream to prevent damage from particulates).
  • Not applicable for measuring corrosive fluids.
  • May not function properly with high viscosity fluids where the flow profile is laminar.
  • Cannot maintain calibration characteristics for a long time.

The gas turbine flowmeter uses a turbine for measurement. It first converts the flow rate into the rotational speed of the turbine, and then converts the rotational speed into an electrical signal proportional to the flow rate.

Gas turbine flowmeter is used to detect instantaneous flow and total integrated flow. Its output signal is frequency, which is easy to digitize.

The induction coil and the permanent magnet are fixed on the housing together. When the ferromagnetic turbine blade passes the magnet, the reluctance of the magnetic circuit changes, thereby generating an induction signal.

Gas turbine flow meter working principle.jpg

The signal is amplified and reshaped by the amplifier and sent to the counter or frequency meter. The total accumulated flow is displayed. At the same time, the pulse frequency undergoes frequency-voltage conversion to indicate instantaneous flow.

The speed of the impeller is proportional to the flow, and the number of revolutions of the impeller is proportional to the total amount of flow. The output of the turbine flowmeter is a frequency modulated signal. It not only improves the anti-interference of the detection circuit, but also simplifies the flow detection system.

The gas turbine flowmeter has a turndown ratio of up to 10:1, and the accuracy is within ±0.2%. The time constant of the turbine flowmeter with small inertia and small size can reach 0.01 second.

Liquid Turbine Flow Meter is a speed type flow meter based on the principle of torque balance.

The fluid flows through the sensor housing. Because the blades of the impeller have a certain angle with the flow direction. The impulse of the fluid makes the blades have a rotational torque. After the friction torque and fluid resistance are overcome, the blades rotate. The speed is stable after the torque is balanced.

Under certain conditions, the speed is proportional to the flow rate.

Due to the magnetic permeability of the blade, it is in the magnetic field of the signal detector (composed of permanent magnets and coils). The rotating blade cuts the magnetic lines of force. The magnetic flux of the coil is periodically changed. Electrical pulse signals are induced at both ends of the coil.

This signal is amplified and reshaped by an amplifier. A continuous rectangular pulse wave with a certain amplitude is formed. It can be transmitted to the display instrument remotely. The instantaneous flow or total amount of the fluid is displayed.

Within a certain flow range, the pulse frequency f is proportional to the instantaneous flow Q of the fluid flowing through the sensor. The flow equation is:

f——Pulse frequency [Hz]
k——The meter coefficient of the sensor [1/m3], which is given by the calibration sheet.
Q——The instantaneous flow of fluid (under working condition) [m3/h]
3600-conversion factor in seconds

The meter coefficient of each sensor is filled in the verification certificate by the manufacturer. The k value is set in the matching display instrument. The instantaneous flow and cumulative total can be displayed.

Extended reading: Turbine Insertion Flow Meter for Large Diameter Pipeline

What is k factor in turbine flow meter?

The physical meaning of the meter coefficient K value of a turbine flowmeter is the number of pulses generated by a unit volume of fluid flowing through the flowmeter. Using the international system of units, the unit of the meter coefficient is (1/m3).

Generally, the K factor will not change when the flow rate changes, but it should not exceed the upper limit of the flowmeter too much. The K factor is a constant based on a flow rate under certain process parameters.

How to get k factor on turbine flow meter?

There are two kinds of different manufacturers k:
One is k=f/Q, that is, the number of vortices generated per unit flow;
The other k=Q/f, that is, the plate flow rate corresponding to each vortex.
The k value is calibrated with the right factory water. The sensor measures the vortex number of the instrument and compares it with the volume flow measured by the calibration device to obtain the k value.

The k value is actually related to the internal mechanical structure of the flow meter measuring tube.
Taking k=f/Q as an example, the formula is as follows:

How to get k factor on turbine flow meter


D-measuring tube diameter
St-Strouhal number, constant within a certain range of Reynolds number
d—-The characteristic width of the vortex generator
m—The ratio of the arcuate area on both sides of the vortex generator to the cross-sectional area of ​​the pipe

In fact, this formula has no practical meaning for you. The values ​​of d and m are difficult to measure accurately. Therefore, it is difficult to obtain an accurate k value by calculation.

