Category Archives: Flow Meters

A flow meter (or flow sensor) is an instrument used to measure linear, nonlinear,
mass or volumetric flow rate of a liquid or a gas.
When choosing flow meters,
one should consider such intangible factors as familiarity of plant personnel,
their experience with calibration and maintenance, spare parts availability,
and mean time between failure history, etc., at the particular plant site.
It is also recommended that the cost of the installation be computed,
only after taking these steps
The different sensors include dial, in-line, ultrasonic, orifice plate,
totalizing meters, variable area, venturi, or with switch output.
The different designs of the flow meters have a variety of applications.

What is a Flow Meter and how does it work?

Flowmeter types

Flow Metering Principals

  • Differential Pressure Flowmeters
  • Velocity Flowmeters
  • Positive Displacement Flowmeters
  • Mass Flowmeters
  • For Open Channel Flowmeters – weirs, flumes, submerged orifices, current meters, acoustic flow meters and more

For different working principle, We offer different types of flow meters, like:

Differential Pressure Flow Meters

Orifice Plate

Venturi Tube

Flow Nozzles

The Sonic Nozzle – Critical (Choked) Flow Nozzle
Calorimetric Flowmeter
Ultrasonic Doppler Flowmeter
Positive Displacement Flowmeter

Variable Area Flowmeter or Rotameter

Velocity Flowmeters

Pitot Tubes

Electromagnetic Flowmeter

Turbine Flowmeter

Vortex Flow Meter

Thermal Flowmeter

Coriolis Flowmeter

Mass Flowmeters

Open Channel Flowmeters

 

How to choose your flowmeters?

Important factors when selecting flow metering devices are

  • accuracy
  • cost
  • legal constraints
  • flow rate range
  • head loss
  • operating requirements
  • maintenance
  • lifetime

These factors are more or less related to each other. Example – the cost of flow meters increases with accuracy and lifetime quality.

Sino-Instrument offers over 50 flow meter for level measurement.
About 50% of these are differential pressure flow meters,
40% is the liquid flow sensor,
and 20% are Ultrasonic Level Transmitter and mass flow meter.
A wide variety of flow meters options are available to you,
such as free samples, paid samples.
Sino-Instrument is a globally recognized supplier and manufacturer of flow measurement instrumentation,
located in China.
Choose the right Flow Meters for your application:

Magnetic Water Flow Meter

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Magnetic Water Flow Meter is an electromagnetic flowmeter used to measure conductive fluids. Conductive liquids such as drinking water, sewage, wastewater, seawater, ammonia, cement slurry, etc.

Magnetic Water Flow Meter

Magnetic Water Flow Meter provide highly accurate flow measurement for a wide variety of conductive fluid applications. Magnetic Water Flow Meter is a volumetric flow meter that measures liquids or liquid slurries that have a minimum conductivity of 5 µS/cm. Based on Faraday’s law of electromagnetic induction. Magnetic Water Flow Meter is ideal for wastewater applications or any dirty liquid which is conductive or water based. It is widely used in water treatment, environmental protection sewage measurement and control, papermaking and other industrial and agricultural production processes for flow measurement and control.

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

Request a Quote
Magnetic Flow Meters

Features of Magnetic Water Flow Meter

  • Not affected by changes in fluid density, viscosity, temperature, pressure and conductivity. The linear measurement principle can achieve high-precision measurement;
  • There are no flow blocking parts in the measuring pipe. The pressure loss is small, and the requirements for straight pipe sections are low;
  • Nominal diameter DN6-DN3000 covers a wide range. There are many choices of lining and electrodes. It can meet the requirements of measuring a variety of conductive fluids;
  • The converter adopts programmable frequency low frequency rectangular wave excitation. It improves the stability of flow measurement and has low power loss;
  • The converter adopts 16-bit embedded microprocessor. Full digital processing, fast calculation speed. Strong anti-interference ability, reliable measurement. High accuracy, flow measurement range up to 1500:1;
  • High-definition backlit LCD display. Easy to use, simple to operate, easy to learn and understand;
  • With RS485 or RS232 digital communication signal output;
  • With conductivity measurement function, it can judge whether the sensor is empty or not. With self-check and self-diagnosis function;
  • Adopt SMD devices and surface mount (SMT) technology. High circuit reliability;
  • Can be used in corresponding explosion-proof occasions.

Guess you like: What is Reynolds number?

Specifications of Magnetic Water Flow Meter

Measuring medium:Conductive liquids
Diameter(mm)DN15~DN3000
Pressure(MPa)DN15-DN300, PN<1.6MPa; DN350-DN800, PN<1.0MPa;
above DN900, PN<0.6MPa;
Measuring tube materialCarbon steel,304 stainless steel
The sensor measures the head materialABS/Polypropylene
Electrode materialSUS316,hastelloy B,hastelloy C
Accuracyflow velocity≤0.5m/s,±1.5%,Full range velocity>1m/s,±1.0%
Medium temperature(ºC)ABS:+80ºC, Polypropylene:+80ºC
Environmental conditions-25ºC~+60ºC
relative humidity5%~95%,
Atmospheric pressure86~106kPa
Straight pipe section requirementsupstream 15D,downstream 10D
Ingress protectionIP65,Optional IP68
Connectionflange connection,threaded connection
Power supply mode:24V power supply or 220V power supply, 3.6V lithium battery power supply
Explosion-proof grade:intrinsically safe ExdⅡia CT2-T5 flameproof ExdⅡCT2-T5
Transmission distance:Two-wire 4-20mA standard current output: ≤1500m;
485 output and HART output: ≤1200m

Take a quick look: How electromagnetic flowmeters work ?

