Selection Guide

What is a mechanical flow meter?

Mechanical flow meters are a type of flow meters that use arrangement moving parts to measure flow. The fluid passes through a series of gears or chambers (positive displacement or PD) or through a rotating turbine or rotor. Mechanical flowmeter is different from electromagnetic and ultrasonic in principle. Mechanical flow meters easily monitor liquid flow rates for water, fuels, viscous fluids and more.

Mechanical Flow Meters

Mechanical flow meter types

There are many types of flow meters.

The electromagnetic flowmeter is based on the electromagnetic principle. When a conductive fluid flows through an electromagnetic field, the velocity of the fluid can be obtained by measuring the voltage.

Ultrasonic flow meters use the principle of ultrasonic acoustics to measure flow velocity. The mechanical flow meter is a relative concept.

Compared with other flow meters, the mechanical flowmeter relies on the rotation and displacement of mechanical parts to measure the flow rate. Common mechanical flow meters have the following categories.

Tool: Volumetric Flow Rate & Pipe Diameter to Flow Speed Calculator

A positive displacement flowmeter as a mechanical flow meter is a common type of Volumetric Flow Meter. It can measure the volume flow of high viscosity and corrosive fluids.

Volumetric flow meter working principle

The positive displacement flow meter is a flow meter that uses mechanical measuring elements to continuously divide the fluid into a single known volume, and repeatedly fill and discharge the volume of fluid to accumulate the total amount of fluid.

Read more about: positive displacement flowmeter

A Rotameter flow meter is a variable area flow meter based on float position measurement. It is suitable for liquid and gas volumetric flow measurement and control.

Rotameter flow meter working principle

When the measured fluid passes through the annulus formed by the cone and floats from the bottom to the top. The differential pressure produced at the upper and lower ends of the float forms the force for the float to rise. Until the rising force equals the weight of the float immersed in the fluid, the float will stabilize at a certain height.
The height of the float in the tapered tube and the flow rate through it correspond to each other.

Read more about Rotameter flow meter-Variable Area Flow Meters

Extended reading: Beginner’s Guide: Variable area flow meter

Turbine flow meters are velocity flow meters, also called impeller flow meters. Can be used to measure the instantaneous flow and cumulative flow of liquids and gases.

Turbine Flow Meter Working Principle

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.

Read more about Turbine Flow Meter Working Principle

Gear flow meter is a micro digital positive displacement flow meter. Can measure very small flow rates and quantify small volumes of liquid. High and low temperature resistance (-196℃-200℃).

Gear flow meter working principle

With the flow of the medium, the gears mesh and rotate. Under the action of the fluid flow, a pressure difference is formed at both ends of the instrument inlet and outlet. There is no need for power supply. A pair of gears rotate freely. The cavity between the gears is filled with liquid. Discharge and measure the number of revolutions of the gear to know the flow of liquid and liquid flowing through the instrument.

Read more about Gear flow meter for Microflow

Read more about: Beginner’s Guide: Variable area flow meter

Featured Mechanical Flow Meters

Extended reading: High-Temperature Oval Gear Heating oil Flow Meter

Of course, if you are not clear about the principle and difference of the above flow meters. Can not choose the appropriate Mechanical Flow Meters. Then, you can also choose the appropriate Mechanical Flow Meters according to the fluid conditions that need to be measured.

Extended reading:
What is the K-factor in a flow meter?
Cryogenic Flow Meters|Liquid Nitrogen-Liquid Oxygen-LNG fluids

Below are some of our experience sharing, hoping to help you find the right Mechanical Flow Meters.

In most cases, we will choose an electromagnetic flowmeter to measure the flow rate of water. But if it is pure water and cannot conduct electricity, then an electromagnetic flowmeter cannot be used. You can choose a turbine flowmeter to measure.

Extended reading: 2 inch Water Flow Meter

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3 inch (3″) Water Meter

Low cost 3″ Water Meter 3″ water meter is also DN80 water meter. Easy to read. Totalizing water volume. Intelligent large-caliber remote water meter includes wired remote transmission and wireless remote transmission. RS485 communication equipment, MODBUS, etc. Features of 3″ Read More

2 inch Water Flow Meter

2 inch water flow meter is also written as 2″ flow meter. If you are planning to buy a 2 inch water flow meter, please be sure to read this article. How much is a 2 inch water flow meter? Read More

