Hydraulic Oil Flow Meters

The hydraulic flow meter is mainly for inline hydraulic system instantaneous flow test and high-pressure test. Industrial Hydraulic oil flow meter, also called hydraulic flow gauge.

Sino-Inst offers Turbine, Mass flow, Oval gear, V-cone, Target, and Orifice flow meters for inline hydraulic oil flow. Features like: bidirectional, high pressure, analog, can be customized as customer need.

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

Hydraulic oil flow meters measure the flow of oil in machines. They are important in many industries. These meters help machines work well, last longer, and avoid breaking down. Industries like car-making, mining, and oil & gas use them. Hydraulic oil flow meters are needed for accurate measurements and to keep machines running smoothly.

Featured Hydraulic Flow Meters for Sale

Sino-Inst offers great prices for hydraulic oil flow meters. For example, a turbine flow meter for hydraulic oil:

  • Size: DN50
  • Max pressure: 16 bar
  • Signal output: 4-20mA
  • FOB Price: USD 585.00/set

Please note, this price is just an example. The actual price depends on the user’s specific measurement needs.

Hydraulic oil is the hydraulic medium.

Hydraulic oil is used in hydraulic systems that utilize fluid pressure energy.

Its role is Energy transfer, anti-wear, system lubrication, Anti-corrosion, anti-rust, cooling, etc.

1. Hydraulic systems for automobiles and construction machinery use hydraulic oil as the working medium. In this type of hydraulic system, the fluid velocity is not large and the pressure is high, so it is called static pressure transmission.

2. Hydraulic oil is widely used, and it is the most used product in industrial oil. Hydraulic components are developing in the direction of small size and high power. The system pressure is getting higher and higher, and some have exceeded 50 MPa.


  1. Hydraulic pressure is a term for the machinery industry and electromechanical industry. Hydraulic power can be powered by hydraulic power. Hydraulic pressure can also be used as a control method, which is called hydraulic pressure control.
  2. Hydraulic principle In certain mechanical and electronic systems, the static pressure of the liquid medium is used to complete the backlog, transfer and amplification of energy. Achieve lightweight, scientific, and maximized mechanical functions.
  3. In the hydraulic system, due to some reason, the liquid pressure suddenly rises suddenly at a certain moment, and a high-pressure peak is formed. This phenomenon is called hydraulic shock.
  4. Select the type of hydraulic oil according to the working environment and working conditions. When selecting the hydraulic oil used in hydraulic equipment. It should be comprehensively considered and judged from several aspects such as working pressure, temperature, working environment, hydraulic system and component structure and material, and economy.

Extended reading: High Temperature Flow Meter

The hydraulic flow meter is a flowmeter that can measure hydraulic oil. The hydraulic flow meter is a name called according to the measurement medium in the industry.

There is no hydraulic oil flow meter in the strict sense. It is not accurate to say which flowmeter is a hydraulic flow meter. Which one to use depends on the specific flow measurement conditions.

For example, the hydraulic oil is also labeled, 40 #, 46 #, or other viscosity properties. Then choose a suitable flow meter according to the relevant information such as flow, pressure, viscosity, and so on.

Read more about: What is a Flow Meter? Types and how does it work?

Here are some common types of hydraulic oil flow meters and what they do:

  • Gear Flow Meters: These meters have gears that rotate to measure oil flow. They work well with thick fluids.
  • Turbine Flow Meters: These meters use a spinning part to measure flow. They work with different flow rates and clean fluids.
  • Variable Area Flow Meters: Also called rotameters, these meters use a tube and a moving float to measure flow. They’re simple and work with many fluid types.
  • Positive Displacement Flow Meters: These meters measure fluid flow by trapping and counting fluid. They’re accurate and good for thick fluids like hydraulic oil.
  • Mass Flow Meters: These meters measure the mass of fluid flowing through a system instead of volume. They are useful in situations where fluid density changes can impact the accuracy of volumetric flow meters.
  • Ultrasonic Flow Meters: These meters use sound waves to measure flow without touching the fluid. They’re good when you want to avoid fluid contamination or pressure loss.

Knowing the different types of hydraulic oil flow meters helps you pick the best one for your needs.

High-Pressure Turbine Flow Meter series of turbine flow meters is ideal when measuring the flow of fluids under high pressure, such as in hydraulic testing. 