Magnetic Water Flow Meter Applications

KLD electromagnetic water flowmeter can be used to measure the volume flow of conductive fluid in a closed pipeline. It is widely applied in the flow measurement and control in the fields of chemical and petroleum industry, metallurgy industry, water and wastewater, agriculture and irrigation, paper making, food and beverage industry and pharmaceutical industry.

The premise of using Magnetic Water Flow Meter is that the measured liquid must be conductive. The conductivity of the liquid cannot be lower than the threshold, the lower limit. If the conductivity is lower than the threshold, it will cause measurement error until it can not be used.

It can be measured even if the value exceeds the threshold, and the indication error does not change much. The threshold value of general electromagnetic flowmeter is between 10-4～(5×10-6)S/cm, depending on the model. It also depends on the length of the flow signal line between the sensor and the converter and its distributed capacitance. The product manual usually stipulates the signal line length corresponding to the conductivity.

Read more about: Digital Water Flow Meters

Magnetic Water Flow Meter to Measure Waste Water

The sewage treatment process is mainly through biological oxidation, flocculation, precipitation and other processes to achieve the purpose of sewage purification. At each stage, a certain gauge is needed to measure.

In the sewage industry, according to the characteristics of the corrosiveness, abrasiveness, temperature and condensation of the tested substance and the price tolerance. Different lining and electrode materials should be selected.

In the sewage treatment process, it is necessary to configure corresponding detection instruments according to the process requirements to form a reliable control system.

Generally, sewage treatment plants are equipped with flow meters in the following process inspection procedures:

  1. Water inlet pipe.
  2. Detection of mud volume from primary settling tank to mud storage tank.
  3. Detection of surplus and sludge flow in the sludge pump room.
  4. Detection of the return sludge flow in the sludge pump room.
  5. Detection of the effluent flow of the secondary settling tank distribution well.
  6. Detection of the sludge intake of the digestion tank.
  7. Digestion tank Mud output detection. 8. Flocculation tank reagent input detection, etc.

More about: Sewage Flow Meter Selection

Magnetic Water Flow Meter to Measure Industrial Water

The conductivity of industrial water and its aqueous solution is greater than 10-4S/cm. The conductivity of acid, alkali and salt solution is between 10-4～10-1S/cm, so there is no problem in use. Low distilled water is 10-5S/cm and there is no problem.

The electromagnetic flowmeter cannot measure liquids with very low conductivity. Such as petroleum products and organic solvents. Cannot measure gas, steam and liquids containing more and larger bubbles.

It is found from the data that some pure liquids or aqueous solutions have low conductivity and are considered unusable. However, in actual work, we will encounter examples that can be used because of impurities. Such impurities are beneficial to increase conductivity.

For aqueous solutions, the conductivity in the data is measured in the laboratory with pure water ratio. The actual aqueous solution may be proportioned with industrial water. The conductivity will be higher than found, which is also conducive to flow measurement.

Extended reading: Industrial VS Residential inline water flow meters

Magnetic Flow Meter Price

Electromagnetic flowmeter selection table
KLD               SENSOR
Nominal
diameter		 15             DN15 0.19-3.18m³/h
…             … Unit:mm
3000             DN3000 
Pressure rating 6           0.6Mpa
10           1.0Mpa
16           1.6Mpa
40           4.0Mpa
…           Special requirements
160           16.0Mpa
Connection mode F         Flange
I         plug-in
C         Sanitary type-clamping connection
ST         Sanitary-thread connection
Lining material 1       Polytetrafluoroethylene(PTEE)
2       Polychloroprene
3       Polyurethane rubber
4       F46
5       Fluorosilicone gum
6       PFA
Electrode material Y     One body
F     Separate type
L     Separate type/immersion
Structure of flowmeter 1   SUS316L
2   Hastelloy b 2B
3   Hastelloy b 2C
4   Titanium
5   Tantalum
6   Platinum iridium alloy
7   Stainless steel coated tungsten carbide
Output signal P Volume flow4-20mA/pulse
B Volume flow4-20mA/RS232
M Volume flow4-20mA/RS485
H Volume flow HART protocal output

Extended Reading: LORA water meter

Main performance of lining material:

Lining materialMain performanceScope of application
Polytetrafluoroethylene (PTFE)1. A material with relatively stable chemical properties in plastics can withstand boiling hydrochloric acid, sulfuric acid and aqua regia, but also resistant to concentrated alkalis and various organic solvents, and is not resistant to chlorine trifluoride, high-flow liquid fluorine, liquid oxygen, and ozone. corrosion.
2. Poor wear resistance		Strong corrosive media
such as concentrated acid and alkali
PFACorrosion resistance is the same as PTFE, strong resistance to negative pressureCan be used in negative pressure state
F461. Corrosion resistance is the same as PTFE 2. Low abrasion resistance 3. Strong negative pressure resistance1. Same as PTFD
2. Can be used for low-wear media
Neoprene1. Excellent elasticity, high breaking force, good wear resistance
2. Resistant to the corrosion of a certain low concentration of acid, alkali, and salt media, and not resistant to the corrosion of oxidizing media		Water, sewage, ore slurry, weak abrasive mud
Polyurethane1. Excellent abrasion resistance (equivalent to 10 times of natural rubber)
2. Poor acid and alkali resistance
3. Cannot be used for water mixed with organic solvents		Neutral and strong abrasion slurry, coal slurry, mud, etc.

