Liquid flow meter is a kind of meter that measures the flow of liquid fluid in pipes or open channels. Liquid flow meters can effectively monitor liquid flow rates for water, fuels, chemicals and more fluids.

If you need to purchase Liquid Flow Meter, this article will be your best Purchasing Guide. Keep reading, Please!

Flow meters are classified into liquid flow meters and gas flow meters according to the medium. Then the common liquid flow meters mainly include: vortex flowmeter, turbine flowmeter, electromagnetic flowmeter, ultrasonic flowmeter, differential pressure flowmeter, open channel flowmeter, Coriolis mass flowmeter, etc.

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

Featured Liquid Flow Meters

Liquid Flow Meter Types

Turbine flow meter liquid flow metering

Turbine flow meters are the main type of velocity flow meters. It uses a multi-blade rotor (turbine) to sense the average flow velocity of the fluid. A meter from which the flow or total volume is derived. Generally, it is composed of two parts: sensor and display instrument, and it can also be made into an integral type.

Application: Turbine flowmeter is widely used in measuring petroleum, organic liquid, inorganic liquid, liquefied gas, natural gas and cryogenic fluid.

Turbine flowmeter product features

  1. Strong resistance to impurities.
  2. Strong anti-electromagnetic interference and anti-vibration ability.
  3. Its structure and principle are simple and easy to maintain.
  4. Almost no pressure loss, saving power and electricity consumption.

Electromagnetic flow meter liquid flow metering

Electromagnetic flowmeter is an instrument for measuring conductive liquid made according to Faraday’s law of electromagnetic induction.


The electromagnetic flowmeter has a series of excellent characteristics, which can solve the problems that other flowmeters are not easy to apply, such as the measurement of dirty flow and corrosion flow.

  • Electromagnetic flowmeters have a wide range of applications, and large-caliber meters are mostly used in water supply and drainage projects;
  • Small and medium calibers are often used in high-demand or difficult-to-measure occasions, such as the cooling water control of the blast furnace tuyere in the iron and steel industry, the measurement of pulp and black liquor in the paper industry, the strong corrosive liquid in the chemical industry, and the ore pulp in the non-ferrous metallurgical industry;
  • Small calibers and tiny calibers are often used in places with hygiene requirements such as the pharmaceutical industry, food industry, and biochemistry.

Electromagnetic flowmeter product features

  1. Two-way measurement system.
  2. The straight pipe section required by the sensor is shorter, and the length is 5 times the pipe diameter.
  3. Low pressure loss
  4. The measurement is not affected by changes in fluid density, viscosity, temperature, pressure and conductivity
  5. Mainly used in sewage treatment.

Vortex flow meter liquid flow metering

The vortex flowmeter is a meter in which a non-streamline vortex generator is placed in the fluid, and the fluid is alternately separated on both sides of the generator to release two series of regularly staggered vortices. When the flow cross section is constant, the flow velocity is proportional to the volume flow. Therefore, the flow can be measured by measuring the oscillation frequency.

Application: The vortex flowmeter has developed rapidly and has become a general-purpose flowmeter.

Vortex Flowmeter Product Features

  1. The structure is simple, firm, no moving parts, high reliability, and reliable long-term operation.
  2. The installation is simple and the maintenance is very convenient.
  3. The detection sensor does not directly contact the measured medium, with stable performance and long life.
  4. The output is a pulse signal proportional to the flow rate, with no zero drift and high accuracy.
  5. The measurement range is wide, and the range ratio can reach 1:10.
  6. The pressure loss is small, the operating cost is low, and it is more energy-saving.

Mass flow meter liquid flow metering

The principle of flow is directly related to the measurement; the indirect mass flowmeter is indirectly multiplied by the density meter and the volume flow to obtain the mass flow.

In the case of high temperature and high pressure in modern industrial production, the application of direct mass flowmeter encounters difficulties due to factors such as material and structure;
However, indirect mass flow meters are not suitable for practical applications due to their density being limited by the scope of application of humidity and pressure.

Mass flow meter product features

  1. No mechanical transmission mechanism, small size, light weight, easy to maintain
  2. High precision
  3. No moving parts inside, good stability
  4. Wide range ratio, much better than other traditional instruments

Ultrasonic flow meter liquid flow metering

The ultrasonic flowmeter is designed based on the principle that the speed of ultrasonic propagation in the flowing medium is equal to the geometric sum of the average flow velocity of the measured medium and the speed of the sound wave itself. It also reflects the flow rate by measuring the flow rate. Ultrasonic flow meters can be divided into time difference type and Doppler type according to the measurement principle.