How to Calibrate a Turbine Flow Meter?

Before the turbine flowmeter leaves the factory, the coefficients have been set in the table.
When the user requests to display in mass units, the coefficient has been corrected and put into the table according to the medium density provided by the user before leaving the factory. It can be used directly on site.
If the physical properties of the measured medium on site differ greatly from those of water, on-site calibration can be performed.
Specific steps are as follows:

1. Install the turbine flowmeter as required. Turn on the valve to fill the pipeline with medium to ensure that the meter works normally. Close the valve and prepare for calibration;

2. Prepare a standard container or weighing equipment, and use the weighing method as an example here (record the tare weight);

3. First record the cumulative flow of the turbine flowmeter. Turn on the valve to make the flowmeter work within the flow range. When the container is almost full, close the valve. Record the cumulative flow of the flowmeter. Read the net weight of the measured medium on the scale;

4. Put the newly measured meter coefficient into the table again;

High Pressure Turbine Flow Meter

The high-pressure liquid turbine flowmeter is a special high-pressure flowmeter designed for hydraulic equipment, engineering machinery, chemical and other high-pressure fluid industries. The housing is made of stainless steel. The table structure is simple, and the structure design is optimized. It adopts high pressure butt welding flange clamp or high pressure screw connection structure.

Wide range of applications:
High-pressure liquid measurement occasions such as chemical high-pressure pipelines, hydraulic equipment, engineering machinery, and test benches. Hydraulic oil, circulating oil, oil station, construction machinery and other high-pressure liquids.

High pressure structure design, up to 40MPa

Turbine Flow Meter Price

Compared to other liquid flow meters. The price of turbine flowmeter is more advantageous.

For example: 4″, DN100 liquid turbine flowmeter. RS485 output. Accuracy ±1.0%R. SS304 material. Reference price USD600.00.

Reference price: US $200-1,500/ Piece. Contact Sino-Inst sales manager now to request a quotation!

Extended reading: Quantitative control with turbine flowmeter


How do I choose a flow meter?

Sino-Inst recommends that you refer to the following factors to select the flowmeter.
1.Fluid type
For clear and mixed liquids, clean gases, and mixed gases, different flow meters are required. For example, liquids are generally suitable for turbine flowmeters, and for gas, vortex flowmeters are more popular. Of course, this is only the choice of most people, not a certain one, and can be chosen according to specific needs.
2.Flow range
The fluid flow rate range should be moderate, not exceeding the range of the flowmeter.
3.Pipe size
For smaller pipe sizes, rotors, turbines, and mass flow meters are generally used. For large pipe diameters, electromagnetic flowmeters and ultrasonic flowmeters are generally used. Some pipes are not suitable for electromagnetic and ultrasonic applications.
4.Signal output
If the signal output is not required, rotameter and mechanical water meter are generally used.
The output signal has an analog quantity (4-20mA, 0-10V) and pulse output, these flowmeters can have a digital display.
5.Pressure range
Depending on the material of the flowmeter’s wetted parts, the pressure resistance is different, and the pressure resistance range of stainless steel and copper is larger. If the flow rate is relatively low, pressure loss needs to be considered. In this case, turbines and positive displacement flow meters are not suitable.

Refer to: Liquid Flow Meters Selection Guide

What is water flow meter?

Water flow meter refers to a flow meter that can measure water flow. The common water flow meter is an electromagnetic flow meter. Of course, it can also be a turbine flowmeter, an ultrasonic flowmeter, etc., as required.

What is target flow meter?

Target flow meter, also called drag force flowmeter. Target flow meter inserts a target (drag element) into the flow field. The traget usually is a flat disc or a sphere with an extension rod. There will be a differential pressure. And then target flow meters measure the drag force on the inserted target and convert it to the flow rate. Sino-Inst manufactures target flow meters for liquid, gas and steam measurement.

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