Corrosion resistance of electrode material:

Electrode materialCorrosion resistance
SUS316Used for industrial water, domestic water, and weak alkali corrosive media,
Widely used in petroleum, chemical, urea, vinylon and other industries
Stainless steel coated tungsten carbideFor non-corrosive, strong abrasive media
Hastelloy B (HB)It has good corrosion resistance to all concentrations of hydrochloric acid below the boiling point, and it is also resistant to sulfuric acid, phosphoric acid, hydrofluoric acid, organic acids, etc.
Corrosion of oxidizing acid, alkali, and non-oxidizing salt solution
Hastelloy C (HC)It is resistant to oxidizing acids, oxidizing salts or other oxidizing agents.
Titanium (Ti)It is resistant to corrosion by sea water, various chlorides and hypochlorites, oxidizing acids, organic acids, alkalis, etc., but not resistant to corrosion by purer reducing acids. But if the acid contains an oxidant, the corrosion is greatly reduced
Tantalum (ta)It has excellent corrosion resistance, which is very similar to glass, except for hydrofluoric acid, fuming sulfuric acid and alkali, it can withstand the corrosion of almost all chemical media.
Platinum-iridium alloyAlmost suitable for all chemical substances, but not suitable for aqua regia and ammonium salt.

Extended Reading: 3 inch (3″) Water Flow Meter

The price of electromagnetic flowmeter is determined by the selection of electromagnetic flowmeter. The Magnetic Water Flow Meter reference price is USD550.00-3000.

The key questions which need to be answered before selecting a magnetic flow meter are:

  • Is the fluid conductive or water based?
  • Is the fluid or slurry abrasive?
  • Do you require an integral display or remote display?
  • Do you require an analog output?
  • What are the minimum and maximum flow rate for the flow meter?
  • What are the minimum and maximum process pressure?
  • What are the minimum and maximum process temperature?
  • Is the fluid chemically compatible with the flow meter wetted parts?
  • What is the size of the pipe?
  • Is the pipe always full?

How much is a 2 inch water flow meter? Let’s find out.

If you have question about Magnetic flow meter,

Please contact us, our engineer will offer help.

Extended Reading: Guide: Magnetic Flowmeter Installation

Featured Water Flow Meters

Remote Magnetic Sewage Flow Meter
Insertion Magnetic Flow Meter
Magnetic Sanitary Flow Meter
Handheld Ultrasonic Flow Meter
Ultrasonic Clamp on Flow Meter
Ultrasonic Insertion Flow Meter
Liquid Turbine Flow Meter
Turbine Insertion Flow Meter

Extended reading: Sludge flow meter for sewage treatment return activated sludge system

Sino-Inst offers over 50 magnetic water flow meter for flow measurement. About 50% of these are wastewater flow meters, 40% is the liquid flow sensor. And 20% are Ultrasonic Flow Transmitter and mass flow meter.

A wide variety of flow meters options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.

Request a Quote

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SI-LG Orifice Plate Flow Meter

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Orifice plate flow meter also called orifice flow meter or orifice plate. Orifice plate flow meter is a kind of differential pressure flow meter.

Orifice plate flow meter works together with an orifice plate, differential pressure transmitter, with Differential Pressure Measurement principle. Easy installation. Orifice plate flow meters can be used with gases, liquids, corrosive, and high temperature fluids. Orifice flow meters can measure steam, gas, liquids, and many industrial areas. Applications include steam flow, boiler feedwater, and fluid flow rates in building water lines.

Sino-Inst, Manufacturer for differential pressure flow meters. Including the Orifice plate, Venturi, Annubar, etc. Suitable for liquid, gas, and steam flow measurement. Please contact our sales engineers for technical support!

Get a Quote DP Flowmeters

Features of Orifice Plate Flow Meter

  • The structure of the throttling device is easy to copy, simple, firm, stable and reliable in performance, long in service life, and low in price.
  • Orifice flowmeter calculation adopts international standards and processing
  • Wide application range, all single-phase flows can be measured, and some mixed-phase flows can also be applied.
  • The standard throttling device can be put into use without real flow calibration.
  • The integrated orifice plate is simpler to install, no pressure pipe is needed, and it can be directly connected to a differential pressure transmitter and a pressure transmitter.
  • It has a wide range of applications, including all single-phase fluids (liquid, gas, steam) and partial mixed-phase flows. The pipe diameter and working conditions (temperature, pressure) of the general production process can be measured;

Orifice Plate Flow Meter Specification

SI-LG integrated orifice flowmeter is a high-range ratio differential pressure flow device. Composed of standard orifice plate and multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter and pressure transmitter).

It can measure the flow of gas, steam, liquid and natural gas, and is widely used in process control and measurement in petroleum, chemical, metallurgy, electric power, heating, water supply, and other fields.

