Liquid Turbine Flow Meter Installation Guidelines

Installation Location

The sensor should be installed in a place that is easy to maintain, has no vibration in the pipeline, and is not affected by strong electromagnetic interference and heat radiation.

A typical installation piping system for a turbine flowmeter is shown in the figure.

The configuration of each part in the figure depends on the situation of the measured object, not necessarily all of them.

Turbine flowmeters are sensitive to distortion of flow velocity distribution and swirling flow in the pipeline, and the flow into the sensor should be fully developed. Therefore, the necessary straight pipe section or flow regulator should be equipped according to the type of choke on the upstream side of the sensor, as shown in the table below.

If the condition of the upstream side choke is not clear, it is generally recommended that the length of the upstream straight pipe section is not less than 20D, and the length of the downstream straight pipe section is not less than 5D. If the installation space cannot meet the above requirements, a flow regulator can be installed between the choke and the sensor.

When the sensor is installed outdoors, measures should be taken to avoid direct sunlight and rain.

Type of spoiler on the upstream side	Single 90° elbow	Two 90° elbows on the same plane	Two 90° elbows on different planes	Concentric reducer	Fully open valve	Hhalf open valve	Downstream side length
L/DN	20	25	40	15	20	50	5

Installation Requirements for Connecting Pipelines

The sensor installed horizontally requires that the pipeline should not have a visually detectable inclination (generally within 5°). The verticality deviation of the sensor pipe installed vertically should also be less than 5°. The fluid direction must be upward when installed vertically.

Where continuous operation is required and the flow cannot be stopped, bypass pipes and reliable stop valves should be installed. When measuring, make sure that there is no leakage in the bypass pipe.

In the position where the sensor is installed in the newly laid pipeline, a short pipe is first inserted to replace the sensor. After the “line sweeping” work is completed and the pipeline is cleaned, the sensor is formally connected. Due to neglect of this task, it is not uncommon for wire sweeping to damage the sensor.

If the fluid contains impurities, a filter should be installed on the upstream side of the sensor. For those that cannot stop the flow, two sets of filters should be installed in parallel to remove impurities in turn, or self-cleaning filters should be selected.

If the measured liquid contains gas, a muffler should be installed on the upstream side of the sensor. The sewage outlet and air elimination outlet of the filter and muffler should lead to a safe place.

If the installation position of the sensor is at the low point of the pipeline, in order to prevent the impurities in the fluid from settling and stagnating. A discharge valve should be installed in the subsequent pipeline to discharge the precipitated impurities regularly.

The flow regulating valve should be installed downstream of the sensor, and the stop valve on the upstream side should be fully open when measuring. And these valves must not produce vibration and leak outward. For processes that may generate reverse flow, check valves should be added to prevent reverse flow of fluid.

The sensor should be concentric with the pipe, and the sealing gasket should not protrude into the pipe. Liquid sensors should not be installed at the highest point of the horizontal pipeline. In order to prevent the gas accumulated in the pipeline (such as mixed gas when the flow is stopped) staying at the sensor, it is not easy to discharge and affect the measurement.

The pipelines before and after the sensor should be supported firmly without vibration. For condensable fluids, thermal insulation measures should be taken for the sensor and its front and rear pipelines.

Installation Requirements

1. The pipe must be completely filled with liquid. It is important to keep the tubing completely filled with fluid at all times. Otherwise the traffic display will be affected. Measurement errors may result.
2. Avoid air bubbles. If air bubbles enter the measuring tube, the flow display may be affected, possibly causing measurement errors.

Straight pipe requirements

1. Generally
2. 90° elbow
3. Two 90° elbows on the same plane
4. Two 90° elbows on different planes
5. shrink tube
6. Expansion
7. Fully open valve
8. half open valve
9. If the condition of the upstream side choke is not clear, it is generally recommended that the length of the upstream straight pipe section is not less than 20D, and the length of the downstream straight pipe section is not less than 5D.
10. If the installation control cannot meet the above requirements, a rectifier can be installed between the baffle and the sensor.

Gas Turbine Flow Meter Installation Guidelines

When installing the Gas Turbine Flow Meter, the user must carefully read the following content. Because the condition of the installation of the flowmeter directly affects the accuracy and life of the flowmeter, and even safety issues during work.

• The installation work must be performed by personnel with corresponding pipeline equipment installation skills;
• The flowmeter should be installed in a place that is convenient for maintenance, no strong electromagnetic field interference, no mechanical vibration and thermal radiation influence;
• When the flowmeter is installed outdoors, there should be a cover on the upper part to prevent rainwater and hot sun from affecting the service life of the flowmeter;
• When the flowmeter is installed, it is strictly forbidden to conduct electric welding directly at its inlet flange to avoid burning the internal parts of the flowmeter;
• The newly installed or overhauled pipeline must be cleaned, and the flowmeter can be installed after removing the debris in the pipeline;
• The flowmeter can only be installed horizontally, not vertically. The fluid flow direction should be consistent with the direction marked on the housing. There should be a straight pipe section ≥ 2DN upstream of the flowmeter, and a straight pipe section ≥ 1DN downstream of the flowmeter. Straight pipe section, and the filter of the corresponding specification must be installed at the upstream of the flowmeter (≥2DN) (the company can match) to prevent excessive particulate impurities in the pipeline from entering the flowmeter and affecting the service life of the meter;
• The flowmeter should not be used in occasions where the flow is frequently interrupted and there is a strong pulsating flow or pressure pulsation;
• Ensure that the connection between the pipeline and the inlet and outlet of the flowmeter is coaxial, and prevent gaskets and welds from protruding into the pipeline, otherwise the flow profile will be disturbed;
• In order to facilitate the maintenance of the instrument, it is recommended to install the bypass pipeline according to Figure 6. Open the bypass when the instrument is maintained so as not to affect the normal production, and close the bypass pipeline during normal use.
• When the flowmeter is put into operation, the upstream valve of the flowmeter should be slowly opened, and then the downstream valve of the flowmeter should be slowly opened, so as to avoid the instantaneous air flow that will destroy the turbine flowmeter;
• The flowmeter must be reliably grounded as specified, but must not share the ground wire with the strong current system; during pipeline installation or maintenance, the ground wire of the electric welding system must not be overlapped with the flowmeter;
• During use, users are not allowed to change the connection method of the explosion-proof system and change the lead interface arbitrarily;

Read more about: What are the application of turbine flow meters?