It is also perfect for chemical injection systems, as it withstands pressures up to 20,000 psi and is available in a variety of flow ranges (0.08 to 32 gallons/minute).

High Pressure Hydraulic Flow Meter
Accuracy0.5% to 2.0% of reading
Temp. range-20~+150℃
Pressure40 MPa
Flow rate0.5~6m/s
Straight pipe requiredUp stream≥5DN, down stream≥3DN

The wireless flow meter is integrated with the instrument and control part on the basis of accurate measurement. Realize automatic cut-off and connection operation of the pipeline.

The wireless flowmeter avoids the liquid flowing too fast and causing damage to the instrument itself. Prevent dangerous accidents.

Wireless flow meter realizes the operation of automatic two-way flow measurement. Instantaneous flow on site. Total forward and reverse total display. Self-diagnostic fault alarm. Full use of GSM / GPRS data wireless remote transmission and other functions to realize wireless remote transmission of flow data, Storage and other functions.

GSM / GPRS remote monitoring and management software system is matched with wireless remote transmission flowmeter with remote transmission function.

This system can query, statistics, analyze and display the water consumption situation and pipeline pressure of each measurement point in the form of charts or curves.

Users can easily manage water consumption at each measurement point. When abnormal water conditions occur at the measurement point or the battery capacity of the on-site flow meter is insufficient. The system can issue an alarm message.

  • Can display the meter’s flow rate, flow rate, cumulative quantity, pressure, working status, and other data.
  • Can print all the data of the query directly.
  • Can directly export the data of all meters to the computer.
  • Can directly see the flow curve of the query meter. Directly print out the flow curve graph.
  • You can check the working status of the field instrument and whether the instrument has an alarm condition.
  • Can display the annual, monthly, and daily water consumption of all the instruments in the form of a report. You can directly print the report.
  • You can directly export the report to the computer. All meter data can be backed up directly to the computer.

Extended Reading: Insertion Flowmeter Types

You may like: High-Temperature Oval Gear Heating oil Flow Meter

How to use a hydraulic flow meter?

  • A flow meter can be placed in any location of the hydraulic line to detect the flow rate. Flow meters with variable port sizes are available that are suitable for different hydraulic systems.
  • When the hydraulic system operates, the fluid is passed towards the flow meter.
  • A flow meter mainly contains 3 parts; the primary device, a transducer and a transmitter. The transducer senses the hydraulic fluid passing through the primary device.
  • And a usable flow signal is generated by the transmitter when the sensed signal is sent by the transducer.
  • The volume is calculated based on the principle that the volume of fluid passing is directly proportional to the cross-sectional area and the fluid velocity.
  • Also, the mass flow is directly proportional to fluid density and volume.
  • Then, this calculated hydraulic measurement is displayed on the hydraulic flow meter gauge.
  • All standard hydraulic oil flow meters supports unidirectional flow.
  • But, reverse flow by-pass options are also available with some selected flow meters.
  • Selecting a hydraulic flow meter is a difficult procedure. A wrong selection will cause errors in the diagnosed result.
  • The factors that need to be considered while selecting a hydraulic flow meter are:
    • the hydraulic fluid properties.
    • operating condition of the hydraulic system.
    • the need for measuring flow.
    • the level of accuracy required.
    • the effect of fluid on flow meter and vice-versa.
    • and finally the budget.

More about inline oil flow meter

Digital inline oil flow meter

What is an inline flow meter?

The online flow meter is actually a flow meter displayed on the spot. At present, all integrated flow meters are online flow meters. All have local display function.

For example, the split-type flowmeter has no local display function. Its meter head and sensor are connected through conduction, and the online flowmeter is the mainstream measuring instrument in current flow measurement.

What are the advantages of online flow meters in the flow measurement process? In some measurements with a control system, the advantage of the online flowmeter is not great. Because the size of the flow can be monitored through the PLC system. And there is no PLC system in the working condition. The online flowmeter can show its advantages, and it can display the accumulated flow and instantaneous flow online.

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

Inline hydraulic oil flow meter

Inline hydraulic oil flow meter measures the hydraulic oil flow directly on the pipeline, and then displays the flow on the meter.

Hydraulic oil flowmeter is a flowmeter that can measure hydraulic oil. It is the name given by the industry based on the measurement medium. There is no hydraulic oil flow meter in the strict sense.

It is foolish to say which flowmeter is the hydraulic oil flowmeter.