Execution standardDesign, manufacture, and installation in accordance with international standard ISO5167-1(1991)(national standard GB/T2624-93),
British standard BS1042 and other standards
Precision level(1)Standard orifice plate, standard nozzle: there are many factors that affect the measurement error.
If the installation and use meet the relevant provisions of international standard ISO5167-1 (1991), the accuracy level can generally reach level 1 ~1.5.

(2) For non-standard orifice plates (such as double orifice plates, circular missing orifice plates, small orifice plates, etc.).
Due to insufficient test data, there is no “standard” to check, so calibration should be conducted after the design and manufacture is completed. (liquid flow is usually calibrated with water. And the air calibrates the gas flow.
The level of accuracy (basic error) can be achieved after calibration: level 1 ~1.5, if not calibrated.
Only by empirical data calculation, design, accuracy in ±2.5%.
Diameter(mm)25,40,50,65,80,100,125,300,350,400, 450,500,600,700,800,900,1000,1200
Nominal working pressure(MPa)0.6,1.0,1.6,2.5,4.0,6.3,10.0,16.0, ≤40Mpa.
(when ≥20Mpa ,it can use high pressure lens orifice plate or welding type)
Conditions of useThe environment temperature:-30ºC~60ºC
Medium temperature:-30ºC~550ºC
Working power supply24VDC/220VAC
Singal remote output4~20mA
Communication outputRS485 communication(Modbus-RTU);
Hart protocol
Signal interfaceInternal thread M20*1.5
(NPT1/2 needs to be customized, long delivery time)
Protection levelIP65 (customized  IP68 for basic model)
Explosion-proof levelExdIICT6 GB
DisplayDifferential pressure, instantaneous flow, cumulative flow

Orifice Plate Types

Sino-Inst supplies all kinds of the orifice plate, for differential applications.

SQUARE EDGE (STANDARD) BORE

For the common square edge concentric bore orifice, the bore and bevel is the standard method of limiting the plate edge thickness.

Unless otherwise specified, plates will be beveled to the currently accepted standards.

QUADRANT EDGE BORE

The quadrant edge bore is an orifice with the inlet edge rounded. Instead of beveling, the plate is counterbored to the desired edge thickness.

The radius of the quarter circle bore is a function of the orifice-to-pipe ratio (d/D). Thickness at the throat is equal to the radius.

This bore is specifically designed for viscous fluids such as heavy crudes, syrups, and slurries with Reynolds Numbers below 100,000.

ECCENTRIC BORE

Eccentrically bored orifice plates are plates, with the orifice off-center, or eccentric, as opposed to concentric.

The bore of the eccentric orifice normally is inscribed in a circle, which is 98% of the pipe diameter, so that solids or slurries may pass through.

Eccentric orifice plates are used in many industries, including heavy and light chemicals, steel, paper, nuclear and petrochemicals.

SEGMENTAL BORE

Segmentally bored orifice plates are provided for measurement, where solids are entrained in a gas or liquid flow stream.

The circular portion of the bore is inscribed within a circle, which is normally 98% of the pipe diameter.

The segmental opening may be placed either at the top or bottom of the pipe.

Industries using these bores include sewage treatment, steel, chemical, water conditioning, paper, and petrochemical.

RTJ Type Orifice Plates

The RTJ type orifice plate incorporates an integral gasket, either oval or octagonal ring, for mounting between ring type joint flanges.

It is based on proven technology, has no moving parts and is suitable for high temperature and pressure applications.

RTJ type orifice plates can be supplied complete with ANSI B16.36 orifice flanges.

Extended reading: Integral DP Flow Meter|Gas, liquid, steam|Compact structure

Orifice plates are recommended for clean liquids, gases, and low-velocity stream flows.

Plate thicknesses depend on line size and differential pressure and should be sufficient, to prevent the plate from bending under operating conditions. Orifice plates can be made in accordance with customer drawings as required.

If you still have questions about orifice plate flow meters, Just contact us. Our engineers will offer help.

Advantages of Orifice Plate Flow Meter

  • The Orifice meter is very cheap as compared to other types of flow meters.
  • Less space is required to Install and hence ideal for space-constrained applications
  • The operational response can be designed with perfection.
  • Installation direction possibilities: Vertical / Horizontal / Inclined.

Orifice Flow Meter Applications

  • Natural Gas
  • Water Treatment Plants
  • Oil Filtration Plants
  • Petrochemicals and Refineries
Orifice Plate
Orifice flow meter diagram
orifice flow meter diagram

Of course, in the water supply or wastewater treatment industry, in addition to orifice flowmeters, electromagnetic flowmeters are also the first consideration for many users in the measurement of water flow.
For example, if you need to measure the flow of wastewater in a 2-inch pipe. Then you may refer to: Magnetic Flow Meters Guides.

How much is a 2 inch water flow meter? Let’s find out.

Orifice Plate Flow Meter Installation


Orifice plate installation

Orifice plate installation

1. Meter manifold piping should always be installed to enable calibration as well as to protect the differential element against overage.

2. The meter should be installed as close as possible to the orifice fitting.

3. Always slope the manifold lines gently from the orifice fitting to the meter to eliminate any high or low points in the manifold lines.

4. Use condensate chambers or air traps to remove either liquid from a gas system or gas from a liquid system if lows or highs in the manifold piping cannot be avoided.