Turbine Flow Meter Installation Troubleshooting

Fault phenomenon	Causes and Solution
1. There is no display when the liquid flows normally, and the cumulative volume does not increase	1) The power supply circuit or signal circuit is disconnected or poorly connected. Troubleshooting method: check with a multimeter to eliminate the fault point; 2) The printed circuit board of the display instrument, the connector is faulty or the contact is poor. Remedy: replace the printed circuit board; 3) The preamplifier is faulty. Troubleshooting method: Use an iron bar to move quickly under the detection head, if there is no signal output, check whether the coil is disconnected or the solder joint is desoldered; 4) The voltage supplied to the preamplifier is too low. Troubleshooting method: increase the power supply voltage to the specified requirements; 5) The impeller is stuck and does not rotate. Troubleshooting method: remove foreign matter, and clean or replace damaged parts, and re-calibrate after replacing parts;
2. When the flow is zero, the flow display is not zero, and the displayed value is unstable	1) Poor shielding and grounding of the transmission line, interference from the external electromagnetic field. Troubleshooting method: check the grounding and eliminate interference; 2) The pipeline vibrates, causing the impeller to vibrate. Troubleshooting method: strengthen the pipeline or install brackets before and after the flowmeter; 3) The shut-off valve is leaking. Troubleshooting method: overhaul or replace the valve; 4) Interference between circuit boards or electronic components inside the display is deteriorated and damaged. Troubleshooting method: take short circuit method”” or check one by one to find out the fault point;”
3. The displayed traffic does not match the actual traffic	1) The impeller is corroded and the blades are deformed. Troubleshooting method: Repair the impeller or re-calibrate after replacement; 2) The sundries hinder the rotation of the impeller. Troubleshooting: Clearing Debris; 3) The output signal of the detection coil is abnormal. Troubleshooting method: check the coil insulation resistance and conduction resistance; 4) The bypass valve is leaking. Troubleshooting method: close the bypass valve and replace it if necessary; 5) The flow velocity distribution upstream of the flowmeter is distorted or pulsating flow occurs. Troubleshooting method: find out the cause of distortion or pulsating flow, and take measures to eliminate it; 6) Display instrument failure. Troubleshooting method: repair display instrument; 7) The wiring of the display instrument is incorrect. Troubleshooting method: Correct the wiring; 8) Display instrument setting error. Troubleshooting: Correct settings; 9) The actual flow exceeds the specified flow range. Troubleshooting method: replace the flowmeter with a suitable caliber;

Featured Turbine Flow Meters for Sale

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Sino-Inst, Manufacuturer for Turbine Flow Meters, like: gas turbine flow meter, liquid turbine flow meter, sanitary turbine flow meter, insertion turbine flow meter, steam turbine flow meter, and natural gas turbine flow meter.

Sino-Inst’s Turbine 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.

If you have any questions about Turbine Flow Meter Installation Guidelines and Troubleshooting, please feel free to contact us.

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Importance of Sea Water Flow Measurement

Seawater stores 96.54% of the earth’s fresh water, which contains a huge amount of minerals, energy and other resources. The current forms of seawater resources development and utilization mainly include: seawater desalination, direct utilization of seawater and utilization of seawater chemical resources.

In seawater desalination

In coastal cities and islands where water resources are seriously short. Mainly large-scale industrial seawater desalination projects. Mainly concentrated in high water consumption industries such as electric power and steel. Seawater desalination projects for islands used in offshore cities.

In terms of direct use of seawater

Mainly for seawater cooling applications. Among them, seawater DC cooling technology is mature and is mainly used in coastal thermal power, nuclear power, petrochemical, steel and other industries. Seawater circulating cooling technology has been gradually applied in the coastal power industry.

In the utilization of seawater chemical resources

It mainly includes salt production from seawater, potassium extraction from seawater, bromine extraction from seawater, magnesium extraction from seawater, etc. In addition to seawater salt production, the main products include bromine, potassium chloride, magnesium chloride, magnesium sulfate, and potassium sulfate.

Therefore, the utilization rate of seawater is getting higher and higher. Even in the future, people will find more favorable treatment and utilization of seawater. Among them, flow measurement before and after seawater treatment, or flow measurement before and after seawater use will become more and more important.

Difficulties in sea water measurement

Seawater is a highly corrosive fluid. Seawater is a very complex multi-component aqueous solution, which contains various ions such as sodium, potassium, calcium, magnesium, copper, zinc, manganese, etc. Its salt content is very high and it is highly corrosive.

Simultaneously, waves and tides create low-frequency mutual stress and impact metal parts. Marine microorganisms, attached organisms and their metabolites also produce direct or indirect accelerated corrosion processes.

Marine corrosion is mainly localized corrosion, which starts at the surface of the component and occurs in a small area. Examples include galvanic corrosion, pitting and crevice corrosion.

Therefore, it is very necessary to consider corrosion issues when selecting seawater flowmeter sensors.

Magnetic flowmeter to measure sea water

Electromagnetic flow is the preferred flowmeter for measuring the volume flow of liquids with a certain conductivity.
Electromagnetic flowmeter is a flow measuring instrument that works based on the principle of electromagnetic induction. It consists of sensors and transmitters.