Which one to use depends on the specific working conditions. For example, hydraulic oil also has a label, is it 40#, 46# or other viscosity properties. It is necessary to see clearly, and then select an appropriate flow meter based on the flow, pressure and other related information.

Extended Reading: Summary Of Crude Oil Flow Measurement Options

Oil Flow Meter Types

At present, the following types of flow meters can be used to measure oil:

Turbine flow meters. Gear flow meter. Vortex flowmeter. Ultrasonic flow meter. Mass flowmeter. Differential pressure flow meters.

Read more: Top 8 petroleum flow meters for Measuring Oil and Gas

Flow Meter Selection Guide 101: Find the Perfect Fit for Your Application

How to Select Hydraulic flow Meter?

When searching for a flow meter for use in a particular hydraulic application, these five questions can help:

  1. What are the fluid properties?
  2. What is the hydraulic system operating condition
  3. Why is flow being measured; how accurately does the flow measurement need to be?
  4. What effect might the flow meter have on the fluid and vice-versa?
  5. How important is it to measure flow;
  6. What is your budget?

Extended Reading: Mechanical oil flow meter

Technical Support

The D represents the diameter of the pipe. For the orifice plate in the orifice plate flowmeter, the minimum requirements for the front and rear straight pipe sections are 10D Upstream and 5D Downstream. If there is a pump or regulating valve in front of the orifice plate, then the requirements for the straight pipe section are greater.

There are many types of flow meters.

According to the different structural principles of the flowmeter, it is divided into:

  1. Differential pressure flowmeter: orifice plate, bar type such as Annubar, V cone, wedge type, elbow, nozzle, target type, etc.
  2. Variable area flowmeter: rotor, open channel, etc.
  3. Velocity flowmeter: electromagnetic, ultrasonic, turbine, vortex street, precession vortex, rotor, etc.
  4. Positive displacement flowmeter: waist wheel, oval gear, piston, scraper, etc.
  5. Mass flowmeter: Coriolis, thermal, etc.

Extended reading: Metal Tube Flow Meter-Variable Area Flow Meters Principle

Flow is the amount of fluid that passes through a pipe or device at a cross-section in a unit of time. This quantity is expressed by mass and is called mass flow. Expressed by volume, called volume flow. Expressed by weight, called weight flow.

Because the density of a fluid changes with changes in the state parameters of the fluid, the volume state must be given while specifying the state of the fluid.

Especially for gas, its density varies significantly with pressure and temperature. In order to facilitate the comparison of the volume flow rate, the volume flow rate in the working state is often converted to the volume flow rate in the standard state (temperature is 20 ° C and absolute pressure is 101325Pa).

Commonly used flow measurement methods include speed-type flow measurement methods, volumetric flow measurement methods, and direct or indirect methods to measure the mass of fluid flowing through the cross section of the pipe per unit time.

In the above method, more speed-type flow measurement method instruments are applied.

Except for the standard throttling device which does not need to be tested for the current flowmeter, almost all other flowmeters need to be calibrated when leaving the factory. During the use of the flowmeter, it should also be calibrated frequently.

The volume method is most commonly used. This is a method of measuring the volume of fluid flowing into a constant volume container within a measurement time to obtain the flow rate.

The mass method is a method of weighing the mass of a fluid flowing into a container within a measurement time to obtain a flow rate.

During calibration, a pump is used to draw the test fluid from the liquid storage container through the calibrated flowmeter and enter the liquid container.

The temperature of the fluid is measured while the weight is weighed to determine the density of the measured fluid at that temperature.

Divide the weight of the measured fluid by the density of the fluid at the measured temperature to obtain the volume of the fluid.

Comparing it with the meter’s volume indication (accumulated pulse number), the meter constant and accuracy of the calibrated flowmeter can be determined. The accuracy of this system can reach 0.1%.

The working principle of the standard volume tube method is based on the volumetric method (standard volumetric method), but it is a dynamic measurement.

The standard flowmeter comparison method is to connect the calibrated flowmeter and the standard flowmeter in series to the pipeline flowing through the test fluid, and compare the two measured values ​​to find the error. The accuracy of the standard flowmeter is 2 to 3 times higher than that of the calibrated flowmeter.

Where are flow meters used? Or, What does a flow meter measure?

At industrial sites, meters that measure fluid flow are referred to as flow meters or flow sensors.

It is one of the most important instruments in industrial measurement.

With the development of industry, the accuracy and range of flow measurement requirements are getting higher and higher.