It is important when pressurizing or depressurizing differential measuring devices to apply or release pressure to or from the high and low meter chambers uniformly, so as not to impose excessive overage.

What is an Orifice Meter?

An orifice meter is a conduit and a restriction to create a pressure drop.

An hourglass is a form of the orifice.

A nozzle, venturi or thin sharp-edged orifice can be used as the flow restriction.

In order to use any of these devices for measurement, it is necessary to empirically calibrate them.

That is, pass a known volume through the meter and note the reading in order to provide a standard for measuring other quantities.

Due to the ease of duplicating and the simple construction, the thin sharp-edged orifice has been adopted as a standard and extensive calibration work has been done, so that it is widely accepted as a standard means of measuring fluids.

Provided the standard mechanics of construction are followed no further calibration is required.

The minimum cross-sectional area of the jet is known as the “vena contract”.

How does an orifice flow meter work?

I guess most people wondered: What is the working principle of orifice meter?

As the fluid approaches the orifice the pressure increases slightly and then drops suddenly as the orifice is passed.

It continues to drop until the “vena contract” is reached, and then gradually increases, until at approximately 5 to 8 diameters downstream, a maximum pressure point is reached, that will be lower than the pressure upstream of the orifice.

The decrease in pressure as the fluid passes thru the orifice, is a result of the increased velocity of the gas passing thru the reduced area of the orifice.

When the velocity decreases as the fluid leaves the orifice the pressure increases, and tends to return to its original level (To level transmitters).

All the pressure loss is not recovered because of friction, and turbulence losses in the stream.

The pressure drop across the orifice increases when the rate of flow increases.

When there is no flow there is no differential.

The differential pressure is proportional to the square of the velocity, it thus follows that if all other factors remain constant, then the differential is proportional to the square of the rate of flow.

Video source: https://www.youtube.com/embed/oUd4WxjoHKY?rel=0

Equations used in this orifice plate Calculator

Qv = 218.527*Cd*Ev*Y1*(d2 )*[Tb/Pb]*[(Pf1*Zb*hw)/(Gr*Zf1*Tf)]0.5 (3-6)

Where

Cd = Orifice plate coefficient of discharge

d = Orifice plate bore diameter calculated at flowing temperature (Tf) – in.

Gr = Real gas relative density (specify gravity)

hw = Orifice differential pressure in inches of water at 60 degF

Ev = Velocity of approach factor

Pb = Base pressure – psia

Pf1 = Flowing pressure (upstream tap – psia

Qv = Standard volume flow rate – SCF/hr.

Tb = Base temperature – degR

Tf = Flowing temperature – degR

Y2 = Expansion factor (downstream tap)

Zb = Compressibility at base conditions (Pb,Tb)

Zf1 = Compressibility (upstream flowing conditions – Pf1, Tf)

Orifice Plate Flow Meter Calculation

Converters for conversion and calculation of flow. Or a calculation tool that requires flow measurement to obtain other measurement parameters. Help users choose the right flow sensor and transmitter!

DP Flow Meter Output CalculatorFlow Meter 4-20mA Current Output CalculatorFlow Velocity & Pipe Diameter to Volumetric Flow Rate Calculator
Mass Flow & Density to Volume Flow CalculatorMass Flow Rate Unit ConverterVolume Flow Rate Converter
Volume Flow & Density to Mass Flow CalculatorVolumetric Flow Rate & Pipe Diameter to Flow Speed Calculator

Venturi Flow Meter

Venturi flow meter is also called classical venturi, and is used to call venturi meter, standard venturi. It is used to measure the flow of single-phase stable fluid in closed pipelines.

Venturi flow meter is a flow measurement method based on the principle of differential pressure. Commonly used to measure the flow of fluids such as air, natural gas, coal gas, and water. In the standard throttling device, the upstream and downstream straight pipe sections required by it are short. The lasting pressure loss is small, the performance is stable, and the maintenance is convenient.

What is the difference between Venturimeter and orifice meter?

The difference between venturi flowmeter and orifice flowmeter:

Orifice flow meters and Venturi flow meters are very different in many aspects.

In order to reduce the loss of the kinetic energy of the fluid mechanics flowing through the saving components, the Venturi flowmeter uses each section of tapered and divergent tubes to replace the orifice.

The orifice flowmeter is equipped with an interchangeable orifice plate with a small circular hole on the upper side, which is much smaller than the diameter of the pipe. The orifice plate is placed on the side of the fluid mechanics pipe.

More about: Venturi Tube Flowmeter

1.The orifice flowmeter is similar to the Venturi flowmeter in the working principle. But some of the main differences are: the orifice plate can be easily replaced to accommodate a wide range of different flow rates.

The throat diameter of the venturi is fixed, so that the measured flow rate range is limited by the actual pressure difference.

Due to the vortex on the downstream side of the orifice, the permanent loss of the orifice flowmeter is very large.

The structure and shape of the Venturi flowmeter can avoid the formation of vortices, which can greatly reduce permanent losses.

2.The energy loss of Venturi flowmeter in measuring flow is much smaller than that of orifice flowmeter.
However, because the venturi flowmeter is more time-consuming in manufacturing and processing than the orifice flowmeter, and the price is high, the orifice flowmeter has the least trouble and the lowest cost during pipeline installation.

