Thermal Mass Flow Meter
Thermal Mass Flow Meter
Thermal Mass Flow Meter
Thermal Mass Flow Meter

Thermal Mass Flow Meter

Measuring Medium: Various of Gas (Except acetylene)
Pipe Size: (Insert connection) DN50-DN2000mm ,In-line connection(DN10-DN2000mm)
Velocity: 0.1-100Nm/s
Accuracy: +/-1~2.5%
Working Temperature: Sensor:-40~+220 degC Transmitter:-20~+45 degC
Technical Data
Flange thermal gas mass flow meter is one of kind mass flow meter which
Is popular in industrial applications is the way they are designed and built. The feature is no moving parts, nearly unobstructed straight through flow path, require no temperature or pressure corrections and retain accuracy over a wide range of flow rates. Straight pipe runs can be reduced by using dual-plate flow conditioning elements and installation is very simple with minimal pipe intrusions.
Flange thermal gas mass flow meter size from DN10~DN2000mm
Flange thermal gas mass flow meter advantanges :
(1)Wide range ratio 1000:1;
(2)Large diameter, low flow rate, negligible pressure loss;
(3)Direct mass flow measurement without temperature and pressure compensation;
(4)Very sensitive for low flow rate measurement;
(5)Easy to design and select, easy to install and use;
(6)Suitable for all kinds of single or mixed gas flow measurement Could measure gas with flow velocity from 100Nm/s to 0.1Nm/s, which can be used for gas leak detection;
(7) The sensor has no moving parts and pressure sensing parts, and is not affected by vibration on the measurement accuracy. It has good seismic performance and high measurement reliability;
(8) No pressure loss or very small pressure loss.
(9) When measuring the gas flow, it is often expressed in the volume flow unit under the standard state, and the medium temperature/pressure change hardly affects the measured value. If the density is constant in the standard state (that is, the composition is unchanged), it is similar to a mass flow meter;
(10) Support multiple communication methods, such as RS485 communication, MODBUS protocol, etc., which can realize factory automation and integration
Flange thermal gas mass flow meter application:
Thermal gas air flow meter widely use for Electric power, Petrochemical industry, Glass, Ceramics and Building materials industry, and mainly be used to meausre Dry gas, such as Air, Natural gas, LPG gas, Biogas, ect. But thermal gas mass flow couldn'd be used to measure Vapour, Humidity gas and Ethyne.
Electric Power
Electric Power
Building Materials
Building Materials
Meausre Dry Gas
Meausre Dry Gas
Technical Data

Table 1: Flange Thermal Gas Mass Flow Meter Parameter

Measuring Medium  Various of Gas (Except acetylene)
Pipe Size  (Insert connection) DN50-DN2000mm ,In-line connection(DN10-DN2000mm)
Velocity  0.1-100Nm/s
Accuracy  +/-1~2.5%
Working Temperature  Sensor:-40~+220 degC  Transmitter:-20~+45 degC
Working Pressure

 Insertion Sensor:medium pressure ≤1.6Mpa

 Flanged Sensor:medium pressure ≤4.0Mpa

 Special pressure please double check

Power Supply

 Compact type: 24VDC or 220VAC, Power consumption ≤18W

 Remote type:220VAC,Power consumption ≤19W

Response Time  1s
Output  4-20mA(optoelectronic isolation,maximum load 500Ω),Pulse RS485(optoelectronic   isolation) and HART
Alarm Output  1-2 line Relay, Normally Open state, 10A/220V/AC or 5A/30V/DC
Sensor Type  Standard Insertion, Hot-tapped Insertion and Flanged
Construction  Compact and Remote
Pipe Material  Carbon Steel, Stainless Steel,Plastic etc.
Display  4 lines LCD Mass flow, Volume flow in standard condition, Flow totalizer, Date and   Time, Working time, and Velocity, etc.


Table 2: Flange Thermal Gas Mass Flow Meter Sizing

Nominal Diameter Flange outer diameter Center hole Bolt hole Screw Threads Sealing face Flange thickness Installation length
DN D k n x L d f C L
15 95 65 4x14 M12 46 2 14 280
20 105 75 4x14 M12 56 2 16 280
25 115 85 4x14 M12 65 2 16 280
32 140 100 4x18 M16 76 2 18 350
40 150 110 4x18 M16 84 2 18 350
50 165 125 4x18 M16 99 2 20 350
65 185 145 4x18 M16 118 2 20 400
80 200 160 8x18 M16 132 2 20 400
100 220 180 8x18 M16 156 2 22 500

 Table 3: Common Use Gas Maximum Range 


( mm )


Nitrogen ( N2 )

Oxygen ( O2 )

Hydrogen ( H2 )

15 65 65 32 10
25 175 175 89 28
32 290 290 144 45
40 450 450 226 70
50 700 700 352 110
65 1200 1200 600 185
80 1800 1800 900 280
100 2800 2800 1420 470
125 4400 4400 2210 700
150 6300 6300 3200 940
200 10000 10000 5650 1880
250 17000 17000 8830 2820
300 25000 25000 12720 4060
350 45000 45000 22608 5600
400 70000 70000 35325 7200
450 100000 100000 50638 9200
500 135000 135000 69240 11280
600 180000 180000 90432 16300
700 220000 220000 114500 22100
800 280000 280000 141300 29000
900 400000 400000 203480 36500
1000 600000 600000 318000 45000
2000 700000 700000 565200 18500

Table 4: Flange Thermal Gas Mass Flow Meter Model Selection

Model QTMF X X X X X X X
Caliber   DN15-DN4000              
Structure   Compact C
  Remote R
Senor type   Insertion I
  Flange F
  Clamp C
  Screw S
Material   SS304 304
  SS316 316
Pressure   1.6Mpa 1.6
  2.5Mpa 2.5
  4.0Mpa 4.0
Teperature   -40-200℃ T1
  -40-450℃ T2
Power Supply   AC85~250V AC
  DC24~36V DC
Signal Output   4-20mA+Pulse+RS485 RS
  4-20mA+Pulse+HART HT
Flange thermal gas mass flow meter installation:
① Observe the recommended inlet and outlet requirements.
② Good engineering practice is necessary for the associated pipe work and installation.
③ Ensure correct alignment and orientation of the sensor.
④ Take measures to reduce or avoid condensation (e.g. install a condensation trap, thermal insulation, etc.).
⑤ The maximum permitted ambient temperatures and the medium temperature range must be observed.
⑥ Install the transmitter in a shaded location or use a protective sun shield.
⑦ For mechanical reasons, and in order to protect the pipe, it is advisable to support heavy sensors.
⑧ No installation in where large vibration exists
⑨ No exposure in the environment containing a lot of corrosive gas
⑩ No sharing power supply with frequency converter, electric welding machine and other machines which can make power-line interference.

Daily maintenance for flange thermal gas mass flow meter:
In the daily operation of the thermal gas mass flowmeter, check and clean the flowmeter, tighten the loose parts, find and deal with the abnormality of the flowmeter in operation in time, ensure the normal operation of the flowmeter, reduce and delay the wear of components, Extend the service life of the flowmeter. Some flowmeters will become fouling after being used for a period of time, and it must be cleaned by pickling etc. depending on the degree of fouling
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