Advantages

1. There are no moving parts and bluff bodies in the measuring conduit. Therefore, the pressure loss is very small, and there is no mechanical inertia, so the response is sensitive;
2. Wide measurable range: the turndown ratio is generally 10:1, up to 100:1. The flow velocity range is generally 1-6m/s, and can be extended to 0.5-10m/s. The flow range can be from 90mL/h to hundreds of thousands of m3/h. Pipe diameters can range from 2mm to 2400mm or 3000mm.
3. It can measure the volume flow of liquids containing solid particles, suspended matter, or acids, alkalis, and salt solutions with certain conductivity. It can also measure pulsating flow, and can carry out two-way measurement.
4. There is a linear relationship between the flow signal and the fluid volume flow, so the meter has a uniform scale. And the volume flow rate of the fluid has nothing to do with the physical properties and flow state of the medium. Therefore, the electromagnetic flowmeter only needs to be calibrated with water, and it can be used to measure the volume flow of other conductive liquids without correction.
5. Compared with most other flow meters, the requirements for the front straight pipe section are lower.

Disadvantages

1. The temperature and pressure should not be too high;
2. The scope of application is limited. It cannot be used to measure the flow of non-conductive fluids such as gas, steam and petroleum products, and fluids containing more and larger bubbles;
3. When the flow rate and velocity distribution do not meet the set conditions, large measurement errors will occur;
4. When the flow rate is too low, it is difficult to amplify and measure the induced potential of the order of magnitude opposite to the interference signal. And the instrument is also prone to zero drift;
5. The signal of the electromagnetic flowmeter is relatively weak. A little interference from the outside world can affect the accuracy of the measurement.

Extended Reading: Special Magnetic Flowmeter Installation situation

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ultrasonic flowmeter to measure sea water

Ultrasonic flowmeters are instruments that measure volume flow by detecting the action of ultrasonic beams (or ultrasonic pulses) when fluid flows.

The sound wave propagates in the fluid, and the sound wave propagation speed will increase in the downstream direction. , the countercurrent direction decreases, and the same propagation distance has different propagation times. The propagation time method is to calculate the flow velocity by using the relationship between the difference of the propagation velocity and the flow velocity of the measured liquid. Combined with the pipe diameter to obtain the flow rate.

Advantages

1. Ultrasonic flowmeter can be used for non-contact measurement. The clip-on transducer ultrasonic flowmeter can be installed without stopping the flow-carrying tube. Just install the transducer outside the pipeline to be tested. That is, the flow can be measured with an ultrasonic flowmeter on existing pipelines that cannot be cut off or drilled;
2. Ultrasonic flowmeters measure without flow obstruction. No additional pressure loss;
3. The instrument factor of the measuring meter can be calculated from the geometric dimensions of the actual measurement pipe and sound channel. The dry method can be used for calibration. Except for the type with measuring pipe section, it generally does not need to do real flow calibration;
4. Ultrasonic flow meters are suitable for large round and rectangular pipes. And it is not limited by pipe diameter in principle. Its cost basically has nothing to do with the pipe diameter;
5. Doppler ultrasonic flowmeters can measure liquids with high solid content or bubbles.

More about: Insertion Type Ultrasonic Flow Meter Applications

Disadvantages

1. The ultrasonic flowmeter in the propagation time method can only be used for clean liquids and gases, and cannot measure liquids with suspended particles and air bubbles exceeding a certain range. On the contrary, the Doppler method LSF can only be used to measure liquids containing certain heterogeneous phases;
2. Ultrasonic flowmeters with external transducers cannot be used in lined or heavily scaled pipes. And it cannot be used for stripping the lining (or rust layer) from the inner pipe. If there is gas in the interlayer, the ultrasonic signal will be seriously attenuated. Or pipes with severe corrosion (changing the ultrasonic path);
3. In most cases, the Doppler method ultrasonic flowmeter has a low measurement rate;
4. It cannot be used for pipes with a diameter smaller than DN15mm.

Read more about: Flow Meter Selection Guide

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conclusion

So, which flow meter should you choose for Sea Water Flow Measurement or salt water flow?
We believe that:

1. If the seawater concentration is low and the salinity is small.

Then ultrasonic flowmeter is a better choice. Such flow meters do not require contact with seawater and avoid corrosion.
At the same time, its flow sensor is not a metal part and is not afraid of corrosive materials.

For this type of seawater, if you choose an electromagnetic flowmeter. Then a 316L stainless steel electrode and rubber lining material should work well.

2. If the seawater has high concentration and high salinity.

Then the external clamp ultrasonic flowmeter is a better solution.

If you want to choose an online electromagnetic flowmeter for better performance. The best choice is Hastelloy C electrode and PTFE lining material. Hastelloy C electrodes are suitable for oxidation of salts such as Fe++, Cu++ and seawater.

3. For seawater desalination projects, plastic pipes are mainly used as water delivery equipment.

Many pipes are in the air. If an in-line electromagnetic flowmeter is used, the electromagnetic flowmeter is heavy. And the plastic tube doesn’t hold it in place very well. As a result, support brackets have to be installed, which adds a lot of cost and inconvenience.

Therefore, we recommend using a transit-time ultrasonic water flow meter. No pipe cutting required, light weight, easy installation, no maintenance etc.

4. If it is to measure the pipeline above DN3000.

Then the external clamp ultrasonic flowmeter is a better choice. For large diameter pipes, clamp-on ultrasonic flowmeters are less costly.

Read more about: Hydrostatic Submersible Level Transmitter-Straight Rod Insertion

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Sino-Inst is a manufacturer of electromagnetic flowmeters and ultrasonic flowmeters. It has been used for sea water-salt water flow measurement for a long time.