3.In terms of fluid measurement, Venturi flowmeters are generally used for low-velocity gas flow measurement.

The flow coefficient of the orifice plate in the orifice flowmeter is significantly affected by the fluid disturbance, and this disturbance comes from the influence of the valves, elbows and other pipe fittings installed upstream of the orifice plate. The value of its discharge coefficient is less affected by downstream disturbances. Generally, this kind of flowmeter should be installed at a distance of 50 times and 10 times the pipe diameter from the upstream and downstream disturbance components, respectively. Obviously the required distance is related to the nature of the disturbance.

Therefore, when measuring with an orifice flowmeter, the orifice flowmeter must be installed correctly according to the disturbance of the fluid.

The above is a detailed introduction to the question of “What is the difference between a venturi flowmeter and an orifice flowmeter”, I hope to help everyone.
If you have any other questions about this issue, please click Online Consultation and consult online customer service.

Extended reading:  Flow Nozzle for Steam Flow Measurement

Orifice flow meter

Frequently
Asked
Questions

Help Center

Orifice Meter is a liquid and gas flow measuring instrument. It is mainly used in high temperature and high pressure measurement conditions. Orifice Meter has the characteristics of high temperature resistance, the temperature can reach 700 degrees, and the pressure is 30MPa. In the field of high temperature and high pressure measurement, Orifice Meter is Use more differential pressure flowmeters.

What is the calibration accuracy of the orifice flowmeter?
The orifice flowmeter is a flow measuring instrument. The accuracy of the orifice flowmeter is within the range of ±0.5% to 1.5%. The orifice flowmeter has the characteristics of high temperature and high pressure. It is mainly used to measure steam and hot air. , Measurement conditions of heat transfer oil.

DPT meter is also a differential pressure transmitter.

DP transmitters are Differential Pressure Transmitters. DP transmitter measures the pressure difference between the gas or liquid at both ends of the transmitter. Output 4~20mA, 0~5V. Used for liquid level, density and pressure of liquid, gas and steam.

DP transmitters are different from pressure transmitters as they have 2 pressure interfaces. With flanges, capillaries, valve, brackets, throttle devices. Differential pressure transmitters are used to measure the level, density, and flow of liquids, gases, and vapors. Then convert it into 4–20mADC current signal output.

More Featured Products

Magnetic Water Flow Meter
Remote Magnetic Sewage Flow Meter
Insertion Magnetic Flow Meter
Magnetic Sanitary Flow Meter
Gas Turbine Flow Meter
Liquid Turbine Flow Meter
Turbine Insertion Flow Meter
Turbine Pulse Flow Meter

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Sino-Inst offers 12 orifice plate flow meter products. About 90% of these are flow meters.

A wide variety of orifice flow meter options are available to you, such as brass, carbon steel. You can also choose from free samples.

Sino-Inst is an orifice plate flow meter supplier. Orifice plate flow meter products are most popular in Domestic Market, Southeast Asia, and Mid East.

You can ensure product safety by selecting from certified suppliers, including 375 with ISO9001, ISO14001, and Other certification.

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Gas Thermal Mass Flow Meter

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What is a Thermal Mass Flow Meter?

Thermal Mass Flow Meter, also called calorimetric flow meter, is an instrument that measures gas flow based on the principle of thermal diffusion. When the fluid passes through a pipe heated by a heat source, the temperature field will change. The thermal mass flow meter uses this The fluid flow rate is measured based on the change or the relationship between the energy required to increase the fluid temperature and the fluid mass. Generally used to measure the mass flow of gas. It is widely used in many industrial fields.

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Figure 1. Simplified thermal gas mass flow meter-suitable for pipe diameters above DN80 and below DN500
Figure 2. Full-tube thermal gas mass flowmeter-suitable for pipe diameters above DN15 and below DN80
Figure-3.-Standard thermal gas mass flow meter (special models need to be customized)-suitable for pipe diameters above DN80 and below DN4000
Figure 4. Flange plug-in gas mass flow meter
Figure-5.-Simplified-split-display-gas-mass-flow-meter
Figure-6.-Flange-mounted-gas-mass-flowmeter

Thermal mass flow meter specification

DescriptionSpecifications
Measuring MediumVarious gases (Except the acetylene)
Pipe SizeDN10～DN4000mm
Velocity0.1～100 Nm/s
Accuracy±1～2.5%
Working TemperatureSensor: -40℃～+220℃
Transmitter: -20℃～+45℃
Working PressureInsertion Sensor: medium pressure≤ 1.6MPa
Flanged Sensor: medium pressure≤ 1.6MPa
Special pressure please contact us
Power SupplyCompact type: 24VDC or 220VAC, Power consumption ≤18W
Remote type: 220VAC, Power consumption ≤19W
Response Time1s
Output4-20mA (optoelectronic isolation, maximum load 500Ω), Pulse,
RS485 (optoelectronic isolation) and HART
Alarm Output1-2 line Relay, Normally Open state, 10A/220V/AC or 5A/30V/DC
Sensor TypeStandard Insertion, Hot-tapped Insertion and Flanged
ConstructionCompact and Remote
Pipe MaterialCarbon steel, stainless steel, plastic, etc
Display4 lines LCD
Mass flow, Volume flow in standard condition, Flow totalizer, Date and Time, Working time, and Velocity, etc.
Protection ClassIP65
Sensor Housing
Material		Stainless steel (316)