The propagation time method is applied to clean, single-phase liquids and gases. Typical applications include factory discharge liquid, strange liquid, liquefied natural gas, etc.;
Gas application has good experience in the field of high pressure natural gas;

The Doppler method is suitable for two-phase fluids with low heterogeneous content. Such as untreated sewage, factory effluent, and dirty process fluids, it is usually not suitable for very clean liquids.

Target flow meter liquid flow metering

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.


  1. The whole instrument has a solid structure and no moving parts, plug-in structure, easy to disassemble
  2. The dry calibration method can be used on the spot, that is, the weight hanging method is used.
  3. With integrated temperature and pressure compensation, directly output quality or standard
  4. The measuring range can be changed by replacing the baffle (target) according to actual needs
  5. Strong vibration resistance, pulsating flow can be measured within a certain range.

Differential pressure flow meter liquid flow metering

The differential pressure flowmeter is a meter that calculates the flow rate based on the differential pressure generated by the flow detection element installed in the pipeline, the known fluid conditions and the combined size of the detection element and the pipeline.

Application: Differential pressure flowmeter has a wide range of applications, and various objects have applications in the flow measurement of closed pipelines.
Such as fluid: single-phase, miscible, clean, dirty, viscous flow, etc.;
Work: normal pressure, high pressure, vacuum, normal temperature, high temperature, low temperature, etc.;
Pipe diameter: from a few millimeters to a few meters; flow: subsonic speed, sound speed, pulsating flow, etc.
Its consumption in various industrial sectors accounts for about 1/4 to 1/3 of all flow meters.

The most commonly used liquid differential pressure flowmeter is the orifice flowmeter.

Product features of orifice flowmeter:

  1. The structure of the throttling device is easy to replicate, simple, firm, stable and reliable in performance, long in service life and low in price.
  2. Wide application range, all single-phase flow can be measured, and part of mixed-phase flow can also be applied.
  3. The standard throttling device can be put into use without real flow calibration.
  4. The integrated orifice plate is simpler to install, no pressure pipe is needed, and it can be directly connected to a differential pressure transmitter and a pressure transmitter.

Oval gear flowmeter


  1. It relies on the pressure head of the measured medium to push the oval gear to rotate for measurement.
  2. The greater the viscosity of the medium, the smaller the leakage from the gear and the metering gap. Therefore, the larger the sticky skin of the nuclear test medium, the smaller the leakage error, and the more beneficial it is for measurement.
  3. It is suitable for the measurement of the flow of high-viscosity media, but not for fluids containing solid particles (solid particles will jam the gear, so that the flow cannot be measured). If the measured liquid medium contains gas, it will also cause measurement errors.

Positive displacement flow meter

Positive displacement flow meter, also called fixed displacement flow meter, PD flow meter for short. It is the most accurate type among flow meters. It uses mechanical measuring elements to continuously divide the fluid into individual known volume parts. The total volume of fluid is measured according to the number of times that the measuring chamber is filled and discharged with this volume of fluid one after another.

Application: Positive displacement flow meters, differential pressure flow meters, and float flow meters are listed as the three most used flow meters. They are often used for total measurement of expensive media (oil, natural gas, etc.).

Float flow meter

Float flowmeter, also known as rotameter, is a kind of variable area flowmeter. In a vertical cone tube that expands from bottom to top, the gravity of the float of circular cross section is borne by the hydrodynamic force, so that the float can be Rise and fall freely in the cone.

Application: Float flowmeter is the most widely used type of flowmeter after differential pressure flowmeter, especially in small and micro flow.

Features of Rotameter:

  1. The most commonly used flow meter in industry and laboratories.
  2. The structure is simple, intuitive, low pressure loss and convenient maintenance.
  3. It must be installed on a vertical pipe section, and the fluid medium passes through the rotameter from bottom to top.

Water Flow Meter

Water flow meter is an instrument specially used to measure the flow of water in pipes. You can get many different types of water flow meters from your facility.

When used in certain applications, each flow meter has its own advantages. For many pipelines and similar systems, the water must be maintained at a specified flow rate to ensure the effective operation of the system.