Sino-Inst supplies more than 30 types of seawater flow meters for sea water flow measurement. 55% are electromagnetic flowmeters and 45% are ultrasonic flowmeters.

Electromagnetic flowmeters and ultrasonic flowmeters have their own advantages in Sea Water Flow Measurement. You can choose the appropriate model based on your measurement needs and cost budget.

Sino-Inst’s Sea Water Flow Measurement – Magnetic vs Ultrasonic Flowmeters are the most commonly used sensors in industrial applications. Widely used in water conservancy and hydropower, railway transportation, intelligent building, production control, aerospace, military chemicall, military industry, electric power, ship, machine tool, pipeline and other industries.

Sino-Inst’s entire team is well trained, so we can ensure that each customer’s needs are met. If you need any help with your product requirements, whether it is a Sea Water Flow Meter, level sensors, or other equipment, please give us a call.

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The working principle of High Pressure Rotameter:

The high-pressure metal tube rotameter is the force that the upper and lower ends of the float generate differential pressure to form a rising force when the measured medium passes through the conical measuring tube from bottom to top.

When the lifting force on the float is greater than the weight of the float immersed in the fluid, the float will rise. The area of ​​the annulus will increase accordingly. The fluid velocity at the annulus will drop immediately. The differential pressure at the upper and lower ends of the float will decrease. The float is stabilized at a certain height until the lift force is equal to the weight of the float immersed in the fluid.

The height of the float position corresponds to the flow rate of the measured medium.

The float has a built-in magnet. When the float moves up and down with the medium, the magnetic field changes with the movement of the float.

a. For the local type, the rotating magnet in the local indicator is coupled with the magnetic steel in the float to rotate. At the same time, the pointer is driven to indicate the flow rate at this time through the dial.

b. For the intelligent type, the change of the magnetic field is converted into an electrical signal by a solid-state magnetic sensor in the intelligent indicator. After A/D conversion, microprocessor. D/A output, LCD liquid crystal display, to display the flow rate size and cumulative flow.

Extended reading: High Pressure Flow Meters for Liquids-Steam-Gas

High Pressure Rotameter Features:

1. All-metal structure design. Sturdy, simple, high pressure resistance, high temperature resistance, anti-corrosion, long service life;
2. Short stroke, total height 250mm, easy installation;
3. The mechanical pointer indicates the instantaneous flow on the spot. LCD liquid crystal displays the instantaneous flow and cumulative flow;
4. Intelligent indicator. Using signal acquisition and processing chip, modular design, no magnetic lag;
5. With data recovery, data backup, power failure protection and error self-diagnosis functions;
6. HART type indicator, two-wire 24VDC power supply. 4-20mA standard current signal output superimposed with HART protocol;
7. Parameter configuration and on-site adjustment can be performed through the HART communication hand-held communicator;
8. Connect with the PC serial port. Through the Windows program, the instrument can be calibrated on site;
9. Can be used in flammable and explosive hazardous situations;
10. Various installation forms such as vertical, horizontal, top in and bottom out, bottom in and side out, side in and side out. Flange or threaded connection.

High Pressure Rotameter Applications:

The metal tube rotameter has a simple structure, reliable operation, high accuracy and wide application range. Can withstand higher pressures than glass rotameters.

LZ series flowmeters have local indication, electric remote transmission, limit switch alarm, corrosion resistance, jacket type, damping type and explosion-proof varieties.

It is widely used in the measurement and automatic control of liquid and gas flow in national defense, chemical industry, petroleum, metallurgy, electric power, environmental protection, medicine and light industry and other departments.

Read more about: Benefits Of Digital Gas Mass Flow Meters

What Is Difference Between Rotameter and Flow Meter?

A rotameter is a device that measures the flow rate of liquid or gas in a closed system. It consists of a float that moves up and down in a tube, based on the fluid’s flow rate. The faster the fluid flows, the higher the float rises.

A flowmeter is a device that measures the volume of liquid or gas that flows through it. There are many different types of flowmeters, each designed to measure different types of fluids. For example, positive displacement flowmeters measure the volume of fluid that passes through them, while rotameters measure the rate of flow.

Read more about:

• What is the difference between an orifice flowmeter and a rotameter?
• What is the difference between a rotameter and a turbine flowmeter?
• What is the difference between a mass flowmeter and a rotameter?

More Featured High Pressure Flow Meters for Liquids-Steam-Gas

Are high pressure flow meters the same as regular flow meters? Can high pressure flow meters be replaced by ordinary flow meters?
Of course not.

You need to measure the flow of fluids under high pressure, but you’re not sure which type of flow meter is best for your application.

Choosing the right flow meter can be difficult, because there are so many different types available on the market. How do you know which one is right for your specific application?

Sino-Inst offers a wide range of high pressure flow meters that are specifically designed to operate in demanding applications. Our high pressure flowmeters are made from stainless steel construction and are ideal when measuring the flow of fluids under high pressures.

Read more about: High Pressure Flow Meters Types

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High Pressure Rotameter for Liquids/gas-Upto 25 Mpa is mainly used for small and medium diameter flow measurement. It can measure liquid, gas, steam, etc. Complete product series specifications, in all walks of life are widely used.

Extended Reading: What is difference between rotameter and flow meter

High Pressure Rotameter for Liquids/gas-Upto 25 Mpa can be stable flow measurement without modifying the pipeline. This greatly meets the measurement needs of many applications. From small tubes to large tubes can be used.

Sino-Inst’s High Pressure Rotameter for Liquids/gas-Upto 25 Mpa, made in China, have good quality, with better prices. Our flow measuring instruments are widely used in China, India, Pakistan, USA and other countries.

Sino-Inst’s entire team is well trained, so we can ensure that each customer’s needs are met. If you need any help with your product requirements, whether it is a metal tube flow meters, level sensors, or other equipment, please give us a call.