Thermal mass flow meter advantages and disadvantages

Pros

  1. No need for temperature and pressure compensation for gas flow measurement. Convenient and accurate measurement;
  2. Wide range ratio, can be used for gas leak detection;
  3. Measuring flow rate range: 0.1Nm/s～100Nm/s.
  4. Good seismic performance and long service life, free from the influence of vibration on measurement accuracy;
  5. Overall digital circuit measurement, accurate measurement and convenient maintenance;
  6. Using RS-485 communication, factory automation and integration can be realized. click for inqueries
  7. No pressure loss, suitable for pipes of any shape with known cross-sectional area.
  8. Corrosion-resistant sensor, suitable for measuring corrosive gas.
  9. It is especially suitable for large-caliber measurement to ensure the accuracy of measurement and is suitable for trade settlement.
  10. The amount of construction is very small. Due to the plug-in structure, it can be installed and maintained online.
  11. The base-type instrument can display on-site and control with alarm.

Cons

  1. The thermal mass flow meter responds slowly.
  2. Places where the measured gas composition changes greatly. Due to changes in the cp value and thermal conductivity, the measured value will vary greatly and cause errors.
  3. For small flow, the meter will bring considerable heat to the gas to be measured. 　
  4. For thermally distributed thermal gas mass flow meters, if the measured gas deposits a scale layer on the pipe wall, the measured value will be affected. Must be cleaned regularly. The thin tube type instrument has the disadvantage of being easy to be blocked, and it cannot be used under normal circumstances.
  5. The use of pulsating flow will be restricted.
  6. Thermal mass flow meters for liquids are also restricted in the use of viscous liquids.

Thermal mass flow meter applications

The thermal measuring principle is widespread in the industry, and is being used successfully in many applications with gas flow, for example:

  1. Gas flow measurement in steel plants and coking plants;
  2. Boiler air flow, measure secondary air volume;
  3. Measurement of flue gas flow from chimney;
  4. Measurement of waterfall gas flow in water treatment;
  5. Gas flow measurement during the production process of cement, cigarette and glass factories;
  6. Compressed air flow measurement;
  7. Gas flow measurement of natural gas, coal gas, liquefied gas, torch gas, hydrogen and other gases.
  8. Carbon dioxide (for beverage production and chilling)
  9. Argon (in steel production)
  10. Nitrogen and oxygen (production)
  11. Natural gas (for burners and boiler feed control)
  12. Air and biogas measurement (e.g. in wastewater plants)
Applications of Thermal Mass Flow Meter

Thermal mass flow meter for liquids

Generally, Thermal mass flow meters produced in China are used to measure gas mass flow.

If you need to measure liquid mass flow. Please contact our sales engineer. We will provide you with detailed product recommendations.

Thermal mass flow meter installation

insertion mass flow meter:

  1. Position determination: Keep away from elbows, solenoid valves, and other parts to ensure a stable flow field;
  2. Welding of the welding base: drill a Φ22 round hole in the pipe, and weld the welding base;
  3. Install the instrument: put the locking head into the probe rod during installation, and tighten it with a wrench after confirming the insertion depth;
  4. It is recommended that the user adopt a continuous flow ball valve when selecting the model, which is easy to disassemble. Especially in the medium place that is harmful to the human body.
  5. In the caliber smaller than DN300, the insertion depth is 1/2D+15mm. In the DN300-DN1000 caliber, the insertion depth is 1/4D+15mm. Above DN1000, the insertion depth is 1/8D+15mm.

Pipe inline thermal mass flow meter:

  • Can be installed horizontally and vertically.
  • When installing, first weld the special flange to the front and rear straight pipe sections.
  • Then clamp the front and rear straight pipe sections, gaskets, and instruments with stud bolts and connect them into one.
  • Then install this component on the pipeline. When installing, pay attention to the direction marked on the instrument should be consistent with the direction of the fluid.

Note:

(1) The integrated plug-in type should be inserted into the axis of the pipeline to be tested, so the length of the measuring rod depends on the diameter of the measuring pipe. It should be stated when ordering. If it cannot be inserted into the axis of the pipeline, the manufacturer will provide calibration coefficients to complete accurate measurement.

(2) The one-piece full-tube type adopts the national standard GB/T9119-2000 and is produced in accordance with the GB/T9119-2000 standard. (Other standards will be implemented after consultation and confirmation with the manufacturer.)

Thermal Gas Mass Flow Meter PDFDownload

This measuring principle is based on the fact that heat is drawn from a heated body when a fluid flows past.

The thermal mass flow meter is a flow meter based on the principle of thermal diffusion.

That is when the fluid flows through the object, the amount of heat loss of the heat-generating object is proportional to the flow rate of the fluid.

SI-RSL Thermal mass flowmeters

Specifically, the flowmeter sensor has two standard RTDs. One for the heat source and one for measuring the temperature of the fluid.

When the fluid passes, the temperature difference between the two is nonlinear with the flow rate.

The meter can convert this relationship into a linear output, that measures the flow signal.

There are two design methods for the flowmeter manufactured, by the principle of thermal diffusion: one is based on the principle of constant temperature difference. The other is based on the principle of constant power.

Based on a common data model:

P / ▷ T = A + B (Q) N.