At low flow rates, the speed of the water may be so low that suspended solids settle to the bottom of the pipe, which will deteriorate the efficiency of the pipe and eventually lead to the accumulation of contaminants, which can cause damage.

Since water flow meters can be used in a wide range of applications, there are many reasons to need these flow meters.

On the one hand, knowing that the fluid is in the right place at the right time is very beneficial to ensure that operating costs and efficiency are maintained.

These meters can also be used to ensure that fluids are kept in motion or to determine if the tank is properly balanced.

Any drop in the flow rate may indicate that the water quality is deteriorating and requires treatment.

In some applications, accurate flow measurement is critical to product quality and the health and safety of the final product. These meters are relatively easy to install in the pipeline, depending on the type of meter you choose.

Read More.

Wastewater Flow Meter

Sewage flow, or wastewater can be a pain to accurately measure. The environment is corrosive and humid. While the flow itself can experience wide swings due inflow and infiltration. Wastewater is usually carried in non-full open channel pipes.

So, all the flow measurement instruments suitable for the Sewage flow are called Sewage flow meters, or wastewater flow meters.

Here you can find a Sewage flow meter to measure the flow of wastewater for your application.


How does a liquid flow meter work?

Liquid flow meter can be divided into the following categories according to the measurement principle:
Mechanics principles: instruments that fall into this category include differential pressure type and rotor type using Bernoulli’s theorem; impulse type and movable tube type using momentum theorem; direct mass type using Newton’s second law; using fluid momentum principle Target type; turbine type using the angular momentum theorem; vortex type and vortex type using the principle of fluid oscillation; pitot tube type using total static pressure difference, volume type, weir, trough type, etc.
Electrical principle: The instruments used for this kind of principle include electromagnetic, differential capacitive, inductive, strain resistance, etc.
Acoustic principle: There is an ultrasonic method for flow measurement using the acoustic principle. Acoustic (shock wave) etc. Thermal principle: There are calorimetric, direct calorimetry, indirect calorimetry, etc. that use the thermal principle to measure flow. Optical principle: laser type, photoelectric type, etc. are instruments of this type of principle. Principles of atomic physics: nuclear magnetic resonance, nuclear radiation, etc. are instruments that belong to this type of principle. Other principles: There are marking principles (tracing principles, nuclear magnetic resonance principles), related principles, etc.

What is a flow meter used for?

A meter that indicates the measured flow rate and/or the total amount of fluid in a selected time interval. Simply put, it is an instrument used to measure fluid flow in pipes or open channels.

Where should a flow meter be placed?

Most in-line flow meters are inline flow meters. They are all connected with the pipeline under test. Connect by flange, thread, etc.
The Insertion flowmeter is installed on the pipe under test by plug-in type. Suitable for larger pipe diameters.
Clamp-on flowmeter. The sensor is clamped outside the pipe for flow measurement.

How to choose a suitable liquid flow meter?

1.According to the process requirements, observe the on-site environment and determine the real need to install a flow meter on site.
2.After confirming the installation of the flow meter, it is necessary to understand the production process requirements and the various conditions of on-site installation in detail.
3.Analyze and determine each plan, fully understand the performance of the flowmeter specifications, and consider five factors according to performance requirements and instrument specifications, fluid characteristics, installation locations, environmental conditions and economics.
4.The performance of the flow meter is required for installation and measurement. After the measurement method is determined, select whether the meter needs instantaneous flow or cumulative flow in performance requirements, accuracy, repeatability, linearity, flow range and range, pressure loss, output signal characteristics and response Time and so on.
5.The instantaneous flow rate is still the cumulative amount. There are generally two types of measurement purposes: instantaneous flow rate and cumulative flow rate.
6.The requirements of measurement accuracy, how much is the overall measurement accuracy required?

Sino-Inst offers over 30 Liquid Flow Meters products. About 50% of these are differential pressure flow meters. 40% are water meters (like the Insertion Turbine Flow Meter), and 40% are water treatment (like the Annubar flow meter ).

A wide variety of Liquid Flow Meters options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Liquid Flow Meters, located in China.

The top supplying country is China (Mainland), which supply 100% of the Liquid Flow Meters respectively.

Sino-Inst sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. Liquid Flow Meters products are most popular in Domestic Market, Southeast Asia, and Mid East.

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

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