Thermal insulation Oval Gear flow meter- Liquid Bitumen/Asphalt Flow Meter

How to choose an asphalt flow meter? Liquid asphalt flow measurement has always been a difficulty. Liquid asphalt and other media that are easy to solidify and crystallize need to be measured with an oval gear flowmeter with heat preservation or heating function.

Thermal insulation Oval Gear flow meter- Liquid Bitumen/Asphalt Flow Meter

Oval gear flow meters (also known as displacement flow meters, gear flow meters) are a type of positive displacement flow meters, which are the most accurate type of flow meters. The oval gear flowmeter can be made of different materials (cast iron, cast steel, 304 stainless steel, 316 stainless steel). It is suitable for various high viscosity and high temperature liquids. For example: asphalt, heat transfer oil, paraffin, etc.

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

Features of Liquid asphalt flow measurement

Asphalt is solid at room temperature, but at a certain temperature, asphalt is liquid. And it is a liquid with high viscosity. It is usually measured by an oval gear flowmeter. It is especially suitable for measuring medium with high viscosity, and it is not sensitive to the change of the viscosity of the liquid being measured.

Liquid asphalt flow measurement

For the medium that is easy to solidify at normal temperature or easy to condense and crystallize at a certain temperature (for example: asphalt) in the pipeline, it is often necessary to heat the medium in the system pipeline to melt and keep the medium warm.

However, direct steam is not allowed at the place where the oval gear flowmeter is installed (to prevent damage to the flowmeter). For this reason, our factory has designed a flowmeter with insulation jacket for this situation. That is, an insulation jacket is added outside the flowmeter housing, and hot water, heat transfer oil or steam below 200°C can be used to pass into the insulation jacket. Melt the solidified medium in the flowmeter. And keep a certain temperature. So as to ensure the normal operation of the flowmeter.

Extended reading: Hot Water Flow Meters Improve Heating-Boiler System

The filter installed in front of the oval gear flowmeter can be in the form of a thermal insulation jacket, and the user can make special orders if needed. The nominal pressure of the insulation jacket is 0.5MPa.

Product performance standards

  1. JB/T9242-1999 (General technical conditions for positive displacement flow meters)
  2. JJG667-2010 (Verification Regulation of Positive Displacement Flowmeter)
  3. JB/T79~80-1994, GB/T9112-2000 (standard for connecting flange)

Specifications of Thermal insulation Oval Gear flow meter

  1. Accuracy: ±0.2%, ±0.5%
  2. Nominal diameter: DN10~DN200
  3. Nominal pressure: E cast steel 1.6~6.4MPa; B stainless steel 1.6MPa~4.0MPa
  4. Temperature: normal temperature -20~100℃, high temperature +100~+200℃ (with radiator), please consult the manufacturer for higher temperature
  5. Medium viscosity: 0.3 ~ 200mpa·s, 2000mpa.s or higher
  6. Output signal: pulse, 4~20mA, 232, 485
  7. Explosion-proof grade: ExiaIICT5, dIIBT4
  8. Protection grade: IP65

Read more about Positive Displacement Flowmeter Technology

What flow meter is used for Liquid asphalt flow measurement?

Oval gear flowmeters are generally used to measure high-viscosity media such as liquid asphalt, with accurate measurement accuracy.

Of course, the Target type flowmeter can also be used to measure the Liquid asphalt flow measurement. The principle of differential target flowmeter is adopted to ensure the durability, practicability, and long service life of the asphalt flow meter.

Extended reading: Stainless steel flow meters|304-316 optional

The difference between target flowmeter and oval gear flowmeter

  1. The difference in principle:

Target type asphalt flow meter is when the medium flows through, it impacts on the target, and forms a certain force on it, and the target produces a certain displacement. The flow rate through the medium is measured by the magnitude of the displacement. The accuracy is 1.0 level.

Oval gear asphalt flow meter is a positive displacement flowmeter. It uses mechanical measuring elements to continuously divide the fluid into a single known volume. The flow rate of the medium is measured according to the number of times that the metering chamber fills and discharges the volume of fluid successively and repeatedly. The accuracy can reach 0.5 level.

Extended reading: Cylinder Gear flow meter for micro flow measurement.

  1. Different connection methods:

Target type asphalt flow meter can be made into clip type connection, pipe segment type connection, plug-in connection. Choose the appropriate connection method according to the size of the pipe diameter.