Among them:

P—dissipated power,

▷T—the temperature difference between the two sensors,

Q—mass flow,

N—exponential coefficient,

A, B is the coefficient related to the thermal performance of the gas.

The principle of constant temperature difference:

▷T remains unchanged, and the dissipated power P and the flow rate Q of the fluid are exponentially increasing.

Constant power principle:

The dissipated power is constant, and the temperature difference ▷T is in a decreasing relationship with the flow rate Q of the fluid.

Know more about How Thermal Mass Flow Meter Technology Works?

Video source: https://www.youtube.com/watch?v=YfQSf2NBGqc

Thermal meters require a fully developed flow profile as a prerequisite for correct flow measurement. For this reason, please note the following points when installing the device.

  • Observe the recommended inlet and outlet requirements.
  • Good engineering practice is necessary for the associated pipe work and installation.
  • Ensure correct alignment and orientation of the sensor.
  • Take measures to reduce or avoid condensation (e.g. install a condensation trap, thermal insulation, etc.).
  • The maximum permitted ambient temperatures and the medium temperature range must be observed.
  • Install the transmitter in a shaded location or use a protective sun shield.
  • For mechanical reasons, and in order to protect the pipe, it is advisable to support heavy sensors.
  • No installation in where large vibration exists.
  • No exposure in the environment containing a lot of corrosive gas.
  • No sharing power supply with frequency converter, electric welding machine and other machines which can make power-line interference. If necessary, please add power conditioner for transmitter power supply

The minimum recommendations for inlet and outlet runs (without flow conditioner) are:

Flanged sensor

1 = Reduction, 2 = Expansion, 3 = 90° elbow or T-piece, 4 = 2 × 90° elbow, 5 = 2 × 90° elbow (3-dimensional), 6 = Control valve.

Insertion sensor

1 = Reduction, 2 = Expansion, 3 = 90° elbow or T-piece, 4 = 2 × 90° elbow, 5 = 2 × 90° elbow (3-dimensional), 6 = Control valve or pressure regulator.

A specially designed perforated plate flow conditioner can be installed if it is not possible to observe the inlet runs required.

Extended reading: Gas mass flow controller working principle

Thermal mass flow meter and Coriolis flow meter are both flow meters used to measure fluid mass flow rate.

The thermal type can only be used in gases. It uses the different heat conduction and absorption capabilities of various gases to measure the heat transfer or heat energy loss from heating to induction to correspond to the flow rate.

Thermal Mass Flowmeters (Thermal Mass Flowmeters, TMF for short) are used to measure thermal flow meters in China. The fluid mass flow is measured by the temperature field change generated when the fluid flows through the pipe heated by the external heat source. Or a flow meter that uses the relationship between the energy required to increase the temperature of the fluid and the mass of the fluid when the fluid is heated to a certain value to measure the mass flow of the fluid. Generally used to measure the mass flow of gas.

Thermal Mass Flowmeters have the characteristics of low pressure loss; large flow range; high precision, high repeatability and high reliability; no moving parts and can be used for extremely low gas flow monitoring and control. Utilizes the heat (or temperature) of the heated fluid Changing the mass flow of fluids has a long history.

Read more about: Applications Of Digital Gas Mass Flow Meters

The usual mass flowmeter refers to Coriolis flowmeter. Use the Coriolis principle (the interference of the earth’s rotation on the curved material) to directly measure the mass of fluid flowing through. Can measure gas and liquid.

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.

As mentioned earlier, the flow measurement values ​​of commonly used flow meters, such as orifice flow meters, turbine flow meters, vortex flow meters, electromagnetic flow meters, rotameters, ultrasonic flow meters, and oval gear flow meters, are fluid. Volume flow.

Extended reading: Fuel Flow Meter for Boat-Selection & Application

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FAQ

A thermal mass flow meter measures the flow of gas or liquid using heat. Think of it like this: it heats up a small part of the fluid and then checks how quickly the heat moves. Faster heat movement means more fluid is flowing.

Thermal mass flow meters are usually very accurate. They can give readings that are close to the actual flow. But, just like any tool, they can sometimes be a little off. It’s always good to make sure they’re set up right for the best results.

No, they’re not the same. A vortex flow meter measures how swirls or “vortices” are made when fluid flows past an object. A thermal mass flow meter, on the other hand, uses heat. So, they work in different ways. Read more about: vortex flow meter straight run requirement.

There are many good thermal mass flow meters out there. The best one depends on what you need it for. It’s a good idea to talk to someone who knows a lot about them or read reviews before buying one.

Sino-Inst offer over 10 Thermal Mass Flow Meters, with Best Price.

A wide variety of Thermal Mass Flow Meters options are available to you, such as free samples, paid samples. All of our flow meters can work with the AMS NEW TREX. About 13% of these are magnetic flow meter. 14% are Insertion Magnetic Flow Meter. 25% are Venturi flow meter. 13% are Handheld ultrasonic flow meter, and others are Liquid Turbine Flow Meters.

Sino-Inst is Thermal Mass Flow Meter supplier and Manufacturer, located in China. Mass flow meter products are most popular in North America, Mid East, and Eastern Europe.

The United States, and India, which export 99%, 1%, and 1% of Thermal Mass Flow Meter respectively.

You can ensure product safety by selecting from a certified supplier, with ISO9001, ISO14001 certification.

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