Request a Quote

Sino-Inst mechanical diesel flow meter solutions come together here and allow you to select from various flow rates or technologies. When it comes to technologies, the turbine or oval gear type diesel flow meters can all be purchased directly from our website. We have a variety of mechanical diesel flow meters suitable for most fuels, including diesel, bio-diesel, kerosene, gasoline, oil, DEF, heating oil, grease and certain chemicals. mechanical Diesel fuel meters are available in several sizes from 1/2″ up to 8 “.

Featured Mechanical Diesel Flow Meters

Characteristics of Diesel Flow

Diesel is a kind of light petroleum, which belongs to the fuel of diesel engine. The use of high-speed diesel engines on cars is more fuel-efficient than gasoline engines.

Diesel demand is growing faster than gasoline. Diesel engines have higher thermal efficiency and higher power than gasoline engines. The fuel consumption per unit is low and relatively economical, so the application is increasing day by day. In many occasions, it needs to be measured.

For oil tanker or diesel storage tank pipeline transportation, it is more suitable to choose a flowmeter with higher measurement accuracy. Because it is not only convenient for trade settlement, but also high precision. The measurement is accurate and can be used for a long time.

According to the role of diesel: the use can be divided into marine diesel engine, locomotive diesel engine, automobile diesel engine, power generation diesel engine, agricultural diesel engine, construction machinery diesel engine, etc.

Diesel Fuel: Diesel fuel is primarily diesel. Light diesel oil is usually used for high-speed diesel engines. Light diesel or heavy diesel for medium and low speed diesel engines.

Extended reading: mechanical oil flow meter

Mechanical Diesel Flow Meter Working Principle

Oval gear flow meters are our most commonly used Mechanical Diesel Flow Meters.

The oval gear flowmeter is composed of a metering box and a pair of elliptical gears installed in the metering box, and the upper and lower cover plates form a sealed crescent-shaped cavity (due to the rotation of the gear, it is not sealed) as the calculation unit of a displacement .

The flow meter is mainly composed of a housing, a counter, an elliptical gear, and a coupling (magnetic coupling and axial coupling), etc. As shown in the figure.

1.Counter 2. Transmitter

3. Accuracy adjuster (used above DN50)

4. Sealed coupling

5. Front cover 6. Cover plate

7. Oval gear 8. Shell

9. Rear cover

When the measured liquid enters the flowmeter through the pipeline, the pressure difference generated at the inlet and outlet pushes a pair of gears to continuously rotate, and the liquid measured by the crescent-shaped cavity is continuously transported to the outlet. The product of four times the secondary displacement is the total amount of the measured liquid flow.

The elliptical gear generates a torque to make it rotate under the action of the pressure difference △p of the measured medium.

The rotor 1 and the rotor 2 are alternately driven by one to rotate the other. There are two magnets on each rotor as signal generating elements. There is a magnetic signal detecting element at the center of the two axes at the bottom of the cavity. Whenever the magnet turns to the detecting element, the sensor counts as a pulse.

Each pulse corresponds to a certain amount of medium discharge F, F=XXml/p, so the volume flow Qm per unit time can be obtained: Qm=F*H, F is the amount of medium removed by each pulse; H pulse per unit time number.

Read more about Mass Flow Rate vs Volumetric Flow Rate

Advantages of Oval Gear Mechanical Diesel Flow Meters

• High measurement accuracy: 0.2 and 0.5;
• The mechanism is simple, firm and reliable;
• Especially suitable for measuring medium with high viscosity. And it is not sensitive to changes in the viscosity of the liquid being measured;
• Easy to install. No straight pipe sections are required before and after the flowmeter. Even if the flowmeter is close to valves, elbows, shrinks, and expansions, there is no need to add straight pipe sections.
• In order to prevent the gear of the flowmeter from being stuck by impurities. A filter must be installed upstream of the flow meter

Extended reading: Advantages of Oval Gear Mechanical Diesel Flow Meters

More Inline Digital Diesel Fuel Flow Meters

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Read more about: The Pros and Cons of Micro Motion Flow Transmitters

Sino-Inst is Manufacturer of Mechanical Diesel Flow Meters for diesel flow measurement. We supply more than 20 kinds of Mechanical Diesel Flow Meters. 80% oval gear flow meter, 20% other types flow sensors.

Mechanical Diesel Flow Meters for diesel fuel measurement are mainly used for flow measurement of various oils pipes.

Mechanical Diesel Flow Meters enable stable flow measurement. This greatly meets the measurement needs of many applications. Can be used from small to large pipes.

Sino-Inst’s Mechanical Diesel Flow Meters for diesel fuel flow measurement, 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 Mechanical Diesel Flow Meters for diesel measurement, flow sensor, or other device, give us a call.

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If you’re not sure which high pressure flow meter is right for your application, please contact us and we will be happy to help you select the best model for your needs.

High Pressure Flow Meters Types

There are various types of high pressure flow meters available on the market including: positive displacement, turbine, magnetic, gear, coriolis mass flow meters. Each type of meter has its own advantages and disadvantages that should be considered when selecting a high pressure flow meter for a particular application. Read more about: Flow Meter Selection Guide

Read more about: Condensate Flow Meter-Steam Condensate Flow Meter|Types & Selection Guide

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High pressure flow meters Applications

High pressure flow meters are recommended based on the application. High pressure gas, High pressure water, High pressure liquid, High pressure steam or High pressure air. High pressure oxygen is also a common application. Read more Turbine Flow Meter Application Case: Demineralized Water.

Some common applications for high pressure flow meters include:

• – High pressure gas flow measurement
• – High pressure water flow measurement
• – High pressure hydraulic flow measurement
• – High pressure steam flow measurement
• – High pressure air flow measurement
• – High pressure oxygen flow measurement

Read more about: High Pressure Hydraulic Flow Meter

When selecting a high pressure flow meter, it is important to consider the nature of the fluid being measured, the operating conditions and the required degree of accuracy. Each type of high pressure flow meter has its own advantages and disadvantages that should be considered in order to select the best meter for the application.