In order to adapt to various purposes, various types of flowmeters have been successively launched,

widely used in oil and gas, petrochemical, water treatment, food and beverage.

Industries such as pharmaceuticals, energy, metallurgy, pulp and paper, and building materials.

  1. Measurement of gas mass flow in industrial pipelines
  2. Smoke flow rate measurement from the chimney
  3. Calciner flue gas flow measurement
  4. Air flow measurement during gas process
  5. Compressed air flow measurement
  6. Gas flow measurement during semiconductor chip manufacturing process
  7. Gas flow measurement in sewage treatment
  8. Gas flow measurement in heating ventilation and air conditioning systems
  9. Flux recovery system gas flow measurement
  10. Measurement of combustion gas flow in a combustion boiler
  11. Gas flow measurement of natural gas, flare gas, hydrogen, etc.
  12. Measurement of carbon dioxide gas flow during beer production
  13. Measurement of gas mass flow in the production process of cement, cigarette and glass factory
  14. Open channel

Flowmeters are devices that measure the rate of liquid, gas or vapor that passes through them.

Some flowmeters measure flow as the amount of fluid passing through the flowmeter during a time period (such as 100 liters per minute).

Other flowmeters measure the totalized amount of fluid that has passed through the flowmeter (such as 100 liters).

Flow measurement can be described by :
Q = A x v

Q is flow rate, A is the crosssectional area of the pipe, and v is the average fluid velocity in the pipe.

Putting this equation into action, the flow of a fluid traveling at an average velocity of a 1 meter per second,

through a pipe with a 1 square meter cross-sectional area is 1 cubic meter per second.

Note that Q is a volume per unit time, so Q is commonly denoted as the “volumetric” flow rate.

Now consider the following equation:
W = rho x Q

Where W is flow rate (again – read on), and rho is the fluid density.

Putting this equation into action, the flow rate will be 1 kilogram per second,

when 1 cubic meter per second of a fluid with a density of 1 kilogram per cubic meter is flowing.

(The same can be done for the commonly-used “pounds”. Without getting into details — a pound is assumed to be a mass unit.)

Note that W is a mass per unit time, so W is commonly denoted as the “mass” flow rate.

Now — which flow do you want to measure? Not sure? In some applications, measuring the volumetric flow is the thing to do.

Consider filling a tank.

Volumetric flow may be of interest to avoid overflowing a tank,

where liquids of differing densities can be added.

(Then again, a level transmitter and high level switch/shutoff may obviate the need for a flowmeter.)

Consider controlling fluid flow into a process that can only accept a limited volume per unit time.

Volumetric flow measurement would seem applicable.

In other processes, mass flow is important.

Consider chemical reactions,where it is desirable to react substances A, B and C.

Of interest is the number of molecules present (its mass), not its volume.

Similarly, when buying and selling products (custody transfer) the mass is important, not its volume.

In recent years, flow measurement technology has developed rapidly. Most of the steam flow measurement uses differential pressure flowmeters and vortex flowmeters.

In practical applications, the maximum diameter of the high temperature vortex flowmeter can only be 300mm and the maximum temperature is 450℃. Therefore, in the measurement of high temperature and high pressure large-diameter steam flow, the differential pressure flowmeter still has unique advantages. For example, Annubar flowmeter, differential pressure orifice flowmeter, etc.

Differential pressure flowmeter manufacturing technology and national and international standards are quite mature. With the introduction of the multivariable transmitter dynamic full compensation intelligent technology, the accuracy of high temperature pressure and large diameter steam flow measurement has been greatly improved, and the installation and maintenance workload has been reduced.

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Sino-Inst is Manufacturer of Hydraulic Oil Flow Meters. We supply more than 20 kinds of Hydraulic Flow Meters. 50% turbine flowmeters, 20% oval gear flow meters, 20% DP flow meters and other types of flowmeters.

Hydraulic Oil Flow Meters are mainly used for flow measurement of various oils.
It can measure even liquids such as crude oil, lubricating oil, gasoline, diesel etc.

Hydraulic Oil Flow Meters enable stable flow measurement. This greatly meets the measurement needs of many applications. Can be used from small to large tubes.

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

The entire team at Sino-Inst’s has received excellent training, so we can ensure that every client’s needs are met. For assistance with your product requirements, whether it’s a Hydraulic Flow Meters, level sensor, or other device, give us a call.

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