The oval gear asphalt flow meter can only be made into a pipe segment connection. If the pipe diameter is large, it is not recommended to choose an oval gear asphalt flow meter.

  1. Differences in price:

Target type asphalt flow meter can choose carbon steel and stainless steel materials;
The oval gear asphalt flow meter can be made of cast iron, cast steel, and stainless steel.
In terms of the price of stainless steel, the two types of flow meters are much cheaper.

Due to the high temperature and high viscosity of asphalt media, high temperature and high viscosity protection is sometimes required. Both flowmeters can meet this requirement.

Read more about: Find your suitable industrial oil flow meter with best price

Oval Gear flow meter Troubleshooting

The following introduces the seven common faults and treatment methods of oval gear flow meters.

Oval gear does not rotate

The reason:

  1. There is debris in the pipeline;
  2. The filter is damaged and debris enters the meter, causing the gear to be stuck;
  3. Due to excessive flow and wear of the bearings, the oval gears collide with the inner bore, causing the gears to jam.


  1. Clean the flow meter and pipeline;
  2. Repair the filter;
  3. Replace the bearing to ensure flexible operation of the gap.

The oval gear rotates, the pointer does not move or stops at all times

The reason:

  1. The rotating fastener is sliding, damaged or inflexible;
  2. The magnetic coupling slides;
  3. The character wheel parts are stuck.


  1. Retighten the fasteners and remove inflexible parts;
  2. Check whether the magnetic coupling is flexible and magnetic;
  3. Eliminate the faults of the character wheel components.

Large negative error of flowmeter

The reason:

  1. Leakage of bypass valve;
  2. The inner wall or bearing of the oval gear metering is damaged or corroded by wear;
  3. The flow is lower than the lower limit;
  4. Magnetic coupling sliding or periodic obstacles in gear system;
  5. The actual liquid viscosity is less than the detected liquid viscosity.


  1. Check the bypass valve;
  2. Replace bearings, check gears, and adjust gaps;
  3. Increase the flow;
  4. Repair or replace the magnetic coupling or gear system;
  5. Check the flow meter or make the viscosity correction by selecting the inspection liquid close to the actual liquid viscosity.

Large positive error of flowmeter

The reason:

  1. The flow has large pulsation or contains gas;
  2. The actual liquid viscosity is greater than the test liquid viscosity;
  3. When the inlet valve is closed, the medium does not fill the metering chamber and is measured out.


  1. Reduce flow pulsation or increase gas separator;
  2. Choose a test liquid with a viscosity similar to the actual liquid to inspect the flow meter or make a viscosity correction;
  3. Use the flow meter outlet valve to control the medium flow.

The indicated value of the secondary meter is more than that of the primary meter

This fault is mostly caused by the vibration of the transmitting blade, which can be solved by appropriately adjusting the pressure of the damping plate on the blade.

The indicated value of the secondary meter is less than the indicated value of the primary meter

The reason:

  1. The fastening screws at the sending blade are loose;
  2. The transmitter dropped.


  1. Tighten the locking screw;
  2. Adjust the gap between the transmitting blade and the transmitting device.

Secondary table does not indicate

The reason:

  1. The line is open or short;
  2. The transmitter is damaged.


  1. Check the line carefully;
  2. Replace the transmitter.

The oval gear flowmeter is mainly composed of a body, a pair of oval gears, a magnetic coupling, a speed reduction mechanism, a high-speed gear, a counter and a signaling device.

In general, the possible failures of the flowmeter can be found in the above description and the corresponding reasons and treatment methods.

If the cause cannot be found for a certain fault, the manufacturer of the flowmeter can find a solution.

Extended reading: Mechanical flow meter types

More Featured Bitumen/Asphalt Flow Meters

In addition to the oval gear flowmeter is commonly used Bitumen/Asphalt Flow Meters. In fact, other flowmeters can also be selected. Such as mass flowmeters, circular gear flowmeters, and the target flowmeters mentioned above.

Mass flow meter directly measures the mass flow of the medium passing through the flow meter. It can also measure the density, temperature and viscosity of the medium

Mass flow meter is a flow measuring instrument that measures the mass flow in the pipeline. The volume of a fluid is a function of fluid temperature and pressure and is a dependent variable. The quality of a fluid is a quantity that does not change with time, space temperature, and pressure.