Read More about: What is the difference between rotameter and flowmeter?

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Extended Reading: Special Magnetic Flowmeter Installation situation

Sino-Inst is a manufacturer of High Pressure Flow Meters for Liquids-Steam-Gas. We offer more than 20 types of High Pressure Flow Meters, 40% for gas, 30% for liquid and the rest for steam. High Pressure Flow Meters include turbine, coriolis mass, and more DP flow meters.

High Pressure Flow Meter is mainly used for small and medium diameter flow measurement. It can measure liquid, gas, steam, etc. Complete product series specifications, in all walks of life are widely used.

High Pressure Flow Meters can be stable flow measurement without modifying the pipeline. This greatly meets the measurement needs of many applications. From small tubes to large tubes can be used.

Sino-Inst’s High Pressure Flow Meters, made in China, have good quality, with better prices. Our flow measuring instruments are widely used in China, India, Pakistan, USA and other countries.

Sino-Inst’s entire team is well trained, so we can ensure that each customer’s needs are met. If you need any help with your product requirements, whether it is a High Pressure Flow Meter, level sensors, or other equipment, please give us a call.

Request a Quote

Updated: April 15, 2026

A metal tube flow meter is a variable-area (VA) rotameter built with a stainless steel measuring tube instead of glass. A float inside the tube rises to a height proportional to the flow rate, and a magnetic coupling transfers that position to an external scale or a 4–20 mA transmitter. It’s the standard choice for high-pressure, high-temperature, or opaque fluids where a glass rotameter won’t survive.

This guide covers the working principle, when to pick metal tube over glass or digital flow meters, accuracy and pressure limits, and what to specify when ordering one. If you already know you need a rotameter and just want the specs, jump to the comparison table and product cards below.

Contents

• What Is a Metal Tube Flow Meter?
• How Does a Metal Tube Rotameter Work?
• Metal Tube vs Glass Tube vs Digital Rotameter
• What Pressure, Temperature and Accuracy Can It Handle?
• Where Are Metal Tube Flow Meters Used?
• How to Specify a Metal Tube Flow Meter
• Featured Metal Tube Rotameters
• FAQ

What Is a Metal Tube Flow Meter?

A metal tube flow meter — also called a metal tube rotameter or LZ-series variable area flow meter — measures liquid or gas flow using a float suspended in a vertical metal tube. “Metal tube” distinguishes it from the glass-tube rotameters used for low-pressure water and air service.

Typical construction: 304 or 316L stainless tube, a stainless or Hastelloy float, and an external magnetic indicator with pointer or LCD display. Wetted parts can be PTFE-lined for acid and chlorine service. Connection is flanged or threaded, sizes DN15–DN200.

How Does a Metal Tube Rotameter Work?

Fluid enters the bottom, flows upward, and lifts a float until the upward drag force balances gravity. Higher flow pushes the float higher. A permanent magnet inside the float couples through the stainless wall to an external indicator or transmitter — no mechanical feedthrough, no seals to leak.

The governing equation is a balance between float weight and the dynamic pressure of flow through the annular gap:

Q = C_d × A × √(2 × g × V_f × (ρ_f − ρ) / (A_f × ρ))

Where Q is volumetric flow, A is the annular flow area, V_f and A_f are the float volume and cross-section, ρ_f and ρ are float and fluid density. What this tells you in practice: a float calibrated for water will read wrong on heavier oils or gases — always calibrate for the specific fluid.

For a deeper comparison of variable-area flow measurement vs other technologies, see our rotameter vs flow meter comparison.

Metal Tube vs Glass Tube vs Digital Rotameter

Metal tube is the right answer when pressure, temperature, or opacity rules out glass. Digital VA meters add outputs but cost more.

Parameter	Glass Tube	Metal Tube	Digital VA
Max Pressure	1 MPa (145 psi)	25 MPa (3,600 psi)	25 MPa
Max Temperature	120 °C	300 °C	300 °C
Accuracy	±2% – ±5% FS	±1.5% – ±2.5% FS	±1% FS
Turndown	10:1	10:1	20:1
Output	Visual only	Visual + 4–20 mA / HART / alarm	4–20 mA / HART / Modbus
Opaque / colored fluid	Unreadable	OK (magnetic coupling)	OK
Relative cost	1×	3–4×	5–7×

Pick metal tube when you’re above 10 bar, above 120 °C, or measuring oil, slurry, or steam condensate. Stick with glass for clean low-pressure water and air. Pay for digital VA only if you need remote output on fluids where a magnetic flow meter or vortex flow meter won’t work.

What Pressure, Temperature and Accuracy Can It Handle?

Typical metal tube rotameter specs for standard LZ-series:

• Size range: DN15 to DN200 (½” to 8″)
• Flow range: 2.5 L/h to 100 m³/h for water; 0.1 to 1,000 Nm³/h for air
• Pressure: PN16 to PN64 standard; PN250 on request
• Temperature: −40 °C to +300 °C; higher with remote indicator
• Accuracy: ±1.5% of full scale (±1% for calibrated premium units)
• Repeatability: ±0.5%
• Turndown ratio: 10:1
• Outputs: local pointer, LCD, 4–20 mA, HART, alarm contact, pulse

Where Are Metal Tube Flow Meters Used?

Metal tube rotameters dominate three duty areas where digital flow meters either cost too much or can’t cope with the fluid.

