I. Overview
The metal tube float flowmeter has the characteristics of small volume, large detection range, and easy use, and can be used to measure the flow rate of liquids, gases, and vapors. The caliber ranges from DN15 to DN200, with an accuracy level of 1.5, making it particularly suitable for flow measurement of low flow rate and small flow medium, as well as flow measurement of high temperature, high pressure, opaque and corrosive medium.
2、 Measurement principle
The detection part of the metal tube float flowmeter consists of a vertically expanding conical tube from bottom to top and a float that can move freely up and down along the axis of the conical tube. When the fluid being tested passes through the annular gap formed by the cone tube and the float from bottom to top, a differential pressure is generated at the upper and lower ends of the float, forming a force for the float to rise. When the upward force acting on the float is greater than the weight of the float immersed in the fluid, the float rises, and the annular gap area increases accordingly. The fluid flow velocity at the annular gap immediately decreases, and the differential pressure between the upper and lower ends of the float decreases. The upward force acting on the float also decreases until the upward force is equal to the weight of the float immersed in the fluid, and the float stabilizes at a certain height. There is a corresponding relationship between the height of the float in the cone tube and the flow rate it passes through. The DWLZ series intelligent metal tube float flowmeter is a variable area flow meter produced using patented technology and is a commonly used variable area flow meter in industrial automation detection processes.
3、 Structural characteristics
● Suitable for flow measurement of small diameters and low flow rate media
● Can be used for flow measurement of media with low Reynolds numbers
Low pressure loss
● Simple structure, reliable operation, low maintenance, long service life
Low requirements for upstream straight pipe sections
● Wide range ratio 10:1
● Single axis sensitive indication
Non contact coupled transmission structure ensures stable displacement transmission
There are two types of intelligent KVD converters: local display type and intelligent remote transmission type. It has the function of online dual row LCD display for instantaneous flow and cumulative flow; Can achieve parameter setting; Capable of data power failure recovery

4、 Technical parameters
Measurement range: Water (20 ℃) 1~200000 l/h Air (20 ℃, 0.1013MPa) 0.03~4000m3/h
Range ratio: 10:1
Accuracy: Level 1.5
Pressure rating: 1.6Mpa, 4.0Mpa, 16Mpa, 25Mpa
Pressure loss: 7KPa to 70KPa
● Medium temperature: Standard type (E): -80 ℃ to 200 ℃;
PTFE： 0℃～85℃；
high temperatureType: -80 ℃~300 ℃
Allowable viscosity range of the medium: Below this upper limit, flow measurement is not affected by viscosity
DN15：the <5mPa.s (KV15.1-KV15.3)
DN20：the <30mPa.s (KV15.4-KV15.8)
DN25：the <250mPa.s
DN50-DN150: the <300mPa. S
● Environmental temperature: Indicator with LCD display: -30 ℃~65 ℃;
Local indication type: -40 ℃~80 ℃
● Connection type: flange connection HG20594, HG20595
● Cable interface: M20X1.5
Power supply: Standard type: 24VDC, two-wire system 4-20mA
Communication type: 85-265VAC 50HZ
Battery type: 3.6V@7.5AH Lithium battery, with a continuous service life of more than three years
Output signal: 4-20mA
● Alarm output: upper or lower limit instantaneous flow alarm
● Open collector output: maximum 100mA@30VDC Impedance of 100 ohms
Relay output: Contact capacity: 1A@30VDC or 0.25A@250VAC or 0.5A@125VAC
● Pulse output: Accumulated pulse output, with a minimum interval of 50 milliseconds (only one of alarm and pulse can be selected)
LCD display: instantaneous flow display value range: 0-50000, cumulative flow display range: 0-99999999
● Protection level: IP65
Explosion proof mark: Intrinsic safety type: Exia II CT5 Explosion proof type: Exd II Bt6
Intelligent remote transmission type with multi parameter calibration function, data recovery, data backup and power failure protection functions

Fa standard type external dimensions and weight pressure loss table

5、 Product selection

• DWLZ metal tube float flowmeter. pdf