How to use the liquid turbine flowmeters in the diesel industry

The liquid turbine flowmeter is more widely used in diesel flow measurement, mainly because diesel is a good lubricant. In the flow measurement process, it can be good lubrication between the shaft and bearings, which is beneficial to the reliable long-term operation of the instrument. Shaft and bearing are by the unique design of the turbine flowmeter in the more difficult liquefied petroleum gas flow measurement; it also can be successfully applied.

How to use the liquid turbine flowmeters in the diesel industry

Advantages of Liquid Turbine Flowmeters 

  1. Good repeatability,  short-term repeatability can reach 0.05%. If the meter is often calibrated, it can get high accuracy. In the quantitative dispensing, quantitative barrel filling operation process, it can get the reason effect.
  2. High Accuracy.
  3. Output pulse frequency signal, in connection with the batch controller, flow display meter for signal processing, can not increase the error.
  4. Wide range, the maximum and minimum flow rate can reach: 6:1 ~ 10:1, medium and large diameter even up to 40:1
  5. Simple structure, it is easy to install and maintain and has large-circulation capacity. If a failure occurs, it will not affect the transport of liquid in the pipeline.
  6. Small inertia, fast response, the time constant of 1~50ms, the low change rate of pulsating flow, the error introduced can be ignored.
  7. Corrosion resistance, the sensor is made of corrosion-resistant materials, can be resistant to general corrosive media corrosion.
  8. High-pressure resistance can be used for high-pressure fluid measurement.

The disadvantages of liquid turbine flow meters

    1. The general turbine flowmeter is not suitable for high viscosity fluids. With the increase in viscosity, the flowmeter measurement of the lower limit value will increase. Therefore, while the range is reduced, the linearity becomes poor.
    2. If the bearings and shaft of the turbine have friction, it will lead to wear and tear, so that the accuracy of the meter changes, so the meter for trade settlement must be regularly calibrated. Some products use jewel bearings and nickel-based tungsten carbide shafts so that wear resistance is improved and accuracy can be maintained to 3~4 years unchanged.
    3. The turbine flowmeters are strict in fluid cleanliness. Therefore, the filters should install the number of filters and instrument caliber; large and small diameter number of more, large-diameter number of less.

liquid turbine flowmeters


Design features

Turbine flowmeter working pressure can be up to 50Mpa. They are mainly used for oilfield water injection systems for high-pressure water metering. It is also suitable for flow detection in various high and low-pressure water engine systems.

Adopt full carbide (tungsten carbide) shield type cantilever beam structure bearing, set rotation bearing, and pressure bearing in one, significantly improve the bearing life, and work in a small amount of mud and dirt media.

The sensor is of all stainless steel construction (2Cr13 for the turbine) with good corrosion resistance. The samarium cobalt permanent magnet alloy is used as a signal detector with a strong output signal, good magnetic stability and can generally work in media from 0-120°C.

The flowmeter has a self rectifying structure, is small and light, and is easy to maintain. The simple design can be combined and disassembled in a short time, clear and straightforward inside.

liquid turbine flowmeters

Oil Viscosity

The accuracy of the Turbine flow meter is Related toViscosity.For the same turbine flowmeter, when the measured viscosity of the fluid changes, its measurement accuracy, and range will have significant differences. Density rises, the scope of the degree of narrowing, the error moves in the negative direction. Therefore, the viscosity and temperature are high occasions, should not use turbine flowmeter.

Meter Range Range

The Accuracy of the Meter is related to its Range Range. This is similar to the volumetric flowmeter. Instrument error with the relative flow changes, in 20% to 30% FS, the instrument error “peak,” the reasons for people are still under discussion, in practice, to avoid the interval error to obtain high accuracy, thus causing a reduction in the range. The meter operates in a very narrow flow range in batch dispensing and dosing operations, where high accuracy can be achieved.