• Chemical injection and dosing. Low flow, aggressive fluids, and the need for a local visual indicator make rotameters the default on batch reactors and wastewater treatment skids.
• Utility gas and steam condensate. Where upstream straight run is short and accuracy requirements are moderate, a metal tube VA is simpler than Coriolis or thermal mass.
• Oil and lubricant supply lines. Dark fluids make glass rotameters unreadable. Magnetic coupling solves this without electronics.
• High-pressure gas cylinders and analyzers. PN64+ rating handles industrial gas distribution without bulky electronics.

How to Specify a Metal Tube Flow Meter

Get these six items right on the RFQ and you’ll receive a workable quote without back-and-forth.

1. Fluid. Name and density/viscosity. “Water” isn’t enough — brine, DI water, and boiler feed all calibrate differently.
2. Flow range. Minimum and maximum normal flow. Size for the meter’s mid-range, not the max.
3. Operating pressure and temperature. Nominal and maximum. Adds 20% margin as a default.
4. Connection type. Flanged (ANSI B16.5 or EN 1092-1) vs threaded; pipe size and rating.
5. Output and display. Local pointer only, LCD+4–20 mA, HART, alarm switches — each adds cost.
6. Orientation and mounting. Vertical is standard. Horizontal or top-mount needs a specific float design — call it out.

Common mistake on RFQs: asking for a single meter to cover 0–100 m³/h on the same spec sheet. Turndown is 10:1, so that unit will not read below 10 m³/h reliably. Either split into two meters or switch to a vortex or electromagnetic meter with 100:1 turndown.

Featured Metal Tube Rotameters

FAQ

What does LZ mean on a metal tube rotameter?

LZ is the Chinese industry naming code for metal tube variable-area flow meters. LZD is a version with damping, LZB has been superseded by LZ for glass-tube designs. Spec sheets from Chinese manufacturers will use LZ-, LZB-, LZD- prefixes interchangeably.

Does a metal tube rotameter need straight pipe upstream?

Yes — 5 pipe diameters upstream and 250 mm downstream is the standard recommendation. Turbulence pushes the float off centre and skews the reading. See the full flow meter straight length requirements.

Can a metal tube rotameter measure gas and liquid with the same unit?

No. The float is sized for the fluid’s density. A float calibrated for air won’t measure water correctly. Order separate units or ask for a dual-calibration chart if flow alternates between two known fluids.

How often does a metal tube rotameter need recalibration?

Every 2–3 years for process use. Check the float visually after any line flush — debris wedged in the annular gap causes readings to stick at specific values. Our flow meter calibration guide covers the full procedure.

What’s the minimum viscosity a metal tube rotameter can handle?

Viscosity immunity varies by float type. Standard ball floats work up to ~30 cP. For heavier lubricants and syrups, specify a viscosity-immune float (V-shape or dual-ring) which extends the range to ~300 cP.

Are metal tube rotameters ATEX certified?

Yes — most manufacturers offer ATEX Ex ia or Ex d versions for hazardous area installation. Specify the zone and gas group on the order. Standard mechanical pointer units without electronics are inherently suitable for most hazardous areas.

Ready to spec a metal tube rotameter? Send us fluid, flow range, pressure, temperature, and connection size. Our engineers reply within 24 hours with a sized unit and a price — no account needed.

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Featured Insertion Flowmeters for Sale

insertion flowmeter types

insertion flow meter wastewater

If an insertion flowmeter is to be selected for a wastewater pipeline, an insertion electromagnetic flowmeter must be the first choice.​​

The Insertion wastewater flowmeter can be widely used to measure the flow of conductive fluids in tap water, steel, petroleum, chemical industry, electric power, industry, water conservancy, water administration and water resources. It can also measure corrosive conductive liquids such as acids, alkalis, and salts.

The Insertion sewage flowmeter is mainly composed of a measuring head (or measuring tube), an excitation system, an insertion rod, a junction box, a mounting base, and a sealing and positioning mechanism.

Measuring head (or measuring tube): The measuring head (measuring tube) is located at the particle point of the measured flow velocity in the pipeline, and is used to detect the flow velocity at this point. A measuring head (or measuring tube) is a tip or conduit made of insulating material on which a pair of electrodes is mounted. Except for the electrode tip or the inner wall of the measuring tube, other parts are insulated from the fluid to be measured.

Excitation system: The function of the excitation system is to generate a working magnetic field. It consists of an excitation coil and an iron core. It is insulating sealed into the insertion rod.

Insert rod: Made of stainless steel material. The measuring head and the measuring tube are fixed in the insertion rod. The excitation lead and electrode lead are sealed with the measured medium and connected to the junction box through the insertion rod. A direction indicator is welded on the insertion rod to ensure that the working magnetic field, the flow rate and the electrode connection are perpendicular to each other during installation, which meets the requirements of Faraday’s law of electromagnetic induction.

Junction Box: The junction box is located on the top of the sensor. The terminals in the junction box connect the sensor and the converter to each other.

Mounting base: The mounting base is welded on the pipeline under test, used to connect with the mounting ball valve and insert the part of the sewage flowmeter sensor.

Sealing mechanism: It consists of a compression thread seat made of stainless steel, a compression nut, a rubber washer and a positioning screw. It is used to seal and insert the sewage sensor, so that it can avoid a certain working pressure.

insertion flow meter for air/compressed air

If you choose an insertion flowmeter for an air line, or a compressed air line. Then the insertion thermal mass flow meter can be said to be the first choice.

Because, the insertion thermal mass flow meter has obvious advantages:

• Wide range ratio 1000:1; large diameter, low flow rate, negligible pressure loss;
• Direct measurement of mass flow without temperature and pressure compensation;
• Very sensitive measurement of low flow rates;
• Easy to design and select, easy to install and use;
• Suitable for all kinds of single or mixed gas flow measurement.

If you need to measure high temperature air, or high temperature compressed air. Then another type of flow meter may need to be selected. Such as high temperature Annubar flowmeter.

