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.

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:

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.

2. 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.

3. 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.

Approach:

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.

Approach:

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.

Approach:

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.

Approach:

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.

Approach:

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.

Approach:

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.

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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.