Read More About: Mass Flow Meter Types

Read more about: Coriolis meter for High viscosity liquid

A Cylinder 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℃).

Cylinder Gear flow meter is a type of positive displacement flow transmitter. It is a high-precision transmitter for measuring volumetric flow. With the flow of the medium, the gears mesh and rotate. Under the action of fluid flow. Measure the number of revolutions of the gear to know the flow of liquid and liquid flowing through the instrument. It is especially suitable for the flow measurement of heavy oil, polyvinyl alcohol, grease, and other high-viscosity media. It can measure the viscosity of Fluid up to 10000Pa.s.

Read more about: Gear flow meter working principle


The price of the flow meter is not fixed. Different types of flowmeters, different measurement parameters, the price of flowmeters are different.

When you need to consult the price of the flowmeter, please confirm the measurement parameters, and then contact our sales engineer.

Extended Reading: Mechanical flow meter for diesel

If you want to divide the commonly used flow meters into three categories. Then I will be divided into: positive displacement flowmeter, mass flowmeter and velocity flowmeter.

Of course, in fact, the types of flowmeters should be:

  • Coriolis.
  • DP Meters.
  • Magnetic Meters.
  • Multiphase Meters.
  • Ultrasonic Meters.
  • Vortex Meters.

Extended reading: Flow meter totalizer calculation

Different types of flowmeters have different installation requirements.

For example, the asphalt flow meter in this article. We briefly introduce the Installation and Use of Oval Gear Flowmeter.

  1. A matching filter shall be installed before the flowmeter, and the outlet of the matching filter is connected to the inlet of the flowmeter. The arrow points on both bodies are consistent with the flow direction of the liquid.
  2. When the liquid under test contains gas, the gas elimination filter should be installed before the Flowmeter.
  3. No matter whether the pipeline is installed vertically or horizontally, the oval gear in the flowmeter shall be installed in a horizontal position (i.e. the gauge disc shall be perpendicular to the ground).
  4. When the flowmeter is properly installed, if it is not easy to read, turn the counter to 180 degrees or 90 degrees.
    5.The new flowmeter pushes the elliptical gear several times from the exit with a bamboo stick before installation. If it doesn’t move, soak in diesel oil (Avoid sediment after factory check).
    6.Flow control valve should be installed at the inlet of the Flowmeter, and open and close valve is installed at the outlet. When using open and close valve, start slowly, do not suddenly open to prevent “water hammer” phenomenon.
  5. Before installing the flowmeter on the new pipeline, the pipeline needs to be flushed, and the straight pipe section (instead of the position of the Flowmeter) is used to prevent welding slag, sundries and so on from entering the flowmeter.
  6. It is strictly forbidden to check the flowmeter of cast iron and steel with water.
  7. The flow size of the flowmeter in use shall not exceed the technical requirements. The flowmeter operates at a maximum flow rate of 50-80%.
    10.If the tested liquid is chemically corrosive, a flowmeter of stainless steel should be selected.

Extended reading: High Temperature Flow Meter

Each flowmeter works differently.

For example: the working principle of the orifice flowmeter is that the fluid filled with the pipeline flows through the throttling device in the pipeline. It causes local contraction near the throttling part. The flow velocity increases, and the static pressure difference is generated on the upstream and downstream sides. Under the condition of known product parameters, the flow is obtained by deriving the relationship between differential pressure and flow according to the principle of flow continuity.

Digital flow meter working principle

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Sino-Inst, Manufacuturer for Asphalt flow meters for Liquid asphalt flow measurement. For example: crude oil flowmeter, diesel flowmeter, gasoline flowmeter.

Sino-Inst’s Asphalt flow meters, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, US, and other countries.

Bitumen/Asphalt flow meter|Thermal insulation Oval Gear Flow Meter

How to choose an asphalt flow meter? Liquid asphalt flow measurement has always been a difficulty. Liquid asphalt and other media that are easy to solidify and crystallize need to be measured with an oval gear flowmeter with heat preservation or heating function.

Product SKU: Thermal insulation Oval Gear flow meter

Product Brand: Sino-Inst

Product Currency: USD

Product Price: 600

Price Valid Until: 2059-09-30

Product In-Stock: InStock

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This entry was posted in Volumetric Flow Meters, Flow Meters by KimGuo11. Bookmark the permalink.

About KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects. Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.