Inline water flow meters

Featured inline water flow meters Strap on flow meter X3  External clamp-on flow sensor. Easy to install. Suitable for measuring pipe diameter Φ9.53~Φ90. Ultrasonic Water Meter for Residential Water DN15-DN40, RS485. LORA/ NB-IoT, WIFI, Output MBUS, MODBUS, ASCII, CJ188 are Read More

Hot Water Flow Meters

Hot Water Flow Meters Improve Heating-Boiler System Hot water flow meters refer to flow meters that can measure and indicate the flow of high temperature water. Hot water is widely used in industry and civil use. Such as heating systems, Read More

Extended reading: Insertion Ultrasonic Water Flow Meter – Designed for Agricultural Irrigation, Garden Management

Diesel Fuel Flow Meters

Diesel Fuel flow meters are digital flow meters for liquid fuel consumption measurement.

Most widely used types are mechanical and digital inline fuel meters. Differential flow sensors are avilable. Like: the turbine, positive displacement (oval gear), Coriolis, and differential pressure flow meters.

Read more about: Diesel Fuel Flow Meters

Industrial Fuel Flow Meters

The oval gear flowmeter is particularly suitable for measuring high viscosity media. And it is not sensitive to changes in the viscosity of the liquid being measured.

Measurable medium:
Fuel, diesel, gasoline, heat transfer oil, hydraulic oil, kerosene, tar, petroleum, crude oil, asphalt, resin and other liquids. Especially suitable for the measurement of high viscosity liquids.

Read more about:

LCD display Oval Gear High Viscosity Flow Meter

T-series Coriolis Mass Flowmeter for High Viscosity Liquids


Mechanical flow meters that can measure gas flow mainly include metal float flow meters and turbine gas flow meters.

A Rotameter flow meter is a variable area flow meter based on float position measurement. It is suitable for liquid and gas volumetric flow measurement and control.

Gas turbine flow meter is a velocity flow meter that measures gas flow. For natural gas, nitrogen, and gas trade measurement.

Relatively speaking, the cost of gas turbine flow meters is higher than that of Rotameter flow meters. But the service life will be longer.

Extended reading: How does a rotameter work

Extended reading: Gas Rotameter Tips

For cryogenic fluids, such as liquid nitrogen, liquid oxygen, etc. It can reach -196 degrees Celsius.

For cryogenic fluids, we provide gear flow meters and low-temperature turbine flow meters.

You can choose the right one according to the flow range.

Read more General-purpose Flow Totalizer for Data collection and calculation

Extended reading: Make Ultrasonic Open Channel Flow Meter Work for You


What are the different types of flow meters?

Flow Metering Principals
Differential Pressure Flowmeters
Velocity Flowmeters
Positive Displacement Flowmeters
Mass Flowmeters
For Open Channel Flowmeters – weirs, flumes, submerged orifices, current meters, acoustic flow meters, and more
For different working principle, We offer different types of flow meters, like:
Differential Pressure Flow Meters
Orifice Plate
Venturi Tube
Flow Nozzles
The Sonic Nozzle – Critical (Choked) Flow Nozzle
Calorimetric Flowmeter
Ultrasonic Doppler Flowmeter
Positive Displacement Flowmeter
Variable Area Flowmeter or Rotameter
Velocity Flowmeters
Pitot Tubes
Electromagnetic Flowmeter
Turbine Flowmeter
Vortex Flow Meter
Thermal Flowmeter
Coriolis Flowmeter
Mass Flowmeters
Open Channel Flowmeters

What are water meters used for?

Residential water meters can measure the water consumption of a household.
Industrial water meters mainly refer to water flow meters. Can measure the amount of industrial water. For example, the amount of wastewater discharged.
Extended reading: 2 inch Water Flow Meter

What is a digital flow meter?

Digital flow meter is a flow meter with digital display and signal output. Digital flow meter refers to a flow meter with digital display and signal output.Different digital flow sensors include turbine, thermal mass, electromagnetic, ultrasonic, orifice plate, venturi. The different designs of the flowmeters have a variety of applications. With 4-20ma, RS485, or others output.
Extended reading: Hot Water Flow Meters Improve Heating-Boiler System

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Mechanical flow meter price

Sino-Inst offers Mechanical Flow Meters with best price. Please contact our sale engineer for quotation.

Sino-Inst offers over 50 Mechanical Flow Meters for flow measurement. About 50% of these are differential pressure flow meters, 40% is the turbine flow sensor, and 20% are dp flow meters and gear flow meters.

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

Sino-Instrument is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.

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