Classification of turbine flowmeters

A turbine is placed in the center of the pipe and supported by bearings at both ends. When the fluid through the line impacts the turbine flowmeter blade, the turbine flowmeter drives torque so that the turbine flowmeter to overcome the friction torque and fluid resistance torque and produce rotation. Therefore, in a specific flow range, the turbine flowmeter rotational angular velocity and liquid flow rate are proportional for a particular fluid medium viscosity. As a result, the fluid flow rate can be obtained by the rotational angular speed of the turbine flowmeter so that the fluid flow through the pipe can be calculated.

The rotational speed of the turbine flowmeter is detected by a sensing coil mounted on the outside of the housing. When the turbine flowmeter blades cut the magnetic lines of force generated by the permanent magnets in the housing, this causes a change in the magnetic flux in the sensing coil.

The sensing coil feeds the detected flux cycle change signal into the preamplifier, amplifying and shaping the movement. After generating a pulse signal proportional to the flow rate, which is fed into the unit conversion and flow accumulation circuit to obtain and display the cumulative flow value; the pulse signal is also fed into the frequency-current conversion circuit, which converts the pulse signal into an analog electrical flow, thus indicating the instantaneous flow value.

Working principle

The turbine flowmeter for liquids uses a turbine for measurement. It first converts the flow rate into the turbine’s rotational speed and then converts it into an electrical signal proportional to the flow rate. This type of flowmeter is used to detect instantaneous flow and total cumulative flow, and its output signal is frequency, which is easily digitized. The induction coil is shown fixed to the housing together with a permanent magnet. When a ferromagnetic turbine blade passes over the appeal, the magneto-resistance of the magnetic circuit will change, resulting in an inductive signal. The signal is amplified and shaped by an amplifier and sent to a counter or frequency meter, displaying the accumulated flow.

Working principle liquid turbine flowmeters (2)

The pulse frequency is also converted from frequency to voltage to indicate the instantaneous flow rate. Thus, the speed of the impeller is proportional to the flow rate, and the number of revolutions of the impeller is proportional to the total amount of flow passing through. The output of the turbine flowmeter is a frequency modulated signal, which improves the immunity of the detection circuit and simplifies the flow detection system. It has a range ratio of up to 10:1 and an accuracy of ±0.2% or less: small inertia and small size of the turbine flowmeter time constant up to 0.01 seconds.

The Liquid Turbine Flowmeter is extensively applied to petroleum, organic liquids, inorganic liquids, liquefied gas, natural gas, low-temperature fluids, etc. The turbine flowmeter output signal is a pulse, easy to digitize. Turbine flowmeter pressure loss is slight; the blade can be anti-corrosion, can measure viscous and corrosive media.

Working principle liquid turbine flowmeters

Blade of the liquid turbine flowmeter, when the turbine flowmeter blade cutting by the shell of the permanent magnet occurrence of the magnetic force line, the fluid flow rate can be lost through the turbine flowmeter tampering angular velocity, the pulse flags into the analog electric flow, the viscosity of the fixed fluid medium, the turbine replacement meter speed through the sensing coil mounted on the outside of the housing to detect. Bearings support both ends. The flow rate of the fluid through the pipe is thus essentially compared. The flow rate is measured in a range of flow rates, indicating the instantaneous flow rate. This is fed into the unit conversion and flow accumulation circuit to obtain and display the stacked flow values.


The liquid turbine flowmeter is a precision flow measurement instrument, and the corresponding flow accumulation instrument can be used to measure the flow and total amount of liquid. The liquid turbine flowmeter is widely used in petroleum, chemical, metallurgy, scientific research, and other fields of metering, control systems. Liquid turbine flowmeters equipped with sanitary fittings can be used in the pharmaceutical industry. Liquid turbine flowmeter is widely used in petroleum, chemical, metallurgy, scientific research, and other fields of measurement, control systems. Liquid turbine flow meters with hygienic fittings can be used in the pharmaceutical industry.

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