What Is An Oval Gear Flow Meter

Oval gear flow meter (also known as displacement flow meter, gear flow meter), belongs to the volumetric flow meter. And in the flow meter, it is a higher accuracy of a class. It uses the mechanical measuring element to continuously divide the fluid into a single known volume part. According to the metering chamber one by one, it repeatedly filled and emptied the volume part of the number of times the fluid to measure the total volume of flow. Oval gear flow meter can choose different materials (cast iron, cast steel, 304 stainless steel, 316 stainless steel) manufacturing, suitable for chemical, petroleum, pharmaceutical, electric power, metallurgy and food and other industrial sectors of the flow measurement work.

Oval Gear Flow Meters

Working Principle

Flow meter is measured by the box and mounted in the measuring box of a pair of oval gears. And the upper and lower cover plate constitutes a sealing of the first moon shaped cavity (due to the rotation of the gears, so it is not absolute sealing) as a primary displacement of the unit of calculation. When the measured liquid passes through the pipeline into the flow meter, due to the pressure difference between the imports and exports to promote a pair of gears rotating continuously, and constantly measured by the crescent-shaped cavity of the liquid transported to the exit, the number of oval gears and the four times the product of each displacement that is the total amount of measured liquid flow. The flow meter is mainly composed of shell, counter, oval gears and coupling (divided into magnetic coupling and axial coupling) and so on.


  • Direct volume measurement:

Oval gear flow meter determines the flow rate by measuring the volume of liquid passing through the rotating oval gear, which realizes the direct volume flow measurement without converting into other parameters.

  • High-precision measurement:

It has a high measurement accuracy, and can meet the flow measurement accuracy requirements of higher applications, usually up to 0.5% to 1% of the measurement accuracy.

  • Wide flow range applications:

The flow meter is suitable for smaller to larger flow range, and can meet the different flow requirements of the application.

  • Suitable for a wide range of liquids:

It’s suitable for measurement of a wide range of liquids, including water, oil, fuel, solvents, chemical liquids and so on.

  • Able to measure high viscosity liquids:

The flow meter has lower viscosity requirements for liquids, and can measure higher viscosity liquids.

  • Good pressure resistance:

Oval gear flow meter has high pressure resistance, general working pressure range up to 16 bar (232 psi).

  • Adapt to poor working conditions:

It can be adapted to a certain range of operating temperatures and harsh environmental conditions.

  • With a certain degree of pulsation inhibition:

The design structure makes its pulsation of the fluid has a certain degree of inhibition, reducing the impact of pulsation on the measurement accuracy.

oval gear flowmeter

Application and Prospect


  • Petroleum industry

In the petroleum industry, oval gear flow meter is widely used in the measurement and control of crude oil, oil and natural gas and other fluids. Its measurement range in piping can be realized as high as 3000:1 and its accuracy can reach 0.2%. In addition, the oval gear flow meter is small in size, light in weight, easy to install, and can adapt to a variety of installation environments.

  • Chemical industry

In the chemical industry, oval gear flow meter is widely used in acid, alkali, solvent, suspension flow measurement. It will not cause pollution to the material, and can ensure product quality. At the same time, oval gear flow meter can measure materials with high viscosity, such as syrup, polymer, grease, etc..

  • Metallurgical industry

In the metallurgical industry, oval gear flow meter is widely used in the flow measurement of metal liquids such as steel liquid, aluminum liquid, copper liquid and so on. Because the oval gear flow meter can withstand high pressure, high temperature and corrosion and other harsh environments, so in the metallurgical industry has a wide range of application prospects.

Application Prospects

  • Industrial automation:

It can be used to monitor the flow of liquid and gas in industrial processes, such as chemical plants, oil and gas industry. Its high accuracy and reliability make it ideal for ensuring the stability and safety of the production process.

  • Fuel consumption monitoring:

It can be used for real-time monitoring of fuel consumption in vehicles such as automobiles, ships and airplanes, as well as in generator sets. This helps to improve energy efficiency, manage costs and reduce environmental impact.

  • Water treatment and supply systems:

Oval gear flow meter can be used to monitor water flow in water supply systems, including tap water, sewage treatment and industrial water. And it can help provide accurate measurements to optimize water management and control waste.

  • Medical equipment:

It is also used in medical equipment, such as hemodialysis machines, ventilators and anesthesia machines. Besides, it can measure the flow of liquids and gases to ensure the safety and accuracy of medical procedures.

4 Precautions for Use

  • Cleaning pipeline:

New cast pipeline to clean before operation, often followed by solid flow flushing to remove residual welding debris scale skin, etc.. At this time, you should first close the instrument before and after the shut-off valve, so that the liquid flow from the bypass pipe; if there is no bypass pipe, the instrument position should be installed instead of a short tube.

  • Exhaust gas:

After the real liquid sweep line, the pipeline is still left with more air. With the pressurized operation and the air to a higher flow rate through the volumetric flow meter, the activity of the measuring element may be over-speed operation, damage to the shaft and bearings. Therefore, the flow rate should be increased slowly at the beginning, so that the air is gradually overflowed.

  • Measurement of high-viscosity liquids with:

In high-viscosity liquids, generally are heated to make it flow. When the instrument is out of service, the internal liquid cooling and thickening, and then start must first be heated to reduce the viscosity of the liquid before allowing the liquid to flow through the instrument, otherwise it will bite the activity of the measuring element so that the instrument is damaged.

  • Add lubricant:

Gas and other PDF must be added before the opening of the lubricant, daily operation of the level meter also often check the lubricant inventory.


To summarize, oval gear flow meter is a flow meter with excellent performance and wide range of applications. Its application in the fields of petroleum, chemical industry, metallurgy and other fields is remarkable, providing strong support for industrial production.

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