Sino-Inst is Manufacturer of Insertion Flowmeters. We supply more than 20 kinds of Insertion Flow Meters. 40% insertion magnetic flowmeters, 30% insertion vortex flow meter and other types of flowmeters.

Insertion Flowmeters are mainly used for flow measurement of various liquids and gas.
It can measure even liquids such as water, seawater, oil, and slurry.

Insertion Flowmeters enable stable flow measurement without piping modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tubes.

Sino-Inst’sInsertion Flowmeters, 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 an Insertion Flowmeter, level sensor, or other device, give us a call.

Request a Quote

Featured crude oil flow meters

types of crude oil flow meters

In terms of the medium to be measured, the crude oil containing impurities needs flow measurement, and the flow measurement of the working conditions with impurities itself is a big problem. Choosing the right crude oil flow meter is even harder.

Based on years of service experience, the following 7 type flowmeters are the types of flowmeters that we believe can effectively measure the flow of crude oil.

Read more about: The Pros and Cons of Micro Motion Flow Transmitters

Summary of Crude Oil Flow Measurement Options

Flowmeters are the most commonly used instruments in oil exploration enterprises. The selection of flowmeters used in many production sites in oil fields is not reasonable, and some have installation errors, resulting in excessive measurement errors, and some cannot meet the needs of production or crude oil transfer measurement.

Many forms of flowmeters can measure crude oil, but when choosing a model based on experience and simply considering the purchase cost, you may lose the opportunity to choose the most suitable meter.

For example, the flow range of the instrument does not match the actual flow, and the instrument with high precision is selected for places with low measurement requirements.

It can be seen that the correct selection and use of flow meters is not an easy task. To choose a crude oil flowmeter correctly and efficiently. The following five factors must be considered, namely: performance requirements, physical properties of crude oil, installation requirements, environmental conditions and costs.

Read more about: Flow Meter Selection Guide

The selection of crude oil flowmeter should comprehensively consider the five factors of instrument performance, fluid characteristics, installation conditions, environmental conditions and economy.

Encounter the phenomenon that the physical properties of crude oil, especially the viscosity-temperature characteristics, are not very clear. Special units should be invited to do a complete set of crude oil tests and make a physical property report.

Consult with the flowmeter manufacturer or technical department about the adaptability of various flowmeters and the influence of physical property changes on the performance of the flowmeter. Choose a flowmeter that meets your needs.

flow measurement in oil and gas industry

Every day, a large amount of oil and gas are transported back and forth, refined, and then transported, as well as custody transfer. Difficult oil and gas flow measurement challenges such as corrosive media and harsh environments are our daily work. This requires mature and safe technology. Through instrument measurement and display monitoring, safe and reliable operation can be achieved.

Many types of flow meters are used to measure oil and gas flow. Each type has its advantages and disadvantages.

Read more content discusses these advantages and disadvantages.

More oil and gas measurement solutions

Sino-Inst is Manufacturer of Crude Oil Flow Meters. We supply more than 20 kinds of Crude Oil Flow Meters. 40% mass flowmeters,30% oval gear flow meters and other types of flowmeters.

Crude Oil Flow Meters are mainly used for flow measurement of high viscosity crude oil flow.

Crude Oil Flow Meters enable stable flow measurement without piping modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tubes.

Sino-Inst’s Crude 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 Crude Oil Flow Meter, level sensor, or other device, give us a call.

Request a Quote

Featured Non Contact Flow Meters

Types of Non Contact Flow Meters

Currently, the main Types of Non Contact Flow Meters on the market are ultrasonic flow meters and radar flow meters.

Non-contact ultrasonic flowmeters account for 90% of non-contact measurement applications. Mainly used for flow measurement of various pipeline fluids.

Non-contact radar flowmeter is suitable for non-contact flow measurement of rivers, channels, pipelines, etc.

Read more about: Shop 101: Key Factors In Selecting A Pipe Flow Meter

Strap on Flow Meter for Small Pipes Φ9.53~Φ90

Product	Strap on Flow meter
Model	X3
Flow range	0.1m/s~5.0m/s
Accuracy	±2.0%
Repeatability	0.80%
Pipe size	φ6.35~φ90
Data storage	Daily, monthly, and Annual. Flow Totalizer
Analog output	4~20mA, Maximum load: 600Ω
Alarm output	DCT, Upper and lower limit alarm function(optional)
Communication	RS485,support Modbus communication protocol
Power supply	24VDC
Cable length	2.0m
Keypad	Four light touch buttons
Screen	OLED 128*64 displayscreen
Units	Metric and imperial units are available, Cubic Meters(m3), Liters(L), USA Gallons(GAL)/hour,/min,Default unit setting:m3/h
Totalizer	Six bit digit
Piper material	Stainless steel pipe, carbon steel pipe, copper pipe, plastic pipe
Case material	Aluminum alloy
Environment temp.	0℃~50℃（32°F~122°F)
Medium temp.	0℃~50℃（32°F~122°F)
Environment humidit	0-95% relative humidity, without condensation
IP Grade	IP54

Extended Reading: Types Of Crude Oil Flow Meters

More Featured Liquid Flow Meters

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

Non Contact Liquid Measurement Solutions

Gas and Liquid Measurement Solutions

Sino-Inst is Manufacturer of Non Contact Flow Meters. We supply more than 20 kinds of Non Contact Flow Meters. 90% ultrasonic flowmeters, and other types of flowmeters.

Non Contact Flow Meters are mainly used for flow measurement of various liquids.
It can measure even liquids such as water, seawater, oil, and slurry.

Non Contact Flow Meters enable stable flow measurement without piping modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tubes. For efficient non-contact flow measurement of flexible and rigid plastic pipes.

Sino-Inst’s Non Contact 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 non-contact flow sensor, level sensor, or other device, give us a call.

Request a Quote